<?php

namespace Leantime\Core\Exceptions;

use Closure;
use Exception;
use Illuminate\Contracts\Container\BindingResolutionException;
use Illuminate\Contracts\Debug\ExceptionHandler as ExceptionHandlerContract;
use Illuminate\Contracts\Support\Responsable;
use Illuminate\Http\Exceptions\HttpResponseException;
use Illuminate\Http\JsonResponse;
use Illuminate\Http\RedirectResponse;
use Illuminate\Http\Response;
use Illuminate\Session\TokenMismatchException;
use Illuminate\Support\Arr;
use Illuminate\Support\Facades\Log;
use Illuminate\Support\Reflector;
use Illuminate\Support\Traits\ReflectsClosures;
use InvalidArgumentException;
use Leantime\Core\Application;
use Leantime\Core\Exceptions\Contracts\LeantimeExceptionInterface;
use Leantime\Core\Http\ApiRequest;
use Leantime\Core\UI\Template;
use Psr\Log\LoggerInterface;
use Sentry\Laravel\Integration;
use Symfony\Component\Console\Application as ConsoleApplication;
use Symfony\Component\ErrorHandler\ErrorRenderer\HtmlErrorRenderer;
use Symfony\Component\HttpFoundation\Exception\SuspiciousOperationException;
use Symfony\Component\HttpFoundation\RedirectResponse as SymfonyRedirectResponse;
use Symfony\Component\HttpFoundation\Response as SymfonyResponse;
use Symfony\Component\HttpKernel\Exception\HttpException;
use Symfony\Component\HttpKernel\Exception\HttpExceptionInterface;
use Throwable;
use Whoops\Handler\HandlerInterface;
use Whoops\Run as Whoops;

class ExceptionHandler implements ExceptionHandlerContract
{
    use ReflectsClosures;

    /**
     * The container implementation.
     */
    protected Application $container;

    /**
     * A list of the exception types that are not reported.
     *
     * @var string[]
     */
    protected $dontReport = [];

    /**
     * The callbacks that should be used during reporting.
     *
     * @var ReportableHandler[]
     */
    protected $reportCallbacks = [];

    /**
     * The callbacks that should be used during rendering.
     *
     * @var \Closure[]
     */
    protected $renderCallbacks = [];

    /**
     * The registered exception mappings.
     *
     * @var array<string, \Closure>
     */
    protected $exceptionMap = [];

    /**
     * A list of the internal exception types that should not be reported.
     *
     * @var string[]
     */
    protected $internalDontReport = [
        HttpException::class,
        HttpResponseException::class,
        SuspiciousOperationException::class,
        TokenMismatchException::class,
    ];

    /**
     * A list of the inputs that are never flashed for validation exceptions.
     *
     * @var string[]
     */
    protected $dontFlash = [
        'current_password',
        'password',
        'password_confirmation',
    ];

    /**
     * Create a new exception handler instance.
     *
     * @return void
     */
    public function __construct(Application $container)
    {
        $this->container = $container;

        $this->register();
    }

    /**
     * Register the exception handling callbacks for the application.
     *
     * @return void
     */
    public function register()
    {
        $this->reportable(function (Throwable $e) {
            Integration::captureUnhandledException($e);
        });
    }

    /**
     * Register a reportable callback.
     *
     * @return \Leantime\Core\Exceptions\ReportableHandler
     */
    public function reportable(callable $reportUsing)
    {
        if (! $reportUsing instanceof Closure) {
            $reportUsing = Closure::fromCallable($reportUsing);
        }

        return tap(new ReportableHandler($reportUsing), function ($callback) {
            $this->reportCallbacks[] = $callback;
        });
    }

    /**
     * Register a renderable callback.
     *
     * @return $this
     */
    public function renderable(callable $renderUsing)
    {
        if (! $renderUsing instanceof Closure) {
            $renderUsing = Closure::fromCallable($renderUsing);
        }

        $this->renderCallbacks[] = $renderUsing;

        return $this;
    }

    /**
     * Register a new exception mapping.
     *
     * @param  \Closure|string  $from
     * @param  \Closure|string|null  $to
     * @return $this
     *
     * @throws \InvalidArgumentException
     */
    public function map($from, $to = null)
    {
        if (is_string($to)) {
            $to = function ($exception) use ($to) {
                return new $to('', 0, $exception);
            };
        }

        if (is_callable($from) && is_null($to)) {
            $from = $this->firstClosureParameterType($to = $from);
        }

        if (! is_string($from) || ! $to instanceof Closure) {
            throw new InvalidArgumentException('Invalid exception mapping.');
        }

