<?php

namespace Mpociot\ApiDoc\Commands;

use ReflectionClass;
use Illuminate\Routing\Route;
use Illuminate\Console\Command;
use Mpociot\Reflection\DocBlock;
use Illuminate\Support\Collection;
use Mpociot\Documentarian\Documentarian;
use Mpociot\ApiDoc\Postman\CollectionWriter;
use Mpociot\ApiDoc\Generators\DingoGenerator;
use Mpociot\ApiDoc\Generators\LaravelGenerator;
use Mpociot\ApiDoc\Generators\AbstractGenerator;
use Illuminate\Support\Facades\Route as RouteFacade;

class GenerateDocumentation extends Command
{
    /**
     * The name and signature of the console command.
     *
     * @var string
     */
    protected $signature = 'api:generate
                            {--output=public/docs : The output path for the generated documentation}
                            {--routeDomain= : The route domain (or domains) to use for generation}
                            {--routePrefix= : The route prefix (or prefixes) to use for generation}
                            {--routes=* : The route names to use for generation}
                            {--middleware= : The middleware to use for generation}
                            {--noResponseCalls : Disable API response calls}
                            {--noPostmanCollection : Disable Postman collection creation}
                            {--useMiddlewares : Use all configured route middlewares}
                            {--authProvider=users : The authentication provider to use for API response calls}
                            {--authGuard=web : The authentication guard to use for API response calls}
                            {--actAsUserId= : The user ID to use for API response calls}
                            {--router=laravel : The router to be used (Laravel or Dingo)}
                            {--force : Force rewriting of existing routes}
                            {--bindings= : Route Model Bindings}
                            {--header=* : Custom HTTP headers to add to the example requests. Separate the header name and value with ":"}
    ';

    /**
     * The console command description.
     *
     * @var string
     */
    protected $description = 'Generate your API documentation from existing Laravel routes.';

    /**
     * Create a new command instance.
     *
     * @return void
     */
    public function __construct()
    {
        parent::__construct();
    }

    /**
     * Execute the console command.
     *
     * @return false|null
     */
    public function handle()
    {
        if ($this->option('router') === 'laravel') {
            $generator = new LaravelGenerator();
        } else {
            $generator = new DingoGenerator();
        }

        $allowedRoutes = $this->option('routes');
        $routeDomain = $this->option('routeDomain');
        $routePrefix = $this->option('routePrefix');
        $middleware = $this->option('middleware');

        $this->setUserToBeImpersonated($this->option('actAsUserId'));

        if ($routePrefix === null && $routeDomain === null && ! count($allowedRoutes) && $middleware === null) {
            $this->error('You must provide either a route prefix, a route domain, a route or a middleware to generate the documentation.');

            return false;
        }

        $generator->prepareMiddleware($this->option('useMiddlewares'));

        $routePrefixes = explode(',', $routePrefix ?: '*');
        $routeDomains = explode(',', $routeDomain ?: '*');

        $parsedRoutes = [];

        foreach ($routeDomains as $routeDomain) {
            foreach ($routePrefixes as $routePrefix) {
                $parsedRoutes += $this->processRoutes($generator, $allowedRoutes, $routeDomain, $routePrefix, $middleware);
            }
        }
        $parsedRoutes = collect($parsedRoutes)->groupBy('resource')->sort(function ($a, $b) {
            return strcmp($a->first()['resource'], $b->first()['resource']);
        });

        $this->writeMarkdown($parsedRoutes);
    }

    /**
     * @param  Collection $parsedRoutes
     *
     * @return void
     */
    private function writeMarkdown($parsedRoutes)
    {
        $outputPath = $this->option('output');
        $targetFile = $outputPath.DIRECTORY_SEPARATOR.'source'.DIRECTORY_SEPARATOR.'index.md';
        $compareFile = $outputPath.DIRECTORY_SEPARATOR.'source'.DIRECTORY_SEPARATOR.'.compare.md';
        $prependFile = $outputPath.DIRECTORY_SEPARATOR.'source'.DIRECTORY_SEPARATOR.'prepend.md';
        $appendFile = $outputPath.DIRECTORY_SEPARATOR.'source'.DIRECTORY_SEPARATOR.'append.md';

