// Copyright 2015 - Present, The Gogs Authors. All rights reserved.
// Copyright 2018 - Present, Gitote. All rights reserved.
//
// This source code is licensed under the MIT license found in the
// LICENSE file in the root directory of this source tree.

package user

import (
	"fmt"
	"gitote/gitote/models"
	"gitote/gitote/models/errors"
	"gitote/gitote/pkg/context"
	"gitote/gitote/pkg/form"
	"gitote/gitote/pkg/mailer"
	"gitote/gitote/pkg/setting"
	"gitote/gitote/pkg/tool"
	"net/url"

	raven "github.com/getsentry/raven-go"
	"github.com/go-macaron/captcha"
	log "gopkg.in/clog.v1"
)

const (
	// LoginTPL page template
	LoginTPL = "user/auth/login"

	// TwoFactorTPL page template
	TwoFactorTPL = "user/auth/two_factor"

	// TwoFactorRecoveryCodeTPL page template
	TwoFactorRecoveryCodeTPL = "user/auth/two_factor_recovery_code"

	// SignupTPL page template
	SignupTPL = "user/auth/signup"

	// ActivateTPL page template
	ActivateTPL = "user/auth/activate"

	// ForgotPasswordTPL page template
	ForgotPasswordTPL = "user/auth/forgot_passwd"

	// ResetPasswordTPL page template
	ResetPasswordTPL = "user/auth/reset_passwd"
)

// AutoLogin reads cookie and try to auto-login.
func AutoLogin(c *context.Context) (bool, error) {
	if !models.HasEngine {
		return false, nil
	}

	uname := c.GetCookie(setting.CookieUserName)
	if len(uname) == 0 {
		return false, nil
	}

	isSucceed := false
	defer func() {
		if !isSucceed {
			log.Trace("auto-login cookie cleared: %s", uname)
			c.SetCookie(setting.CookieUserName, "", -1, setting.AppSubURL)
			c.SetCookie(setting.CookieRememberName, "", -1, setting.AppSubURL)
			c.SetCookie(setting.LoginStatusCookieName, "", -1, setting.AppSubURL)
		}
	}()

	u, err := models.GetUserByName(uname)
	if err != nil {
		if !errors.IsUserNotExist(err) {
			return false, fmt.Errorf("GetUserByName: %v", err)
		}
		return false, nil
	}

	if val, ok := c.GetSuperSecureCookie(u.Rands+u.Passwd, setting.CookieRememberName); !ok || val != u.Name {
		return false, nil
	}

	isSucceed = true
	c.Session.Set("uid", u.ID)
	c.Session.Set("uname", u.Name)
	c.SetCookie(setting.CSRFCookieName, "", -1, setting.AppSubURL)
	if setting.EnableLoginStatusCookie {
		c.SetCookie(setting.LoginStatusCookieName, "true", 0, setting.AppSubURL)
	}
	return true, nil
}

//Login is the handler for "/login"
func Login(c *context.Context) {
	c.Title("sign_in")

	// Check auto-login
	isSucceed, err := AutoLogin(c)
	if err != nil {
		c.ServerError("AutoLogin", err)
		return
	}

	redirectTo := c.Query("redirect_to")
	if len(redirectTo) > 0 {
		c.SetCookie("redirect_to", redirectTo, 0, setting.AppSubURL)
	} else {
		redirectTo, _ = url.QueryUnescape(c.GetCookie("redirect_to"))
	}

	if isSucceed {
		if tool.IsSameSiteURLPath(redirectTo) {
			c.Redirect(redirectTo)
		} else {
			c.SubURLRedirect("/")
		}
		c.SetCookie("redirect_to", "", -1, setting.AppSubURL)
		return
	}

