package service

import (
	"errors"
	"fmt"
	"photowall/internal/model"

	"gorm.io/gorm"
)

type UserService struct {
	db *gorm.DB
}

func NewUserService(db *gorm.DB) *UserService {
	return &UserService{db: db}
}

// ProfileResp 用户完整资料
type ProfileResp struct {
	User      model.User              `json:"user"`
	Contacts  []model.UserContact     `json:"contacts"`
	Education []model.EducationHistory `json:"education"`
}

func (s *UserService) GetProfile(userID uint) (*ProfileResp, error) {
	var user model.User
	if err := s.db.First(&user, userID).Error; err != nil {
		return nil, errors.New("用户不存在")
	}
	var contacts []model.UserContact
	s.db.Where("user_id = ?", userID).Order("type, is_primary desc, id").Find(&contacts)
	var edu []model.EducationHistory
	s.db.Where("user_id = ?", userID).Order("start_year desc, id desc").Find(&edu)
	return &ProfileResp{User: user, Contacts: contacts, Education: edu}, nil
}

type UpdateProfileReq struct {
	Nickname string `json:"nickname"`
	Bio      string `json:"bio"`
	Avatar   string `json:"avatar"`
}

func (s *UserService) UpdateProfile(userID uint, req *UpdateProfileReq) error {
	updates := map[string]interface{}{}
	if req.Nickname != "" {
		updates["nickname"] = req.Nickname
	}
	if req.Bio != "" {
		updates["bio"] = req.Bio
	}
	if req.Avatar != "" {
		updates["avatar"] = req.Avatar
	}
	if len(updates) == 0 {
		return nil
	}
	return s.db.Model(&model.User{}).Where("id = ?", userID).Updates(updates).Error
}

// AddContact 添加联系方式，校验各类型数量上限
func (s *UserService) AddContact(userID uint, contactType model.ContactType, value string, isPrimary bool) (*model.UserContact, error) {
	if value == "" {
		return nil, errors.New("联系方式不能为空")
	}
	max, ok := model.ContactMaxCount[contactType]
	if !ok {
		return nil, errors.New("不支持的联系方式类型")
	}
	var count int64
	s.db.Model(&model.UserContact{}).Where("user_id = ? AND type = ?", userID, contactType).Count(&count)
	if int(count) >= max {
		return nil, fmt.Errorf("%s 最多只能添加 %d 个", contactType, max)
	}
	// 如果设为主，先取消同类型其他主
	if isPrimary {
		s.db.Model(&model.UserContact{}).Where("user_id = ? AND type = ?", userID, contactType).Update("is_primary", false)
	}
	c := &model.UserContact{
		UserID:    userID,
		Type:      contactType,
		Value:     value,
		IsPrimary: isPrimary,
	}
	if err := s.db.Create(c).Error; err != nil {
		return nil, err
	}
	return c, nil
}

func (s *UserService) UpdateContact(userID, contactID uint, value string, isPrimary *bool) error {
	var c model.UserContact
	if err := s.db.Where("id = ? AND user_id = ?", contactID, userID).First(&c).Error; err != nil {
		return errors.New("联系方式不存在")
	}
	if value != "" {
		c.Value = value
	}
	if isPrimary != nil && *isPrimary {
		s.db.Model(&model.UserContact{}).Where("user_id = ? AND type = ?", userID, c.Type).Update("is_primary", false)
		c.IsPrimary = true
	}
	return s.db.Save(&c).Error
}

func (s *UserService) DeleteContact(userID, contactID uint) error {
	res := s.db.Where("id = ? AND user_id = ?", contactID, userID).Delete(&model.UserContact{})
	if res.Error != nil {
		return res.Error
	}
	if res.RowsAffected == 0 {
		return errors.New("联系方式不存在")
	}
	return nil
}

// AddEducation 添加学习履历
func (s *UserService) AddEducation(userID uint, e *model.EducationHistory) error {
	e.UserID = userID
	e.ID = 0
	return s.db.Create(e).Error
}

func (s *UserService) UpdateEducation(userID, id uint, e *model.EducationHistory) error {
	res := s.db.Model(&model.EducationHistory{}).
		Where("id = ? AND user_id = ?", id, userID).
		Updates(map[string]interface{}{
			"school_id":   e.SchoolID,
			"college_id":  e.CollegeID,
			"class_id":    e.ClassID,
			"school_name": e.SchoolName,
			"college_name": e.CollegeName,
			"major":       e.Major,
			"degree":      e.Degree,
			"start_year":  e.StartYear,
			"end_year":    e.EndYear,
			"description": e.Description,
		})
	if res.Error != nil {
		return res.Error
	}
	if res.RowsAffected == 0 {
		return errors.New("履历不存在")
	}
	return nil
}

func (s *UserService) DeleteEducation(userID, id uint) error {
	res := s.db.Where("id = ? AND user_id = ?", id, userID).Delete(&model.EducationHistory{})
	if res.Error != nil {
		return res.Error
	}
	if res.RowsAffected == 0 {
		return errors.New("履历不存在")
	}
	return nil
}

// HasEducation 检查用户是否有至少一条学习履历（创建班级前置条件）
func (s *UserService) HasEducation(userID uint) bool {
	var count int64
	s.db.Model(&model.EducationHistory{}).Where("user_id = ?", userID).Count(&count)
	return count > 0
}

// GetUserByID 公开用户信息（班级成员查看）
func (s *UserService) GetUserByID(userID uint) (*model.User, error) {
	var u model.User
	if err := s.db.First(&u, userID).Error; err != nil {
		return nil, errors.New("用户不存在")
	}
	return &u, nil
}

// GetUserContacts 公开用户联系方式（同班同学可查看）
func (s *UserService) GetUserContacts(userID uint) []model.UserContact {
	var list []model.UserContact
	s.db.Where("user_id = ?", userID).Order("type, is_primary desc").Find(&list)
	return list
}