package repositories

import (
	"log"
	"time"

	"github.com/niangaodev/art-code/config"
	"github.com/niangaodev/art-code/models"
	"gorm.io/gorm"
)

// GetColumns 获取所有专栏
func GetColumns() ([]models.Column, error) {
	var columns []models.Column
	err := config.DB.Model(&models.Column{}).
		Where("deleted_at = ?", 0).
		Order("sort_order ASC, created_at DESC").
		Find(&columns).Error
	if err != nil {
		log.Printf("Error querying columns: %v", err)
		return nil, err
	}
	return columns, nil
}

// GetColumnByID 根据ID获取专栏
func GetColumnByID(id uint) (*models.Column, error) {
	var col models.Column
	err := config.DB.Model(&models.Column{}).
		Where("id = ? AND deleted_at = ?", id, 0).
		First(&col).Error
	if err != nil {
		if err == gorm.ErrRecordNotFound {
			return nil, nil
		}
		log.Printf("Error getting column by ID: %v", err)
		return nil, err
	}
	return &col, nil
}

// GetColumnStats 获取专栏统计信息（文章数量和最近更新时间）
func GetColumnStats(columnID uint) (int64, int64, error) {
	var postCount int64

	// 统计文章数量
	err := config.DB.Model(&models.Post{}).
		Joins("JOIN column_posts cp ON posts.id = cp.post_id").
		Where("cp.column_id = ? AND posts.deleted_at = ? AND posts.is_published = ?", columnID, 0, 1).
		Count(&postCount).Error
	if err != nil {
		log.Printf("Error counting posts for column: %v", err)
		return 0, 0, err
	}

	// 获取最近更新时间
	var lastUpdated int64
	if postCount > 0 {
		err = config.DB.Model(&models.Post{}).
			Select("COALESCE(MAX(posts.updated_at), 0)").
			Joins("JOIN column_posts cp ON posts.id = cp.post_id").
			Where("cp.column_id = ? AND posts.deleted_at = ? AND posts.is_published = ?", columnID, 0, 1).
			Scan(&lastUpdated).Error
		if err != nil {
			log.Printf("Error getting last updated time for column: %v", err)
			// 如果查询失败，使用专栏的更新时间
			var col models.Column
			if err2 := config.DB.Model(&models.Column{}).
				Select("updated_at").
				Where("id = ?", columnID).
				First(&col).Error; err2 == nil {
				lastUpdated = col.UpdatedAt
			}
		}
	} else {
		// 如果没有文章，使用专栏的更新时间
		var col models.Column
		if err := config.DB.Model(&models.Column{}).
			Select("updated_at").
			Where("id = ?", columnID).
			First(&col).Error; err == nil {
			lastUpdated = col.UpdatedAt
		}
	}

	return postCount, lastUpdated, nil
}

// BuildColumnResponse 构建专栏响应（包含统计信息）
func BuildColumnResponse(col *models.Column) *models.ColumnResponse {
	postCount, lastUpdated, _ := GetColumnStats(col.ID)

	return &models.ColumnResponse{
		ID:          col.ID,
		Name:        col.Name,
		Description: col.Description,
		Cover:       col.Cover,
		IsActive:    col.IsActive,
		SortOrder:   col.SortOrder,
		CreatedAt:   formatTimestamp(col.CreatedAt),
		UpdatedAt:   formatTimestamp(col.UpdatedAt),
		PostCount:   postCount,
		LastUpdated: formatTimestamp(lastUpdated),
	}
}

// BuildColumnItemResponse 构建专栏列表项响应（不含统计）
func BuildColumnItemResponse(col *models.Column) *models.ColumnResponse {
	return &models.ColumnResponse{
		ID:          col.ID,
		Name:        col.Name,
		Description: col.Description,
		Cover:       col.Cover,
		IsActive:    col.IsActive,
		SortOrder:   col.SortOrder,
		CreatedAt:   formatTimestamp(col.CreatedAt),
		UpdatedAt:   formatTimestamp(col.UpdatedAt),
	}
}

