package models

import (
	"database/sql"

	"github.com/pkg/errors"
	"golang.org/x/crypto/bcrypt"
)

type User struct {
	id         int    // Integer ID (index primary key)
	Username   string // Username (unique)
	Created_at int64  // Epoch timestamp when the user was added to the database
	Bio        string // Short byline set by the user
}

func (u User) ID() int {
	return u.id
}

// Uses bcrypt to set the users Password_hash from the given password
func (user *User) SetPassword(
	tx *sql.Tx,
	password string,
) error {
	hashedPassword, err := bcrypt.GenerateFromPassword([]byte(password), bcrypt.DefaultCost)
	if err != nil {
		return errors.Wrap(err, "bcrypt.GenerateFromPassword")
	}
	newPassword := string(hashedPassword)
	query := `UPDATE users SET password_hash = ? WHERE id = ?`
	_, err = tx.Exec(query, newPassword, user.id)
	if err != nil {
		return errors.Wrap(err, "tx.Exec")
	}
	return nil
}

// Uses bcrypt to check if the given password matches the users Password_hash
func (user *User) CheckPassword(tx *sql.Tx, password string) error {
	query := `SELECT password_hash FROM users WHERE id = ? LIMIT 1`
	row := tx.QueryRow(query, user.id)
	var hashedPassword string
	err := row.Scan(&hashedPassword)
	if err != nil {
		return errors.Wrap(err, "row.Scan")
	}
	err = bcrypt.CompareHashAndPassword([]byte(hashedPassword), []byte(password))
	if err != nil {
		return errors.Wrap(err, "Username or password incorrect")
	}
	return nil
}

// Change the user's username
func (user *User) ChangeUsername(tx *sql.Tx, newUsername string) error {
	query := `UPDATE users SET username = ? WHERE id = ?`
	_, err := tx.Exec(query, newUsername, user.id)
	if err != nil {
		return errors.Wrap(err, "tx.Exec")
	}
	return nil
}

// Change the user's bio
func (user *User) ChangeBio(tx *sql.Tx, newBio string) error {
	query := `UPDATE users SET bio = ? WHERE id = ?`
	_, err := tx.Exec(query, newBio, user.id)
	if err != nil {
		return errors.Wrap(err, "tx.Exec")
	}
	return nil
}