import { sql, type SQL } from 'drizzle-orm'
import {
  bigint,
  boolean,
  bytea,
  customType,
  index,
  integer,
  jsonb,
  pgEnum,
  pgTable,
  primaryKey,
  text,
  timestamp,
  uniqueIndex,
  uuid,
  varchar
} from 'drizzle-orm/pg-core'
import type { AnyPgColumn } from 'drizzle-orm/pg-core'

// == CUSTOM TYPES =====================

// -> Typed as a string: an ltree path comes back from the driver as its dotted text form, and every
//    caller treats it as one
const ltree = customType<{ data: string }>({
  dataType() {
    return 'ltree'
  }
})
const tsvector = customType({
  dataType() {
    return 'tsvector'
  }
})

// == TABLES ===========================

// API KEYS ----------------------------
export const apiKeys = pgTable('apiKeys', {
  id: uuid().primaryKey().defaultRandom(),
  name: varchar({ length: 255 }).notNull(),
  // -> Only the tail of the token, to tell keys apart in the admin list. The token itself is a
  //    signed JWT shown once at creation and never stored: it is a bearer credential, and
  //    verification needs the public key plus this row's state, not the token.
  keyShort: varchar({ length: 8 }).notNull(),
  // -> IDs of the groups whose permissions the key carries. Resolved on every request, so editing a
  //    group immediately affects the keys pointing at it.
  groups: jsonb().notNull().default([]),
  expiration: timestamp().notNull().defaultNow(),
  isRevoked: boolean().notNull().default(false),
  createdAt: timestamp().notNull().defaultNow(),
  updatedAt: timestamp().notNull().defaultNow()
})

// APPROVAL RULES ----------------------
/**
 * Which pages accept edit suggestions, who may submit them, and who reviews them.
 *
 * Per site, and matched the way group page rules are: a mode plus a pattern. A page no rule matches
 * accepts no suggestions at all, so this table being empty means the feature is off.
 */
export const approvalRules = pgTable(
  'approvalRules',
  {
    id: uuid().primaryKey().defaultRandom(),
    name: varchar({ length: 255 }).notNull().default(''),
    // -> A rule can be turned off without losing what it says, which is how an administrator suspends
    //    suggestions on a section without having to write the rule again afterwards.
    isEnabled: boolean().notNull().default(true),
    // -> One of START / EXACT / END / REGEX / TAG / TAGALL, matched the way group page rules are. A
    //    varchar rather than an enum so that adding a mode does not need a migration; the API schema
    //    is what rejects an unknown one.
    match: varchar({ length: 16 }).notNull().default('START'),
    path: varchar({ length: 2048 }).notNull().default(''),
    // -> Group IDs. Resolved on use rather than joined, so deleting a group takes effect at once, the
    //    way `apiKeys.groups` works.
    submitterGroups: jsonb().notNull().default([]),
    reviewerGroups: jsonb().notNull().default([]),
    createdAt: timestamp().notNull().defaultNow(),
    updatedAt: timestamp().notNull().defaultNow(),
    siteId: uuid()
      .notNull()
      .references(() => sites.id)
  },
  (table) => [index('approvalRules_siteId_idx').on(table.siteId)]
)

// ASSETS ------------------------------
export const assetKindEnum = pgEnum('assetKind', ['document', 'image', 'other'])
export const assets = pgTable(
  'assets',
  {
    id: uuid().primaryKey().defaultRandom(),
    fileName: varchar({ length: 255 }).notNull(),
    fileExt: varchar({ length: 255 }).notNull(),
    isSystem: boolean().notNull().default(false),
    kind: assetKindEnum().notNull().default('other'),
    mimeType: varchar({ length: 255 }).notNull().default('application/octet-stream'),
    fileSize: bigint({ mode: 'number' }), // in bytes
    meta: jsonb().notNull().default({}),
    createdAt: timestamp().notNull().defaultNow(),
    updatedAt: timestamp().notNull().defaultNow(),
    // -> Set only while the database is one of the targets configured to store this kind of file.
    //    An asset is written to every target that claims it, and each derives where its own copy
    //    sits from the tree, so there is nothing to record here about where the bytes went.
    data: bytea(),
    preview: bytea(),
    authorId: uuid()
      .notNull()
      .references(() => users.id),
    siteId: uuid()
      .notNull()
      .references(() => sites.id)
  },
  (table) => [index('assets_siteId_idx').on(table.siteId)]
)

// AUDIT LOG ---------------------------
/**
 * What somebody did, one row per action.
 *
 * Only actions a *person* took: every row is written from an API route handler, which is the one
 * place the requester's identity and address are both in hand, and is by construction never reached
 * by the scheduler or a storage sync. A job that creates a page therefore leaves no row here, which
 * is the point — an audit log is a record of who did something, and "the wiki did it" is not an
 * answer anybody audits.
 *
 * Reads are not recorded. Page views would outnumber everything else by orders of magnitude and
 * bury the log, and failed logins are left out on purpose: a credential-stuffing run would otherwise
 * fill the table on demand from the outside. A login that *succeeded* is recorded, since that is the
 * event with consequences.
 *
 * Nothing here duplicates what another table already keeps. A page edit records the `pageHistory`
 * version its change produced and nothing about the change itself — the before and after live there,
 * and copying them would make this table enormous as well as wrong the moment the two disagreed.
 */
export const auditLog = pgTable(
  'auditLog',
  {
    id: uuid().primaryKey().defaultRandom(),
    ts: timestamp().notNull().defaultNow(),
    /**
     * Which part of the wiki the action belongs to: `page`, `asset`, `auth`, `profile` or `admin`.
     * A varchar rather than an enum, for the same reason `pageHistory.action` is one — naming
     * another area later should not need a migration. `AUDIT_KINDS` in `models/auditLog.ts` is the
     * list that decides.
     */
    kind: varchar({ length: 16 }).notNull(),
    /**
     * What was done, camelCase — `createPage`, `editSite`, `login`. Deliberately a key rather than a
     * sentence: it is what the interface looks a translation up by, and what a filter matches on.
     * `AUDIT_ACTIONS` in `models/auditLog.ts` is the full list.
     */
    action: varchar({ length: 64 }).notNull(),
    /** Where the request came from. 45 characters is the longest an IPv6 address can be written. */
    clientIP: varchar({ length: 45 }).notNull().default(''),
    /**
     * The context of the action: which page, site or account it touched, and always an `actor` block
     * carrying the email, display name and address the requester had AT THE TIME. That copy is the
     * point of it — `userId` goes null when the account is deleted, and a log that then said only
     * "somebody" would have lost exactly what it existed to record.
     *
     * Never anything secret. `sanitizeMeta` in `helpers/audit.ts` is the backstop, but the rule is
     * that a route does not put a password, a token or a module's sensitive prop in here to begin
     * with.
     */
    meta: jsonb().notNull().default({}),
    // -> Set null rather than cascade: deleting an account must not delete the record of what it
    //    did. The name and email on `meta.actor` are what the row is read by afterwards.
    userId: uuid().references(() => users.id, { onDelete: 'set null' })
  },
  (table) => [
    // -> The unfiltered view: newest first, which is the only order this table is ever read in
    index('auditLog_ts_idx').on(table.ts.desc()),
    // -> One index per filter, each carrying `ts` so that narrowing by it still comes back ordered
    index('auditLog_userId_idx').on(table.userId, table.ts.desc()),
    index('auditLog_kind_idx').on(table.kind, table.ts.desc()),
    index('auditLog_action_idx').on(table.action, table.ts.desc())
  ]
)