        $this->exceptionMap[$from] = $to;

        return $this;
    }

    /**
     * Indicate that the given exception type should not be reported.
     *
     * @return $this
     */
    protected function ignore(string $class)
    {
        $this->dontReport[] = $class;

        return $this;
    }

    /**
     * Report or log an exception.
     *
     * @return void
     *
     * @throws \Throwable
     */
    public function report(Throwable $e)
    {
        $e = $this->mapException($e);

        if ($this->shouldntReport($e)) {
            return;
        }

        if (Reflector::isCallable($reportCallable = [$e, 'report'])) {
            if ($this->container->call($reportCallable) !== false) {
                return;
            }
        }

        foreach ($this->reportCallbacks as $reportCallback) {
            if ($reportCallback->handles($e)) {
                if ($reportCallback($e) === false) {
                    return;
                }
            }
        }

        try {
            $logger = app(LoggerInterface::class);
        } catch (Exception $ex) {
            throw $e; // throw the original exception
        }

        $logger->error($e->getMessage(), ['exception' => $e]);

    }

    /**
     * Determine if the exception should be reported.
     *
     * @return bool
     */
    public function shouldReport(Throwable $e)
    {
        return ! $this->shouldntReport($e);
    }

    /**
     * Determine if the exception is in the "do not report" list.
     *
     * @return bool
     */
    protected function shouldntReport(Throwable $e)
    {
        $dontReport = array_merge($this->dontReport, $this->internalDontReport);

        return ! is_null(Arr::first($dontReport, function ($type) use ($e) {
            return $e instanceof $type;
        }));
    }

    /**
     * Get the default exception context variables for logging.
     *
     * @return array
     */
    protected function exceptionContext(Throwable $e)
    {
        if (method_exists($e, 'context')) {
            return $e->context();
        }

        return [];
    }

    /**
     * Get the default context variables for logging.
     *
     * @return array
     */
    protected function context()
    {
        try {
            return array_filter([

            ]);
        } catch (Throwable $e) {
            return [];
        }
    }

    /**
     * Render an exception into an HTTP response.
     *
     * @param  \Illuminate\Http\Request  $request
     * @return \Symfony\Component\HttpFoundation\Response
     *
     * @throws \Throwable
     */
    public function render($request, Throwable $e)
    {
        if (method_exists($e, 'render') && $response = $e->render($request)) {
            return $response;
        } elseif ($e instanceof Responsable) {
            return $e->toResponse($request);
        }

        $e = $this->prepareException($this->mapException($e));

        foreach ($this->renderCallbacks as $renderCallback) {
            foreach ($this->firstClosureParameterTypes($renderCallback) as $type) {
                if (is_a($e, $type)) {
                    $response = $renderCallback($e, $request);

                    if (! is_null($response)) {
                        return $response;
                    }
                }
            }
        }

        if ($e instanceof HttpResponseException) {
            return $e->getResponse();
        }

        return $this->shouldReturnJson($request, $e)
            ? $this->prepareJsonResponse($request, $e)
            : $this->prepareResponse($request, $e);
    }

    /**
     * Map the exception using a registered mapper if possible.
     *
     * @return \Throwable
     */
    protected function mapException(Throwable $e)
    {
        foreach ($this->exceptionMap as $class => $mapper) {
            if (is_a($e, $class)) {
                return $mapper($e);
            }
        }

        return $e;
    }

    /**
     * Prepare exception for rendering.
     *
     * @return \Throwable
     */
    protected function prepareException(Throwable $e)
    {

        return $e;
    }

    /**
     * Determine if the exception handler response should be JSON.
     *
     * @param  \Illuminate\Http\Request  $request
     * @return bool
     */
    protected function shouldReturnJson($request, Throwable $e)
    {
        // API requests (x-api-key / bearer) are JSON by contract even when the client omits an
        // Accept header, so they get a JSON error body instead of an HTML error page.
        return $request instanceof ApiRequest || $request->expectsJson();
    }

    /**
     * Prepare a response for the given exception.
     *
     * @param  \Illuminate\Http\Request  $request
     * @return \Symfony\Component\HttpFoundation\Response
     */
    protected function prepareResponse($request, Throwable $e)
    {
        if (! $this->isHttpException($e) && config('debug')) {
            return $this->toIlluminateResponse($this->convertExceptionToResponse($e), $e);
        }

        if (! $this->isHttpException($e)) {
            $e = new HttpException(500, $e->getMessage());
        }

        return $this->toIlluminateResponse(
            $this->renderHttpException($e),
            $e
        );
    }

    /**
     * Create a Symfony response for the given exception.
     *
     * @return \Symfony\Component\HttpFoundation\Response
     */
    protected function convertExceptionToResponse(Throwable $e)
    {
        return new SymfonyResponse(
            $this->renderExceptionContent($e),
            $this->isHttpException($e) ? $e->getStatusCode() : 500,
            $this->isHttpException($e) ? $e->getHeaders() : []
        );
    }

    /**
     * Get the response content for the given exception.
     *
     * @return string
     */
    protected function renderExceptionContent(Throwable $e)
    {
        try {
            return config('debug') && class_exists(Whoops::class)
                ? $this->renderExceptionWithWhoops($e)
                : $this->renderExceptionWithSymfony($e, config('debug'));
        } catch (Exception $e) {
            return $this->renderExceptionWithSymfony($e, config('debug'));
        }
    }

