package httpserver

import (
	"log/slog"
	"net/http"
	"time"

	"warpbox.dev/backend/libs/config"
	"warpbox.dev/backend/libs/handlers"
	"warpbox.dev/backend/libs/middleware"
	"warpbox.dev/backend/libs/services"
	"warpbox.dev/backend/libs/web"
)

func New(cfg config.Config, logger *slog.Logger) (*http.Server, error) {
	renderer, err := web.NewRenderer(cfg.TemplateDir, cfg.AppName, cfg.BaseURL)
	if err != nil {
		return nil, err
	}

	uploadService, err := services.NewUploadService(cfg.MaxUploadSize, cfg.DataDir, cfg.BaseURL, logger)
	if err != nil {
		return nil, err
	}
	stopCleanup := startCleanup(uploadService, cfg.CleanupEvery, logger)
	stopThumbnails := startThumbnails(uploadService, cfg.ThumbnailEvery, logger)
	app := handlers.NewApp(cfg, logger, renderer, uploadService)

	router := http.NewServeMux()
	app.RegisterRoutes(router)

	handler := middleware.Chain(
		router,
		middleware.Recoverer(logger),
		middleware.RequestID,
		middleware.SecurityHeaders,
		middleware.Gzip,
		middleware.Logger(logger),
	)

	server := &http.Server{
		Addr:         cfg.Addr,
		Handler:      handler,
		ReadTimeout:  cfg.ReadTimeout,
		WriteTimeout: cfg.WriteTimeout,
		IdleTimeout:  cfg.IdleTimeout,
	}
	server.RegisterOnShutdown(func() {
		stopCleanup()
		stopThumbnails()
		if err := uploadService.Close(); err != nil {
			logger.Error("failed to close upload service", "source", "shutdown", "severity", "error", "error", err.Error())
		}
	})

	return server, nil
}

func startCleanup(uploadService *services.UploadService, interval time.Duration, logger *slog.Logger) func() {
	if interval <= 0 {
		return func() {}
	}

	stop := make(chan struct{})
	go func() {
		if cleaned, err := uploadService.CleanupExpired(); err != nil {
			logger.Warn("initial cleanup failed", "source", "housekeeping", "severity", "warn", "code", 4201, "error", err.Error())
		} else if cleaned > 0 {
			logger.Info("initial cleanup complete", "source", "housekeeping", "severity", "user_activity", "code", 2202, "cleaned", cleaned)
		}

		ticker := time.NewTicker(interval)
		defer ticker.Stop()
		for {
			select {
			case <-ticker.C:
				if _, err := uploadService.CleanupExpired(); err != nil {
					logger.Warn("scheduled cleanup failed", "source", "housekeeping", "severity", "warn", "code", 4202, "error", err.Error())
				}
			case <-stop:
				return
			}
		}
	}()

	return func() {
		close(stop)
	}
}

func startThumbnails(uploadService *services.UploadService, interval time.Duration, logger *slog.Logger) func() {
	if interval <= 0 {
		return func() {}
	}

	stop := make(chan struct{})
	run := func(source string) {
		result, err := uploadService.GenerateMissingThumbnails()
		if err != nil {
			logger.Warn("thumbnail job failed", "source", "thumbnail", "severity", "warn", "code", 4203, "error", err.Error())
			return
		}
		if result.Generated > 0 || result.Failed > 0 {
			logger.Info("thumbnail job run", "source", source, "severity", "user_activity", "code", 2204, "generated", result.Generated, "failed", result.Failed)
		}
	}

	go func() {
		run("thumbnail")

		ticker := time.NewTicker(interval)
		defer ticker.Stop()
		for {
			select {
			case <-ticker.C:
				run("thumbnail")
			case <-stop:
				return
			}
		}
	}()

	return func() {
		close(stop)
	}
}