package repository

import (
	"chat/internal/domain/entity"
	"chat/internal/domain/repository"
	"chat/internal/library/cassandra"
	"context"
	"fmt"
	"math"
)

type messageRepository struct {
	repo cassandra.Repository[entity.Message]
	db   *cassandra.DB
}

// NewMessageRepository 創建新的訊息 Repository
func NewMessageRepository(db *cassandra.DB, keyspace string) (repository.MessageRepository, error) {
	repo, err := cassandra.NewRepository[entity.Message](db, keyspace)
	if err != nil {
		return nil, fmt.Errorf("failed to create message repository: %w", err)
	}

	return &messageRepository{
		repo: repo,
		db:   db,
	}, nil
}

// Insert 插入訊息
func (r *messageRepository) Insert(ctx context.Context, msg *entity.Message) error {
	return r.repo.Insert(ctx, *msg)
}

// ListByRoom 查詢房間訊息（分頁）
func (r *messageRepository) ListByRoom(ctx context.Context, roomID string, bucketDay string, pageSize int, pageIndex int) ([]entity.Message, int64, error) {
	// 計算分頁
	if pageSize <= 0 {
		pageSize = 20
	}
	if pageIndex <= 0 {
		pageIndex = 1
	}

	// 構建查詢條件
	query := r.repo.Query().
		Where(cassandra.Eq("room_id", roomID)).
		Where(cassandra.Eq("bucket_day", bucketDay)).
		OrderBy("ts", cassandra.DESC).
		OrderBy("message_id", cassandra.DESC).
		Limit(pageSize)

	// 先查詢總數
	total, err := r.repo.Query().
		Where(cassandra.Eq("room_id", roomID)).
		Where(cassandra.Eq("bucket_day", bucketDay)).
		Count(ctx)
	if err != nil {
		return nil, 0, fmt.Errorf("failed to count messages: %w", err)
	}

	// 執行查詢
	var messages []entity.Message
	if err := query.Scan(ctx, &messages); err != nil {
		return nil, 0, fmt.Errorf("failed to query messages: %w", err)
	}

	// 計算總頁數
	totalPages := int64(math.Ceil(float64(total) / float64(pageSize)))

	return messages, totalPages, nil
}