package playback

import (
	"context"
	"errors"

	"github.com/google/uuid"
	"github.com/jackc/pgx/v5"

	"pipu/api/internal/api/gen"
	"pipu/api/internal/platform/apperr"
)

// Repeated sharing preserves the existing URL. After revocation a fresh UUID is allocated.
func (st *Store) sharePlaylist(ctx context.Context, owner, id uuid.UUID) (uuid.UUID, error) {
	var shareID uuid.UUID
	err := st.pool.QueryRow(ctx, `UPDATE playlists SET share_id=COALESCE(share_id,$3)
        WHERE id=$1 AND user_id=$2 RETURNING share_id`, id, owner, uuid.New()).Scan(&shareID)
	if errors.Is(err, pgx.ErrNoRows) {
		return uuid.Nil, apperr.NotFound("playlist.not_found", "playlist not found")
	}
	return shareID, err
}

func (st *Store) revokePlaylistShare(ctx context.Context, owner, id uuid.UUID) error {
	result, err := st.pool.Exec(ctx, `UPDATE playlists SET share_id=NULL WHERE id=$1 AND user_id=$2`, id, owner)
	if err != nil {
		return err
	}
	if result.RowsAffected() == 0 {
		return apperr.NotFound("playlist.not_found", "playlist not found")
	}
	return nil
}

func (h *Handler) SharePlaylist(ctx context.Context, req gen.SharePlaylistRequestObject) (gen.SharePlaylistResponseObject, error) {
	user, err := principal(ctx)
	if err != nil {
		return nil, err
	}
	shareID, err := h.store.sharePlaylist(ctx, user.UserID, req.Id)
	if err != nil {
		return nil, err
	}
	return gen.SharePlaylist200JSONResponse{ShareId: shareID}, nil
}

func (h *Handler) RevokePlaylistShare(ctx context.Context, req gen.RevokePlaylistShareRequestObject) (gen.RevokePlaylistShareResponseObject, error) {
	user, err := principal(ctx)
	if err != nil {
		return nil, err
	}
	if err = h.store.revokePlaylistShare(ctx, user.UserID, req.Id); err != nil {
		return nil, err
	}
	return gen.RevokePlaylistShare204Response{}, nil
}

func (h *Handler) GetSharedPlaylist(ctx context.Context, req gen.GetSharedPlaylistRequestObject) (gen.GetSharedPlaylistResponseObject, error) {
	user, err := principal(ctx)
	if err != nil {
		return nil, err
	}
	p, err := h.readPlaylist(ctx, user.UserID, req.ShareId, true)
	if err != nil {
		return nil, err
	}
	return gen.GetSharedPlaylist200JSONResponse(p), nil
}