	// Display normal login page
	loginSources, err := models.ActivatedLoginSources()
	if err != nil {
		c.ServerError("ActivatedLoginSources", err)
		return
	}
	c.Data["LoginSources"] = loginSources

	for i := range loginSources {
		if loginSources[i].IsDefault {
			c.Data["DefaultSource"] = *loginSources[i]
			c.Data["login_source"] = loginSources[i].ID
			newLoginSources := append(loginSources[:i], loginSources[i+1:]...)
			c.Data["LoginSources"] = newLoginSources
			break
		}
	}

	c.Success(LoginTPL)
}

//afterLogin set sessions cookies and redirect to "/"
func afterLogin(c *context.Context, u *models.User, remember bool) {
	if remember {
		days := 86400 * setting.LoginRememberDays
		c.SetCookie(setting.CookieUserName, u.Name, days, setting.AppSubURL, "", setting.CookieSecure, true)
		c.SetSuperSecureCookie(u.Rands+u.Passwd, setting.CookieRememberName, u.Name, days, setting.AppSubURL, "", setting.CookieSecure, true)
	}

	c.Session.Set("uid", u.ID)
	c.Session.Set("uname", u.Name)
	c.Session.Delete("twoFactorRemember")
	c.Session.Delete("twoFactorUserID")

	// Clear whatever CSRF has right now, force to generate a new one
	c.SetCookie(setting.CSRFCookieName, "", -1, setting.AppSubURL)
	if setting.EnableLoginStatusCookie {
		c.SetCookie(setting.LoginStatusCookieName, "true", 0, setting.AppSubURL)
	}

	redirectTo, _ := url.QueryUnescape(c.GetCookie("redirect_to"))
	c.SetCookie("redirect_to", "", -1, setting.AppSubURL)
	if tool.IsSameSiteURLPath(redirectTo) {
		c.Redirect(redirectTo)
		return
	}

	c.SubURLRedirect("/")
}

//LoginPost is the POST handler for "/login"
func LoginPost(c *context.Context, f form.SignIn) {
	c.Title("sign_in")

	loginSources, err := models.ActivatedLoginSources()
	if err != nil {
		c.ServerError("ActivatedLoginSources", err)
		return
	}
	c.Data["LoginSources"] = loginSources

	if c.HasError() {
		c.Success(LoginTPL)
		return
	}

	u, err := models.UserLogin(f.UserName, f.Password, f.LoginSource)
	if err != nil {
		switch err.(type) {
		case errors.UserNotExist:
			c.FormErr("UserName", "Password")
			c.RenderWithErr(c.Tr("form.username_password_incorrect"), LoginTPL, &f)
		case errors.LoginSourceMismatch:
			c.FormErr("LoginSource")
			c.RenderWithErr(c.Tr("form.auth_source_mismatch"), LoginTPL, &f)

		default:
			c.ServerError("UserLogin", err)
		}

		for i := range loginSources {
			if loginSources[i].IsDefault {
				c.Data["DefaultSource"] = *loginSources[i]
				c.Data["login_source"] = loginSources[i].ID
				newLoginSources := append(loginSources[:i], loginSources[i+1:]...)
				c.Data["LoginSources"] = newLoginSources
				break
			}
		}

		return
	}

	if !u.IsEnabledTwoFactor() {
		afterLogin(c, u, f.Remember)
		return
	}

	c.Session.Set("twoFactorRemember", f.Remember)
	c.Session.Set("twoFactorUserID", u.ID)
	c.SubURLRedirect("/login/two_factor")
}

//LoginTwoFactor is the handler for "/login" with two factors authentication
func LoginTwoFactor(c *context.Context) {
	_, ok := c.Session.Get("twoFactorUserID").(int64)
	if !ok {
		c.NotFound()
		return
	}

	c.Success(TwoFactorTPL)
}

//LoginTwoFactorPost is the POST handler for "/login" with two factors authentication
func LoginTwoFactorPost(c *context.Context) {
	userID, ok := c.Session.Get("twoFactorUserID").(int64)
	if !ok {
		c.NotFound()
		return
	}

	t, err := models.GetTwoFactorByUserID(userID)
	if err != nil {
		c.ServerError("GetTwoFactorByUserID", err)
		return
	}

	passcode := c.Query("passcode")
	valid, err := t.ValidateTOTP(passcode)
	if err != nil {
		c.ServerError("ValidateTOTP", err)
		return
	} else if !valid {
		c.Flash.Error(c.Tr("settings.two_factor_invalid_passcode"))
		c.SubURLRedirect("/login/two_factor")
		return
	}

	u, err := models.GetUserByID(userID)
	if err != nil {
		c.ServerError("GetUserByID", err)
		return
	}

