<?php

namespace Knuckles\Scribe\GroupedEndpoints;

use Illuminate\Support\Arr;
use Illuminate\Support\Collection;
use Illuminate\Support\Str;
use Knuckles\Camel\Camel;
use Knuckles\Camel\Extraction\ExtractedEndpointData;
use Knuckles\Camel\Output\OutputEndpointData;
use Knuckles\Scribe\Commands\GenerateDocumentation;
use Knuckles\Scribe\Exceptions\CouldntGetRouteDetails;
use Knuckles\Scribe\Extracting\ApiDetails;
use Knuckles\Scribe\Extracting\Extractor;
use Knuckles\Scribe\Matching\MatchedRoute;
use Knuckles\Scribe\Matching\RouteMatcherInterface;
use Knuckles\Scribe\Tools\ConsoleOutputUtils as c;
use Knuckles\Scribe\Tools\DocumentationConfig;
use Knuckles\Scribe\Tools\ErrorHandlingUtils as e;
use Knuckles\Scribe\Tools\PathConfig;
use Knuckles\Scribe\Tools\Utils;
use Knuckles\Scribe\Tools\Utils as u;
use Mpociot\Reflection\DocBlock;
use Mpociot\Reflection\DocBlock\Tag;
use ReflectionClass;
use Symfony\Component\Yaml\Yaml;

class GroupedEndpointsFromApp implements GroupedEndpointsContract
{
    private DocumentationConfig $docConfig;
    private bool $encounteredErrors = false;

    public static string $camelDir;
    public static string $cacheDir;

    public function __construct(
        private GenerateDocumentation $command,
        private RouteMatcherInterface $routeMatcher,
        protected PathConfig $paths,
        private bool $preserveUserChanges = true
    ) {
        $this->docConfig = $command->getDocConfig();

        static::$camelDir = Camel::camelDir($this->paths);
        static::$cacheDir = Camel::cacheDir($this->paths);
    }

    public function get(): array
    {
        $groupedEndpoints = $this->extractEndpointsInfoAndWriteToDisk($this->routeMatcher, $this->preserveUserChanges);
        $this->extractAndWriteApiDetailsToDisk();

        return $groupedEndpoints;
    }

    public function hasEncounteredErrors(): bool
    {
        return $this->encounteredErrors;
    }

    protected function extractEndpointsInfoAndWriteToDisk(RouteMatcherInterface $routeMatcher, bool $preserveUserChanges): array
    {
        $latestEndpointsData = [];
        $cachedEndpoints = [];

        if ($preserveUserChanges && is_dir(static::$camelDir) && is_dir(static::$cacheDir)) {
            $latestEndpointsData = Camel::loadEndpointsToFlatPrimitivesArray(static::$camelDir);
            $cachedEndpoints = Camel::loadEndpointsToFlatPrimitivesArray(static::$cacheDir);
        }

        $routes = $routeMatcher->getRoutes($this->docConfig->get('routes', []));
        $endpoints = $this->extractEndpointsInfoFromLaravelApp($routes, $cachedEndpoints, $latestEndpointsData);

        $groupedEndpoints = collect($endpoints)->groupBy('metadata.groupName')->map(function (Collection $endpointsInGroup) {
            return [
                'name' => $endpointsInGroup->first(function (ExtractedEndpointData $endpointData) {
                        return !empty($endpointData->metadata->groupName);
                    })->metadata->groupName ?? '',
                'description' => $endpointsInGroup->first(function (ExtractedEndpointData $endpointData) {
                        return !empty($endpointData->metadata->groupDescription);
                    })->metadata->groupDescription ?? '',
                'endpoints' => $endpointsInGroup->toArray(),
            ];
        })->all();
        $this->writeEndpointsToDisk($groupedEndpoints);

        return $groupedEndpoints;
    }

    /**
     * @param MatchedRoute[] $matches
     * @param array $cachedEndpoints
     * @param array $latestEndpointsData
     *
     * @return array
     * @throws \Exception
     */
    private function extractEndpointsInfoFromLaravelApp(array $matches, array $cachedEndpoints, array $latestEndpointsData): array
    {
        $extractor = $this->makeExtractor();

        $parsedEndpoints = [];

        foreach ($matches as $routeItem) {
            $route = $routeItem->getRoute();

            $routeControllerAndMethod = u::getRouteClassAndMethodNames($route);
            if (!$this->isValidRoute($routeControllerAndMethod)) {
                c::warn('Skipping invalid route: ' . c::getRouteRepresentation($route));
                continue;
            }

            if (!$this->doesControllerMethodExist($routeControllerAndMethod)) {
                c::warn('Skipping route: ' . c::getRouteRepresentation($route) . ' - Controller method does not exist.');
                continue;
            }

            if ($this->isRouteHiddenFromDocumentation($routeControllerAndMethod)) {
                c::warn('Skipping route: ' . c::getRouteRepresentation($route) . ': @hideFromAPIDocumentation was specified.');
                continue;
            }

            try {
                c::info('Processing route: ' . c::getRouteRepresentation($route));
                $currentEndpointData = $extractor->processRoute($route, $routeItem->getRules());
                // If latest data is different from cached data, merge latest into current
                $currentEndpointData = $this->mergeAnyEndpointDataUpdates($currentEndpointData, $cachedEndpoints, $latestEndpointsData);
                $parsedEndpoints[] = $currentEndpointData;
                c::success('Processed route: ' . c::getRouteRepresentation($route));
            } catch (\Exception $exception) {
                $this->encounteredErrors = true;
                c::error('Failed processing route: ' . c::getRouteRepresentation($route) . ' - Exception encountered.');
                e::dumpExceptionIfVerbose($exception);
            }
        }

        return $parsedEndpoints;
    }

    /**
     * @param ExtractedEndpointData $endpointData
     * @param array[] $cachedEndpoints
     * @param array[] $latestEndpointsData
     *
     * @return ExtractedEndpointData The extracted endpoint data
     */
    private function mergeAnyEndpointDataUpdates(ExtractedEndpointData $endpointData, array $cachedEndpoints, array $latestEndpointsData): ExtractedEndpointData
    {
        // First, find the corresponding endpoint in cached and latest
        $thisEndpointCached = Arr::first($cachedEndpoints, function (array $endpoint) use ($endpointData) {
            return $endpoint['uri'] === $endpointData->uri && $endpoint['httpMethods'] === $endpointData->httpMethods;
        });
        if (!$thisEndpointCached) {
            return $endpointData;
        }