        $infoText = view('apidoc::partials.info')
            ->with('outputPath', ltrim($outputPath, 'public/'))
            ->with('showPostmanCollectionButton', ! $this->option('noPostmanCollection'));

        $parsedRouteOutput = $parsedRoutes->map(function ($routeGroup) {
            return $routeGroup->map(function ($route) {
                $route['output'] = (string) view('apidoc::partials.route')->with('parsedRoute', $route)->render();

                return $route;
            });
        });

        $frontmatter = view('apidoc::partials.frontmatter');
        /*
         * In case the target file already exists, we should check if the documentation was modified
         * and skip the modified parts of the routes.
         */
        if (file_exists($targetFile) && file_exists($compareFile)) {
            $generatedDocumentation = file_get_contents($targetFile);
            $compareDocumentation = file_get_contents($compareFile);

            if (preg_match('/---(.*)---\\s<!-- START_INFO -->/is', $generatedDocumentation, $generatedFrontmatter)) {
                $frontmatter = trim($generatedFrontmatter[1], "\n");
            }

            $parsedRouteOutput->transform(function ($routeGroup) use ($generatedDocumentation, $compareDocumentation) {
                return $routeGroup->transform(function ($route) use ($generatedDocumentation, $compareDocumentation) {
                    if (preg_match('/<!-- START_'.$route['id'].' -->(.*)<!-- END_'.$route['id'].' -->/is', $generatedDocumentation, $routeMatch)) {
                        $routeDocumentationChanged = (preg_match('/<!-- START_'.$route['id'].' -->(.*)<!-- END_'.$route['id'].' -->/is', $compareDocumentation, $compareMatch) && $compareMatch[1] !== $routeMatch[1]);
                        if ($routeDocumentationChanged === false || $this->option('force')) {
                            if ($routeDocumentationChanged) {
                                $this->warn('Discarded manual changes for route ['.implode(',', $route['methods']).'] '.$route['uri']);
                            }
                        } else {
                            $this->warn('Skipping modified route ['.implode(',', $route['methods']).'] '.$route['uri']);
                            $route['modified_output'] = $routeMatch[0];
                        }
                    }

                    return $route;
                });
            });
        }

        $prependFileContents = file_exists($prependFile)
            ? file_get_contents($prependFile)."\n" : '';
        $appendFileContents = file_exists($appendFile)
            ? "\n".file_get_contents($appendFile) : '';

        $documentarian = new Documentarian();

        $markdown = view('apidoc::documentarian')
            ->with('writeCompareFile', false)
            ->with('frontmatter', $frontmatter)
            ->with('infoText', $infoText)
            ->with('prependMd', $prependFileContents)
            ->with('appendMd', $appendFileContents)
            ->with('outputPath', $this->option('output'))
            ->with('showPostmanCollectionButton', ! $this->option('noPostmanCollection'))
            ->with('parsedRoutes', $parsedRouteOutput);

        if (! is_dir($outputPath)) {
            $documentarian->create($outputPath);
        }

        // Write output file
        file_put_contents($targetFile, $markdown);

        // Write comparable markdown file
        $compareMarkdown = view('apidoc::documentarian')
            ->with('writeCompareFile', true)
            ->with('frontmatter', $frontmatter)
            ->with('infoText', $infoText)
            ->with('prependMd', $prependFileContents)
            ->with('appendMd', $appendFileContents)
            ->with('outputPath', $this->option('output'))
            ->with('showPostmanCollectionButton', ! $this->option('noPostmanCollection'))
            ->with('parsedRoutes', $parsedRouteOutput);

        file_put_contents($compareFile, $compareMarkdown);

        $this->info('Wrote index.md to: '.$outputPath);

        $this->info('Generating API HTML code');

        $documentarian->generate($outputPath);