	// Prevent same passcode from being reused
	if c.Cache.IsExist(u.TwoFactorCacheKey(passcode)) {
		c.Flash.Error(c.Tr("settings.two_factor_reused_passcode"))
		c.SubURLRedirect("/login/two_factor")
		return
	}
	if err = c.Cache.Put(u.TwoFactorCacheKey(passcode), 1, 60); err != nil {
		raven.CaptureErrorAndWait(err, nil)
		log.Error(2, "Failed to put cache 'two factor passcode': %v", err)
	}

	afterLogin(c, u, c.Session.Get("twoFactorRemember").(bool))
}

//LoginTwoFactorRecoveryCode is the handler to recover Two Factor Code
func LoginTwoFactorRecoveryCode(c *context.Context) {
	_, ok := c.Session.Get("twoFactorUserID").(int64)
	if !ok {
		c.NotFound()
		return
	}

	c.Success(TwoFactorRecoveryCodeTPL)
}

//LoginTwoFactorRecoveryCodePost is the POST handler to recover Two Factor Code
func LoginTwoFactorRecoveryCodePost(c *context.Context) {
	userID, ok := c.Session.Get("twoFactorUserID").(int64)
	if !ok {
		c.NotFound()
		return
	}

	if err := models.UseRecoveryCode(userID, c.Query("recovery_code")); err != nil {
		if errors.IsTwoFactorRecoveryCodeNotFound(err) {
			c.Flash.Error(c.Tr("auth.login_two_factor_invalid_recovery_code"))
			c.SubURLRedirect("/login/two_factor_recovery_code")
		} else {
			c.ServerError("UseRecoveryCode", err)
		}
		return
	}

	u, err := models.GetUserByID(userID)
	if err != nil {
		c.ServerError("GetUserByID", err)
		return
	}
	afterLogin(c, u, c.Session.Get("twoFactorRemember").(bool))
}

//SignOut is the handler for "/user/logout"
func SignOut(c *context.Context) {
	c.Session.Flush()
	c.Session.Destory(c.Context)
	c.SetCookie(setting.CookieUserName, "", -1, setting.AppSubURL)
	c.SetCookie(setting.CookieRememberName, "", -1, setting.AppSubURL)
	c.SetCookie(setting.CSRFCookieName, "", -1, setting.AppSubURL)
	c.SubURLRedirect("/")
}

//SignUp is the handler for "/signup"
func SignUp(c *context.Context) {
	c.Title("sign_up")

	c.Data["EnableCaptcha"] = setting.Service.EnableCaptcha

	if setting.Service.DisableRegistration {
		c.Data["DisableRegistration"] = true
		c.Success(SignupTPL)
		return
	}

	c.Success(SignupTPL)
}

//SignUpPost is the POST handler for "/join"
func SignUpPost(c *context.Context, cpt *captcha.Captcha, f form.Register) {
	c.Title("sign_up")

	c.Data["EnableCaptcha"] = setting.Service.EnableCaptcha

	if setting.Service.DisableRegistration {
		c.Status(403)
		return
	}

	if c.HasError() {
		c.Success(SignupTPL)
		return
	}

	if setting.Service.EnableCaptcha && !cpt.VerifyReq(c.Req) {
		c.FormErr("Captcha")
		c.RenderWithErr(c.Tr("form.captcha_incorrect"), SignupTPL, &f)
		return
	}

	if f.Password != f.Retype {
		c.FormErr("Password")
		c.RenderWithErr(c.Tr("form.password_not_match"), SignupTPL, &f)
		return
	}

