package main

import (
	"bytes"
	"crypto/rand"
	"encoding/binary"
	"encoding/hex"
	"fmt"
	"html/template"
	"log"
	"net/http"
	"regexp"
	"strings"

	// "github.com/emersion/go-sasl"
	// "github.com/emersion/go-smtp"
	"github.com/go-ldap/ldap/v3"
	"github.com/gorilla/mux"
	"golang.org/x/crypto/argon2"
)

var EMAIL_REGEXP = regexp.MustCompile("^[a-zA-Z0-9.!#$%&'*+\\/=?^_`{|}~-]+@[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?(?:\\.[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?)*$")

func checkInviterLogin(w http.ResponseWriter, r *http.Request) *LoginStatus {

	login := checkLogin(w, r)
	if login == nil {
		return nil
	}

	// if !login.CanInvite {
	// 	http.Error(w, "Not authorized to invite new users.", http.StatusUnauthorized)
	// 	return nil
	// }

	return login
}

// New account creation directly from interface

type PasswordFoundData struct {
	ErrorMessage string
	Success      bool
	Username     string
	Mail         string
	OtherMailbox string
	CanAdmin     bool
	LoggedIn     bool
}

type PasswordLostData struct {
	ErrorMessage string
	Success      bool
	Username     string
	Mail         string
	OtherMailbox string
	CanAdmin     bool
	LoggedIn     bool
}

func openNewUserLdap(config *ConfigFile) (*ldap.Conn, error) {
	l, err := openLdap(config)
	if err != nil {
		log.Printf(fmt.Sprintf("openNewUserLdap 1 : %v %v", err, l))
		log.Printf(fmt.Sprintf("openNewUserLdap 1 : %v", config))
		// data.ErrorMessage = err.Error()
	}
	err = l.Bind(config.NewUserDN, config.NewUserPassword)
	if err != nil {
		log.Printf(fmt.Sprintf("openNewUserLdap 2 : %v", err))
		log.Printf(fmt.Sprintf("openNewUserLdap 2 : %v", config.NewUserDN))
		log.Printf(fmt.Sprintf("openNewUserLdap 2 : %v", config.NewUserPassword))
		log.Printf(fmt.Sprintf("openNewUserLdap 2 : %v", config))
		// data.ErrorMessage = err.Error()
	}
	return l, err
}

func handleLostPassword(w http.ResponseWriter, r *http.Request) {
	templateLostPasswordPage := getTemplate("password_lost.html")
	if checkLogin(w, r) != nil {
		http.Redirect(w, r, "/", http.StatusTemporaryRedirect)
	}

	data := PasswordLostData{
		CanAdmin: false,
		LoggedIn: false,
	}

	if r.Method == "POST" {
		r.ParseForm()
		data.Username = strings.TrimSpace(strings.Join(r.Form["username"], ""))
		data.Mail = strings.TrimSpace(strings.Join(r.Form["mail"], ""))
		data.OtherMailbox = strings.TrimSpace(strings.Join(r.Form["othermailbox"], ""))
		user := User{
			CN:           strings.TrimSpace(strings.Join(r.Form["username"], "")),
			UID:          strings.TrimSpace(strings.Join(r.Form["username"], "")),
			Mail:         strings.TrimSpace(strings.Join(r.Form["mail"], "")),
			OtherMailbox: strings.TrimSpace(strings.Join(r.Form["othermailbox"], "")),
		}
		ldapConn, err := openNewUserLdap(config)
		if err != nil {
			log.Printf(fmt.Sprintf("handleLostPassword 99 : %v %v", err, ldapConn))
			data.ErrorMessage = err.Error()
		}
		err = passwordLost(user, config, ldapConn)
		if err != nil {
			log.Printf(fmt.Sprintf("handleLostPassword 104 : %v %v", err, ldapConn))
			data.ErrorMessage = err.Error()
		} else {
			err = ldapConn.Bind(config.NewUserDN, config.NewUserPassword)
			if err != nil {
				log.Printf(fmt.Sprintf("handleLostPassword 109 : %v %v", err, ldapConn))
				data.ErrorMessage = err.Error()
			} else {
				data.Success = true
			}
		}
	}
	data.CanAdmin = false
	templateLostPasswordPage.Execute(w, data)
}

func handleInviteNewAccount(w http.ResponseWriter, r *http.Request) {
	l, err := ldapOpen(w)
	if err != nil {
		log.Printf(fmt.Sprintf("58: %v %v", err, l))
	}
	// l.Bind(config.NewUserDN, config.NewUserPassword)

