<?php

declare(strict_types=1);

namespace App\Exceptions;

use App\Services\AlertService;
use Illuminate\Auth\Access\AuthorizationException;
use Illuminate\Auth\AuthenticationException;
use Illuminate\Database\QueryException;
use Illuminate\Foundation\Exceptions\Handler as ExceptionHandler;
use Illuminate\Support\Facades\Cache;
use Illuminate\Support\Facades\Log;
use Illuminate\Validation\ValidationException;
use Throwable;

class Handler extends ExceptionHandler
{
    #[\Override]
    protected $levels = [
        //
    ];

    #[\Override]
    protected $dontReport = [
        //
    ];

    #[\Override]
    protected $dontFlash = [
        'current_password',
        'password',
        'password_confirmation',
    ];

    private const string CACHE_KEY_ERROR_COUNT = 'error_count_';

    private const int ERROR_COUNT_DURATION = 300;

    #[\Override]
    public function register(): void
    {
        $this->reportable(function (Throwable $e) {
            $this->handleExceptionAlert($e);
        });

        $this->renderable(function (Throwable $e) {
            $this->handleExceptionAlert($e);
        });
    }

    private function handleExceptionAlert(Throwable $e): void
    {
        if (! $this->shouldAlertException($e)) {
            return;
        }

        try {
            $alertService = app(AlertService::class);

            $errorMessage = $e->getMessage() ?: $e::class;

            $alertService->sendCriticalError($errorMessage, $e);

            $this->trackErrorRate();

            Log::channel('emergency')->error('Critical exception reported via alert', [
                'exception' => $e::class,
                'message' => $e->getMessage(),
                'file' => $e->getFile(),
                'line' => $e->getLine(),
            ]);
        } catch (\Exception $alertException) {
            Log::error('Failed to send exception alert: ' . $alertException->getMessage());
        }
    }

    private function shouldAlertException(Throwable $e): bool
    {
        if (! app()->isBooted()) {
            return false;
        }

        if (! (bool) setting('alert_errors_enabled', true)) {
            return false;
        }

        $criticalExceptions = [
            QueryException::class,
            RconConnectionException::class,
        ];

        foreach ($criticalExceptions as $criticalException) {
            if ($e instanceof $criticalException) {
                return true;
            }
        }

        if ($this->isHighErrorRate()) {
            return true;
        }

        $minSeverity = setting('alert_min_severity', 'error');

        return $this->isSeverityHighEnough($e, $minSeverity);
    }

    private function trackErrorRate(): void
    {
        if (! app()->isBooted()) {
            return;
        }

        $key = self::CACHE_KEY_ERROR_COUNT . now()->format('YmdHi');

        $count = Cache::get($key, 0);
        Cache::put($key, $count + 1, self::ERROR_COUNT_DURATION);
    }

    private function isHighErrorRate(): bool
    {
        if (! app()->isBooted()) {
            return false;
        }

        $threshold = (int) setting('alert_error_threshold', 10);
        $key = self::CACHE_KEY_ERROR_COUNT . now()->format('YmdHi');

        $count = Cache::get($key, 0);

        return $count >= $threshold;
    }

    private function isSeverityHighEnough(Throwable $e, string $minSeverity): bool
    {
        $severityLevel = [
            'info' => 0,
            'warning' => 1,
            'error' => 2,
            'critical' => 3,
        ];

        $exceptionSeverity = $this->determineExceptionSeverity($e);
        $minLevel = $severityLevel[$minSeverity] ?? 2;

        return $exceptionSeverity >= $minLevel;
    }

    private function determineExceptionSeverity(Throwable $e): int
    {
        if ($e instanceof \Error) {
            return 3;
        }

        if ($e instanceof ValidationException) {
            return 0;
        }

        if ($e instanceof AuthenticationException) {
            return 1;
        }

        if ($e instanceof AuthorizationException) {
            return 1;
        }

        return 2;
    }
}