package repository

import (
	"errors"
	"time"

	"github.com/topfans/backend/services/taskService/model"
	"gorm.io/gorm"
)

// DailyTaskRepository 每日任务数据访问层接口
type DailyTaskRepository interface {
	// GetUserDailyProgress 获取用户指定每日任务的进度
	GetUserDailyProgress(userID, starID int64, taskKey string) (*model.UserDailyTaskProgress, error)
	// GetOrCreateDailyProgress 获取或创建用户每日任务进度
	GetOrCreateDailyProgress(userID, starID int64, taskKey string, def *model.TaskDefinition) (*model.UserDailyTaskProgress, error)
	// ListDailyTasksByUser 获取用户的所有每日任务进度
	ListDailyTasksByUser(userID, starID int64) ([]*model.UserDailyTaskProgress, error)
	// ListCompletedDailyTasks 获取用户已完成但未领取的每日任务进度
	ListCompletedDailyTasks(userID, starID int64) ([]*model.UserDailyTaskProgress, error)
	// ListActiveDailyTaskDefinitions 获取所有活跃的每日任务定义（包括star特定和全局默认）
	ListActiveDailyTaskDefinitions(starID int64) ([]*model.TaskDefinition, error)
	// UpdateDailyProgress 更新每日任务进度
	UpdateDailyProgress(progress *model.UserDailyTaskProgress) error
	// ResetAllDailyTasks 重置所有非pending状态的每日任务为pending
	ResetAllDailyTasks() (int64, error)
	// InitDailyTasksForUser 为用户初始化该star的所有每日任务进度
	InitDailyTasksForUser(userID, starID int64) error
	// AcquireAdvisoryLock 获取PostgreSQL advisory lock
	AcquireAdvisoryLock(lockID int64) bool
	// ReleaseAdvisoryLock 释放PostgreSQL advisory lock
	ReleaseAdvisoryLock(lockID int64)
}

// dailyTaskRepository Repository实现
type dailyTaskRepository struct {
	db *gorm.DB
}

// NewDailyTaskRepository 创建Repository实例
func NewDailyTaskRepository(db *gorm.DB) DailyTaskRepository {
	return &dailyTaskRepository{db: db}
}

// GetUserDailyProgress 获取用户指定每日任务的进度
func (r *dailyTaskRepository) GetUserDailyProgress(userID, starID int64, taskKey string) (*model.UserDailyTaskProgress, error) {
	var progress model.UserDailyTaskProgress
	err := r.db.Where("user_id = ? AND star_id = ? AND task_key = ?", userID, starID, taskKey).
		First(&progress).Error
	if err != nil {
		if errors.Is(err, gorm.ErrRecordNotFound) {
			return nil, nil
		}
		return nil, err
	}
	return &progress, nil
}

// GetOrCreateDailyProgress 获取或创建用户每日任务进度
func (r *dailyTaskRepository) GetOrCreateDailyProgress(userID, starID int64, taskKey string, def *model.TaskDefinition) (*model.UserDailyTaskProgress, error) {
	progress, err := r.GetUserDailyProgress(userID, starID, taskKey)
	if err != nil {
		return nil, err
	}
	if progress != nil {
		return progress, nil
	}

	// 创建新的进度记录
	now := time.Now().UnixMilli()
	progress = &model.UserDailyTaskProgress{
		UserID:    userID,
		StarID:    starID,
		TaskKey:   taskKey,
		Status:    "pending",
		CreatedAt: now,
		UpdatedAt: now,
	}

	if def != nil {
		progress.CreatedAt = now
		progress.UpdatedAt = now
	}

	err = r.db.Create(progress).Error
	if err != nil {
		return nil, err
	}
	return progress, nil
}

