// Copyright 2024 Patial Tech. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package user

import (
	"context"
	"errors"
	"fmt"
	"net/mail"
	"strings"
	"time"

	"gitserver.in/patialtech/rano/config"
	"gitserver.in/patialtech/rano/db"
	"gitserver.in/patialtech/rano/db/ent/user"
	"gitserver.in/patialtech/rano/mailer"
	"gitserver.in/patialtech/rano/mailer/message"
	"gitserver.in/patialtech/rano/util/crypto"
	"gitserver.in/patialtech/rano/util/validate"
)

type CreateInput struct {
	Email      string `validate:"email"`
	Phone      string
	Pwd        string `validate:"required"`
	ConfirmPwd string `validate:"required"`
	FirstName  string `validate:"required"`
	MiddleName string
	LastName   string
	RoleID     uint8 `validate:"required"`
}

var (
	ErrCreateInpNil    = errors.New("user: create input is nil")
	ErrWrongConfirmPwd = errors.New("user: confirm password does not match")
)

// Create user record in DB
//
// will return created userID on success
func Create(ctx context.Context, inp *CreateInput) (int64, error) {
	// Check for nil input.
	if inp == nil {
		return 0, ErrCreateInpNil
	}

	// Validate struct.
	if err := validate.Struct(inp); err != nil {
		return 0, err
	}

	// Compare pwd and comparePwd.
	if inp.Pwd != inp.ConfirmPwd {
		return 0, ErrWrongConfirmPwd
	}

	h, salt, err := crypto.PasswordHash(inp.Pwd)
	if err != nil {
		return 0, err
	}

	// Begin a transaction.
	tx, err := db.Client().BeginTx(ctx, nil)
	if err != nil {
		return 0, err
	}

	// Save User to DB.
	u, err := tx.User.Create().
		SetEmail(inp.Email).
		SetPwdHash(h).
		SetPwdSalt(salt).
		SetFirstName(inp.FirstName).
		SetMiddleName(inp.MiddleName).
		SetLastName(inp.LastName).
		SetStatus(user.StatusActive).
		Save(ctx)
	if err != nil {
		return 0, errors.New("failed to create user")
	}

	// Get a new email-verification token
	tokenDuration := time.Hour * 6
	token, err := newTokenToVerifyEmail(u.ID, tokenDuration)
	if err != nil {
		_ = tx.Rollback()
		return 0, err
	}

	// Save token to DB
	err = tx.VerifyToken.Create().
		SetToken(token).
		SetExpiresAt(time.Now().Add(tokenDuration).UTC()).
		SetPurpose("VerifyEmail").
		SetUserID(u.ID).Exec(ctx)
	if err != nil {
		_ = tx.Rollback()
		return 0, err
	}

	name := fullName(inp.FirstName, inp.MiddleName, inp.LastName)
	// Send a welcome email with a link to verigy email-address.
	err = mailer.Send(
		[]mail.Address{
			{Name: name, Address: inp.Email},
		},
		&message.Welcome{
			Name:      name,
			VerifyURL: config.VerifyEmailURL(token),
		},
	)
	if err != nil {
		_ = tx.Rollback()
		return 0, err
	}

	// Commit transaction
	err = tx.Commit()
	if err != nil {
		return 0, err
	}

	// ALL Done!
	// Created a new user in system.
	return u.ID, nil
}

func fullName(fName, mName, lName string) string {
	name := fmt.Sprintf("%s %s %s", fName, mName, lName)
	return strings.Join(strings.Fields(name), " ")
}