package worker

import (
	"context"
	"log/slog"
	"time"

	"github.com/TopherMayor/unified-media-manager/internal/config"
	"github.com/TopherMayor/unified-media-manager/internal/db"
	"github.com/TopherMayor/unified-media-manager/internal/service"
)

type RSSSyncWorker struct {
	database   *db.DB
	mediaSvc   *service.MediaService
	searchSvc  *service.SearchService
	dcSvc      *service.DownloadClientService
	qualitySvc *service.QualityService
	cfg        *config.Config
}

func NewRSSSyncWorker(database *db.DB, mediaSvc *service.MediaService, searchSvc *service.SearchService, dcSvc *service.DownloadClientService, qualitySvc *service.QualityService, cfg *config.Config) *RSSSyncWorker {
	return &RSSSyncWorker{
		database:   database,
		mediaSvc:   mediaSvc,
		searchSvc:  searchSvc,
		dcSvc:      dcSvc,
		qualitySvc: qualitySvc,
		cfg:        cfg,
	}
}

func (w *RSSSyncWorker) Name() string {
	return "rss_sync"
}

func (w *RSSSyncWorker) CronExpr() string {
	return w.cfg.WorkerRSSSyncInterval
}

func (w *RSSSyncWorker) Run(ctx context.Context) error {
	ctx, cancel := context.WithTimeout(ctx, 5*time.Minute)
	defer cancel()

	searched := 0
	grabs := 0
	errors := 0

	seen := make(map[int64]bool)

	missing, _, err := w.mediaSvc.SearchMissing(ctx, service.MediaFilters{PageSize: 100})
	if err != nil {
		slog.Error("failed to search missing media", "error", err)
		errors++
	}
	for i := range missing {
		seen[missing[i].ID] = true
	}

	upgrades, _, err := w.mediaSvc.SearchUpgrades(ctx, service.MediaFilters{PageSize: 100})
	if err != nil {
		slog.Error("failed to search upgrade media", "error", err)
		errors++
	}
	for i := range upgrades {
		seen[upgrades[i].ID] = true
	}

	var allItems []service.Media
	for _, m := range missing {
		allItems = append(allItems, m)
	}
	for _, m := range upgrades {
		if !seen[m.ID] {
			allItems = append(allItems, m)
			seen[m.ID] = true
		}
	}

	for _, item := range allItems {
		var hasPending bool
		err := w.database.Pool.QueryRow(ctx,
			`SELECT EXISTS(SELECT 1 FROM download_queue WHERE media_id = $1 AND status IN ('pending', 'downloading'))`,
			item.ID).Scan(&hasPending)
		if err != nil {
			slog.Error("failed to check pending queue", "media_id", item.ID, "error", err)
			continue
		}
		if hasPending {
			continue
		}

		_, err = w.database.Pool.Exec(ctx,
			"UPDATE media SET last_search_at = NOW() WHERE id = $1", item.ID)
		if err != nil {
			slog.Error("failed to update last_search_at", "media_id", item.ID, "error", err)
		}

		results, err := w.searchSvc.Search(ctx, service.SearchRequest{
			Query:     item.Title,
			MediaType: item.MediaType,
		})
		if err != nil {
			slog.Error("failed to search indexers", "media_id", item.ID, "title", item.Title, "error", err)
			errors++
			searched++
			continue
		}
		searched++

		if len(results) == 0 {
			continue
		}

		var filtered []service.SearchResult
		for _, r := range results {
			var blocked bool
			err := w.database.Pool.QueryRow(ctx,
				"SELECT EXISTS(SELECT 1 FROM blocklist WHERE release_title = $1)", r.Title).Scan(&blocked)
			if err != nil {
				slog.Error("failed to check blocklist", "error", err)
				continue
			}
			if blocked {
				continue
			}

			if item.QualityProfileID != nil {
				profile, err := w.qualitySvc.GetByID(ctx, *item.QualityProfileID)
				if err != nil {
					slog.Error("failed to get quality profile", "profile_id", *item.QualityProfileID, "error", err)
					filtered = append(filtered, r)
					continue
				}

				if r.QualityTier != nil {
					allowed := false
					for _, name := range profile.AllowedQualities {
						if name == r.QualityTier.Name {
							allowed = true
							break
						}
					}
					if !allowed {
						continue
					}
				}
			}

			filtered = append(filtered, r)
		}

		if len(filtered) == 0 {
			continue
		}

		best := filtered[0]
		for _, r := range filtered[1:] {
			bestRank := 0
			if best.QualityTier != nil {
				bestRank = best.QualityTier.Rank
			}
			rank := 0
			if r.QualityTier != nil {
				rank = r.QualityTier.Rank
			}
			if rank > bestRank || (rank == bestRank && r.Size > best.Size) {
				best = r
			}
		}

		_, err = w.searchSvc.Grab(ctx, service.GrabRequest{
			DownloadURL: best.DownloadURL,
			Title:       best.Title,
			MediaType:   item.MediaType,
			Quality:     best.Quality,
			IndexerName: best.IndexerName,
			MediaID:     item.ID,
		}, w.dcSvc)
		if err != nil {
			slog.Error("failed to auto-grab release", "media_id", item.ID, "release", best.Title, "error", err)
			errors++
			continue
		}

		status := "searching"
		if err := w.mediaSvc.Update(ctx, item.ID, item.MediaType, service.UpdateMediaRequest{Status: &status}); err != nil {
			slog.Error("failed to update media status", "media_id", item.ID, "error", err)
		}

		slog.Info("auto-grabbed release", "media", item.Title, "release", best.Title, "quality", best.QualityTier.Name)
		grabs++
	}

	slog.Info("rss sync completed", "searched", searched, "grabs", grabs, "errors", errors)
	return nil
}