// AUTHENTICATION ----------------------
export const authentication = pgTable('authentication', {
  id: uuid().primaryKey().defaultRandom(),
  module: varchar({ length: 255 }).notNull(),
  isEnabled: boolean().notNull().default(false),
  displayName: varchar({ length: 255 }).notNull().default(''),
  config: jsonb().notNull().default({}),
  registration: boolean().notNull().default(false),
  allowedEmailRegex: varchar({ length: 255 }).notNull().default(''),
  autoEnrollGroups: uuid().array().default([])
})

// BLOCKS ------------------------------
/**
 * One block available to one site — `<block-diagram>` on this wiki.
 *
 * A built-in block's row is metadata only: what it can do comes from the compiled manifest, which
 * `models/blocks.ts` reads off disk at boot and reconciles against these rows. A CUSTOM block has no
 * disk to read, so the three columns below carry the whole of it — what it declares, and the bytes
 * that draw it. See `helpers/wkblock.ts` for the package they arrived in.
 *
 * Per site, package and all: a `.wkblock` imported into three sites is stored three times. That is
 * the same answer every other per-site setting gives, and the alternative — one shared copy with the
 * sites counted off it — buys a few megabytes at the cost of one site's upgrade changing another's
 * block.
 */
export const blocks = pgTable(
  'blocks',
  {
    id: uuid().primaryKey().defaultRandom(),
    block: varchar({ length: 255 }).notNull(),
    name: varchar({ length: 255 }).notNull(),
    description: varchar({ length: 255 }).notNull(),
    icon: varchar({ length: 255 }).notNull(),
    isEnabled: boolean().notNull().default(false),
    isCustom: boolean().notNull().default(false),
    config: jsonb().notNull().default({}),
    /**
     * What a CUSTOM block declares — its props, its template, its content editor — as its package's
     * copy of the component's `static definition`. Empty for a built-in, whose definition is read
     * from the compiled manifest instead, so that an updated block describes itself correctly the
     * moment it is deployed rather than whenever a row was last written.
     */
    definition: jsonb().notNull().default({}),
    /**
     * The `.wkblock` file a custom block was imported from, kept verbatim. Null for a built-in.
     *
     * This is the only copy: the files served to a browser are unpacked from it into
     * `<dataPath>/cache/blocks`, which is a cache and starts empty on a fresh container.
     */
    packageData: bytea(),
    /**
     * SHA-256 of that package, and the name of its directory in the disk cache.
     *
     * Which is what makes re-importing a block take effect: the files on disk are stale exactly when
     * they were unpacked under a different digest, and every instance in an HA set works that out for
     * itself without being told. Empty for a built-in.
     */
    checksum: varchar({ length: 64 }).notNull().default(''),
    siteId: uuid()
      .notNull()
      .references(() => sites.id)
  },
  (table) => [index('blocks_siteId_idx').on(table.siteId)]
)

// COMMENTS ----------------------------
/**
 * One comment on one page, for the BUILT-IN comments provider.
 *
 * The other providers are a snippet of markup and an account somewhere else, so nothing about them
 * reaches this table — it exists for the provider that is this wiki. See `models/comments.ts`.
 *
 * Replies are one level deep and that is enforced in the model: a reply names the comment it answers
 * in `parentId`, and a reply to a reply is attached to that reply's own parent rather than nesting
 * further. The foreign key is self-referential and cascades, so deleting a comment takes the replies
 * under it — which is the whole of what a thread is here.
 *
 * `content` is markdown source and there is no stored render. It is turned into HTML in the reader's
 * browser (`frontend/src/renderers/comment.js`) with raw HTML disabled, the same way a page's
 * markdown becomes HTML in the browser — which also means a mention re-resolves every time it is
 * drawn rather than freezing whatever a handle pointed at on the day it was written.
 */
export const comments = pgTable(
  'comments',
  {
    id: uuid().primaryKey().defaultRandom(),
    pageId: uuid()
      .notNull()
      .references(() => pages.id, { onDelete: 'cascade' }),
    /**
     * The comment this one answers, or null for one that starts a thread.
     *
     * The annotation breaks the circular inference a self-reference would otherwise cause
     * (TS7022/TS7024), the same way the generated column on `pages` does.
     */
    parentId: uuid().references((): AnyPgColumn => comments.id, { onDelete: 'cascade' }),
    /** Markdown source as it was typed. Never HTML — see the note above. */
    content: text().notNull(),
    /**
     * The account that wrote it, or null for a guest — and also null once that account is deleted,
     * which is why the name below is kept alongside rather than only joined for.
     */
    authorId: uuid().references(() => users.id, { onDelete: 'set null' }),
    /**
     * Who it says wrote it. What a guest typed into the form, and for a signed-in author a copy of
     * their display name as it stood — used only when the account behind `authorId` is gone, since a
     * rename should show through everywhere else.
     */
    authorName: varchar({ length: 255 }).notNull(),
    /**
     * A guest's email address. Required of a guest, empty for a signed-in author (the account has
     * one), and never sent to a client: it is here for the spam check and for whatever moderation
     * grows out of it.
     */
    authorEmail: varchar({ length: 255 }).notNull().default(''),
    /** The address it was posted from, kept for the same reasons as the audit log's. Never served. */
    authorIP: varchar({ length: 255 }).notNull().default(''),
    /**
     * Room for what a comment may grow: votes, a pin, a moderation state. Nothing reads it yet, and
     * nothing should write a key into it without deciding what an absent one means.
     */
    meta: jsonb().notNull().default({}),
    createdAt: timestamp().notNull().defaultNow(),
    updatedAt: timestamp().notNull().defaultNow()
  },
  (table) => [
    // -> The talk view's own query: every comment on a page, oldest first
    index('comments_page_created_idx').on(table.pageId, table.createdAt),
    index('comments_parentId_idx').on(table.parentId),
    index('comments_authorId_idx').on(table.authorId)
  ]
)

