package models

import (
	"errors"
	"strings"
	"time"

	"git.kirsle.net/apps/gosocial/pkg/config"
	"git.kirsle.net/apps/gosocial/pkg/log"
	"golang.org/x/crypto/bcrypt"
	"gorm.io/gorm/clause"
)

// User account table.
type User struct {
	ID             uint64 `gorm:"primaryKey"`
	Username       string `gorm:"uniqueIndex"`
	Email          string `gorm:"uniqueIndex"`
	HashedPassword string
	IsAdmin        bool       `gorm:"index"`
	Status         UserStatus `gorm:"index"` // active, disabled
	Visibility     string     `gorm:"index"` // public, private
	Name           *string
	Birthdate      time.Time
	Certified      bool
	CreatedAt      time.Time `gorm:"index"`
	UpdatedAt      time.Time `gorm:"index"`
	LastLoginAt    time.Time `gorm:"index"`

	// Relational tables.
	ProfileField []ProfileField
}

// UserStatus options.
type UserStatus string

const (
	UserStatusActive   = "active"
	UserStatusDisabled = "disabled"
)

// CreateUser. It is assumed username and email are correctly formatted.
func CreateUser(username, email, password string) (*User, error) {
	// Verify username and email are unique.
	if _, err := FindUser(username); err == nil {
		return nil, errors.New("That username already exists. Please try a different username.")
	} else if _, err := FindUser(email); err == nil {
		return nil, errors.New("That email address is already registered.")
	}

	u := &User{
		Username: username,
		Email:    email,
		Status:   UserStatusActive,
	}

	if err := u.HashPassword(password); err != nil {
		return nil, err
	}

	result := DB.Create(u)
	return u, result.Error
}

// GetUser by ID.
func GetUser(userId uint64) (*User, error) {
	user := &User{}
	result := DB.Preload(clause.Associations).First(&user, userId)
	return user, result.Error
}

// FindUser by username or email.
func FindUser(username string) (*User, error) {
	if username == "" {
		return nil, errors.New("username is required")
	}

	u := &User{}
	if strings.ContainsRune(username, '@') {
		result := DB.Preload(clause.Associations).Where("email = ?", username).Limit(1).First(u)
		return u, result.Error
	}
	result := DB.Preload(clause.Associations).Where("username = ?", username).Limit(1).First(u)
	return u, result.Error
}

// HashPassword sets the user's hashed (bcrypt) password.
func (u *User) HashPassword(password string) error {
	passwd, err := bcrypt.GenerateFromPassword([]byte(password), config.BcryptCost)
	if err != nil {
		return err
	}
	u.HashedPassword = string(passwd)
	return nil
}

// CheckPassword verifies the password is correct. Returns nil on success.
func (u *User) CheckPassword(password string) error {
	return bcrypt.CompareHashAndPassword([]byte(u.HashedPassword), []byte(password))
}

// SetProfileField sets or creates a named profile field.
func (u *User) SetProfileField(name, value string) {
	// Check if it exists.
	log.Debug("User(%s).SetProfileField(%s, %s)", u.Username, name, value)
	var exists bool
	for _, field := range u.ProfileField {
		log.Debug("\tCheck existing field %s", field.Name)
		if field.Name == name {
			log.Debug("\tFound existing field!")
			changed := field.Value != value
			field.Value = value
			exists = true

			// Save it now. TODO: otherwise gorm doesn't know we changed
			// it and it won't be inserted when the User is saved. But
			// this is probably not performant to do!
			if changed {
				DB.Save(&field)
			}
			break
		}
	}

	if exists {
		return
	}

	u.ProfileField = append(u.ProfileField, ProfileField{
		Name:  name,
		Value: value,
	})
}

// GetProfileField returns the value of a profile field or blank string.
func (u *User) GetProfileField(name string) string {
	for _, field := range u.ProfileField {
		if field.Name == name {
			return field.Value
		}
	}
	return ""
}

// ProfileFieldIn checks if a substring is IN a profile field. Currently
// does a naive strings.Contains(), intended for the "here_for" field.
func (u *User) ProfileFieldIn(field, substr string) bool {
	value := u.GetProfileField(field)
	return strings.Contains(value, substr)
}

// Save user.
func (u *User) Save() error {
	result := DB.Save(u)
	return result.Error
}