	u := &models.User{
		Name:       f.UserName,
		Email:      f.Email,
		Passwd:     f.Password,
		ThemeColor: "#161616",
		IsActive:   !setting.Service.RegisterEmailConfirm,
	}
	if err := models.CreateUser(u); err != nil {
		switch {
		case models.IsErrUserAlreadyExist(err):
			c.FormErr("UserName")
			c.RenderWithErr(c.Tr("form.username_been_taken"), SignupTPL, &f)
		case models.IsErrEmailAlreadyUsed(err):
			c.FormErr("Email")
			c.RenderWithErr(c.Tr("form.email_been_used"), SignupTPL, &f)
		case models.IsErrNameReserved(err):
			c.FormErr("UserName")
			c.RenderWithErr(c.Tr("user.form.name_reserved", err.(models.ErrNameReserved).Name), SignupTPL, &f)
		case models.IsErrNamePatternNotAllowed(err):
			c.FormErr("UserName")
			c.RenderWithErr(c.Tr("user.form.name_pattern_not_allowed", err.(models.ErrNamePatternNotAllowed).Pattern), SignupTPL, &f)
		default:
			c.ServerError("CreateUser", err)
		}
		return
	}
	log.Trace("Account created: %s", u.Name)

	// Auto-set admin for the only user.
	if models.CountUsers() == 1 {
		u.IsAdmin = true
		u.IsActive = true
		if err := models.UpdateUser(u); err != nil {
			c.ServerError("UpdateUser", err)
			return
		}
	}

	// Auto Follow the first user
	models.FollowUser(u.ID, 1)

	// Send confirmation email, no need for social account.
	if setting.Service.RegisterEmailConfirm && u.ID > 1 {
		mailer.SendActivateAccountMail(c.Context, models.NewMailerUser(u))
		c.Data["IsSendRegisterMail"] = true
		c.Data["Email"] = u.Email
		c.Data["Hours"] = setting.Service.ActiveCodeLives / 60
		c.Success(ActivateTPL)

		if err := c.Cache.Put(u.MailResendCacheKey(), 1, 180); err != nil {
			raven.CaptureErrorAndWait(err, nil)
			log.Error(2, "Failed to put cache key 'mail resend': %v", err)
		}
		return
	}

	c.SubURLRedirect("/login")
}

//Activate activates the code
func Activate(c *context.Context) {
	code := c.Query("code")
	if len(code) == 0 {
		c.Data["IsActivatePage"] = true
		if c.User.IsActive {
			c.NotFound()
			return
		}
		// Resend confirmation email.
		if setting.Service.RegisterEmailConfirm {
			if c.Cache.IsExist(c.User.MailResendCacheKey()) {
				c.Data["ResendLimited"] = true
			} else {
				c.Data["Hours"] = setting.Service.ActiveCodeLives / 60
				mailer.SendActivateAccountMail(c.Context, models.NewMailerUser(c.User))

				if err := c.Cache.Put(c.User.MailResendCacheKey(), 1, 180); err != nil {
					raven.CaptureErrorAndWait(err, nil)
					log.Error(2, "Failed to put cache key 'mail resend': %v", err)
				}
			}
		} else {
			c.Data["ServiceNotEnabled"] = true
		}
		c.Success(ActivateTPL)
		return
	}

	// Verify code.
	if user := models.VerifyUserActiveCode(code); user != nil {
		user.IsActive = true
		var err error
		if user.Rands, err = models.GetUserSalt(); err != nil {
			c.ServerError("GetUserSalt", err)
			return
		}
		if err := models.UpdateUser(user); err != nil {
			c.ServerError("UpdateUser", err)
			return
		}

		log.Trace("User activated: %s", user.Name)

		c.Session.Set("uid", user.ID)
		c.Session.Set("uname", user.Name)
		c.SubURLRedirect("/")
		return
	}

	c.Data["IsActivateFailed"] = true
	c.Success(ActivateTPL)
}

//ActivateEmail is the handler to activate the user email
func ActivateEmail(c *context.Context) {
	code := c.Query("code")
	emailString := c.Query("email")