// GROUPS ------------------------------
export const groups = pgTable(
  'groups',
  {
    id: uuid().primaryKey().defaultRandom(),
    name: varchar({ length: 255 }).notNull(),
    permissions: jsonb().notNull(),
    rules: jsonb().notNull(),
    redirectOnLogin: varchar({ length: 255 }).notNull().default(''),
    redirectOnFirstLogin: varchar({ length: 255 }).notNull().default(''),
    redirectOnLogout: varchar({ length: 255 }).notNull().default(''),
    isSystem: boolean().notNull().default(false),
    /**
     * What the directory provisioning this group calls it, as SCIM's `externalId`.
     *
     * Null for a group created here, and optional even for one that was not: `externalId` is a
     * SHOULD in RFC 7643 and not every client sends it. Which is why it is not the thing that says
     * who owns the group — `isProvisioned` is.
     */
    externalId: varchar({ length: 255 }),
    /**
     * Whether a SCIM client owns this group. Set by the first provisioning write and never cleared
     * automatically; it is what lets SCIM delete a group it created while leaving one an
     * administrator made by hand alone. See `models/scim.ts`.
     */
    isProvisioned: boolean().notNull().default(false),
    createdAt: timestamp().notNull().defaultNow(),
    updatedAt: timestamp().notNull().defaultNow()
  },
  (table) => [
    // -> Nulls are distinct to postgres, which is what lets any number of groups have no external id
    uniqueIndex('groups_externalId_idx').on(table.externalId)
  ]
)

// HOOKS -------------------------------
export const hookStateEnum = pgEnum('hookState', ['pending', 'success', 'error'])
export const hooks = pgTable('hooks', {
  id: uuid().primaryKey().defaultRandom(),
  name: varchar({ length: 255 }).notNull(),
  // -> Event keys such as `page:create`, matched against what the server emits
  events: text()
    .array()
    .notNull()
    .default(sql`ARRAY[]::text[]`),
  url: text().notNull(),
  includeMetadata: boolean().notNull().default(true),
  includeContent: boolean().notNull().default(false),
  acceptUntrusted: boolean().notNull().default(false),
  // -> Sent verbatim as the Authorization header, so it holds whatever secret the remote expects
  authHeader: text(),
  // -> Outcome of the most recent delivery, which is what the admin list shows
  state: hookStateEnum().notNull().default('pending'),
  lastErrorMessage: text(),
  createdAt: timestamp().notNull().defaultNow(),
  updatedAt: timestamp().notNull().defaultNow()
})

// ICONS -------------------------------
// -> An Iconify icon set the wiki draws icons from, e.g. `mdi`. Adding one makes its icons
//    searchable; individual icons are only stored once something references them.
export const iconSets = pgTable('iconSets', {
  // -> The Iconify prefix, which is what content references: `<prefix>:<name>`
  prefix: varchar({ length: 64 }).primaryKey(),
  name: varchar({ length: 255 }).notNull(),
  isEnabled: boolean().notNull().default(true),
  // -> Iconify collection metadata (author, license, total, palette, samples, ...) as published by
  //    the upstream API, refreshed on demand rather than being authored here
  info: jsonb().notNull().default({}),
  refreshedAt: timestamp(),
  createdAt: timestamp().notNull().defaultNow()
})

// -> The permanent home of every icon the wiki has ever served. Fetched from the Iconify API on first
//    use, then never fetched again: the disk cache is derived from these rows and may be empty.
export const icons = pgTable(
  'icons',
  {
    prefix: varchar({ length: 64 })
      .notNull()
      .references(() => iconSets.prefix),
    name: varchar({ length: 255 }).notNull(),
    // -> The SVG markup inside the `<svg>` element, with `currentColor` left as-is
    body: text().notNull(),
    // -> Resolved Iconify icon properties: the viewBox is `left top width height`, and the transform
    //    flags apply on top of it. Aliases are resolved before storing, so a row is self-contained.
    width: integer().notNull().default(16),
    height: integer().notNull().default(16),
    left: integer().notNull().default(0),
    top: integer().notNull().default(0),
    rotate: integer().notNull().default(0),
    hFlip: boolean().notNull().default(false),
    vFlip: boolean().notNull().default(false),
    createdAt: timestamp().notNull().defaultNow()
  },
  (table) => [primaryKey({ columns: [table.prefix, table.name] })]
)

// IMPORT SESSIONS ---------------------
/**
 * One run of **Administration → Utilities → Import from Wiki.js 2.x**, from the moment the operator
 * presses Start until the package has been walked.
 *
 * A row rather than memory, for two reasons that both come from the import living in a browser tab:
 * in an HA set the next batch is answered by a different instance, and a tab that closed has to be
 * able to say where it got to. See `dev/specs/wkbackup.md` §7.
 *
 * Everything the handlers need to agree about across thousands of requests is here — which target
 * site each package site lands in, what the operator ticked, and the group mapping the user records
 * resolve through — so a batch carries only its own records.
 */
export const importSessionStateEnum = pgEnum('importSessionState', ['open', 'finished', 'failed'])
export const importSessions = pgTable(
  'importSessions',
  {
    id: uuid().primaryKey().defaultRandom(),
    /**
     * The UUIDv5 namespace the derived ids of this import are built in.
     *
     * **Derived, not random** — from the source wiki and the site being imported into, so that the
     * same package run into the same site a second time derives the same ids and upserts, while two
     * operators importing two different packages cannot collide. It has to survive the SESSION and
     * not just outlive a batch: an import that fell over is re-run from the top, which would
     * otherwise mean a second copy of every comment and every history entry — the two record kinds
     * with no natural key to match on. See `dev/specs/wkbackup.md` §4.
     */
    namespace: uuid().notNull(),
    /** `manifest.source.kind`. Only `wikijs2` is implemented. */
    source: varchar({ length: 32 }).notNull(),
    /** `[{ sourceId, siteId }]` — each package site paired with the target site it lands in. */
    sites: jsonb().notNull().default([]),
    /** Which content kinds the operator ticked. A stream for anything absent is refused. */
    includes: jsonb().notNull().default([]),
    overwrite: boolean().notNull().default(false),
    /**
     * What to do with a page 2.x wrote as HTML — its WYSIWYG and code editors.
     *
     * `markdown` converts it and files it under 3.x's visual editor, so it stays editable the way it
     * was written; `html` keeps the HTML exactly as it stands, which renders identically but is only
     * editable as source. It is a per-import choice because it is a trade the operator has to make
     * rather than one this code can make for them: a conversion is a rewrite of their content, and
     * the alternative is a wiki nobody can edit visually again.
     */
    htmlConversion: varchar({ length: 16 }).notNull().default('markdown'),
    state: importSessionStateEnum().notNull().default('open'),
    /** `{ <stream>: <records written> }`, which is what a resumed tab reads to find its place. */
    progress: jsonb().notNull().default({}),
    /** Everything the import could not carry, in the order it was found. Shown in the log. */
    warnings: jsonb().notNull().default([]),
    /**
     * Who is running it. Null once that account is gone, which costs nothing: a finished session is
     * a receipt, and the audit log is where the act itself is recorded.
     *
     * Also what `usersStream` compares each record against — the account running the import is never
     * written to, whatever `overwrite` says.
     */
    actorId: uuid().references(() => users.id, { onDelete: 'set null' }),
    createdAt: timestamp().notNull().defaultNow(),
    updatedAt: timestamp().notNull().defaultNow()
  },
  (table) => [index('importSessions_createdAt_idx').on(table.createdAt)]
)

