package main

import (
	"context"
	"crypto/subtle"
	"errors"

	"github.com/jackc/pgx/v5"
)

var dbConnection *pgx.Conn

func InitDatabase(ctx context.Context) {
	conn, err := pgx.Connect(ctx, "postgres://master:secret@localhost:5432")
	if err != nil {
		panic(err)
	}

	_, err = conn.Exec(ctx, `
		CREATE TABLE IF NOT EXISTS users (
		    id SERIAL PRIMARY KEY,
		    name VARCHAR(20) UNIQUE NOT NULL,
		    pass_hash VARCHAR(255) NOT NULL,
		    color VARCHAR(3) NOT NULL
		)
	`)
	if err != nil {
		panic(err)
	}
	dbConnection = conn
}

func AddNewUser(ctx context.Context, user User) (uint, error) {
	if len(user.name) == 0 || len(user.name) > 20 {
		return 0, errors.New("username bad length")
	}
	if user.isPasswordHashed {
		if len(user.password) != 255 {
			return 0, errors.New("password bad length")
		}
	} else {
		// TODO
	}
	if len(user.color) != 1 && len(user.color) != 3 {
		return 0, errors.New("color invalid")
	}
	var id uint
	err := dbConnection.QueryRow(ctx, `
        INSERT INTO users (name, pass_hash, color)
        VALUES ($1, $2, $3)
        RETURNING id
    `, user.name, user.isPasswordHashed, user.color).Scan(&id)
	return id, err
}

func CheckPassword(ctx context.Context, id string, hash string) bool {
	var controlHash string
	err := dbConnection.QueryRow(ctx, "SELECT pass_hash FROM users WHERE id = $1", id).Scan(&controlHash)
	if err != nil {
		return false
	}
	return subtle.ConstantTimeCompare([]byte(controlHash), []byte(hash)) == 1
}

func GetUserData(ctx context.Context, id string) (User, error) {
	var user User
	err := dbConnection.QueryRow(ctx, "SELECT id, name, pass_hash, color FROM users WHERE id = $1", id).
		Scan(&user.id, &user.name, &user.password, &user.color)
	if err != nil {
		return User{}, err
	}
	user.isPasswordHashed = true
	return user, nil
}