	// login := checkInviterLogin(w, r)
	// if login == nil {
	// 	return
	// }
	// l, _ := ldap.DialURL(config.LdapServerAddr)
	// l.Bind(config.NewUserDN, config.NewUserPassword)

	// loginInfo, err := doLogin(w, r, "testuser", config.NewUserDN, config.NewUserPassword)

	// if err != nil {
	// 	log.Printf(fmt.Sprintf("58: %v %v", err, l))
	// }

	// l := ldapOpen(w)
	if l == nil {
		return
	}

	err = l.Bind(config.NewUserDN, config.NewUserPassword)
	if err != nil {
		log.Printf(fmt.Sprintf("58: %v %v", err, l))
	}
	handleNewAccount(w, r, l, config.NewUserDN)
}

// New account creation using code

func handleInvitationCode(w http.ResponseWriter, r *http.Request) {
	code := mux.Vars(r)["code"]
	code_id, code_pw := readCode(code)

	// log.Printf(code_pw)

	login := checkLogin(w, r)

	// l := ldapOpen(w)
	// if l == nil {
	// 	return
	// }

	inviteDn := config.InvitationNameAttr + "=" + code_id + "," + config.InvitationBaseDN
	err := login.conn.Bind(inviteDn, code_pw)
	if err != nil {
		templateInviteInvalidCode := getTemplate("invite_invalid_code.html")
		templateInviteInvalidCode.Execute(w, nil)
		return
	}

	sReq := ldap.NewSearchRequest(
		inviteDn,
		ldap.ScopeBaseObject, ldap.NeverDerefAliases, 0, 0, false,
		fmt.Sprintf("(objectclass=*)"),
		[]string{"dn", "creatorsname"},
		nil)
	sr, err := login.conn.Search(sReq)
	if err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
		return
	}
	if len(sr.Entries) != 1 {
		http.Error(w, fmt.Sprintf("Expected 1 entry, got %d", len(sr.Entries)), http.StatusInternalServerError)
		return
	}

	invitedBy := sr.Entries[0].GetAttributeValue("creatorsname")

	if handleNewAccount(w, r, login.conn, invitedBy) {
		del_req := ldap.NewDelRequest(inviteDn, nil)
		err = login.conn.Del(del_req)
		if err != nil {
			log.Printf("Could not delete invitation %s: %s", inviteDn, err)
		}
	}
}

// Common functions for new account

type NewAccountData struct {
	Username    string
	DisplayName string
	GivenName   string
	Surname     string
	Mail        string
	SuggestPW   string
	OtherEmail  string

	ErrorUsernameTaken    bool
	ErrorInvalidUsername  bool
	ErrorPasswordTooShort bool
	ErrorPasswordMismatch bool
	ErrorMessage          string
	WarningMessage        string
	Success               bool
	CanAdmin              bool
	LoggedIn              bool
}

func handleNewAccount(w http.ResponseWriter, r *http.Request, l *ldap.Conn, invitedBy string) bool {
	templateInviteNewAccount := getTemplate("invite_new_account.html")

	data := &NewAccountData{}

	if r.Method == "POST" {
		r.ParseForm()

		newUser := User{}
		// login := checkLogin(w, r)

		// newUser.Mail = fmt.Sprintf("%s@%s", strings.TrimSpace(strings.Join(r.Form["username"], "")), "lesgv.com")
		newUser.DisplayName = strings.TrimSpace(strings.Join(r.Form["displayname"], ""))
		newUser.GivenName = strings.TrimSpace(strings.Join(r.Form["givenname"], ""))
		newUser.SN = strings.TrimSpace(strings.Join(r.Form["surname"], ""))
		newUser.Mail = strings.TrimSpace(strings.Join(r.Form["mail"], ""))
		newUser.UID = strings.TrimSpace(strings.Join(r.Form["otheremail"], ""))
		newUser.CN = strings.TrimSpace(strings.Join(r.Form["username"], ""))
		newUser.DN = "cn=" + strings.TrimSpace(strings.Join(r.Form["username"], "")) + "," + config.InvitationBaseDN

		password1 := strings.Join(r.Form["password"], "")
		password2 := strings.Join(r.Form["password2"], "")

		if password1 != password2 {
			data.Success = false
			data.ErrorPasswordMismatch = true
		} else {
			newUser.Password = password2
			l.Bind(config.NewUserDN, config.NewUserPassword)
			err := add(newUser, config, l)
			if err != nil {
				data.Success = false
				data.ErrorMessage = err.Error()
			}
			http.Redirect(w, r, "/admin/activate", http.StatusFound)
		}

