<?php

namespace Dedoc\Scramble\Support\OperationExtensions;

use Dedoc\Scramble\Extensions\OperationExtension;
use Dedoc\Scramble\Support\Generator\Combined\AnyOf;
use Dedoc\Scramble\Support\Generator\Operation;
use Dedoc\Scramble\Support\Generator\Response;
use Dedoc\Scramble\Support\Generator\Schema;
use Dedoc\Scramble\Support\Generator\Types as OpenApiTypes;
use Dedoc\Scramble\Support\RouteInfo;
use Dedoc\Scramble\Support\Type\Union;
use Illuminate\Support\Collection;

class ResponseExtension extends OperationExtension
{
    public function handle(Operation $operation, RouteInfo $routeInfo)
    {
        $returnType = $routeInfo->getReturnType();

        if (! $returnType) {
            return [];
        }

        $returnTypes = $returnType instanceof Union
            ? $returnType->types
            : [$returnType];

        $responses = collect($returnTypes)
            ->merge(optional($routeInfo->getMethodType())->exceptions ?: [])
            ->map($this->openApiTransformer->toResponse(...))
            ->filter()
            ->unique(fn ($response) => ($response instanceof Response ? $response->code : 'ref').':'.json_encode($response->toArray()))
            ->values();

        [$responses, $references] = $responses->partition(fn ($r) => $r instanceof Response);

        $responses = $responses
            ->groupBy('code')
            ->map(function (Collection $responses, $code) {
                if (count($responses) === 1) {
                    return $responses->first();
                }

                // @todo: Responses with similar code and type should result in a different example schemas.

                $responsesTypes = $responses->pluck('content.application/json.type')
                    /*
                     * Empty response body can happen, and in case it is going to be grouped
                     * by status, it should become an empty string.
                     */
                    ->map(fn ($type) => $type ?: new OpenApiTypes\StringType)
                    ->unique(fn ($type) => json_encode($type->toArray()))
                    ->values()
                    ->all();

                return Response::make((int) $code)
                    ->description($responses->first()->description)
                    ->setContent(
                        'application/json',
                        Schema::fromType(count($responsesTypes) > 1 ? (new AnyOf)->setItems($responsesTypes) : $responsesTypes[0])
                    );
            })
            ->values()
            ->merge($references)
            ->all();

        foreach ($responses as $response) {
            $operation->addResponse($response);
        }
    }
}