package files

import (
	"errors"
	"fmt"
	_ "image/gif"
	_ "image/jpeg"
	_ "image/png"
	"net/http"

	"github.com/rs/zerolog/log"

	"aether/internal/audit"
	"aether/internal/auth"
	"aether/pkg/response"
)

// Papierkorb: auflisten, wiederherstellen, endgültig entfernen.
//
// Gelöscht wird nie hart, sondern weich – erst von hier aus verschwinden die
// Bytes wirklich.

// GET /api/v1/trash
func (h *Handler) ListTrash(w http.ResponseWriter, r *http.Request) {
	user := auth.UserFromContext(r.Context())
	items, err := h.store.ListTrash(r.Context(), user.ID)
	if err != nil {
		response.Error(w, http.StatusInternalServerError, "database error")
		return
	}
	if items == nil {
		items = []*TrashFile{}
	}
	response.JSON(w, http.StatusOK, items)
}

// POST /api/v1/trash/{id}/restore
func (h *Handler) RestoreFile(w http.ResponseWriter, r *http.Request) {
	id, err := parseID(r, "id")
	if err != nil {
		response.Error(w, http.StatusBadRequest, "invalid file id")
		return
	}

	owner, ok := h.resolveFile(w, r, id, true)
	if !ok {
		return
	}

	trashed, err := h.store.GetTrashedFile(r.Context(), id, owner.OwnerID)
	if errors.Is(err, ErrNotFound) {
		response.Error(w, http.StatusNotFound, "file not found in trash")
		return
	}
	if err != nil {
		response.Error(w, http.StatusInternalServerError, "database error")
		return
	}

	folderPath, err := h.store.GetFolderPath(r.Context(), trashed.FolderID)
	if err != nil {
		response.Error(w, http.StatusInternalServerError, "database error")
		return
	}
	newStorageKey := BuildStorageKey(owner.StorageRoot(), folderPath, trashed.Name)

	if err := h.storage.Move(r.Context(), trashed.StorageKey, newStorageKey); err != nil {
		response.Error(w, http.StatusInternalServerError, "storage error")
		return
	}

	f, err := h.store.RestoreFile(r.Context(), id, owner.OwnerID, newStorageKey)
	if errors.Is(err, ErrNotFound) {
		response.Error(w, http.StatusNotFound, "file not found in trash")
		return
	}
	if err != nil {
		response.Error(w, http.StatusInternalServerError, "database error")
		return
	}
	h.logFile(r, audit.ActionFileRestore, id.String(), trashed.Name, "restored from trash")
	response.JSON(w, http.StatusOK, f)
}

// DELETE /api/v1/trash/{id} – permanent delete
// DELETE /api/v1/trash – leert den Papierkorb vollständig.
func (h *Handler) EmptyTrash(w http.ResponseWriter, r *http.Request) {
	user := auth.UserFromContext(r.Context())

	fileIDs, keys, err := h.store.EmptyTrash(r.Context(), user.ID)
	if err != nil {
		response.Error(w, http.StatusInternalServerError, "database error")
		return
	}

	// Blobs erst nach dem Datenbank-Commit entfernen. Scheitert eine Löschung,
	// bleibt höchstens eine Dateileiche zurück – das ist harmloser als ein
	// Eintrag ohne Inhalt.
	for _, key := range keys {
		if err := h.storage.Delete(r.Context(), key); err != nil {
			log.Ctx(r.Context()).Warn().Err(err).Str("key", key).
				Msg("empty trash: blob not removed")
		}
	}
	for _, id := range fileIDs {
		_ = h.storage.Delete(r.Context(), "thumbs/"+id.String()+".jpg")
	}

	log.Ctx(r.Context()).Info().
		Int("files", len(fileIDs)).Int("blobs", len(keys)).
		Msg("trash emptied")
	h.logFile(r, audit.ActionTrashEmpty, "", "",
		fmt.Sprintf("%d files permanently deleted", len(fileIDs)))
	response.NoContent(w)
}

func (h *Handler) HardDelete(w http.ResponseWriter, r *http.Request) {
	id, err := parseID(r, "id")
	if err != nil {
		response.Error(w, http.StatusBadRequest, "invalid file id")
		return
	}

	owner, ok := h.resolveFile(w, r, id, true)
	if !ok {
		return
	}
	storageKey, versionKeys, err := h.store.HardDeleteFile(r.Context(), id, owner.OwnerID)
	if errors.Is(err, ErrNotFound) {
		response.Error(w, http.StatusNotFound, "file not found in trash")
		return
	}
	if err != nil {
		response.Error(w, http.StatusInternalServerError, "database error")
		return
	}
	_ = h.storage.Delete(r.Context(), storageKey)
	for _, key := range versionKeys {
		_ = h.storage.Delete(r.Context(), key)
	}
	_ = h.storage.Delete(r.Context(), "thumbs/"+id.String()+".jpg")
	h.logFile(r, audit.ActionHardDelete, id.String(), "", "permanently deleted from trash")
	response.NoContent(w)
}