/*
Copyright The Helm Authors.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

package cmd

import (
	"fmt"
	"io"
	"log/slog"
	"strings"

	"github.com/gosuri/uitable"
	"github.com/spf13/cobra"

	"helm.sh/helm/v4/internal/monocular"
	"helm.sh/helm/v4/pkg/cli/output"
)

const searchHubDesc = `
Search for Helm charts in the Artifact Hub or your own hub instance.

Artifact Hub is a web-based application that enables finding, installing, and
publishing packages and configurations for CNCF projects, including publicly
available distributed charts Helm charts. It is a Cloud Native Computing
Foundation sandbox project. You can browse the hub at https://artifacthub.io/

The [KEYWORD] argument accepts either a keyword string, or quoted string of rich
query options. For rich query options documentation, see
https://artifacthub.github.io/hub/api/?urls.primaryName=Monocular%20compatible%20search%20API#/Monocular/get_api_chartsvc_v1_charts_search

Previous versions of Helm used an instance of Monocular as the default
'endpoint', so for backwards compatibility Artifact Hub is compatible with the
Monocular search API. Similarly, when setting the 'endpoint' flag, the specified
endpoint must also be implement a Monocular compatible search API endpoint.
Note that when specifying a Monocular instance as the 'endpoint', rich queries
are not supported. For API details, see https://github.com/helm/monocular
`

type searchHubOptions struct {
	searchEndpoint string
	maxColWidth    uint
	outputFormat   output.Format
	listRepoURL    bool
	failOnNoResult bool
}

func newSearchHubCmd(out io.Writer) *cobra.Command {
	o := &searchHubOptions{}

	cmd := &cobra.Command{
		Use:   "hub [KEYWORD]",
		Short: "search for charts in the Artifact Hub or your own hub instance",
		Long:  searchHubDesc,
		RunE: func(_ *cobra.Command, args []string) error {
			return o.run(out, args)
		},
	}

	f := cmd.Flags()
	f.StringVar(&o.searchEndpoint, "endpoint", "https://hub.helm.sh", "Hub instance to query for charts")
	f.UintVar(&o.maxColWidth, "max-col-width", 50, "maximum column width for output table")
	f.BoolVar(&o.listRepoURL, "list-repo-url", false, "print charts repository URL")
	f.BoolVar(&o.failOnNoResult, "fail-on-no-result", false, "search fails if no results are found")

	bindOutputFlag(cmd, &o.outputFormat)

	return cmd
}

func (o *searchHubOptions) run(out io.Writer, args []string) error {
	c, err := monocular.New(o.searchEndpoint)
	if err != nil {
		return fmt.Errorf("unable to create connection to %q: %w", o.searchEndpoint, err)
	}

	q := strings.Join(args, " ")
	results, err := c.Search(q)
	if err != nil {
		slog.Debug("search failed", slog.Any("error", err))
		return fmt.Errorf("unable to perform search against %q", o.searchEndpoint)
	}

	return o.outputFormat.Write(out, newHubSearchWriter(results, o.searchEndpoint, o.maxColWidth, o.listRepoURL, o.failOnNoResult))
}

type hubChartRepo struct {
	URL  string `json:"url"`
	Name string `json:"name"`
}

type hubChartElement struct {
	URL         string       `json:"url"`
	Version     string       `json:"version"`
	AppVersion  string       `json:"app_version"`
	Description string       `json:"description"`
	Repository  hubChartRepo `json:"repository"`
}

type hubSearchWriter struct {
	elements       []hubChartElement
	columnWidth    uint
	listRepoURL    bool
	failOnNoResult bool
}

func newHubSearchWriter(results []monocular.SearchResult, endpoint string, columnWidth uint, listRepoURL, failOnNoResult bool) *hubSearchWriter {
	var elements []hubChartElement
	for _, r := range results {
		// Backwards compatibility for Monocular
		url := endpoint + "/charts/" + r.ID

		// Check for artifactHub compatibility
		if r.ArtifactHub.PackageURL != "" {
			url = r.ArtifactHub.PackageURL
		}

		elements = append(elements, hubChartElement{url, r.Relationships.LatestChartVersion.Data.Version, r.Relationships.LatestChartVersion.Data.AppVersion, r.Attributes.Description, hubChartRepo{URL: r.Attributes.Repo.URL, Name: r.Attributes.Repo.Name}})
	}
	return &hubSearchWriter{elements, columnWidth, listRepoURL, failOnNoResult}
}

func (h *hubSearchWriter) WriteTable(out io.Writer) error {
	if len(h.elements) == 0 {
		// Fail if no results found and --fail-on-no-result is enabled
		if h.failOnNoResult {
			return fmt.Errorf("no results found")
		}

		_, err := out.Write([]byte("No results found\n"))
		if err != nil {
			return fmt.Errorf("unable to write results: %s", err)
		}
		return nil
	}
	table := uitable.New()
	table.MaxColWidth = h.columnWidth

	if h.listRepoURL {
		table.AddRow("URL", "CHART VERSION", "APP VERSION", "DESCRIPTION", "REPO URL")
	} else {
		table.AddRow("URL", "CHART VERSION", "APP VERSION", "DESCRIPTION")
	}

	for _, r := range h.elements {
		if h.listRepoURL {
			table.AddRow(r.URL, r.Version, r.AppVersion, r.Description, r.Repository.URL)
		} else {
			table.AddRow(r.URL, r.Version, r.AppVersion, r.Description)
		}
	}
	return output.EncodeTable(out, table)
}

func (h *hubSearchWriter) WriteJSON(out io.Writer) error {
	return h.encodeByFormat(out, output.JSON)
}

func (h *hubSearchWriter) WriteYAML(out io.Writer) error {
	return h.encodeByFormat(out, output.YAML)
}

func (h *hubSearchWriter) encodeByFormat(out io.Writer, format output.Format) error {
	// Fail if no results found and --fail-on-no-result is enabled
	if len(h.elements) == 0 && h.failOnNoResult {
		return fmt.Errorf("no results found")
	}

	// Initialize the array so no results returns an empty array instead of null
	chartList := make([]hubChartElement, 0, len(h.elements))

	for _, r := range h.elements {
		chartList = append(chartList, hubChartElement{r.URL, r.Version, r.AppVersion, r.Description, r.Repository})
	}

	switch format {
	case output.JSON:
		return output.EncodeJSON(out, chartList)
	case output.YAML:
		return output.EncodeYAML(out, chartList)
	}

	// Because this is a non-exported function and only called internally by
	// WriteJSON and WriteYAML, we shouldn't get invalid types
	return nil
}