		// tryCreateAccount(l, data, password1, password2, invitedBy)

	} else {
		data.SuggestPW = fmt.Sprintf("%s", suggestPassword())
	}
	data.CanAdmin = false
	data.LoggedIn = false

	templateInviteNewAccount.Execute(w, data)
	return data.Success
}

func tryCreateAccount(l *ldap.Conn, data *NewAccountData, pass1 string, pass2 string, invitedBy string) {
	checkFailed := false

	// Check if username is correct
	if match, err := regexp.MatchString("^[a-z0-9._-]+$", data.Username); !(err == nil && match) {
		data.ErrorInvalidUsername = true
		checkFailed = true
	}

	// Check if user exists
	userDn := config.UserNameAttr + "=" + data.Username + "," + config.UserBaseDN
	searchRq := ldap.NewSearchRequest(
		userDn,
		ldap.ScopeBaseObject, ldap.NeverDerefAliases, 0, 0, false,
		"(objectclass=*)",
		[]string{"dn"},
		nil)

	sr, err := l.Search(searchRq)
	if err != nil {
		data.ErrorMessage = err.Error()
		checkFailed = true
	}

	if len(sr.Entries) > 0 {
		data.ErrorUsernameTaken = true
		checkFailed = true
	}

	// Check that password is long enough
	if len(pass1) < 8 {
		data.ErrorPasswordTooShort = true
		checkFailed = true
	}

	if pass1 != pass2 {
		data.ErrorPasswordMismatch = true
		checkFailed = true
	}

	if checkFailed {
		return
	}

	// Actually create user
	req := ldap.NewAddRequest(userDn, nil)
	req.Attribute("objectclass", []string{"inetOrgPerson", "organizationalPerson", "person", "top"})
	req.Attribute("structuralobjectclass", []string{"inetOrgPerson"})
	pw, err := SSHAEncode(pass1)
	if err != nil {
		data.ErrorMessage = err.Error()
		return
	}
	req.Attribute("userpassword", []string{pw})
	req.Attribute("invitedby", []string{invitedBy})
	if len(data.DisplayName) > 0 {
		req.Attribute("displayname", []string{data.DisplayName})
	}
	if len(data.GivenName) > 0 {
		req.Attribute("givenname", []string{data.GivenName})
	}
	if len(data.Surname) > 0 {
		req.Attribute("sn", []string{data.Surname})
	}
	if len(config.InvitedMailFormat) > 0 {
		email := strings.ReplaceAll(config.InvitedMailFormat, "{}", data.Username)
		req.Attribute("mail", []string{email})
	}

	err = l.Add(req)
	if err != nil {
		data.ErrorMessage = err.Error()
		return
	}

	for _, group := range config.InvitedAutoGroups {
		req := ldap.NewModifyRequest(group, nil)
		req.Add("member", []string{userDn})
		err = l.Modify(req)
		if err != nil {
			data.WarningMessage += fmt.Sprintf("Cannot add to %s: %s\n", group, err.Error())
		}
	}

	data.Success = true
}

// ---- Code generation ----

type SendCodeData struct {
	ErrorMessage      string
	ErrorInvalidEmail bool
	Success           bool
	CodeDisplay       string
	CodeSentTo        string
	WebBaseAddress    string
	CanAdmin          bool
}

type CodeMailFields struct {
	From           string
	To             string
	Code           string
	InviteFrom     string
	WebBaseAddress string
	CanAdmin       bool
}

func handleInviteSendCode(w http.ResponseWriter, r *http.Request) {
	templateInviteSendCode := getTemplate("invite_send_code.html")

	login := checkInviterLogin(w, r)
	if login == nil {
		return
	}

	// carLicense

	if r.Method == "POST" {
		r.ParseForm()
		data := &SendCodeData{
			WebBaseAddress: config.WebAddress,
		}

