<?php

namespace App\Services;

use App\DTOs\MagicTokenResult;
use App\Models\MagicLoginToken;
use App\Models\User;
use Illuminate\Support\Facades\Auth;
use Illuminate\Support\Facades\RateLimiter;
use Illuminate\Validation\ValidationException;

class MagicLinkAuthService
{
    /**
     * Send a magic link to the given email address.
     *
     * @throws ValidationException
     */
    public function sendMagicLink(string $email, ?string $ip, ?string $ua): MagicTokenResult
    {
        $key = 'magic-link:' . User::hashEmail($email);

        if (RateLimiter::tooManyAttempts($key, 5)) {
            $seconds = RateLimiter::availableIn($key);

            throw ValidationException::withMessages([
                'email' => [
                    "Too many magic link requests. Please try again in {$seconds} seconds.",
                ],
            ]);
        }

        RateLimiter::hit($key, 3600);

        if (!User::findByEmail($email)) {
            User::create([
                'email_hash' => User::hashEmail($email),
            ]);
        }

        return MagicLoginToken::generate($email, $ip, $ua);
    }

    /**
     * Verify a magic link token and log the user in.
     */
    public function verifyMagicLink(string $token): bool
    {
        $magicToken = MagicLoginToken::valid()
            ->where('token_hash', hash('sha256', $token))
            ->first();

        if (!$magicToken) {
            return false;
        }

        $user = User::where('email_hash', $magicToken->email_hash)->first();

        if (!$user) {
            return false;
        }

        $magicToken->markAsUsed();

        if (is_null($user->email_verified_at)) {
            $user->email_verified_at = now();
            $user->save();
        }

        Auth::login($user, true);

        return true;
    }

    /**
     * Verify a magic code and log the user in.
     *
     * @throws ValidationException
     */
    public function verifyCode(string $email, string $code): bool
    {
        $emailHash = User::hashEmail($email);
        $key = 'magic-code:' . $emailHash;

        if (RateLimiter::tooManyAttempts($key, 5)) {
            $seconds = RateLimiter::availableIn($key);

            throw ValidationException::withMessages([
                'code' => [
                    "Too many attempts. Please try again in {$seconds} seconds.",
                ],
            ]);
        }

        $magicToken = MagicLoginToken::valid()
            ->where('email_hash', $emailHash)
            ->latest()
            ->first();

        if (!$magicToken || !$magicToken->verifyCode($code)) {
            RateLimiter::hit($key, 300);
            return false;
        }

        $user = User::where('email_hash', $emailHash)->first();

        if (!$user) {
            return false;
        }

        $magicToken->markAsUsed();

        RateLimiter::clear($key);

        if (is_null($user->email_verified_at)) {
            $user->email_verified_at = now();
            $user->save();
        }

        Auth::login($user, true);

        return true;
    }

    /**
     * Clean up expired and used tokens older than 7 days.
     */
    public function cleanupExpiredTokens(): int
    {
        return MagicLoginToken::expiredOrUsed()
            ->where('created_at', '<', now()->subDays(7))
            ->delete();
    }
}