/**
 * What a record from the source wiki became here — its 2.x integer id paired with the row it is now.
 *
 * A table rather than a blob on the session, because the things that have to be looked up this way
 * are unbounded: a page's author is a 2.x user id, a comment names its page by 2.x page id, and a
 * wiki has as many of those as it has users and pages. A jsonb column rewritten once per batch would
 * be megabytes of write amplification by the end of a large import, where this is an insert per
 * record and one indexed read per batch.
 *
 * It exists because the package speaks 2.x's ids and this wiki matches on natural keys — a user by
 * email, a page by path. Those two answers have to be joined up somewhere, and only for the entities
 * something actually references: users, pages and groups.
 *
 * Rows go with the session, which is what stops this becoming a permanent record of somebody's old
 * instance.
 */
export const importIdMap = pgTable(
  'importIdMap',
  {
    sessionId: uuid()
      .notNull()
      .references(() => importSessions.id, { onDelete: 'cascade' }),
    /** `user`, `page` or `group`. */
    entity: varchar({ length: 32 }).notNull(),
    /** The id the source wiki knew it by, as text — 2.x numbers them, a 3.x package would not. */
    sourceId: varchar({ length: 255 }).notNull(),
    targetId: uuid().notNull()
  },
  (table) => [primaryKey({ columns: [table.sessionId, table.entity, table.sourceId] })]
)

// JOB HISTORY -------------------------
export const jobHistoryStateEnum = pgEnum('jobHistoryState', [
  'active',
  'completed',
  'failed',
  'interrupted'
])
export const jobHistory = pgTable('jobHistory', {
  id: uuid().primaryKey().defaultRandom(),
  task: varchar({ length: 255 }).notNull(),
  state: jobHistoryStateEnum().notNull(),
  useWorker: boolean().notNull().default(false),
  wasScheduled: boolean().notNull().default(false),
  payload: jsonb(),
  attempt: integer().notNull().default(1),
  maxRetries: integer().notNull().default(0),
  lastErrorMessage: text(),
  executedBy: varchar({ length: 255 }),
  createdAt: timestamp().notNull(),
  startedAt: timestamp().notNull().defaultNow(),
  completedAt: timestamp()
})

// JOB SCHEDULE ------------------------
export const jobSchedule = pgTable('jobSchedule', {
  id: uuid().primaryKey().defaultRandom(),
  task: varchar({ length: 255 }).notNull(),
  cron: varchar({ length: 255 }).notNull(),
  type: varchar({ length: 255 }).notNull().default('system'),
  payload: jsonb(),
  createdAt: timestamp().notNull().defaultNow(),
  updatedAt: timestamp().notNull().defaultNow()
})

// JOB LOCK ----------------------------
export const jobLock = pgTable('jobLock', {
  key: varchar({ length: 255 }).primaryKey(),
  lastCheckedBy: varchar({ length: 255 }),
  lastCheckedAt: timestamp().notNull().defaultNow()
})

// JOBS --------------------------------
export const jobs = pgTable('jobs', {
  id: uuid().primaryKey().defaultRandom(),
  task: varchar({ length: 255 }).notNull(),
  useWorker: boolean().notNull().default(false),
  payload: jsonb(),
  retries: integer().notNull().default(0),
  maxRetries: integer().notNull().default(0),
  waitUntil: timestamp(),
  isScheduled: boolean().notNull().default(false),
  createdBy: varchar({ length: 255 }),
  createdAt: timestamp().notNull().defaultNow(),
  updatedAt: timestamp().notNull().defaultNow()
})

// LOCALES -----------------------------
export const locales = pgTable(
  'locales',
  {
    code: varchar({ length: 255 }).primaryKey(),
    name: varchar({ length: 255 }).notNull(),
    nativeName: varchar({ length: 255 }).notNull(),
    language: varchar({ length: 8 }).notNull(), // Unicode language subtag
    region: varchar({ length: 3 }).notNull(), // Unicode region subtag
    script: varchar({ length: 4 }).notNull(), // Unicode script subtag
    isRTL: boolean().notNull().default(false),
    /**
     * Whether `strings` holds a real string set. A locale the update task has only seen in the
     * remote metadata gets a row so that it can be offered, but has nothing to serve until it is
     * installed.
     */
    isInstalled: boolean().notNull().default(false),
    /**
     * The remote metadata's hash of the strings file this row was installed from, so that an update
     * only downloads the locales that actually changed. Empty for a locale that came off disk and
     * for one that is not installed yet -- which is exactly what makes the next update fetch it.
     */
    hash: varchar({ length: 64 }).notNull().default(''),
    /**
     * The short code an administrator would rather this locale be shown as -- `zh` for `zh-CN` --
     * overriding the one derived from the tag. An alias and nothing more: `code` stays the identity,
     * so nothing a page, an asset or a storage target already records has to move for this.
     * Null when the derived form is fine, which is the usual case.
     */
    customCode: varchar({ length: 255 }).unique(),
    /**
     * The name an administrator would rather this locale be shown as, overriding the one `Intl`
     * gives for the tag. Display only, and not unique: two locales reading alike in a menu is a
     * choice somebody made, not a collision. Null when the derived name is fine.
     */
    customName: varchar({ length: 255 }),
    strings: jsonb().notNull().default([]),
    completeness: integer().notNull().default(0),
    createdAt: timestamp().notNull().defaultNow(),
    updatedAt: timestamp().notNull().defaultNow()
  },
  (table) => [index('locales_language_idx').on(table.language)]
)

// NAVIGATION --------------------------
export const navigation = pgTable(
  'navigation',
  {
    id: uuid().primaryKey().defaultRandom(),
    items: jsonb().notNull().default([]),
    /**
     * Set only on a site-wide menu, naming the locale it is the menu for — the sidebar a page in that
     * locale falls back to when nothing above it overrides one. Null on a menu belonging to a tree
     * entry, which is identified by that entry's id instead. Postgres lets a unique index hold any
     * number of nulls, which is what lets both kinds share the table.
     */
    locale: varchar({ length: 255 }),
    siteId: uuid()
      .notNull()
      .references(() => sites.id)
  },
  (table) => [
    index('navigation_siteId_idx').on(table.siteId),
    uniqueIndex('navigation_siteId_locale_key').on(table.siteId, table.locale)
  ]
)

