package commands

import (
	"archive/zip"
	"errors"
	"fmt"
	"io"
	"net/http"
	"os"
	"path/filepath"
	"strings"

	"github.com/urfave/cli/v2"

	"github.com/photoprism/photoprism/internal/config"
	"github.com/photoprism/photoprism/pkg/clean"
	"github.com/photoprism/photoprism/pkg/fs"
)

// ClusterThemePullCommand downloads the Portal theme and installs it.
var ClusterThemePullCommand = &cli.Command{
	Name:  "theme",
	Usage: "Theme subcommands",
	Subcommands: []*cli.Command{
		{
			Name:  "pull",
			Usage: "Downloads the theme from a portal and installs it in config/theme or the dest path",
			Flags: []cli.Flag{
				&cli.PathFlag{Name: "dest", Usage: "extract destination `PATH` (defaults to config/theme)", Value: ""},
				&cli.BoolFlag{Name: "force", Aliases: []string{"f"}, Usage: "replace existing files at destination"},
				&cli.StringFlag{Name: "portal-url", Usage: "Portal base `URL` (defaults to global config)"},
				&cli.StringFlag{Name: "portal-token", Usage: "Portal access `TOKEN` (defaults to global config)"},
				JsonFlag,
			},
			Action: clusterThemePullAction,
		},
	},
}

func clusterThemePullAction(ctx *cli.Context) error {
	return CallWithDependencies(ctx, func(conf *config.Config) error {
		portalURL := strings.TrimRight(ctx.String("portal-url"), "/")
		if portalURL == "" {
			portalURL = strings.TrimRight(conf.PortalUrl(), "/")
		}
		if portalURL == "" {
			portalURL = strings.TrimRight(os.Getenv(config.EnvVar("portal-url")), "/")
		}
		if portalURL == "" {
			return fmt.Errorf("portal-url not configured; set --portal-url or PHOTOPRISM_PORTAL_URL")
		}
		token := ctx.String("portal-token")
		if token == "" {
			token = conf.PortalToken()
		}
		if token == "" {
			token = os.Getenv(config.EnvVar("portal-token"))
		}
		if token == "" {
			return fmt.Errorf("portal-token not configured; set --portal-token or PHOTOPRISM_PORTAL_TOKEN")
		}

		dest := ctx.Path("dest")
		if dest == "" {
			dest = conf.ThemePath()
		}
		dest = fs.Abs(dest)

		// Destination must be a directory. Create if needed.
		if fi, err := os.Stat(dest); err == nil && !fi.IsDir() {
			return fmt.Errorf("destination is a file, expected a directory: %s", clean.Log(dest))
		} else if err != nil {
			if err := fs.MkdirAll(dest); err != nil {
				return err
			}
		}

		// If destination contains files and --force not set, refuse.
		if !ctx.Bool("force") {
			if nonEmpty, _ := dirNonEmpty(dest); nonEmpty {
				return fmt.Errorf("destination is not empty; use --force to replace existing files: %s", clean.Log(dest))
			}
		} else {
			// Clean destination contents, but keep the directory itself.
			if err := removeDirContents(dest); err != nil {
				return err
			}
		}

		// Download zip to a temp file.
		zipURL := portalURL + "/api/v1/cluster/theme"
		tmpFile, err := os.CreateTemp("", "photoprism-theme-*.zip")
		if err != nil {
			return err
		}
		defer func() {
			_ = os.Remove(tmpFile.Name())
		}()

		req, err := http.NewRequest(http.MethodGet, zipURL, nil)
		if err != nil {
			return err
		}
		req.Header.Set("Authorization", "Bearer "+token)
		resp, err := http.DefaultClient.Do(req)
		if err != nil {
			return err
		}
		defer resp.Body.Close()
		if resp.StatusCode != http.StatusOK {
			// Map common codes to clearer messages
			switch resp.StatusCode {
			case http.StatusUnauthorized, http.StatusForbidden:
				return fmt.Errorf("unauthorized; check portal token and permissions (%s)", resp.Status)
			case http.StatusTooManyRequests:
				return fmt.Errorf("rate limited by portal (%s)", resp.Status)
			case http.StatusNotFound:
				return fmt.Errorf("portal theme not found (%s)", resp.Status)
			default:
				return fmt.Errorf("download failed: %s", resp.Status)
			}
		}
		if _, err = io.Copy(tmpFile, resp.Body); err != nil {
			return err
		}
		if err := tmpFile.Close(); err != nil {
			return err
		}

		// Extract safely into destination.
		if err := unzipSafe(tmpFile.Name(), dest); err != nil {
			return err
		}

		if ctx.Bool("json") {
			fmt.Printf("{\"installed\":\"%s\"}\n", clean.Log(dest))
		} else {
			log.Infof("installed theme files to %s", clean.Log(dest))
			fmt.Println(dest)
		}
		return nil
	})
}

func dirNonEmpty(dir string) (bool, error) {
	entries, err := os.ReadDir(dir)
	if err != nil {
		return false, err
	}
	for range entries {
		// Ignore typical dotfiles? Keep it simple: any entry counts
		return true, nil
	}
	return false, nil
}

func removeDirContents(dir string) error {
	entries, err := os.ReadDir(dir)
	if err != nil {
		return err
	}
	for _, e := range entries {
		p := filepath.Join(dir, e.Name())
		if err := os.RemoveAll(p); err != nil {
			return err
		}
	}
	return nil
}

func unzipSafe(zipPath, dest string) error {
	r, err := zip.OpenReader(zipPath)
	if err != nil {
		return err
	}
	defer r.Close()
	if len(r.File) == 0 {
		return errors.New("theme archive is empty")
	}
	for _, f := range r.File {
		// Directories are indicated by trailing '/'; ensure canonical path
		name := filepath.Clean(f.Name)
		if name == "." || name == ".." || strings.HasPrefix(name, "../") || strings.Contains(name, ":") {
			continue
		}
		// Disallow absolute and Windows drive paths
		if filepath.IsAbs(name) {
			continue
		}
		target := filepath.Join(dest, name)
		// Ensure path stays within dest
		if !strings.HasPrefix(target+string(os.PathSeparator), dest+string(os.PathSeparator)) && target != dest {
			continue
		}
		// Skip entries that look like hidden files or directories
		base := filepath.Base(name)
		if fs.FileNameHidden(base) {
			continue
		}
		if f.FileInfo().IsDir() {
			if err := fs.MkdirAll(target); err != nil {
				return err
			}
			continue
		}
		// Ensure parent exists
		if err := fs.MkdirAll(filepath.Dir(target)); err != nil {
			return err
		}
		// Open for read
		rc, err := f.Open()
		if err != nil {
			return err
		}
		// Create/truncate target
		out, err := os.OpenFile(target, os.O_CREATE|os.O_TRUNC|os.O_WRONLY, f.Mode())
		if err != nil {
			rc.Close()
			return err
		}
		if _, err := io.Copy(out, rc); err != nil {
			out.Close()
			rc.Close()
			return err
		}
		out.Close()
		rc.Close()
	}
	return nil
}