<?php
namespace App\Search\Engines;

use App\Search\Builders\ElasticsearchBuilder;
use Elasticsearch\Client as Elastic;
use Illuminate\Database\Eloquent\Collection;
use Laravel\Scout\Builder;
use Laravel\Scout\Engines\Engine;
use Monolog\Handler\StreamHandler;
use Monolog\Logger;

class ElasticsearchEngine extends Engine
{

    private $type="doc";
    /**
     * @var Elastic
     */
    private $elastic;


    private $logger;

    /**
     * ElasticsearchEngine constructor.
     * @param Elastic $elastic
     * @throws \Exception
     */
    public function __construct(Elastic $elastic)
    {
        $this->elastic = $elastic;
        $this->logger = new Logger('elastic');
        $this->logger->pushHandler(new StreamHandler(storage_path('logs/elasticsearch/error.log'), Logger::ERROR));
    }


    /**
     * Update the given model in the index.
     *
     * @param  \Illuminate\Database\Eloquent\Collection $models
     * @return void
     */
    public function update($models)
    {
        $params['body'] = [];
        $models->each(function ($model) use (&$params) {
            $params['body'][] = [
                'update' => [
                    '_id' => $model->getKey(),
                    '_index' => $model->searchableAs(),
                    '_type' => $this->type,
                ]
            ];
            $params['body'][] = [
                'doc' => $model->toSearchableArray(),
                'doc_as_upsert' => true
            ];
        });
        $result=$this->elastic->bulk($params);
        if ($result['errors'] === true) {
            $this->logger->error("更新失败", $result);
            //throw new \Exception(json_encode($result));
        }
    }

    /**
     * Remove the given model from the index.
     *
     * @param  \Illuminate\Database\Eloquent\Collection $models
     * @return void
     */
    public function delete($models)
    {
        $params['body'] = [];
        $models->each(function ($model) use (&$params) {
            $params['body'][] = [
                'delete' => [
                    '_id' => $model->getKey(),
                    '_index' => $model->searchableAs(),
                    '_type' => $this->type,
                ]
            ];
        });
        $this->elastic->bulk($params);
    }

    /**
     * Perform the given search on the engine.
     *
     * @param  \Laravel\Scout\Builder $builder
     * @return mixed
     */
    public function search(Builder $builder)
    {
        return $this->performSearch($builder, array_filter([
            'size' => $builder->limit,
        ]));
    }

    /**
     * Perform the given search on the engine.
     *
     * @param  \Laravel\Scout\Builder $builder
     * @param  int $perPage
     * @param  int $page
     * @return mixed
     */
    public function paginate(Builder $builder, $perPage, $page)
    {
        $result = $this->performSearch($builder, [
            'from' => (($page * $perPage) - $perPage),
            'size' => $perPage,
        ]);
        return $result;
    }

    /**
     * Pluck and return the primary keys of the given results.
     *
     * @param  mixed $results
     * @return \Illuminate\Support\Collection
     */
    public function mapIds($results)
    {
        return collect($results['hits']['hits'])->pluck('_id')->values();
    }

    /**
     * Map the given results to instances of the given model.
     *
     * @param  \Laravel\Scout\Builder $builder
     * @param  mixed $results
     * @param  \Illuminate\Database\Eloquent\Model $model
     * @return \Illuminate\Database\Eloquent\Collection
     */
    public function map(Builder $builder, $results, $model)
    {
        if ($results['hits']['total'] === 0) {
            return Collection::make();
        }
        $keys = collect($results['hits']['hits'])
            ->pluck('_id')->values()->all();
        $models = $model->getScoutModelsByIds($builder, $keys)->keyBy(function ($model) {
            return $model->getScoutKey();
        });
        return collect($results['hits']['hits'])->map(function ($hit) use ($model, $models) {
            return isset($models[$hit['_id']]) ? $models[$hit['_id']] : null;
        })->filter()->values();
    }

    /**
     * Get the total count from a raw result returned by the engine.
     *
     * @param  mixed $results
     * @return int
     */
    public function getTotalCount($results)
    {
        return $results['hits']['total']>1000?1000:$results['hits']['total'];
    }

    /**
     * Flush all of the model's records from the engine.
     *
     * @param  \Illuminate\Database\Eloquent\Model $model
     * @return void
     */
    public function flush($model)
    {
        // TODO: Implement flush() method.
    }

    /**
     * Perform the given search on the engine.
     *
     * @param  ElasticsearchBuilder  $builder
     * @param  array  $options
     * @return mixed
     */
    protected function performSearch($builder, array $options = [])
    {
        $params = [
            'index' => $builder->model->searchableAs(),
            'type' => $this->type,
            'body' => [
                'query' => [
                    'bool' => [
                    ]
                ]
            ]
        ];


        if (!empty($query = $builder->getQueryData())) {
            $params['body']['query']['bool']=$query;
        }

        $relation_sotr=[];
        if (!empty($builder->query)) {
            $relation_sotr[]=['_score' => 'desc'];
            $params['body']['query']['bool']['must'][]=[
                'bool'=>[
                    "should"=>[
                        [
                            'match' => [
                                'search_field1' => [
                                    "query" => "{$builder->query}",
                                    "boost" => 2
                                ]
                            ]
                        ],
                        [
                            'match' => [
                                'search_field2' => [
                                    "query" => "{$builder->query}",
                                    "boost" => 0
                                ]
                            ]
                        ]
                    ]
                ]

            ];
        }

        if (empty($params['body']['query']['bool'])) {
            $params['body']['query']['bool']['must'][]=['match_all'=>new \ArrayObject()];
        }

        if ($sort = $this->sort($builder)) {
            if (!empty($relation_sotr)) {
                $sort =array_merge($relation_sotr, $sort);
            }
            $params['body']['sort'] = $sort;
        }
        if (isset($options['from'])) {
            $params['body']['from'] = $options['from'];
        }
        if (isset($options['size'])) {
            $params['body']['size'] = $options['size'];
        }

        if ($builder->callback) {
            return call_user_func(
                $builder->callback,
                $this->elastic,
                $builder->query,
                $params
            );
        }
        return $this->elastic->search($params);
    }

    /**
     * Generates the sort if theres any.
     *
     * @param  Builder $builder
     * @return array|null
     */
    protected function sort($builder)
    {
        if (count($builder->orders) == 0) {
            return null;
        }
        return collect($builder->orders)->map(function ($order) {
            if (is_array($order['column'])) {
                return ['_geo_distance'=> $order['column']];
            }
            return [$order['column'] => $order['direction']];
        })->toArray();
    }
}