        $this->info('Wrote HTML documentation to: '.$outputPath.'/index.html');

        if ($this->option('noPostmanCollection') !== true) {
            $this->info('Generating Postman collection');

            file_put_contents($outputPath.DIRECTORY_SEPARATOR.'collection.json', $this->generatePostmanCollection($parsedRoutes));
        }
    }

    /**
     * @return array
     */
    private function getBindings()
    {
        $bindings = $this->option('bindings');
        if (empty($bindings)) {
            return [];
        }

        $bindings = explode('|', $bindings);
        $resultBindings = [];
        foreach ($bindings as $binding) {
            list($name, $id) = explode(',', $binding);
            $resultBindings[$name] = $id;
        }

        return $resultBindings;
    }

    /**
     * @param $actAs
     */
    private function setUserToBeImpersonated($actAs)
    {
        if (! empty($actAs)) {
            if (version_compare($this->laravel->version(), '5.2.0', '<')) {
                $userModel = config('auth.model');
                $user = $userModel::find($actAs);
                $this->laravel['auth']->setUser($user);
            } else {
                $provider = $this->option('authProvider');
                $userModel = config("auth.providers.$provider.model");
                $user = $userModel::find($actAs);
                $this->laravel['auth']->guard($this->option('authGuard'))->setUser($user);
            }
        }
    }

    /**
     * @return mixed
     */
    private function getRoutes($routePrefix)
    {
        if ($this->option('router') === 'laravel') {
            return RouteFacade::getRoutes();
        } else {
            return app('Dingo\Api\Routing\Router')->getRoutes($routePrefix)->getRoutes();
        }
    }

    /**
     * @param AbstractGenerator  $generator
     * @param $allowedRoutes
     * @param $routeDomain
     * @param $routePrefix
     *
     * @return array
     */
    private function processRoutes(AbstractGenerator $generator, array $allowedRoutes, $routeDomain, $routePrefix, $middleware)
    {
        $withResponse = $this->option('noResponseCalls') == false;
        $routes = $this->getRoutes($routePrefix);
        $bindings = $this->getBindings();
        $parsedRoutes = [];
        foreach ($routes as $route) {
            /** @var Route $route */
            if (in_array($route->getName(), $allowedRoutes)
                || (str_is($routeDomain, $generator->getDomain($route))
                    && str_is($routePrefix, $generator->getUri($route)))
                || in_array($middleware, $route->middleware())
               ) {
                if ($this->isValidRoute($route) && $this->isRouteVisibleForDocumentation($route->getAction()['uses'])) {
                    $parsedRoutes[] = $generator->processRoute($route, $bindings, $this->option('header'), $withResponse && in_array('GET', $generator->getMethods($route)));
                    $this->info('Processed route: ['.implode(',', $generator->getMethods($route)).'] '.$generator->getUri($route));
                } else {
                    $this->warn('Skipping route: ['.implode(',', $generator->getMethods($route)).'] '.$generator->getUri($route));
                }
            }
        }

        return $parsedRoutes;
    }

    /**
     * @param $route
     *
     * @return bool
     */
    private function isValidRoute(Route $route)
    {
        return ! is_callable($route->getAction()['uses']) && ! is_null($route->getAction()['uses']);
    }

    /**
     * @param $route
     *
     * @return bool
     */
    private function isRouteVisibleForDocumentation($route)
    {
        list($class, $method) = explode('@', $route);
        $reflection = new ReflectionClass($class);
        $comment = $reflection->getMethod($method)->getDocComment();
        if ($comment) {
            $phpdoc = new DocBlock($comment);

            return collect($phpdoc->getTags())
                ->filter(function ($tag) use ($route) {
                    return $tag->getName() === 'hideFromAPIDocumentation';
                })
                ->isEmpty();
        }

        return true;
    }

    /**
     * Generate Postman collection JSON file.
     *
     * @param Collection $routes
     *
     * @return string
     */
    private function generatePostmanCollection(Collection $routes)
    {
        $writer = new CollectionWriter($routes);

        return $writer->getCollection();
    }
}