package files

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

	"github.com/google/uuid"

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

// Favoriten der Seitenleiste: anlegen, entfernen, sortieren, auf- und
// zuklappen. Der Zustand liegt serverseitig, damit er auf jedem Gerät gleich ist.

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

// POST /api/v1/favorites
func (h *Handler) AddFavorite(w http.ResponseWriter, r *http.Request) {
	user := auth.UserFromContext(r.Context())
	var body struct {
		FolderID string `json:"folder_id"`
	}
	if err := json.NewDecoder(r.Body).Decode(&body); err != nil || body.FolderID == "" {
		response.Error(w, http.StatusBadRequest, "folder_id required")
		return
	}
	folderID, err := uuid.Parse(body.FolderID)
	if err != nil {
		response.Error(w, http.StatusBadRequest, "invalid folder_id")
		return
	}
	// Lesezugriff genügt: Ein Favorit ist ein Lesezeichen, keine Änderung.
	// Die frühere Besitzprüfung schloss Gruppenordner und geteilte Ordner aus –
	// sie gehören dem Anfragenden nicht, sind aber genau die, die man sich
	// merken will.
	if _, ok := h.resolveFolder(w, r, &folderID, false); !ok {
		return
	}
	fav, err := h.store.AddFavorite(r.Context(), user.ID, folderID)
	if err != nil {
		response.Error(w, http.StatusInternalServerError, "database error")
		return
	}
	response.JSON(w, http.StatusCreated, fav)
}

// DELETE /api/v1/favorites/{folderId}
func (h *Handler) RemoveFavorite(w http.ResponseWriter, r *http.Request) {
	user := auth.UserFromContext(r.Context())
	folderID, err := parseID(r, "folderId")
	if err != nil {
		response.Error(w, http.StatusBadRequest, "invalid folder id")
		return
	}
	if err := h.store.RemoveFavorite(r.Context(), user.ID, folderID); errors.Is(err, ErrNotFound) {
		response.Error(w, http.StatusNotFound, "favorite not found")
		return
	} else if err != nil {
		response.Error(w, http.StatusInternalServerError, "database error")
		return
	}
	response.NoContent(w)
}

// PATCH /api/v1/favorites/{folderId}/expand
func (h *Handler) SetFavoriteExpanded(w http.ResponseWriter, r *http.Request) {
	user := auth.UserFromContext(r.Context())
	folderID, err := parseID(r, "folderId")
	if err != nil {
		response.Error(w, http.StatusBadRequest, "invalid folder id")
		return
	}
	var body struct {
		Expanded bool `json:"expanded"`
	}
	if err := json.NewDecoder(r.Body).Decode(&body); err != nil {
		response.Error(w, http.StatusBadRequest, "invalid body")
		return
	}
	if err := h.store.SetFavoriteExpanded(r.Context(), user.ID, folderID, body.Expanded); errors.Is(err, ErrNotFound) {
		response.Error(w, http.StatusNotFound, "favorite not found")
		return
	} else if err != nil {
		response.Error(w, http.StatusInternalServerError, "database error")
		return
	}
	response.NoContent(w)
}

// PATCH /api/v1/favorites/reorder
func (h *Handler) ReorderFavorites(w http.ResponseWriter, r *http.Request) {
	user := auth.UserFromContext(r.Context())
	var body struct {
		FolderIDs []string `json:"folder_ids"`
	}
	if err := json.NewDecoder(r.Body).Decode(&body); err != nil {
		response.Error(w, http.StatusBadRequest, "invalid body")
		return
	}
	ids := make([]uuid.UUID, 0, len(body.FolderIDs))
	for _, s := range body.FolderIDs {
		id, err := uuid.Parse(s)
		if err != nil {
			response.Error(w, http.StatusBadRequest, "invalid folder_id: "+s)
			return
		}
		ids = append(ids, id)
	}
	if err := h.store.ReorderFavorites(r.Context(), user.ID, ids); err != nil {
		response.Error(w, http.StatusInternalServerError, "database error")
		return
	}
	response.NoContent(w)
}