package repository

import (
	"carrot_bbs/internal/model"

	"gorm.io/gorm"
)

// GroupRepository 群组仓库接口
type GroupRepository interface {
	// 群组操作
	Create(group *model.Group) error
	GetByID(id string) (*model.Group, error)
	Update(group *model.Group) error
	Delete(id string) error
	GetByOwnerID(ownerID string, page, pageSize int) ([]model.Group, int64, error)

	// 群成员操作
	AddMember(member *model.GroupMember) error
	GetMember(groupID string, userID string) (*model.GroupMember, error)
	GetMembers(groupID string, page, pageSize int) ([]model.GroupMember, int64, error)
	UpdateMember(member *model.GroupMember) error
	RemoveMember(groupID string, userID string) error
	GetMemberCount(groupID string) (int64, error)
	IsMember(groupID string, userID string) (bool, error)
	GetUserGroups(userID string, page, pageSize int) ([]model.Group, int64, error)

	// 角色相关
	GetMemberRole(groupID string, userID string) (string, error)
	SetMemberRole(groupID string, userID string, role string) error
	GetAdmins(groupID string) ([]model.GroupMember, error)

	// 群公告操作
	CreateAnnouncement(announcement *model.GroupAnnouncement) error
	GetAnnouncements(groupID string, page, pageSize int) ([]model.GroupAnnouncement, int64, error)
	GetAnnouncementByID(id string) (*model.GroupAnnouncement, error)
	DeleteAnnouncement(id string) error
}

// groupRepository 群组仓库实现
type groupRepository struct {
	db *gorm.DB
}

// NewGroupRepository 创建群组仓库
func NewGroupRepository(db *gorm.DB) GroupRepository {
	return &groupRepository{db: db}
}

// Create 创建群组
func (r *groupRepository) Create(group *model.Group) error {
	return r.db.Create(group).Error
}

// GetByID 根据ID获取群组
func (r *groupRepository) GetByID(id string) (*model.Group, error) {
	var group model.Group
	err := r.db.First(&group, "id = ?", id).Error
	if err != nil {
		return nil, err
	}
	return &group, nil
}

// Update 更新群组
func (r *groupRepository) Update(group *model.Group) error {
	return r.db.Save(group).Error
}

// Delete 删除群组
func (r *groupRepository) Delete(id string) error {
	return r.db.Transaction(func(tx *gorm.DB) error {
		// 删除群成员
		if err := tx.Where("group_id = ?", id).Delete(&model.GroupMember{}).Error; err != nil {
			return err
		}
		// 删除群公告
		if err := tx.Where("group_id = ?", id).Delete(&model.GroupAnnouncement{}).Error; err != nil {
			return err
		}
		// 删除群组
		if err := tx.Delete(&model.Group{}, "id = ?", id).Error; err != nil {
			return err
		}
		return nil
	})
}

// GetByOwnerID 根据群主ID获取群组列表
func (r *groupRepository) GetByOwnerID(ownerID string, page, pageSize int) ([]model.Group, int64, error) {
	var groups []model.Group
	var total int64

	query := r.db.Model(&model.Group{}).Where("owner_id = ?", ownerID)
	query.Count(&total)

	offset := (page - 1) * pageSize
	err := query.Offset(offset).Limit(pageSize).Order("created_at DESC").Find(&groups).Error
	return groups, total, err
}

// AddMember 添加群成员
func (r *groupRepository) AddMember(member *model.GroupMember) error {
	return r.db.Transaction(func(tx *gorm.DB) error {
		if err := tx.Create(member).Error; err != nil {
			return err
		}
		// 更新群组成员数量
		return tx.Model(&model.Group{}).Where("id = ?", member.GroupID).
			Update("member_count", gorm.Expr("member_count + ?", 1)).Error
	})
}

// GetMember 获取群成员
func (r *groupRepository) GetMember(groupID string, userID string) (*model.GroupMember, error) {
	var member model.GroupMember
	err := r.db.First(&member, "group_id = ? AND user_id = ?", groupID, userID).Error
	if err != nil {
		return nil, err
	}
	return &member, nil
}

// GetMembers 获取群成员列表
func (r *groupRepository) GetMembers(groupID string, page, pageSize int) ([]model.GroupMember, int64, error) {
	var members []model.GroupMember
	var total int64

	query := r.db.Model(&model.GroupMember{}).Where("group_id = ?", groupID)
	query.Count(&total)

	offset := (page - 1) * pageSize
	err := query.Offset(offset).Limit(pageSize).Order("created_at ASC").Find(&members).Error
	return members, total, err
}

