package main

import (
	"context"
	"errors"
	"flag"
	"fmt"
	"log"
	"os"
	"path/filepath"
	"time"

	"git.meatbag.se/varl/subsyt/internal/config"
	"git.meatbag.se/varl/subsyt/internal/dl"
	"git.meatbag.se/varl/subsyt/internal/format"
	"git.meatbag.se/varl/subsyt/internal/metadata"
	"git.meatbag.se/varl/subsyt/internal/scheduler"
	"git.meatbag.se/varl/subsyt/internal/server"
)

func run(cfg config.Config) {
	provider := cfg.Provider["youtube"]

	if err := dl.UpgradeYtDlp(provider.Cmd); err != nil {
		log.Fatalf("failed to ensure yt-dlp is up to date: %v", err)
	}

	opml, err := format.OpmlLoad(provider.Opml_file)
	if err != nil {
		panic(err)
	}

	for _, outlines := range opml.Body.Outline {
		log.Printf("Archiving videos from OPML: %s\n", outlines.Title)

		for _, outline := range outlines.Outlines {
			rssData, err := dl.RssDownloader(outline.XmlUrl)
			if err != nil {
				log.Printf("Failed to download RSS for %s: %v", outline.Title, err)
				continue
			}

			feed, err := format.RssLoad(rssData)
			if err != nil {
				log.Printf("Failed to parse RSS for %s: %v", feed.Title, err)
				continue
			}

			dl.Youtube(dl.Download{
				Url:      feed.Author.Uri,
				OutDir:   filepath.Join(cfg.Out_dir, outline.Title),
				DryRun:   cfg.Dry_run,
				Metadata: true,
			}, provider)

			log.Printf("Downloaded RSS feed for %s with %d entries", feed.Title, len(feed.Entries))

			for _, entry := range feed.Entries {
				url := fmt.Sprintf("%s/watch?v=%s", provider.Url, entry.VideoId)

				log.Printf("Entry: %#v", entry)
				dl.Youtube(dl.Download{
					Url:      url,
					OutDir:   filepath.Join(cfg.Out_dir, feed.Title),
					DryRun:   cfg.Dry_run,
					Metadata: false,
				}, provider)
			}

			metadata.Generate(cfg.Out_dir, feed.Title, cfg.Dry_run)
		}
	}
}

func main() {
	ctx, cancel := context.WithCancel(context.Background())
	defer cancel()

	configPtr := flag.String("config", "", "path to config file")
	flag.Parse()

	configEnv := os.Getenv("CONFIG")

	var configPath string
	if *configPtr != "" {
		configPath = *configPtr
	} else if configEnv != "" {
		configPath = configEnv
	} else {
		configPath = "./config.json"
	}

	log.Println("resolved config file", configPath)

	cfg, err := config.Load(configPath)
	if err != nil {
		panic(err)
	}

	provider, ok := cfg.Provider["youtube"]
	if !ok {
		log.Fatal("youtube provider configuration missing")
	}

	if cfg.Http_api.Enable {
		if err := setupAPIServer(ctx, cfg, provider); err != nil {
			log.Fatalf("failed to start http api: %v", err)
		}
	}

	if cfg.Daemon {
		log.Println("running with scheduler")
		s := scheduler.Scheduler{}
		s.Start(run, cfg)
	} else {
		log.Println("running standalone")
		run(cfg)
	}
}

func setupAPIServer(ctx context.Context, cfg config.Config, provider config.Provider) error {
	queue, err := server.NewQueue(cfg.Http_api.Queue_file)
	if err != nil {
		return fmt.Errorf("load queue: %w", err)
	}

	go queueWorker(ctx, queue, cfg, provider)

	srv := server.NewServer(cfg.Http_api, cfg.Out_dir, queue)
	go func() {
		if err := srv.Start(ctx); err != nil {
			log.Printf("http api server stopped with error: %v", err)
		}
	}()

	return nil
}

func queueWorker(ctx context.Context, q *server.Queue, cfg config.Config, provider config.Provider) {
	for {
		item, err := q.Next(ctx)
		if err != nil {
			if errors.Is(err, context.Canceled) {
				return
			}
			log.Printf("queue wait error: %v", err)
			select {
			case <-time.After(5 * time.Second):
			case <-ctx.Done():
				return
			}
			continue
		}

		outPath := filepath.Join(cfg.Out_dir, "_misc")

		dl.Youtube(dl.Download{
			Url:      item.Request.URL,
			OutDir:   outPath,
			DryRun:   cfg.Dry_run,
			Metadata: false,
		}, provider)

		metadata.Generate(cfg.Out_dir, "_misc", cfg.Dry_run)

		if err := q.MarkDone(item.ID); err != nil {
			log.Printf("queue mark done failed: %v", err)
		}
	}
}