package model

import (
	"encoding/json"
	"github.com/HFO4/cloudreve/pkg/util"
	"github.com/jinzhu/gorm"
	"path/filepath"
	"strconv"
	"sync"
	"time"
)

// Policy 存储策略
type Policy struct {
	// 表字段
	gorm.Model
	Name               string
	Type               string
	Server             string
	BucketName         string
	IsPrivate          bool
	BaseURL            string
	AccessKey          string `gorm:"size:512"`
	SecretKey          string `gorm:"size:512"`
	MaxSize            uint64
	AutoRename         bool
	DirNameRule        string
	FileNameRule       string
	IsOriginLinkEnable bool
	Options            string `gorm:"size:4096"`

	// 数据库忽略字段
	OptionsSerialized PolicyOption `gorm:"-"`
}

// PolicyOption 非公有的存储策略属性
type PolicyOption struct {
	OPName               string   `json:"op_name"`
	OPPassword           string   `json:"op_pwd"`
	FileType             []string `json:"file_type"`
	MimeType             string   `json:"mimetype"`
	RangeTransferEnabled bool     `json:"range_transfer_enabled"`
}

// 存储策略缓存，部分情况下需要频繁查询存储策略
var policyCache = make(map[uint]Policy)
var rw sync.RWMutex

// GetPolicyByID 用ID获取存储策略
func GetPolicyByID(ID interface{}) (Policy, error) {
	// 尝试读取缓存
	rw.RLock()
	if policy, ok := policyCache[ID.(uint)]; ok {
		rw.RUnlock()
		return policy, nil
	}
	rw.RUnlock()

	var policy Policy
	result := DB.First(&policy, ID)

	// 写入缓存
	if result.Error == nil {
		rw.Lock()
		policyCache[policy.ID] = policy
		rw.Unlock()
	}

	return policy, result.Error
}

// AfterFind 找到存储策略后的钩子
func (policy *Policy) AfterFind() (err error) {
	// 解析存储策略设置到OptionsSerialized
	err = json.Unmarshal([]byte(policy.Options), &policy.OptionsSerialized)
	if policy.OptionsSerialized.FileType == nil {
		policy.OptionsSerialized.FileType = []string{}
	}
	return err
}

// BeforeSave Save策略前的钩子
func (policy *Policy) BeforeSave() (err error) {
	err = policy.SerializeOptions()
	return err
}

//SerializeOptions 将序列后的Option写入到数据库字段
func (policy *Policy) SerializeOptions() (err error) {
	optionsValue, err := json.Marshal(&policy.OptionsSerialized)
	policy.Options = string(optionsValue)
	return err
}

// GeneratePath 生成存储文件的路径
func (policy *Policy) GeneratePath(uid uint, path string) string {
	dirRule := policy.DirNameRule
	replaceTable := map[string]string{
		"{randomkey16}": util.RandStringRunes(16),
		"{randomkey8}":  util.RandStringRunes(8),
		"{timestamp}":   strconv.FormatInt(time.Now().Unix(), 10),
		"{uid}":         strconv.Itoa(int(uid)),
		"{datetime}":    time.Now().Format("20060102150405"),
		"{date}":        time.Now().Format("20060102"),
		"{path}":        path + "/",
	}
	dirRule = util.Replace(replaceTable, dirRule)
	return filepath.Clean(dirRule)
}

// GenerateFileName 生成存储文件名
func (policy *Policy) GenerateFileName(uid uint, origin string) string {
	// 未开启自动重命名时，直接返回原始文件名
	if !policy.AutoRename {
		return origin
	}

	fileRule := policy.FileNameRule

	replaceTable := map[string]string{
		"{randomkey16}": util.RandStringRunes(16),
		"{randomkey8}":  util.RandStringRunes(8),
		"{timestamp}":   strconv.FormatInt(time.Now().Unix(), 10),
		"{uid}":         strconv.Itoa(int(uid)),
		"{datetime}":    time.Now().Format("20060102150405"),
		"{date}":        time.Now().Format("20060102"),
	}

	// 部分存储策略可以使用{origin}代表原始文件名
	switch policy.Type {
	case "qiniu":
		// 七牛会将$(fname)自动替换为原始文件名
		replaceTable["{originname}"] = "$(fname)"
	case "local":
		replaceTable["{originname}"] = origin
	case "oss":
		// OSS会将${filename}自动替换为原始文件名
		replaceTable["{originname}"] = "${filename}"
	case "upyun":
		// Upyun会将{filename}{.suffix}自动替换为原始文件名
		replaceTable["{originname}"] = "{filename}{.suffix}"
	}

	fileRule = util.Replace(replaceTable, fileRule)
	return fileRule
}