package repository

import (
	"time"

	"carrot_bbs/internal/model"

	"gorm.io/gorm"
)

// PushRecordRepository 推送记录仓储
type PushRecordRepository struct {
	db *gorm.DB
}

// NewPushRecordRepository 创建推送记录仓储
func NewPushRecordRepository(db *gorm.DB) *PushRecordRepository {
	return &PushRecordRepository{db: db}
}

// Create 创建推送记录
func (r *PushRecordRepository) Create(record *model.PushRecord) error {
	return r.db.Create(record).Error
}

// GetByID 根据ID获取推送记录
func (r *PushRecordRepository) GetByID(id int64) (*model.PushRecord, error) {
	var record model.PushRecord
	err := r.db.First(&record, "id = ?", id).Error
	if err != nil {
		return nil, err
	}
	return &record, nil
}

// Update 更新推送记录
func (r *PushRecordRepository) Update(record *model.PushRecord) error {
	return r.db.Save(record).Error
}

// GetPendingPushes 获取待推送记录
func (r *PushRecordRepository) GetPendingPushes(limit int) ([]*model.PushRecord, error) {
	var records []*model.PushRecord
	err := r.db.Where("push_status = ?", model.PushStatusPending).
		Where("expired_at IS NULL OR expired_at > ?", time.Now()).
		Order("created_at ASC").
		Limit(limit).
		Find(&records).Error
	return records, err
}

// GetByUserID 根据用户ID获取推送记录
// userID 参数为 string 类型（UUID格式），与JWT中user_id保持一致
func (r *PushRecordRepository) GetByUserID(userID string, limit, offset int) ([]*model.PushRecord, error) {
	var records []*model.PushRecord
	err := r.db.Where("user_id = ?", userID).
		Order("created_at DESC").
		Offset(offset).
		Limit(limit).
		Find(&records).Error
	return records, err
}

// GetByMessageID 根据消息ID获取推送记录
func (r *PushRecordRepository) GetByMessageID(messageID int64) ([]*model.PushRecord, error) {
	var records []*model.PushRecord
	err := r.db.Where("message_id = ?", messageID).
		Order("created_at DESC").
		Find(&records).Error
	return records, err
}

// GetFailedPushesForRetry 获取失败待重试的推送
func (r *PushRecordRepository) GetFailedPushesForRetry(limit int) ([]*model.PushRecord, error) {
	var records []*model.PushRecord
	err := r.db.Where("push_status = ?", model.PushStatusFailed).
		Where("retry_count < max_retry").
		Where("expired_at IS NULL OR expired_at > ?", time.Now()).
		Order("created_at ASC").
		Limit(limit).
		Find(&records).Error
	return records, err
}

// BatchCreate 批量创建推送记录
func (r *PushRecordRepository) BatchCreate(records []*model.PushRecord) error {
	if len(records) == 0 {
		return nil
	}
	return r.db.Create(&records).Error
}

// BatchUpdateStatus 批量更新推送状态
func (r *PushRecordRepository) BatchUpdateStatus(ids []int64, status model.PushStatus) error {
	if len(ids) == 0 {
		return nil
	}
	updates := map[string]interface{}{
		"push_status": status,
	}
	if status == model.PushStatusPushed {
		updates["pushed_at"] = time.Now()
	}
	return r.db.Model(&model.PushRecord{}).
		Where("id IN ?", ids).
		Updates(updates).Error
}

// UpdateStatus 更新单条记录状态
func (r *PushRecordRepository) UpdateStatus(id int64, status model.PushStatus) error {
	updates := map[string]interface{}{
		"push_status": status,
	}
	if status == model.PushStatusPushed {
		updates["pushed_at"] = time.Now()
	}
	return r.db.Model(&model.PushRecord{}).
		Where("id = ?", id).
		Updates(updates).Error
}

// MarkAsFailed 标记为失败
func (r *PushRecordRepository) MarkAsFailed(id int64, errMsg string) error {
	return r.db.Model(&model.PushRecord{}).
		Where("id = ?", id).
		Updates(map[string]interface{}{
			"push_status":   model.PushStatusFailed,
			"error_message": errMsg,
			"retry_count":   gorm.Expr("retry_count + 1"),
		}).Error
}

// MarkAsDelivered 标记为已送达
func (r *PushRecordRepository) MarkAsDelivered(id int64) error {
	return r.db.Model(&model.PushRecord{}).
		Where("id = ?", id).
		Updates(map[string]interface{}{
			"push_status":  model.PushStatusDelivered,
			"delivered_at": time.Now(),
		}).Error
}

// DeleteExpiredRecords 删除过期的推送记录（软删除）
func (r *PushRecordRepository) DeleteExpiredRecords() error {
	return r.db.Where("expired_at IS NOT NULL AND expired_at < ?", time.Now()).
		Delete(&model.PushRecord{}).Error
}

// GetStatsByUserID 获取用户推送统计
func (r *PushRecordRepository) GetStatsByUserID(userID int64) (map[model.PushStatus]int64, error) {
	type statusCount struct {
		Status model.PushStatus
		Count  int64
	}
	var results []statusCount

	err := r.db.Model(&model.PushRecord{}).
		Select("push_status as status, count(*) as count").
		Where("user_id = ?", userID).
		Group("push_status").
		Scan(&results).Error

	if err != nil {
		return nil, err
	}

	stats := make(map[model.PushStatus]int64)
	for _, r := range results {
		stats[r.Status] = r.Count
	}
	return stats, nil
}