// Package catalogcmd resolves a channel's stream credentials from its provider's
// public catalog, with no phone involved. It is provider-agnostic: any app module
// implementing app.Catalog works here.
package catalogcmd

import (
	"encoding/json"
	"flag"
	"fmt"
	"os"
	"sort"
	"strings"

	"drmdecryption/app"
	"drmdecryption/repo"
	"drmdecryption/session"
)

// Run performs a catalog lookup for one channel.
func Run(args []string) error {
	fs := flag.NewFlagSet("catalog", flag.ExitOnError)
	appName := fs.String("app", "", "app module to query")
	channel := fs.String("channel", "", "channel id")
	asJSON := fs.Bool("json", false, "print streamd-ready JSON only")
	list := fs.Bool("list", false, "list the app's channels and their catalog ids")
	writeOut := fs.Bool("out", false, "write outputs/<app>/<stamp>/session.json")
	withKeys := fs.Bool("keys", false, "also fetch PSSH and resolve KID:KEY via the local CDM")
	python := fs.String("python", "", "python for wvkey.py (default: .venv)")
	wvd := fs.String("wvd", "", "path to .wvd device file (required with --keys)")
	// Each module contributes --<app>.<field> overrides for its local values.
	app.BindFlags(fs)
	fs.Usage = func() {
		fmt.Fprintf(fs.Output(), "catalog — resolve a channel from its public catalog (no phone)\n\nUsage:\n  catalog --app <%s> --channel ID [--keys] [--json]\n\nFlags:\n", strings.Join(catalogApps(), "|"))
		fs.PrintDefaults()
	}
	if err := fs.Parse(args); err != nil {
		return err
	}

	available := catalogApps()
	if strings.TrimSpace(*appName) == "" {
		if len(available) != 1 {
			return fmt.Errorf("--app required (apps with a catalog: %s)", strings.Join(available, ", "))
		}
		*appName = available[0]
	}
	a, err := app.Get(*appName)
	if err != nil {
		return err
	}
	cat, ok := a.(app.Catalog)
	if !ok {
		return fmt.Errorf("app %q has no catalog — capture it from the phone instead: drm capture --app %s", a.Name(), a.Name())
	}

	if *list {
		return listChannels(a, cat)
	}
	if strings.TrimSpace(*channel) == "" {
		return fmt.Errorf("--channel required (see: drm catalog --app %s --list)", a.Name())
	}

	info, err := cat.Resolve(*channel)
	if err != nil {
		return err
	}
	if *withKeys {
		fmt.Fprintln(os.Stderr, "[*] fetching PSSH + Widevine keys…")
		if err := cat.EnrichWithKeys(&info, *python, *wvd); err != nil {
			return err
		}
		fmt.Fprintf(os.Stderr, "[+] key %s (%d total)\n", info.Key, len(info.Keys))
	}
	if *writeOut || *withKeys {
		dir, err := session.WriteStream(repo.Root(), a.Name(), info)
		if err != nil {
			return err
		}
		fmt.Fprintf(os.Stderr, "[+] wrote %s\n", dir)
	}
	if *asJSON {
		enc := json.NewEncoder(os.Stdout)
		enc.SetIndent("", "  ")
		return enc.Encode(info)
	}
	printInfo(a.Name(), info)
	return nil
}

// catalogApps lists compiled-in modules that can answer catalog lookups.
func catalogApps() []string {
	out := []string{}
	for _, a := range app.All() {
		if _, ok := a.(app.Catalog); ok {
			out = append(out, a.Name())
		}
	}
	sort.Strings(out)
	return out
}

func listChannels(a app.App, cat app.Catalog) error {
	if l, ok := cat.(app.CatalogLister); ok {
		rows, flags, err := l.ListChannels()
		if err != nil {
			return err
		}
		fmt.Printf("%-10s %-16s %s\n", "CHANNEL", "CATALOG ID", "LABEL")
		sort.Slice(rows, func(i, j int) bool { return rows[i].ID < rows[j].ID })
		for _, r := range rows {
			id := r.CatalogID
			if id == "" {
				id = "-"
			}
			fmt.Printf("%-10s %-16s %s\n", r.ID, id, r.Label)
		}
		if len(flags) > 0 {
			keys := make([]string, 0, len(flags))
			for k := range flags {
				keys = append(keys, k)
			}
			sort.Strings(keys)
			parts := make([]string, 0, len(keys))
			for _, k := range keys {
				parts = append(parts, fmt.Sprintf("%s=%v", k, flags[k]))
			}
			fmt.Printf("\nprovider flags: %s\n", strings.Join(parts, " "))
		}
		return nil
	}
	// Fall back to the plain channel list every app can produce.
	fmt.Printf("%-10s %s\n", "CHANNEL", "LABEL")
	for _, ch := range a.Channels() {
		fmt.Printf("%-10s %s\n", ch.ID, ch.Label)
	}
	return nil
}

func printInfo(appName string, info session.Stream) {
	fmt.Printf("name:          %s\n", info.Name)
	fmt.Printf("title:         %s\n", info.Title)
	fmt.Printf("app/channel:   %s / %s\n", info.App, info.Channel)
	if info.VideoID != "" {
		fmt.Printf("catalog id:    %s\n", info.VideoID)
	}
	fmt.Printf("manifest:      %s\n", info.MPD)
	fmt.Printf("manifest type: %s\n", info.ManifestType)
	fmt.Printf("license_url:   %s\n", truncate(info.LicenseURL, 100))
	if info.PSSH != "" {
		fmt.Printf("pssh:          %s\n", truncate(info.PSSH, 64))
	}
	if info.Key != "" {
		fmt.Printf("key:           %s\n", info.Key)
	}
	for i, k := range info.Keys {
		if k == info.Key {
			continue
		}
		fmt.Printf("key[%d]:        %s\n", i, k)
	}
	body, _ := json.MarshalIndent(map[string]any{
		"name":         info.Name,
		"title":        info.Title,
		"app":          info.App,
		"channel":      info.Channel,
		"mpd":          info.MPD,
		"key":          info.Key,
		"headers_json": info.HeadersJSON,
		"rewriter":     info.Rewriter,
	}, "", "  ")
	fmt.Printf("\nstreamd create body:\n%s\n", body)
	fmt.Printf("\nTip: drm catalog --app %s --channel %s --keys --wvd path/to/device.wvd --json\n",
		appName, info.Channel)
}

func truncate(s string, n int) string {
	if len(s) <= n {
		return s
	}
	return s[:n] + "..."
}