// PAGES ------------------------------
export const pagePublishStateEnum = pgEnum('pagePublishState', ['draft', 'published', 'scheduled'])
export const pages = pgTable(
  'pages',
  {
    id: uuid().primaryKey().defaultRandom(),
    // -> A BCP-47 code, matched only ever for equality. Not `ltree`: a hyphenated code is a single
    //    label to it, so `'pt-BR'::ltree <@ 'pt'` is false and the type buys no locale-family
    //    matching -- see the note on `pageHistory.locale`.
    locale: varchar({ length: 255 }).notNull(),
    path: varchar({ length: 255 }).notNull(),
    hash: varchar({ length: 255 }).notNull(),
    alias: varchar({ length: 255 }),
    title: varchar({ length: 255 }).notNull(),
    description: varchar({ length: 255 }),
    icon: varchar({ length: 255 }),
    publishState: pagePublishStateEnum('publishState').notNull().default('draft'),
    publishStartDate: timestamp(),
    publishEndDate: timestamp(),
    config: jsonb().notNull().default({}),
    relations: jsonb().notNull().default([]),
    /**
     * The set of pages this one is a translation of: every page sharing this id is the same page in
     * another locale, and the locale selector uses it to send a reader to the right one.
     *
     * Null for a page with no counterparts, which is most of them — a null is what makes the unique
     * index below tolerate any number of unrelated pages, since postgres counts nulls as distinct.
     * The group has no row of its own: it is an identity, and its membership IS this column.
     */
    localeGroupId: uuid(),
    content: text(),
    render: text(),
    searchContent: text(),
    ts: tsvector('ts'),
    tags: text()
      .array()
      .notNull()
      .default(sql`ARRAY[]::text[]`),
    toc: jsonb(),
    editor: varchar({ length: 255 }).notNull(),
    contentType: varchar({ length: 255 }).notNull(),
    isBrowsable: boolean().notNull().default(true),
    isSearchable: boolean().notNull().default(true),
    // -> The generated expression references its own table, so the return type must be annotated
    //    explicitly to break the circular inference (TS7022/TS7024).
    isSearchableComputed: boolean('isSearchableComputed').generatedAlwaysAs(
      (): SQL => sql`${pages.publishState} != 'draft' AND ${pages.isSearchable}`
    ),
    password: varchar({ length: 255 }),
    /**
     * How readers have rated the page, per scale: `{ thumbs?: { count, sum, up, down }, stars?: … }`.
     * A cache of the `pageRatings` rows, rewritten by every rating and withdrawal (`models/pageRatings.ts`)
     * so that a page view reads it off the row it already loads instead of aggregating per view.
     */
    ratings: jsonb().notNull().default({}),
    scripts: jsonb().notNull().default({}),
    historyData: jsonb().notNull().default({}),
    createdAt: timestamp().notNull().defaultNow(),
    updatedAt: timestamp().notNull().defaultNow(),
    authorId: uuid()
      .notNull()
      .references(() => users.id),
    creatorId: uuid()
      .notNull()
      .references(() => users.id),
    ownerId: uuid()
      .notNull()
      .references(() => users.id),
    siteId: uuid()
      .notNull()
      .references(() => sites.id)
  },
  (table) => [
    index('pages_authorId_idx').on(table.authorId),
    index('pages_creatorId_idx').on(table.creatorId),
    index('pages_ownerId_idx').on(table.ownerId),
    index('pages_siteId_idx').on(table.siteId),
    index('pages_ts_idx').using('gin', table.ts),
    index('pages_tags_idx').using('gin', table.tags),
    index('pages_isSearchableComputed_idx').on(table.isSearchableComputed),
    // -> One page per locale in a group, enforced here rather than in the model: a group is edited
    //    from any of its members, so two saves racing each other are two writers of the same set
    uniqueIndex('pages_localeGroupId_locale_idx').on(table.localeGroupId, table.locale),
    /*
      Where a page sits, which is what a path addresses it by. Unique because two pages at one path in
      one locale is the thing `createPage` and `movePage` both check for and neither can actually
      prevent -- their check and their write are two statements, so two saves racing each other both
      see a clear path. It is also the index the link table resolves against: "is there a page at this
      address" is asked once per link on a page.
    */
    uniqueIndex('pages_siteId_locale_path_idx').on(table.siteId, table.locale, table.path)
  ]
)

// PAGE HISTORY ------------------------
/**
 * One row per change to a page: what it looked like afterwards, who made it, and what kind of change
 * it was.
 *
 * Every row is a complete version rather than a delta, which is what makes the three things this
 * exists for straightforward: comparing any two versions, putting a page back to one of them, and
 * recovering a page that was deleted. The deletion itself is recorded the same way, carrying the page
 * as it stood when it went — that row is the whole of what a recovery needs.
 *
 * The render is deliberately not kept. It is derived from the content by a pipeline that lives in the
 * frontend, and storing a second copy of every page's HTML for every version is a great deal of space
 * for something a restore can regenerate.
 */
export const pageHistory = pgTable(
  'pageHistory',
  {
    id: uuid().primaryKey().defaultRandom(),
    // -> Not a foreign key: the history of a deleted page is exactly what recovering it needs, so it
    //    has to outlive the row it points at
    pageId: uuid().notNull(),
    /**
     * `created`, `updated`, `moved` or `deleted`. A varchar rather than an enum so that naming another
     * kind of change later does not need a migration.
     */
    action: varchar({ length: 16 }).notNull().default('updated'),
    /** Which fields this change touched, so a history list can summarise it without diffing. */
    changedFields: text()
      .array()
      .notNull()
      .default(sql`ARRAY[]::text[]`),
    /*
      Columns rather than part of `meta` below: a history list shows these for every row, a page that
      has moved needs the path it had at the time rather than the one it has now, and looking a history
      up by where the page was — the only way in once the page itself is gone — means matching on the
      locale and the path together.

      A locale code is BCP-47 with hyphens (`pt-BR`), and every comparison anywhere is an equality
      one. `locales.code`, which these values come from, is a varchar too.
    */
    locale: varchar({ length: 255 }).notNull(),
    path: varchar({ length: 255 }).notNull(),
    title: varchar({ length: 255 }).notNull(),
    content: text(),
    /**
     * The rest of the page as it stood: description, icon, tags, publish state and dates, relations,
     * scripts, config, editor and content type. Kept whole rather than as columns of its own so that a
     * field added to a page does not have to be added here too.
     */
    meta: jsonb().notNull().default({}),
    /**
     * Why the change was made, in the author's words, as the editor's reason-for-change prompt
     * collected it. Null when the site does not ask for one, or asks and is not answered.
     */
    reason: varchar({ length: 255 }),
    versionDate: timestamp().notNull().defaultNow(),
    // -> Null once the account is gone, rather than holding the account hostage: a history row is a
    //    record of what happened to the page, and requiring its author to exist for ever would mean
    //    that editing a page once made an account undeletable — even after the page itself was gone.
    authorId: uuid().references(() => users.id, { onDelete: 'set null' }),
    siteId: uuid()
      .notNull()
      .references(() => sites.id)
  },
  (table) => [
    index('pageHistory_pageId_idx').on(table.pageId, table.versionDate),
    // -> "What happened to the page at this path, in this locale", which is how a deleted page is
    //    found again: there is no page row left to look its ID up from. Leading with `siteId` means
    //    this also serves the plain per-site queries.
    index('pageHistory_siteId_idx').on(table.siteId, table.locale, table.path, table.versionDate),
    index('pageHistory_authorId_idx').on(table.authorId)
  ]
)

