// Package mysql 实现 room-service 的 MySQL 持久化边界。
package mysql

import (
	"context"
	"database/sql"
	"errors"
	"strings"
	"time"

	"hyapp/pkg/appcode"
	roomservice "hyapp/services/room-service/internal/room/service"
)

// SaveRoomMeta 插入房间元数据。
func (r *Repository) SaveRoomMeta(ctx context.Context, meta roomservice.RoomMeta) error {
	// rooms 表只保存恢复初始状态需要的元数据，实时态以 snapshot/command log 为准。
	appCode := normalizedRecordAppCode(ctx, meta.AppCode)
	nowMS := time.Now().UTC().UnixMilli()
	_, err := r.db.ExecContext(ctx,
		`INSERT INTO rooms (app_code, room_id, room_short_id, owner_user_id, seat_count, mode, status, room_password_hash, visible_region_id, created_at_ms, updated_at_ms)
		 VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)`,
		appCode,
		meta.RoomID,
		meta.RoomShortID,
		meta.OwnerUserID,
		meta.SeatCount,
		meta.Mode,
		meta.Status,
		meta.RoomPasswordHash,
		meta.VisibleRegionID,
		nowMS,
		nowMS,
	)

	return mapRoomMetaDuplicateError(err)
}

// GetRoomMeta 查询房间元数据。
func (r *Repository) GetRoomMeta(ctx context.Context, roomID string) (roomservice.RoomMeta, bool, error) {
	// meta 是无内存 Cell 恢复的入口；不存在时上层返回 room not found。
	row := r.db.QueryRowContext(ctx,
		`SELECT app_code, room_id, room_short_id, owner_user_id, seat_count, mode, status, room_password_hash, visible_region_id
		 FROM rooms
		 WHERE app_code = ? AND room_id = ?`,
		appcode.FromContext(ctx),
		roomID,
	)

	var meta roomservice.RoomMeta
	if err := row.Scan(&meta.AppCode, &meta.RoomID, &meta.RoomShortID, &meta.OwnerUserID, &meta.SeatCount, &meta.Mode, &meta.Status, &meta.RoomPasswordHash, &meta.VisibleRegionID); err != nil {
		if errors.Is(err, sql.ErrNoRows) {
			// 未创建房间不是数据库错误，用 exists=false 表达。
			return roomservice.RoomMeta{}, false, nil
		}

		return roomservice.RoomMeta{}, false, err
	}

	return meta, true, nil
}

// GetRoomMetaByOwner 查询用户已经创建的房间。
func (r *Repository) GetRoomMetaByOwner(ctx context.Context, ownerUserID int64) (roomservice.RoomMeta, bool, error) {
	// rooms.owner_user_id 有唯一约束，查询最多返回一条；该读路径用于 CreateRoom 前置失败。
	row := r.db.QueryRowContext(ctx,
		`SELECT app_code, room_id, room_short_id, owner_user_id, seat_count, mode, status, room_password_hash, visible_region_id
		 FROM rooms
		 WHERE app_code = ? AND owner_user_id = ?
		 LIMIT 1`,
		appcode.FromContext(ctx),
		ownerUserID,
	)

	var meta roomservice.RoomMeta
	if err := row.Scan(&meta.AppCode, &meta.RoomID, &meta.RoomShortID, &meta.OwnerUserID, &meta.SeatCount, &meta.Mode, &meta.Status, &meta.RoomPasswordHash, &meta.VisibleRegionID); err != nil {
		if errors.Is(err, sql.ErrNoRows) {
			return roomservice.RoomMeta{}, false, nil
		}

		return roomservice.RoomMeta{}, false, err
	}

	return meta, true, nil
}

// SaveRoomBackground 保存房间背景图素材；相同房间相同 URL 按幂等返回原记录。
func (r *Repository) SaveRoomBackground(ctx context.Context, background roomservice.RoomBackgroundImage) (roomservice.RoomBackgroundImage, error) {
	appCode := normalizedRecordAppCode(ctx, background.AppCode)
	roomID := strings.TrimSpace(background.RoomID)
	imageURL := strings.TrimSpace(background.ImageURL)
	nowMS := background.CreatedAtMS
	if nowMS <= 0 {
		nowMS = time.Now().UTC().UnixMilli()
	}

	_, err := r.db.ExecContext(ctx, `
		INSERT INTO room_background_images (
		  app_code, room_id, image_url, created_by_user_id, created_at_ms, updated_at_ms
		) VALUES (?, ?, ?, ?, ?, ?)
		ON DUPLICATE KEY UPDATE updated_at_ms = VALUES(updated_at_ms)
	`, appCode, roomID, imageURL, background.CreatedByUserID, nowMS, nowMS)
	if err != nil {
		return roomservice.RoomBackgroundImage{}, err
	}

	row := r.db.QueryRowContext(ctx, `
		SELECT app_code, background_id, room_id, image_url, created_by_user_id, created_at_ms, updated_at_ms
		FROM room_background_images
		WHERE app_code = ? AND room_id = ? AND image_url = ?
		LIMIT 1
	`, appCode, roomID, imageURL)
	return scanRoomBackground(row)
}

// GetRoomBackground 精确读取一个房间背景图素材。
func (r *Repository) GetRoomBackground(ctx context.Context, roomID string, backgroundID int64) (roomservice.RoomBackgroundImage, bool, error) {
	row := r.db.QueryRowContext(ctx, `
		SELECT app_code, background_id, room_id, image_url, created_by_user_id, created_at_ms, updated_at_ms
		FROM room_background_images
		WHERE app_code = ? AND room_id = ? AND background_id = ?
		LIMIT 1
	`, appcode.FromContext(ctx), strings.TrimSpace(roomID), backgroundID)

	background, err := scanRoomBackground(row)
	if err != nil {
		if errors.Is(err, sql.ErrNoRows) {
			return roomservice.RoomBackgroundImage{}, false, nil
		}
		return roomservice.RoomBackgroundImage{}, false, err
	}
	return background, true, nil
}

// ListRoomBackgrounds 返回某个房间保存过的背景图素材，按最近保存优先。
func (r *Repository) ListRoomBackgrounds(ctx context.Context, roomID string) ([]roomservice.RoomBackgroundImage, error) {
	rows, err := r.db.QueryContext(ctx, `
		SELECT app_code, background_id, room_id, image_url, created_by_user_id, created_at_ms, updated_at_ms
		FROM room_background_images
		WHERE app_code = ? AND room_id = ?
		ORDER BY created_at_ms DESC, background_id DESC
	`, appcode.FromContext(ctx), strings.TrimSpace(roomID))
	if err != nil {
		return nil, err
	}
	defer rows.Close()

	backgrounds := []roomservice.RoomBackgroundImage{}
	for rows.Next() {
		background, err := scanRoomBackground(rows)
		if err != nil {
			return nil, err
		}
		backgrounds = append(backgrounds, background)
	}
	return backgrounds, rows.Err()
}

func scanRoomBackground(scanner interface{ Scan(dest ...any) error }) (roomservice.RoomBackgroundImage, error) {
	var background roomservice.RoomBackgroundImage
	err := scanner.Scan(
		&background.AppCode,
		&background.BackgroundID,
		&background.RoomID,
		&background.ImageURL,
		&background.CreatedByUserID,
		&background.CreatedAtMS,
		&background.UpdatedAtMS,
	)
	return background, err
}