// UpdateMember 更新群成员
func (r *groupRepository) UpdateMember(member *model.GroupMember) error {
	return r.db.Save(member).Error
}

// RemoveMember 移除群成员
func (r *groupRepository) RemoveMember(groupID string, userID string) error {
	return r.db.Transaction(func(tx *gorm.DB) error {
		// 删除成员
		if err := tx.Where("group_id = ? AND user_id = ?", groupID, userID).Delete(&model.GroupMember{}).Error; err != nil {
			return err
		}
		// 更新群组成员数量
		return tx.Model(&model.Group{}).Where("id = ?", groupID).
			Update("member_count", gorm.Expr("member_count - ?", 1)).Error
	})
}

// GetMemberCount 获取群成员数量
func (r *groupRepository) GetMemberCount(groupID string) (int64, error) {
	var count int64
	err := r.db.Model(&model.GroupMember{}).Where("group_id = ?", groupID).Count(&count).Error
	return count, err
}

// IsMember 检查是否是群成员
func (r *groupRepository) IsMember(groupID string, userID string) (bool, error) {
	var count int64
	err := r.db.Model(&model.GroupMember{}).Where("group_id = ? AND user_id = ?", groupID, userID).Count(&count).Error
	return count > 0, err
}

// GetUserGroups 获取用户加入的群组列表
func (r *groupRepository) GetUserGroups(userID string, page, pageSize int) ([]model.Group, int64, error) {
	var groups []model.Group
	var total int64

	// 通过群成员表查询用户加入的群组
	subQuery := r.db.Model(&model.GroupMember{}).
		Select("group_id").
		Where("user_id = ?", userID)

	query := r.db.Model(&model.Group{}).Where("id IN (?)", subQuery)
	query.Count(&total)

	offset := (page - 1) * pageSize
	err := query.Offset(offset).Limit(pageSize).Order("created_at DESC").Find(&groups).Error
	return groups, total, err
}

// GetMemberRole 获取成员角色
func (r *groupRepository) GetMemberRole(groupID string, userID string) (string, error) {
	member, err := r.GetMember(groupID, userID)
	if err != nil {
		return "", err
	}
	return member.Role, nil
}

// SetMemberRole 设置成员角色
func (r *groupRepository) SetMemberRole(groupID string, userID string, role string) error {
	return r.db.Model(&model.GroupMember{}).
		Where("group_id = ? AND user_id = ?", groupID, userID).
		Update("role", role).Error
}

// GetAdmins 获取群管理员列表
func (r *groupRepository) GetAdmins(groupID string) ([]model.GroupMember, error) {
	var admins []model.GroupMember
	err := r.db.Where("group_id = ? AND role = ?", groupID, model.GroupRoleAdmin).Find(&admins).Error
	return admins, err
}

// CreateAnnouncement 创建群公告
func (r *groupRepository) CreateAnnouncement(announcement *model.GroupAnnouncement) error {
	return r.db.Create(announcement).Error
}

// GetAnnouncements 获取群公告列表
func (r *groupRepository) GetAnnouncements(groupID string, page, pageSize int) ([]model.GroupAnnouncement, int64, error) {
	var announcements []model.GroupAnnouncement
	var total int64

	query := r.db.Model(&model.GroupAnnouncement{}).Where("group_id = ?", groupID)
	query.Count(&total)

	offset := (page - 1) * pageSize
	// 置顶的排在前面，然后按时间倒序
	err := query.Offset(offset).Limit(pageSize).Order("is_pinned DESC, created_at DESC").Find(&announcements).Error
	return announcements, total, err
}

// GetAnnouncementByID 根据ID获取群公告
func (r *groupRepository) GetAnnouncementByID(id string) (*model.GroupAnnouncement, error) {
	var announcement model.GroupAnnouncement
	err := r.db.First(&announcement, "id = ?", id).Error
	if err != nil {
		return nil, err
	}
	return &announcement, nil
}

// DeleteAnnouncement 删除群公告
func (r *groupRepository) DeleteAnnouncement(id string) error {
	return r.db.Delete(&model.GroupAnnouncement{}, "id = ?", id).Error
}