// Copyright 2017 Frédéric Guillot. All rights reserved.
// Use of this source code is governed by the Apache 2.0
// license that can be found in the LICENSE file.

package model

import (
	"errors"
	"time"

	"github.com/miniflux/miniflux/timezone"
)

// User represents a user in the system.
type User struct {
	ID             int64             `json:"id"`
	Username       string            `json:"username"`
	Password       string            `json:"password,omitempty"`
	IsAdmin        bool              `json:"is_admin"`
	Theme          string            `json:"theme"`
	Language       string            `json:"language"`
	Timezone       string            `json:"timezone"`
	EntryDirection string            `json:"entry_sorting_direction"`
	LastLoginAt    *time.Time        `json:"last_login_at,omitempty"`
	Extra          map[string]string `json:"extra"`
}

// NewUser returns a new User.
func NewUser() *User {
	return &User{Extra: make(map[string]string)}
}

// ValidateUserCreation validates new user.
func (u User) ValidateUserCreation() error {
	if err := u.ValidateUserLogin(); err != nil {
		return err
	}

	return u.ValidatePassword()
}

// ValidateUserModification validates user modification payload.
func (u User) ValidateUserModification() error {
	if u.Theme != "" {
		return ValidateTheme(u.Theme)
	}

	if u.Password != "" {
		return u.ValidatePassword()
	}

	return nil
}

// ValidateUserLogin validates user credential requirements.
func (u User) ValidateUserLogin() error {
	if u.Username == "" {
		return errors.New("The username is mandatory")
	}

	if u.Password == "" {
		return errors.New("The password is mandatory")
	}

	return nil
}

// ValidatePassword validates user password requirements.
func (u User) ValidatePassword() error {
	if u.Password != "" && len(u.Password) < 6 {
		return errors.New("The password must have at least 6 characters")
	}

	return nil
}

// Merge update the current user with another user.
func (u *User) Merge(override *User) {
	if override.Username != "" && u.Username != override.Username {
		u.Username = override.Username
	}

	if override.Password != "" && u.Password != override.Password {
		u.Password = override.Password
	}

	if u.IsAdmin != override.IsAdmin {
		u.IsAdmin = override.IsAdmin
	}

	if override.Theme != "" && u.Theme != override.Theme {
		u.Theme = override.Theme
	}

	if override.Language != "" && u.Language != override.Language {
		u.Language = override.Language
	}

	if override.Timezone != "" && u.Timezone != override.Timezone {
		u.Timezone = override.Timezone
	}
}

// UseTimezone converts last login date to the given timezone.
func (u *User) UseTimezone(tz string) {
	if u.LastLoginAt != nil {
		*u.LastLoginAt = timezone.Convert(tz, *u.LastLoginAt)
	}
}

// Users represents a list of users.
type Users []*User

// UseTimezone converts last login timestamp of all users to the given timezone.
func (u Users) UseTimezone(tz string) {
	for _, user := range u {
		user.UseTimezone(tz)
	}
}