		// modify_request := ldap.NewModifyRequest(login.UserEntry.DN, nil)
		// // choice := strings.Join(r.Form["choice"], "")
		// // sendto := strings.Join(r.Form["sendto"], "")
		code, code_id, code_pw := genCode()
		log.Printf(fmt.Sprintf("272: %v %v %v", code, code_id, code_pw))
		// // Create invitation object in database
		// modify_request.Add("carLicense", []string{fmt.Sprintf("%s,%s,%s",code, code_id, code_pw)})
		// err := login.conn.Modify(modify_request)
		// if err != nil {
		// 	data.ErrorMessage = err.Error()
		// 	// return
		// } else {
		// 	data.Success = true
		// 	data.CodeDisplay = code
		// }
		log.Printf(fmt.Sprintf("279: %v %v %v", code, code_id, code_pw))
		addReq := ldap.NewAddRequest("documentIdentifier="+code_id+","+config.InvitationBaseDN, nil)
		addReq.Attribute("objectClass", []string{"top", "document", "simpleSecurityObject"})
		addReq.Attribute("cn", []string{code})
		addReq.Attribute("userPassword", []string{code_pw})
		addReq.Attribute("documentIdentifier", []string{code_id})
		log.Printf(fmt.Sprintf("285: %v %v %v", code, code_id, code_pw))
		log.Printf(fmt.Sprintf("286: %v", addReq))
		err := login.conn.Add(addReq)
		if err != nil {
			data.ErrorMessage = err.Error()
			// return
		} else {
			data.Success = true
			data.CodeDisplay = code
		}
		data.CanAdmin = login.CanAdmin

		templateInviteSendCode.Execute(w, data)

		// if choice == "display" || choice == "send" {
		// 	log.Printf(fmt.Sprintf("260: %v %v %v %v", login, choice, sendto, data))
		// 	trySendCode(login, choice, sendto, data)
		// }
	}

}

func trySendCode(login *LoginStatus, choice string, sendto string, data *SendCodeData) {
	log.Printf(fmt.Sprintf("269: %v %v %v %v", login, choice, sendto, data))
	// Generate code
	code, code_id, code_pw := genCode()
	log.Printf(fmt.Sprintf("272: %v %v %v", code, code_id, code_pw))
	// Create invitation object in database

	// len_base_dn := len(strings.Split(config.BaseDN, ","))
	// dn_split := strings.Split(super_dn, ",")
	// for i := len_base_dn + 1; i <= len(dn_split); i++ {
	// 	path = append(path, PathItem{
	// 		DN:         strings.Join(dn_split[len(dn_split)-i:len(dn_split)], ","),
	// 		Identifier: dn_split[len(dn_split)-i],
	// 	})
	// }
	// data := &SendCodeData{
	// 	WebBaseAddress: config.WebAddress,
	// }
	// // Handle data
	// data := &CreateData{
	// 	SuperDN: super_dn,
	// 	Path:    path,
	// }
	// data.IdType = config.UserNameAttr
	// data.StructuralObjectClass = "inetOrgPerson"
	// data.ObjectClass = "inetOrgPerson\norganizationalPerson\nperson\ntop"
	// data.IdValue = strings.TrimSpace(strings.Join(r.Form["idvalue"], ""))
	// data.DisplayName = strings.TrimSpace(strings.Join(r.Form["displayname"], ""))
	// data.GivenName = strings.TrimSpace(strings.Join(r.Form["givenname"], ""))
	// data.Mail = strings.TrimSpace(strings.Join(r.Form["mail"], ""))
	// data.Member = strings.TrimSpace(strings.Join(r.Form["member"], ""))
	// data.Description = strings.TrimSpace(strings.Join(r.Form["description"], ""))
	// data.SN = strings.TrimSpace(strings.Join(r.Form["sn"], ""))
	// object_class := []string{}
	// for _, oc := range strings.Split(data.ObjectClass, "\n") {
	// 	x := strings.TrimSpace(oc)
	// 	if x != "" {
	// 		object_class = append(object_class, x)
	// 	}
	// }
	// dn := data.IdType + "=" + data.IdValue + "," + super_dn
	// 		req := ldap.NewAddRequest(dn, nil)
	// 		req.Attribute("objectclass", object_class)
	// 		// req.Attribute("mail", []string{data.IdValue})
	//     /*
	// 		if data.StructuralObjectClass != "" {
	// 			req.Attribute("structuralobjectclass", []string{data.StructuralObjectClass})
	// 		}
	//     */
	// 		if data.DisplayName != "" {
	// 			req.Attribute("displayname", []string{data.DisplayName})
	// 		}
	// 		if data.GivenName != "" {
	// 			req.Attribute("givenname", []string{data.GivenName})
	// 		}
	// 		if data.Mail != "" {
	// 			req.Attribute("mail", []string{data.Mail})
	// 		}
	// 		if data.Member != "" {
	// 			req.Attribute("member", []string{data.Member})
	// 		}
	// 		if data.SN != "" {
	// 			req.Attribute("sn", []string{data.SN})
	// 		}
	// 		if data.Description != "" {
	// 			req.Attribute("description", []string{data.Description})
	// 		}
	// 		err := login.conn.Add(req)
	//     // log.Printf(fmt.Sprintf("899: %v",err))
	//     // log.Printf(fmt.Sprintf("899: %v",req))
	//     // log.Printf(fmt.Sprintf("899: %v",data))
	// 		if err != nil {
	// 			data.Error = err.Error()
	// 		} else {
	// 			if template == "ml" {
	// 				http.Redirect(w, r, "/admin/mailing/"+data.IdValue, http.StatusFound)
	// 			} else {
	// 				http.Redirect(w, r, "/admin/ldap/"+dn, http.StatusFound)
	// 			}
	// 		}

