package repository

import (
	"context"

	"gorm.io/gorm"

	"github.com/gochat/gochat/internal/model"
)

// UserRepo implements GORM repository for User.
// Reference: Chatwoot app/models/user.rb
type UserRepo struct {
	db *gorm.DB
}

// NewUserRepo creates a new User repository.
func NewUserRepo(db *gorm.DB) *UserRepo {
	return &UserRepo{db: db}
}

// FindByID retrieves a user by primary key.
func (r *UserRepo) FindByID(ctx context.Context, id uint) (*model.User, error) {
	var user model.User
	err := r.db.WithContext(ctx).First(&user, id).Error
	if err != nil {
		return nil, err
	}
	return &user, nil
}

// FindByIDs retrieves multiple users by their primary keys.
func (r *UserRepo) FindByIDs(ctx context.Context, ids []uint) ([]model.User, error) {
	if len(ids) == 0 {
		return []model.User{}, nil
	}
	var users []model.User
	err := r.db.WithContext(ctx).Where("id IN ?", ids).Find(&users).Error
	return users, err
}

// FindByEmail retrieves a user by email address.
func (r *UserRepo) FindByEmail(ctx context.Context, email string) (*model.User, error) {
	var user model.User
	err := r.db.WithContext(ctx).Where("email = ?", email).First(&user).Error
	if err != nil {
		return nil, err
	}
	return &user, nil
}

// Create inserts a new user.
func (r *UserRepo) Create(ctx context.Context, user *model.User) error {
	return r.db.WithContext(ctx).Create(user).Error
}

// Update modifies an existing user.
func (r *UserRepo) Update(ctx context.Context, user *model.User) error {
	return r.db.WithContext(ctx).Save(user).Error
}

// Delete soft-deletes a user.
func (r *UserRepo) Delete(ctx context.Context, id uint) error {
	return r.db.WithContext(ctx).Delete(&model.User{}, id).Error
}

// List retrieves all users with pagination.
func (r *UserRepo) List(ctx context.Context, offset, limit int) ([]model.User, int64, error) {
	var users []model.User
	var total int64

	if err := r.db.WithContext(ctx).Model(&model.User{}).Count(&total).Error; err != nil {
		return nil, 0, err
	}

	err := r.db.WithContext(ctx).Offset(offset).Limit(limit).Order("id ASC").
		Find(&users).Error
	return users, total, err
}

// Search searches users by name or email.
func (r *UserRepo) Search(ctx context.Context, query string, offset, limit int) ([]model.User, int64, error) {
	var users []model.User
	var total int64

	likeQuery := "%" + query + "%"
	condition := r.db.WithContext(ctx).Model(&model.User{}).
		Where("name ILIKE ? OR email ILIKE ?", likeQuery, likeQuery)

	if err := condition.Count(&total).Error; err != nil {
		return nil, 0, err
	}

	err := condition.Offset(offset).Limit(limit).Order("id ASC").
		Find(&users).Error
	return users, total, err
}

// UpdateAvailability updates user availability status.
// Accepts "online"/"available" → true, anything else → false.
func (r *UserRepo) UpdateAvailability(ctx context.Context, id uint, availability string) error {
	isAvailable := availability == "online" || availability == "available"
	return r.db.WithContext(ctx).Model(&model.User{}).Where("id = ?", id).
		Update("available", isAvailable).Error
}

// UpdateLastSignIn updates sign-in tracking fields.
func (r *UserRepo) UpdateLastSignIn(ctx context.Context, id uint, ip string) error {
	return r.db.WithContext(ctx).Model(&model.User{}).Where("id = ?", id).
		Updates(map[string]interface{}{
			"last_sign_in_ip":    ip,
			"current_sign_in_ip": ip,
			"sign_in_count":      gorm.Expr("sign_in_count + 1"),
		}).Error
}

// FindByAccount retrieves users belonging to an account (delegated to AccountRepo).
func (r *UserRepo) FindByAccount(ctx context.Context, accountID uint, offset, limit int) ([]model.User, int64, error) {
	var users []model.User
	var total int64

	countDB := r.db.WithContext(ctx).Model(&model.User{}).
		Joins("JOIN account_users ON account_users.user_id = users.id").
		Where("account_users.account_id = ?", accountID)
	if err := countDB.Count(&total).Error; err != nil {
		return nil, 0, err
	}

	err := r.db.WithContext(ctx).
		Joins("JOIN account_users ON account_users.user_id = users.id").
		Where("account_users.account_id = ?", accountID).
		Offset(offset).Limit(limit).Order("id ASC").
		Find(&users).Error
	return users, total, err
}

// Count returns total number of users.
func (r *UserRepo) Count(ctx context.Context) (int64, error) {
	var total int64
	err := r.db.WithContext(ctx).Model(&model.User{}).Count(&total).Error
	return total, err
}