    /**
     * Render an exception to a string using "Whoops".
     *
     * @return string
     */
    protected function renderExceptionWithWhoops(Throwable $e)
    {
        return tap(new Whoops, function ($whoops) {
            $whoops->appendHandler($this->whoopsHandler());

            $whoops->writeToOutput(false);

            $whoops->allowQuit(false);
        })->handleException($e);
    }

    /**
     * Get the Whoops handler for the application.
     *
     * @return \Whoops\Handler\HandlerInterface
     */
    protected function whoopsHandler()
    {
        try {
            return app(HandlerInterface::class);
        } catch (BindingResolutionException $e) {
            return (new WhoopsHandler)->forDebug();
        }
    }

    /**
     * Render an exception to a string using Symfony.
     *
     * @param  bool  $debug
     * @return string
     */
    protected function renderExceptionWithSymfony(Throwable $e, $debug)
    {
        $renderer = new HtmlErrorRenderer($debug);

        return $renderer->render($e)->getAsString();
    }

    /**
     * Render the given HttpException.
     *
     * @return \Symfony\Component\HttpFoundation\Response
     */
    protected function renderHttpException(HttpExceptionInterface $e)
    {

        try {
            $view = $this->getHttpExceptionView($e);

            return app()->make(Template::class)->display($view, 'error', $e->getStatusCode());
        } catch (Throwable $e) {
            return $this->convertExceptionToResponse($e);
        }
    }

    /**
     * Register the error template hint paths.
     *
     * @return void
     */
    protected function registerErrorViewPaths() {}

    /**
     * Get the view used to render HTTP exceptions.
     *
     * @return string
     */
    protected function getHttpExceptionView(HttpExceptionInterface $e)
    {
        $status = $e->getStatusCode();

        // Dedicated error pages exist only for these statuses. Anything else (e.g. a 422 from a
        // ValidationException or a 409 from EntityExistsException — now that typed exceptions
        // carry real HTTP statuses) falls back to the generic 500 page instead of throwing a
        // view-not-found that degrades to a raw Symfony error page.
        return in_array($status, [403, 404, 500, 501], true)
            ? "errors.error{$status}"
            : 'errors.error500';
    }

    /**
     * Map the given exception into an Illuminate response.
     *
     * @param  \Symfony\Component\HttpFoundation\Response  $response
     * @return \Illuminate\Http\Response
     */
    protected function toIlluminateResponse($response, Throwable $e)
    {
        if ($response instanceof SymfonyRedirectResponse) {
            $response = new RedirectResponse(
                $response->getTargetUrl(),
                $response->getStatusCode(),
                $response->headers->all()
            );
        } else {
            $response = new Response(
                $response->getContent(),
                $response->getStatusCode(),
                $response->headers->all()
            );
        }

        return $response->withException($e);
    }

    /**
     * Prepare a JSON response for the given exception.
     *
     * @param  \Illuminate\Http\Request  $request
     * @return \Illuminate\Http\JsonResponse
     */
    protected function prepareJsonResponse($request, Throwable $e)
    {
        return new JsonResponse(
            $this->convertExceptionToArray($e),
            $this->isHttpException($e) ? $e->getStatusCode() : 500,
            $this->isHttpException($e) ? $e->getHeaders() : [],
            JSON_PRETTY_PRINT | JSON_UNESCAPED_SLASHES
        );
    }

    /**
     * Convert the given exception to an array.
     *
     * @return array
     */
    protected function convertExceptionToArray(Throwable $e)
    {
        return config('debug') ? [
            'message' => $e->getMessage(),
            'exception' => get_class($e),
            'file' => $e->getFile(),
            'line' => $e->getLine(),
            'trace' => collect($e->getTrace())->map(function ($trace) {
                return Arr::except($trace, ['args']);
            })->all(),
        ] : [
            // Leantime exceptions expose a curated, client-safe message; fall back to the raw
            // HttpException message (or a generic string) for everything else. Mirrors the
            // JSON-RPC surface (JsonRpcErrorResponse::fromException), which also uses getClientMessage().
            'message' => $e instanceof LeantimeExceptionInterface
                ? $e->getClientMessage()
                : ($this->isHttpException($e) ? $e->getMessage() : 'Server Error'),
        ];
    }

    /**
     * Render an exception to the console.
     *
     * @param  \Symfony\Component\Console\Output\OutputInterface  $output
     * @return void
     */
    public function renderForConsole($output, Throwable $e)
    {
        (new ConsoleApplication)->renderThrowable($e, $output);
    }

    /**
     * Determine if the given exception is an HTTP exception.
     *
     * @phpstan-assert-if-true \Symfony\Component\HttpKernel\Exception\HttpExceptionInterface $e
     *
     * @return bool
     */
    protected function isHttpException(Throwable $e)
    {
        return $e instanceof HttpExceptionInterface;
    }
}