	// Verify code.
	if email := models.VerifyActiveEmailCode(code, emailString); email != nil {
		if err := email.Activate(); err != nil {
			c.ServerError("ActivateEmail", err)
		}

		log.Trace("Email activated: %s", email.Email)
		c.Flash.Success(c.Tr("settings.add_email_success"))
	}

	c.SubURLRedirect("/user/settings/email")
	return
}

//ForgotPasswd is the handler for "/user/forget_password"
func ForgotPasswd(c *context.Context) {
	c.Title("auth.forgot_password")

	if setting.MailService == nil {
		c.Data["IsResetDisable"] = true
		c.Success(ForgotPasswordTPL)
		return
	}

	c.Data["IsResetRequest"] = true
	c.Success(ForgotPasswordTPL)
}

//ForgotPasswdPost is the POST handler for "/user/forget_password"
func ForgotPasswdPost(c *context.Context) {
	c.Title("auth.forgot_password")

	if setting.MailService == nil {
		c.Status(403)
		return
	}
	c.Data["IsResetRequest"] = true

	email := c.Query("email")
	c.Data["Email"] = email

	u, err := models.GetUserByEmail(email)
	if err != nil {
		if errors.IsUserNotExist(err) {
			c.Data["Hours"] = setting.Service.ActiveCodeLives / 60
			c.Data["IsResetSent"] = true
			c.Success(ForgotPasswordTPL)
			return
		}
		c.ServerError("GetUserByEmail", err)
		return
	}

	if !u.IsLocal() {
		c.FormErr("Email")
		c.RenderWithErr(c.Tr("auth.non_local_account"), ForgotPasswordTPL, nil)
		return
	}

	if c.Cache.IsExist(u.MailResendCacheKey()) {
		c.Data["ResendLimited"] = true
		c.Success(ForgotPasswordTPL)
		return
	}

	mailer.SendResetPasswordMail(c.Context, models.NewMailerUser(u))
	if err = c.Cache.Put(u.MailResendCacheKey(), 1, 180); err != nil {
		raven.CaptureErrorAndWait(err, nil)
		log.Error(2, "Failed to put cache key 'mail resend': %v", err)
	}

	c.Data["Hours"] = setting.Service.ActiveCodeLives / 60
	c.Data["IsResetSent"] = true
	c.Success(ForgotPasswordTPL)
}

//ResetPasswd is the handler to reset your password
func ResetPasswd(c *context.Context) {
	c.Title("auth.reset_password")

	code := c.Query("code")
	if len(code) == 0 {
		c.NotFound()
		return
	}
	c.Data["Code"] = code
	c.Data["IsResetForm"] = true
	c.Success(ResetPasswordTPL)
}

//ResetPasswdPost is the POST handler to reset your password
func ResetPasswdPost(c *context.Context) {
	c.Title("auth.reset_password")

	code := c.Query("code")
	if len(code) == 0 {
		c.NotFound()
		return
	}
	c.Data["Code"] = code

	if u := models.VerifyUserActiveCode(code); u != nil {
		// Validate password length.
		passwd := c.Query("password")
		if len(passwd) < 6 {
			c.Data["IsResetForm"] = true
			c.Data["Err_Password"] = true
			c.RenderWithErr(c.Tr("auth.password_too_short"), ResetPasswordTPL, nil)
			return
		}

		u.Passwd = passwd
		var err error
		if u.Rands, err = models.GetUserSalt(); err != nil {
			c.ServerError("GetUserSalt", err)
			return
		}
		if u.Salt, err = models.GetUserSalt(); err != nil {
			c.ServerError("GetUserSalt", err)
			return
		}
		u.EncodePasswd()
		if err := models.UpdateUser(u); err != nil {
			c.ServerError("UpdateUser", err)
			return
		}

		log.Trace("User password reset: %s", u.Name)
		c.SubURLRedirect("/login")
		return
	}

	c.Data["IsResetFailed"] = true
	c.Success(ResetPasswordTPL)
}