// PAGE LINKS --------------------------
/**
 * One row per distinct link written on a page, resolved to what it addresses.
 *
 * Derived from the stored render the way `toc` and `searchContent` are, and rewritten wholesale
 * whenever that render is — see `models/pageLinks.ts`. Three questions are asked of it: what links to
 * the page being read, whether what a page links to exists, and which pages have to be revisited when
 * something they point at moves.
 *
 * **The address is what is stored, not a resolved page id.** A link is written as a path, and after a
 * move the pages pointing at the old one still say the old one — which is precisely the thing worth
 * knowing, and precisely what a foreign key would erase by following the page. It also lets a link to
 * a page that does not exist yet be a row like any other, which is what a red link is. Whether a
 * target resolves is a join against `pages` on `(siteId, locale, path)` at read time.
 *
 * `/a/<alias>` and `/i/<id>` are the exception and are stored as the reference they carry: those two
 * survive a move by design, so resolving them to a path at write time would record the opposite of
 * what they mean.
 */
export const pageLinks = pgTable(
  'pageLinks',
  {
    id: uuid().primaryKey().defaultRandom(),
    /**
     * What the link addresses: a page by path (`page`), by alias (`alias`) or by id (`pageId`), or an
     * uploaded file (`asset`).
     *
     * A varchar rather than an enum, for the reason `pageHistory.action` is one — naming another kind
     * of target later should not need a migration. Links leaving the wiki are not recorded at all:
     * nothing asks a question about them until there is a link checker to answer it, and they would
     * be the bulk of the rows on a wiki that cites its sources.
     */
    kind: varchar({ length: 16 }).notNull(),
    /**
     * The href exactly as it appears in the page.
     *
     * Kept because resolving is lossy and the source is what a repair would have to edit: `../two`,
     * `/en/one/two` and `/one/two.md` are one target and three strings, and only the string that was
     * written can be found in the markdown again.
     *
     * Bounded rather than `text` because it is half of a unique btree index below, and a btree entry
     * has a hard ceiling of about 2700 bytes — an href past it would fail the INSERT, and that INSERT
     * is part of saving a page. 2048 is the conventional cap for a URL and far past anything a link
     * in a wiki page is; `resolveLink` drops the ones that would not fit rather than truncating them
     * into a different address.
     */
    href: varchar({ length: 2048 }).notNull(),
    /**
     * Which site the target belongs to. Usually the source's own, and another one for a link written
     * as an absolute URL to a second site of this instance — those are worth following rather than
     * writing off as external, since a move on either site breaks them just the same.
     */
    targetSiteId: uuid()
      .notNull()
      .references(() => sites.id),
    // -> Both null for `alias` and `pageId`, which address a page without saying where it is
    targetLocale: varchar({ length: 255 }),
    targetPath: varchar({ length: 255 }),
    /** The alias or the page id, for the two kinds that carry one. Null for the rest. */
    targetRef: varchar({ length: 255 }),
    createdAt: timestamp().notNull().defaultNow(),
    // -> The page the link is written on. Its rows go with it: a link is part of a page's content,
    //    and nothing is left to point at once the page is gone
    pageId: uuid()
      .notNull()
      .references(() => pages.id, { onDelete: 'cascade' }),
    siteId: uuid()
      .notNull()
      .references(() => sites.id)
  },
  (table) => [
    // -> "What links here", and "what points at this path" for a page about to be moved. Leading with
    //    the site because every one of those questions is asked within one
    index('pageLinks_target_idx').on(table.targetSiteId, table.targetLocale, table.targetPath),
    // -> The same question for the two kinds that address a page without a path
    index('pageLinks_targetRef_idx').on(table.targetSiteId, table.kind, table.targetRef),
    // -> Every link on one page, which is both the read for "do these targets exist" and the delete
    //    half of rewriting a page's links
    index('pageLinks_pageId_idx').on(table.pageId),
    index('pageLinks_siteId_idx').on(table.siteId),
    /*
      One row per spelling, not per target: a page linking to the same place as `../two` and as
      `/one/two` has two links to repair and two rows saying so. Two identical hrefs on one page are
      one row, since there is nothing to tell them apart and nothing that would ask.
    */
    uniqueIndex('pageLinks_pageId_href_idx').on(table.pageId, table.href)
  ]
)

// PAGE EDIT SUBMISSIONS ---------------
/**
 * An edit suggested by somebody who may read a page but not change it, waiting to be reviewed.
 *
 * Both the resulting source and a patch are kept, because they answer different questions. The patch
 * is what a reviewer merges — it is computed against the page as it stood at submission time, so two
 * people suggesting edits to different parts of a page can both be accepted. The source is what the
 * author resumes from and what a review screen shows, and it cannot be reconstructed from the patch
 * alone once the page has moved on.
 */
export const pageEditSubmissions = pgTable(
  'pageEditSubmissions',
  {
    id: uuid().primaryKey().defaultRandom(),
    content: text().notNull(),
    /** Unified diff, from the page content this was based on to `content`. */
    patch: text().notNull(),
    /** SHA-256 of that base content, so a reviewer can tell the page has changed underneath. */
    baseHash: varchar({ length: 64 }).notNull(),
    // -> A guest has no account to attribute the suggestion to, so it says who sent it. Null for a
    //    logged in author, whose name is on `authorId` instead.
    guestName: varchar({ length: 255 }),
    guestEmail: varchar({ length: 255 }),
    createdAt: timestamp().notNull().defaultNow(),
    updatedAt: timestamp().notNull().defaultNow(),
    pageId: uuid()
      .notNull()
      .references(() => pages.id, { onDelete: 'cascade' }),
    siteId: uuid()
      .notNull()
      .references(() => sites.id),
    authorId: uuid().references(() => users.id)
  },
  (table) => [
    index('pageEditSubmissions_pageId_idx').on(table.pageId),
    index('pageEditSubmissions_siteId_idx').on(table.siteId),
    index('pageEditSubmissions_authorId_idx').on(table.authorId),
    // -> One open suggestion per person per page: coming back to the button continues that one rather
    //    than starting a second. Guests are excluded because they are all the same nobody.
    uniqueIndex('pageEditSubmissions_page_author_idx')
      .on(table.pageId, table.authorId)
      .where(sql`"authorId" IS NOT NULL`)
  ]
)

// PAGE WATCHING -----------------------
/**
 * A page somebody asked to be told about, one row per person per page.
 *
 * A row IS the watch: there is no `isEnabled` to turn off, because unwatching a page is not a state a
 * page keeps — it is the absence of interest, and the row goes. Which is also why the whole table can
 * be read as "everyone to notify about this page" when notifications are built on top of it.
 *
 * `siteId` is carried alongside `pageId` rather than reached through the page, since every query here
 * is scoped to one site: the watch list belongs to an inbox, and an inbox belongs to a site.
 */
export const pageWatching = pgTable(
  'pageWatching',
  {
    id: uuid().primaryKey().defaultRandom(),
    createdAt: timestamp().notNull().defaultNow(),
    pageId: uuid()
      .notNull()
      .references(() => pages.id, { onDelete: 'cascade' }),
    siteId: uuid()
      .notNull()
      .references(() => sites.id),
    userId: uuid()
      .notNull()
      .references(() => users.id, { onDelete: 'cascade' })
  },
  (table) => [
    // -> Covers the site scoping too, being the leading column: this is the inbox's own query
    index('pageWatching_user_site_idx').on(table.userId, table.siteId),
    // -> Watching a page twice is watching it once, so the second attempt is a no-op rather than a row
    uniqueIndex('pageWatching_page_user_idx').on(table.pageId, table.userId)
  ]
)