// BuildColumnsResponse 构建专栏列表响应
func BuildColumnsResponse(columns []models.Column) []models.ColumnResponse {
	responses := make([]models.ColumnResponse, 0, len(columns))
	for _, col := range columns {
		responses = append(responses, *BuildColumnItemResponse(&col))
	}
	return responses
}

// CreateColumn 创建专栏
func CreateColumn(col *models.Column) error {
	err := config.DB.Create(col).Error
	if err != nil {
		log.Printf("Error creating column: %v", err)
		return err
	}
	return nil
}

// UpdateColumn 更新专栏
func UpdateColumn(col *models.Column) error {
	err := config.DB.Model(&models.Column{}).
		Where("id = ? AND deleted_at = ?", col.ID, 0).
		Updates(map[string]interface{}{
			"name":        col.Name,
			"description": col.Description,
			"cover":       col.Cover,
			"is_active":   col.IsActive,
			"sort_order":  col.SortOrder,
			"updated_at":  time.Now().Unix(),
		}).Error
	if err != nil {
		log.Printf("Error updating column: %v", err)
		return err
	}
	return nil
}

// DeleteColumn 删除专栏
func DeleteColumn(id uint) error {
	err := config.DB.Model(&models.Column{}).
		Where("id = ?", id).
		Update("deleted_at", time.Now().Unix()).Error
	if err != nil {
		log.Printf("Error deleting column: %v", err)
		return err
	}
	return nil
}

// GetPostsByColumnID 获取专栏下的文章（不含正文 content）
func GetPostsByColumnID(columnID uint) ([]models.Post, error) {
	var posts []models.Post
	err := config.DB.Model(&models.Post{}).
		Select("posts.id", "posts.title", "posts.category_id", "posts.column_id", "posts.excerpt",
			"posts.read_count", "posts.is_published", "posts.user_id", "posts.created_at", "posts.updated_at").
		Preload("Category").
		Preload("Tags").
		Joins("JOIN column_posts cp ON posts.id = cp.post_id").
		Where("cp.column_id = ? AND posts.deleted_at = ? AND posts.is_published = ?", columnID, 0, 1).
		Order("cp.sort_order ASC, posts.created_at DESC").
		Find(&posts).Error
	if err != nil {
		log.Printf("Error querying posts by column ID: %v", err)
		return nil, err
	}
	return posts, nil
}

// GetPostBriefsByColumnID 获取专栏文章目录（仅 id、title）
func GetPostBriefsByColumnID(columnID uint) ([]models.PostBrief, error) {
	var briefs []models.PostBrief
	err := config.DB.Table("posts").
		Select("posts.id, posts.title").
		Joins("JOIN column_posts cp ON posts.id = cp.post_id").
		Where("cp.column_id = ? AND posts.deleted_at = ? AND posts.is_published = ?", columnID, 0, 1).
		Order("cp.sort_order ASC, posts.created_at DESC").
		Scan(&briefs).Error
	if err != nil {
		log.Printf("Error querying post briefs by column ID: %v", err)
		return nil, err
	}
	if briefs == nil {
		briefs = []models.PostBrief{}
	}
	return briefs, nil
}

// AddPostToColumn 添加文章到专栏
func AddPostToColumn(columnID, postID, sortOrder uint) error {
	columnPost := &models.ColumnPost{
		ColumnID:  columnID,
		PostID:    postID,
		SortOrder: sortOrder,
		CreatedAt: time.Now().Unix(),
	}
	// 使用 Clauses 处理 ON DUPLICATE KEY UPDATE
	err := config.DB.Where("column_id = ? AND post_id = ?", columnID, postID).
		Assign(models.ColumnPost{SortOrder: sortOrder}).
		FirstOrCreate(columnPost).Error
	return err
}

// RemovePostFromColumn 从专栏移除文章
func RemovePostFromColumn(columnID, postID uint) error {
	err := config.DB.Where("column_id = ? AND post_id = ?", columnID, postID).
		Delete(&models.ColumnPost{}).Error
	return err
}