	// inviteDn := config.InvitationNameAttr + "=" + code_id + "," + config.InvitationBaseDN
	// req := ldap.NewAddRequest(inviteDn, nil)
	// pw, err := SSHAEncode(code_pw)
	// if err != nil {
	// 	data.ErrorMessage = err.Error()
	// 	return
	// }
	// req.Attribute("employeeNumber", []string{pw})
	// req.Attribute("objectclass", []string{"top", "invitationCode"})

	// err = login.conn.Add(req)
	// if err != nil {
	// 	log.Printf(fmt.Sprintf("286: %v", req))
	// 	data.ErrorMessage = err.Error()
	// 	return
	// }

	// If we want to display it, do so
	if choice == "display" {
		data.Success = true
		data.CodeDisplay = code
		return
	}

	// Otherwise, we are sending a mail
	if !EMAIL_REGEXP.MatchString(sendto) {
		data.ErrorInvalidEmail = true
		return
	}

	templateMail := template.Must(template.ParseFiles(templatePath + "/invite_mail.txt"))
	buf := bytes.NewBuffer([]byte{})
	templateMail.Execute(buf, &CodeMailFields{
		To:             sendto,
		From:           config.MailFrom,
		InviteFrom:     login.WelcomeName(),
		Code:           code,
		WebBaseAddress: config.WebAddress,
	})

	log.Printf("Sending mail to: %s", sendto)
	// var auth sasl.Client = nil
	// if config.SMTPUsername != "" {
	// 	auth = sasl.NewPlainClient("", config.SMTPUsername, config.SMTPPassword)
	// }
	// err = smtp.SendMail(config.SMTPServer, auth, config.MailFrom, []string{sendto}, buf)
	// if err != nil {
	// 	data.ErrorMessage = err.Error()
	// 	return
	// }
	// log.Printf("Mail sent.")

	data.Success = true
	data.CodeSentTo = sendto
}

func genCode() (code string, code_id string, code_pw string) {
	random := make([]byte, 32)
	n, err := rand.Read(random)
	if err != nil || n != 32 {
		log.Fatalf("Could not generate random bytes: %s", err)
	}

	a := binary.BigEndian.Uint32(random[0:4])
	b := binary.BigEndian.Uint32(random[4:8])
	c := binary.BigEndian.Uint32(random[8:12])

	code = fmt.Sprintf("%03d-%03d-%03d", a%1000, b%1000, c%1000)
	code_id, code_pw = readCode(code)
	log.Printf(fmt.Sprintf("342: %v %v %v", code, code_id, code_pw))
	return code, code_id, code_pw
}

func readCode(code string) (code_id string, code_pw string) {
	// Strip everything that is not a digit
	code_digits := ""
	for _, c := range code {
		if c >= '0' && c <= '9' {
			code_digits = code_digits + string(c)
		}
	}

	id_hash := argon2.IDKey([]byte(code_digits), []byte("Guichet ID"), 2, 64*1024, 4, 32)
	pw_hash := argon2.IDKey([]byte(code_digits), []byte("Guichet PW"), 2, 64*1024, 4, 32)

	code_id = hex.EncodeToString(id_hash[:8])
	code_pw = hex.EncodeToString(pw_hash[:16])
	return code_id, code_pw
}