// PAGE RATINGS ------------------------
/**
 * One reader's rating of one page.
 *
 * `kind` is the site's ratings mode the rating was given under — `thumbs` (`value` is 1 or -1) or
 * `stars` (1 to 5) — because the two scales cannot be added together, and a site may switch between
 * them. Only the rows of the mode in force are counted, so switching back finds the old ratings where
 * they were. Rating again under the other mode replaces the row: a reader has one opinion of a page.
 *
 * The totals are cached on the page (`pages.ratings`), one entry per scale, and rewritten from these
 * rows whenever one of the page's changes. A rating removed by a deleted account's cascade is not
 * subtracted until the page is next rated.
 */
export const pageRatings = pgTable(
  'pageRatings',
  {
    pageId: uuid()
      .notNull()
      .references(() => pages.id, { onDelete: 'cascade' }),
    userId: uuid()
      .notNull()
      .references(() => users.id, { onDelete: 'cascade' }),
    kind: varchar({ length: 16 }).notNull(),
    value: integer().notNull(),
    createdAt: timestamp().notNull().defaultNow(),
    updatedAt: timestamp().notNull().defaultNow()
  },
  (table) => [
    primaryKey({ columns: [table.pageId, table.userId] }),
    index('pageRatings_userId_idx').on(table.userId)
  ]
)

// PAGE RENDER QUEUE -------------------
/**
 * A page waiting for the server to render it, one row per page.
 *
 * The markdown pipeline lives in the frontend, so rendering a page here means driving a headless
 * browser — too heavy to hold a request open for, and ruinous to do several times at once. A row is a
 * request for a render, and the `renderPages` task drains the table one page at a time through a
 * single browser (`models/rendering.ts`).
 *
 * A row IS the request, so asking twice for the same page updates the row instead of adding a second:
 * what gets rendered is the content as it stands when the browser reaches it, and rendering it twice
 * would produce the same HTML. `createdAt` keeps its place in the queue across those repeats.
 *
 * The two permissions travel with the row because a render is sanitized against what the person who
 * asked for it may embed, and by the time the job runs there is no session left to ask.
 */
export const pageRenderQueue = pgTable(
  'pageRenderQueue',
  {
    id: uuid().primaryKey().defaultRandom(),
    /** `write:scripts` — whether this render may keep `<script>` and inline handlers. */
    allowScripts: boolean().notNull().default(false),
    /** `write:styles` — whether this render may keep `<style>` and inline `style` attributes. */
    allowStyles: boolean().notNull().default(false),
    createdAt: timestamp().notNull().defaultNow(),
    updatedAt: timestamp().notNull().defaultNow(),
    pageId: uuid()
      .notNull()
      .unique()
      .references(() => pages.id, { onDelete: 'cascade' }),
    siteId: uuid()
      .notNull()
      .references(() => sites.id),
    // -> Only ever logged, and a deleted account is no reason to drop a render somebody is waiting for
    requestedById: uuid().references(() => users.id, { onDelete: 'set null' })
  },
  // -> How the drain picks what to render next
  (table) => [index('pageRenderQueue_createdAt_idx').on(table.createdAt)]
)

// RATE LIMITS -------------------------
/**
 * One counter per rate-limited client, and the ban it has earned itself.
 *
 * In the database rather than in each instance's memory because a limit every instance enforces on
 * its own is a limit multiplied by however many are running — and because a ban has to hold when the
 * next attempt lands on another one. Every read and write of a row happens in a single upserting
 * statement (`models/rateLimits.ts`), which is what makes concurrent attempts count exactly once.
 *
 * Rows are self-correcting: an expired window or ban is reset by the next attempt on that key. They
 * are only ever deleted to reclaim space — see the `purgeRateLimits` task.
 */
export const rateLimits = pgTable(
  'rateLimits',
  {
    /** What is being limited and who by, e.g. `auth:203.0.113.4`. */
    key: varchar({ length: 255 }).primaryKey(),
    /** Attempts made inside the current window. */
    hits: integer().notNull().default(0),
    windowStartedAt: timestamp().notNull().defaultNow(),
    /** When the ban lifts. Null for a client that has not earned one. */
    bannedUntil: timestamp(),
    updatedAt: timestamp().notNull().defaultNow()
  },
  // -> How the purge finds rows nothing has touched in a long while
  (table) => [index('rateLimits_updatedAt_idx').on(table.updatedAt)]
)

// SETTINGS ----------------------------
export const settings = pgTable('settings', {
  key: varchar({ length: 255 }).notNull().primaryKey(),
  value: jsonb().notNull().default({})
})

// SESSIONS ----------------------------
export const sessions = pgTable(
  'sessions',
  {
    id: varchar({ length: 255 }).primaryKey(),
    userId: uuid().references(() => users.id),
    data: jsonb().notNull().default({}),
    createdAt: timestamp().notNull().defaultNow(),
    updatedAt: timestamp().notNull().defaultNow()
  },
  (table) => [index('sessions_userId_idx').on(table.userId)]
)

// SITES -------------------------------
export const sites = pgTable('sites', {
  id: uuid().primaryKey().defaultRandom(),
  hostname: varchar({ length: 255 }).notNull().unique(),
  isEnabled: boolean().notNull().default(false),
  config: jsonb().notNull(),
  createdAt: timestamp().notNull().defaultNow()
})

// -> The images an administrator uploads for a site — its logo, favicon and login background — one row
//    per kind. Held in the database rather than under `dataPath`, which is a cache: an instance that
//    comes back with an empty data directory must still look like itself. Whether a kind has been
//    uploaded at all is mirrored in the site's `config.assets`, so serving a site that has uploaded
//    nothing costs no query here.
export const siteAssets = pgTable(
  'siteAssets',
  {
    siteId: uuid()
      .notNull()
      .references(() => sites.id),
    kind: varchar({ length: 255 }).notNull(),
    data: bytea().notNull()
  },
  (table) => [primaryKey({ columns: [table.siteId, table.kind] })]
)

// STORAGE -----------------------------
export const storage = pgTable(
  'storage',
  {
    id: uuid().primaryKey().defaultRandom(),
    // -> Directory name under `modules/storage`, one row per module per site
    module: varchar({ length: 255 }).notNull(),
    isEnabled: boolean().notNull().default(false),
    // -> `{ activeTypes: string[] }`, i.e. which kinds of content are written here. What counts as a
    //    large file is not among them: that is one answer per site, in the site's own config.
    contentTypes: jsonb().notNull().default({}),
    // -> `{ streaming: boolean, directAccess: boolean, servedTypes: string[] }`. `servedTypes` names
    //    the content types a reader's request is answered from this target, and is a subset of
    //    `contentTypes.activeTypes` — a target can only serve back what it was asked to store.
    assetDelivery: jsonb().notNull().default({}),
    // -> Values for the props the module declares in its `definition.yml`
    config: jsonb().notNull().default({}),
    // -> `{ status: 'healthy' | 'warning' | 'error', message: string, updatedAt: string | null }`:
    //    how the target is actually behaving, as opposed to how it is configured. Written by the
    //    storage model as it dispatches to the module — never by the admin area, which is why it is
    //    absent from the storage PUT — and reported by the Status card on the target's page.
    state: jsonb().notNull().default({}),
    siteId: uuid()
      .notNull()
      .references(() => sites.id)
  },
  // -> Covers lookups by site as well, being the leading column
  (table) => [uniqueIndex('storage_composite_idx').on(table.siteId, table.module)]
)