// ListDailyTasksByUser 获取用户的所有每日任务进度
func (r *dailyTaskRepository) ListDailyTasksByUser(userID, starID int64) ([]*model.UserDailyTaskProgress, error) {
	var progressList []*model.UserDailyTaskProgress
	err := r.db.Where("user_id = ? AND star_id = ?", userID, starID).
		Order("id ASC").
		Find(&progressList).Error
	return progressList, err
}

// ListCompletedDailyTasks 获取用户已完成但未领取的每日任务进度
func (r *dailyTaskRepository) ListCompletedDailyTasks(userID, starID int64) ([]*model.UserDailyTaskProgress, error) {
	var progressList []*model.UserDailyTaskProgress
	err := r.db.Where("user_id = ? AND star_id = ? AND status = ?", userID, starID, "completed").
		Order("id ASC").
		Find(&progressList).Error
	return progressList, err
}

// ListActiveDailyTaskDefinitions 获取所有活跃的每日任务定义（包括star特定和全局默认）
func (r *dailyTaskRepository) ListActiveDailyTaskDefinitions(starID int64) ([]*model.TaskDefinition, error) {
	var definitions []*model.TaskDefinition
	err := r.db.Where("is_active = true AND (star_id = ? OR star_id IS NULL)", starID).
		Where("task_type = ?", "daily").
		Order("sort_order ASC, id ASC").
		Find(&definitions).Error
	return definitions, err
}

// UpdateDailyProgress 更新每日任务进度
func (r *dailyTaskRepository) UpdateDailyProgress(progress *model.UserDailyTaskProgress) error {
	progress.UpdatedAt = time.Now().UnixMilli()
	return r.db.Save(progress).Error
}

// ResetAllDailyTasks 重置所有非pending状态的每日任务为pending
func (r *dailyTaskRepository) ResetAllDailyTasks() (int64, error) {
	now := time.Now().UnixMilli()
	result := r.db.Model(&model.UserDailyTaskProgress{}).
		Where("status != ?", "pending").
		Updates(map[string]interface{}{
			"status":       "pending",
			"completed_at": nil,
			"claimed_at":   nil,
			"updated_at":  now,
		})
	return result.RowsAffected, result.Error
}

// InitDailyTasksForUser 为用户初始化该star的所有每日任务进度
func (r *dailyTaskRepository) InitDailyTasksForUser(userID, starID int64) error {
	// 获取所有活跃的每日任务定义
	definitions, err := r.ListActiveDailyTaskDefinitions(starID)
	if err != nil {
		return err
	}

	if len(definitions) == 0 {
		return nil
	}

	now := time.Now().UnixMilli()

	return r.db.Transaction(func(tx *gorm.DB) error {
		for _, def := range definitions {
			// 检查是否已存在该任务的进度
			var count int64
			err := tx.Model(&model.UserDailyTaskProgress{}).
				Where("user_id = ? AND star_id = ? AND task_key = ?", userID, starID, def.TaskKey).
				Count(&count).Error
			if err != nil {
				return err
			}

			// 如果已存在，跳过
			if count > 0 {
				continue
			}

			// 创建新的进度记录
			progress := &model.UserDailyTaskProgress{
				UserID:    userID,
				StarID:    starID,
				TaskKey:   def.TaskKey,
				Status:    "pending",
				CreatedAt: now,
				UpdatedAt: now,
			}
			if err := tx.Create(progress).Error; err != nil {
				return err
			}
		}
		return nil
	})
}

// AcquireAdvisoryLock 获取PostgreSQL advisory lock
func (r *dailyTaskRepository) AcquireAdvisoryLock(lockID int64) bool {
	var result bool
	err := r.db.Raw("SELECT pg_try_advisory_lock(?)", lockID).Scan(&result).Error
	if err != nil {
		return false
	}
	return result
}

// ReleaseAdvisoryLock 释放PostgreSQL advisory lock
func (r *dailyTaskRepository) ReleaseAdvisoryLock(lockID int64) {
	r.db.Exec("SELECT pg_advisory_unlock(?)", lockID)
}