<?php

namespace App\SearchDisplace;

use App\SearchDisplace\Ingest\SendDocument;
use Illuminate\Support\Facades\Storage;

class SearchAndDisplaceOriginalDocument
{
    /**
     *
     * @throws \Exception
     */
    public function start($document, $searchers)
    {
        $id = time() . '_' . pathinfo($document->getClientOriginalName(), PATHINFO_FILENAME);

        $this->storeSearchers($id, $searchers);
        $this->sendDocumentToIngest($id, $document);

        return $id;
    }

    public function applySD($id, $contents)
    {
        $data = json_decode($contents['document'], true);

        try {
            $searchAndDisplace = new SearchAndDisplace(
                $data['contents']['text'],

                [
                    'searchers' => $this->getSearchers($id),
                ]
            );

            $result = $searchAndDisplace->execute();

            // Update text.
            $data['contents'] = $this->applyResultsOnIngestData($data['contents'], $result);

            \Illuminate\Support\Facades\Log::info($data['contents']);

            // Send to Ingest to recreate doc.
        } catch (\Exception $exception) {
            \Illuminate\Support\Facades\Log::info($exception->getMessage());
            \Illuminate\Support\Facades\Log::info($exception->getTraceAsString());
        }
    }

    public function onIngestFail($id)
    {
        $storage = Storage::disk('local');
        $directory = "contracts/$id";

        $storage->deleteDirectory($directory);
    }

    public function hasFailed($id)
    {
        $storage = Storage::disk('local');
        $directory = "contracts/$id";

        return ! $storage->exists($directory);
    }

    public function isInProgress($id)
    {
        $storage = Storage::disk('local');
        $directory = "contracts/$id";

        return ! $storage->exists("$directory/document");
    }

    /**
     * @param $id
     * @return \Symfony\Component\HttpFoundation\StreamedResponse
     * @throws \Exception
     */
    public function streamFile($id)
    {
        $storage = Storage::disk('local');
        $directory = "contracts/$id";

        if ($this->hasFailed($id) || $this->isInProgress($id)) {
            throw new \Exception('Document is not processed.');
        }

        return $storage->download("$directory/document");
    }

    protected function applyResultsOnIngestData($ingestData, $sdResult)
    {
        $ingestData['text'] = $sdResult['content'];

        // Update index ranges.
        $indexes = [];

        // Use original start for key in order to have the indexes sorted ASC.
        foreach ($sdResult['indexes'] as $searcher => $searcherIndexes) {
            foreach ($searcherIndexes as $index) {
                $indexes[$index['original_start']] = $index;
            }
        }

        // 0 - 20
        // 21 - 32
        // 33 - 174
        //

        $startOffset = 0;

        foreach ($ingestData['elements'] as $element) {
            $currentStartOffset = 0;

            foreach ($indexes as $i => $index) {
                if ($index['original_start'] > $element['range_end']) {
                    break;
                }

                if ($index['original_end'] < $element['range_start']) {
                    continue;
                }

                if (
                    $index['original_start'] >= $element['range_start'] &&
                    $index['original_end'] <= $element['range_end']
                ) {
                    $endDifference = $index['end'] - $index['original_end'];

                    $element['range_end'] += $endDifference;
                    $currentStartOffset += $endDifference;

                    unset($indexes[$i]);
                }
            }

            $element['range_start'] += $startOffset;

            $startOffset += $currentStartOffset;
        }

        return $ingestData;
    }

    protected function storeSearchers($id, $searchers)
    {
        $storage = Storage::disk('local');
        $directory = "contracts/$id";
        $storage->makeDirectory($directory);

        $storage->put("$directory/searchers.json", json_encode($searchers));
    }

    /**
     *
     * @param $id
     * @return string
     * @throws \Illuminate\Contracts\Filesystem\FileNotFoundException
     */
    protected function getSearchers($id)
    {
        $storage = Storage::disk('local');
        $directory = "contracts/$id";

        $searchers = $storage->get("$directory/searchers.json");

        if ( ! $searchers) {
            throw new \Exception('Searchers do not exist.');
        }

        return json_decode($searchers, true);
    }

    /**
     *
     * @param $id
     * @param $document
     * @throws \Exception
     */
    protected function sendDocumentToIngest($id, $document)
    {
        $sendDocument = new SendDocument();

        $sendDocument->execute($id, [
            'path' => $document->getRealPath(),
            'type' => $document->getMimeType(),
            'name' => $document->getClientOriginalName()
        ], 'original');
    }
}