// TAGS --------------------------------
export const tags = pgTable(
  'tags',
  {
    id: uuid().primaryKey().defaultRandom(),
    tag: varchar({ length: 255 }).notNull(),
    usageCount: integer().notNull().default(0),
    createdAt: timestamp().notNull().defaultNow(),
    updatedAt: timestamp().notNull().defaultNow(),
    siteId: uuid()
      .notNull()
      .references(() => sites.id)
  },
  (table) => [
    index('tags_siteId_idx').on(table.siteId),
    uniqueIndex('tags_composite_idx').on(table.siteId, table.tag)
  ]
)

// TREE --------------------------------
export const treeTypeEnum = pgEnum('treeType', ['folder', 'page', 'asset'])
export const treeNavigationModeEnum = pgEnum('treeNavigationMode', [
  'inherit',
  'override',
  'overrideExact',
  'hide',
  'hideExact'
])
export const tree = pgTable(
  'tree',
  {
    id: uuid().primaryKey().defaultRandom(),
    // -> Genuinely hierarchical, and queried as such with `<@`, `@>` and lquery: this is what ltree is
    //    for. The locale beside it is not, and is a plain string.
    folderPath: ltree('folderPath'),
    fileName: varchar({ length: 255 }).notNull(),
    hash: varchar({ length: 255 }).notNull(),
    type: treeTypeEnum('tree').notNull(),
    locale: varchar({ length: 255 }).notNull(),
    title: varchar({ length: 255 }).notNull(),
    navigationMode: treeNavigationModeEnum('navigationMode').notNull().default('inherit'),
    navigationId: uuid(),
    tags: text()
      .array()
      .notNull()
      .default(sql`ARRAY[]::text[]`),
    meta: jsonb().notNull().default({}),
    createdAt: timestamp().notNull().defaultNow(),
    updatedAt: timestamp().notNull().defaultNow(),
    siteId: uuid()
      .notNull()
      .references(() => sites.id)
  },
  (table) => [
    index('tree_folderpath_idx').on(table.folderPath),
    index('tree_folderpath_gist_idx').using('gist', table.folderPath),
    index('tree_fileName_idx').on(table.fileName),
    index('tree_hash_idx').on(table.hash),
    index('tree_type_idx').on(table.type),
    // -> A plain btree: the locale is a string compared for equality, and GiST — which is what an
    //    ltree column wanted — has no operator class for varchar at all
    index('tree_locale_idx').on(table.locale),
    index('tree_navigationMode_idx').on(table.navigationMode),
    index('tree_navigationId_idx').on(table.navigationId),
    index('tree_tags_idx').using('gin', table.tags),
    index('tree_siteId_idx').on(table.siteId)
  ]
)

// USER AVATARS ------------------------
export const userAvatars = pgTable('userAvatars', {
  id: uuid().primaryKey(),
  data: bytea().notNull()
})

// USER KEYS ---------------------------
export const userKeys = pgTable(
  'userKeys',
  {
    id: uuid().primaryKey().defaultRandom(),
    kind: varchar({ length: 255 }).notNull(),
    token: varchar({ length: 255 }).notNull(),
    meta: jsonb().notNull().default({}),
    createdAt: timestamp().notNull().defaultNow(),
    validUntil: timestamp().notNull(),
    userId: uuid()
      .notNull()
      .references(() => users.id)
  },
  (table) => [index('userKeys_userId_idx').on(table.userId)]
)

// USERS -------------------------------
export const users = pgTable(
  'users',
  {
    id: uuid().primaryKey().defaultRandom(),
    email: varchar({ length: 255 }).notNull().unique(),
    name: varchar({ length: 255 }).notNull(),
    /**
     * The name this user is mentioned by in a comment, without the `@`.
     *
     * Null until they pick one, and a user without one is simply not mentionable — nothing is
     * derived from their name on their behalf. Unique case-insensitively: `@Ana` and `@ana` have to
     * be the same person for a mention to mean anything, so the index below is on the folded form
     * while the column keeps the capitalization that was typed.
     */
    handle: varchar({ length: 64 }),
    /**
     * What the directory provisioning this account calls it, as SCIM's `externalId`.
     *
     * The identifier that survives a rename or a change of address at the provider, so it is what a
     * SCIM client looks an account up by. Null for an account created here, and optional even for a
     * provisioned one — see the same column on `groups`.
     */
    externalId: varchar({ length: 255 }),
    /**
     * Whether a SCIM client owns this account. Set by the first provisioning write, which is how an
     * account created by hand is adopted by a directory that later claims it.
     *
     * What it gates is destruction: `DELETE /Users/:id` is only honoured for an account the client
     * owns, so a token sitting in somebody else's console cannot empty the wiki's user list. See
     * `models/scim.ts`.
     */
    isProvisioned: boolean().notNull().default(false),
    auth: jsonb().notNull().default({}),
    meta: jsonb().notNull().default({}),
    passkeys: jsonb().notNull().default({}),
    prefs: jsonb().notNull().default({}),
    hasAvatar: boolean().notNull().default(false),
    isActive: boolean().notNull().default(false),
    isSystem: boolean().notNull().default(false),
    isVerified: boolean().notNull().default(false),
    lastLoginAt: timestamp(),
    createdAt: timestamp().notNull().defaultNow(),
    updatedAt: timestamp().notNull().defaultNow()
  },
  (table) => [
    index('users_lastLoginAt_idx').on(table.lastLoginAt),
    // -> Nulls are distinct to postgres, as for the handle below
    uniqueIndex('users_externalId_idx').on(table.externalId),
    // -> Folded, so that two handles differing only in case cannot both exist. Nulls are distinct to
    //    postgres, which is what lets any number of users have no handle at all.
    uniqueIndex('users_handle_idx').on(sql`lower(${table.handle})`)
  ]
)

// == RELATION TABLES ==================

// USER GROUPS -------------------------
export const userGroups = pgTable(
  'userGroups',
  {
    userId: uuid()
      .notNull()
      .references(() => users.id, { onDelete: 'cascade' }),
    groupId: uuid()
      .notNull()
      .references(() => groups.id, { onDelete: 'cascade' })
  },
  (table) => [
    primaryKey({ columns: [table.userId, table.groupId] }),
    index('userGroups_userId_idx').on(table.userId),
    index('userGroups_groupId_idx').on(table.groupId),
    index('userGroups_composite_idx').on(table.userId, table.groupId)
  ]
)