        $thisEndpointLatest = Arr::first($latestEndpointsData, function (array $endpoint) use ($endpointData) {
            return $endpoint['uri'] === $endpointData->uri && $endpoint['httpMethods'] == $endpointData->httpMethods;
        });
        if (!$thisEndpointLatest) {
            return $endpointData;
        }

        // Then compare cached and latest to see what sections changed.
        $properties = [
            'metadata',
            'headers',
            'urlParameters',
            'queryParameters',
            'bodyParameters',
            'responses',
            'responseFields',
        ];

        $changed = [];
        foreach ($properties as $property) {
            if ($thisEndpointCached[$property] != $thisEndpointLatest[$property]) {
                $changed[] = $property;
            }
        }

        // Finally, merge any changed sections.
        $thisEndpointLatest = OutputEndpointData::create($thisEndpointLatest);
        foreach ($changed as $property) {
            $endpointData->$property = $thisEndpointLatest->$property;
        }
        return $endpointData;
    }

    protected function writeEndpointsToDisk(array $grouped): void
    {
        Utils::deleteFilesMatching(static::$camelDir, function ($file) {
            /** @var array|\League\Flysystem\StorageAttributes $file */
            return !Str::startsWith(basename($file['path']), 'custom.');
        });
        Utils::deleteDirectoryAndContents(static::$cacheDir);

        if (!is_dir(static::$camelDir)) {
            mkdir(static::$camelDir, 0777, true);
        }

        if (!is_dir(static::$cacheDir)) {
            mkdir(static::$cacheDir, 0777, true);
        }

        $fileNameIndex = 0;
        foreach ($grouped as $group) {
            $yaml = Yaml::dump(
                $group, 20, 2,
                Yaml::DUMP_EMPTY_ARRAY_AS_SEQUENCE | Yaml::DUMP_OBJECT_AS_MAP | Yaml::DUMP_MULTI_LINE_LITERAL_BLOCK
            );

            // Format numbers as two digits so they are sorted properly when retrieving later
            // (ie "10.yaml" comes after "9.yaml", not after "1.yaml")
            $fileName = sprintf("%02d.yaml", $fileNameIndex);
            $fileNameIndex++;

            file_put_contents(static::$camelDir . "/$fileName", $yaml);
            file_put_contents(static::$cacheDir . "/$fileName", "## Autogenerated by Scribe. DO NOT MODIFY.\n\n" . $yaml);
        }
    }

    private function isValidRoute(?array $routeControllerAndMethod): bool
    {
        if (is_array($routeControllerAndMethod)) {
            if (count($routeControllerAndMethod) < 2) {
                throw CouldntGetRouteDetails::new();
            }
            [$classOrObject, $method] = $routeControllerAndMethod;
            if (u::isInvokableObject($classOrObject)) {
                return true;
            }
            $routeControllerAndMethod = $classOrObject . '@' . $method;
        }

        return !is_callable($routeControllerAndMethod) && !is_null($routeControllerAndMethod);
    }

    private function doesControllerMethodExist(array $routeControllerAndMethod): bool
    {
        if (count($routeControllerAndMethod) < 2) {
            throw CouldntGetRouteDetails::new();
        }
        [$class, $method] = $routeControllerAndMethod;
        $reflection = new ReflectionClass($class);

        if ($reflection->hasMethod($method)) {
            return true;
        }

        return false;
    }

    private function isRouteHiddenFromDocumentation(array $routeControllerAndMethod): bool
    {
        if (!($class = $routeControllerAndMethod[0]) instanceof \Closure) {
            $classDocBlock = new DocBlock((new ReflectionClass($class))->getDocComment() ?: '');
            $shouldIgnoreClass = collect($classDocBlock->getTags())
                ->filter(function (Tag $tag) {
                    return Str::lower($tag->getName()) === 'hidefromapidocumentation';
                })->isNotEmpty();

            if ($shouldIgnoreClass) {
                return true;
            }
        }

        $methodDocBlock = new DocBlock(u::getReflectedRouteMethod($routeControllerAndMethod)->getDocComment() ?: '');
        $shouldIgnoreMethod = collect($methodDocBlock->getTags())
            ->filter(function (Tag $tag) {
                return Str::lower($tag->getName()) === 'hidefromapidocumentation';
            })->isNotEmpty();

        return $shouldIgnoreMethod;
    }

    protected function extractAndWriteApiDetailsToDisk(): void
    {
        $apiDetails = $this->makeApiDetails();

        $apiDetails->writeMarkdownFiles();
    }

    protected function makeApiDetails(): ApiDetails
    {
        return new ApiDetails($this->paths, $this->docConfig, !$this->command->option('force'));
    }

    /**
     * Make a new extractor.
     *
     * @return Extractor
     */
    protected function makeExtractor(): Extractor
    {
        return new Extractor($this->docConfig);
    }
}
