package api

import (
	"context"
	"fmt"
	"io"
	"net/http"
	"os"

	"gitea.mrixs.me/minecraft-platform/backend/internal/core"
	"gitea.mrixs.me/minecraft-platform/backend/internal/core/importer"
	"gitea.mrixs.me/minecraft-platform/backend/internal/database"
	"gitea.mrixs.me/minecraft-platform/backend/internal/models"
)

type ModpackHandler struct {
	ModpackRepo    *database.ModpackRepository
	JanitorService *core.FileJanitorService
}

// ImportModpack обрабатывает загрузку и импорт модпака.
func (h *ModpackHandler) ImportModpack(w http.ResponseWriter, r *http.Request) {
	if err := r.ParseMultipartForm(512 << 20); err != nil {
		http.Error(w, "File too large", http.StatusBadRequest)
		return
	}

	importerType := r.FormValue("importerType")
	importMethod := r.FormValue("importMethod")
	sourceURL := r.FormValue("sourceUrl")

	var tempZipPath string
	var err error

	// --- Выбираем импортер ---
	var imp importer.ModpackImporter
	storagePath := os.Getenv("MODPACKS_STORAGE_PATH")

	switch importerType {
	case "simple":
		imp = &importer.SimpleZipImporter{StoragePath: storagePath}
	case "curseforge":
		apiKey := os.Getenv("CURSEFORGE_API_KEY")
		if apiKey == "" {
			http.Error(w, "CurseForge API key is not configured on the server", http.StatusInternalServerError)
			return
		}
		imp = importer.NewCurseForgeImporter(storagePath, apiKey)
	case "modrinth":
		imp = importer.NewModrinthImporter(storagePath)
	default:
		http.Error(w, "Invalid importer type", http.StatusBadRequest)
		return
	}

	// --- Получаем zip-файл ---
	if importMethod == "file" {
		file, _, err := r.FormFile("file")
		if err != nil {
			http.Error(w, "Invalid file upload", http.StatusBadRequest)
			return
		}
		defer file.Close()

		tempFile, err := os.CreateTemp("", "modpack-*.zip")
		if err != nil {
			http.Error(w, "Could not create temp file", http.StatusInternalServerError)
			return
		}
		defer tempFile.Close()
		defer os.Remove(tempFile.Name())

		if _, err := io.Copy(tempFile, file); err != nil {
			http.Error(w, "Could not save temp file", http.StatusInternalServerError)
			return
		}
		tempZipPath = tempFile.Name()

	} else if importMethod == "url" {
		cfImporter, ok := imp.(*importer.CurseForgeImporter)
		if !ok {
			http.Error(w, "Importer type does not support URL import", http.StatusBadRequest)
			return
		}
		tempZipPath, err = cfImporter.DownloadModpackFromURL(sourceURL)
		if err != nil {
			http.Error(w, fmt.Sprintf("Failed to download from URL: %v", err), http.StatusInternalServerError)
			return
		}
		defer os.Remove(tempZipPath)

	} else {
		http.Error(w, "Invalid import method", http.StatusBadRequest)
		return
	}

	// --- Запускаем импорт ---
	files, err := imp.Import(tempZipPath)
	if err != nil {
		http.Error(w, fmt.Sprintf("Import failed: %v", err), http.StatusInternalServerError)
		return
	}

	// --- Сохраняем результат в БД ---
	modpack := &models.Modpack{
		Name:             r.FormValue("name"),
		DisplayName:      r.FormValue("displayName"),
		MinecraftVersion: r.FormValue("mcVersion"),
	}

	err = h.ModpackRepo.CreateModpackTx(r.Context(), modpack, files)
	if err != nil {
		http.Error(w, fmt.Sprintf("Database save failed: %v", err), http.StatusInternalServerError)
		return
	}

	w.WriteHeader(http.StatusCreated)
	fmt.Fprintf(w, "Modpack '%s' imported successfully with %d files.", modpack.DisplayName, len(files))

	go h.JanitorService.CleanOrphanedFiles(context.Background())
}