<?php

namespace App\SearchDisplace;

use App\SearchDisplace\Ingest\SendDataToRecreateDocument;
use App\SearchDisplace\Ingest\SendDocument;
use Illuminate\Http\File;
use Illuminate\Http\UploadedFile;
use Illuminate\Support\Facades\Storage;

class SearchAndDisplaceOriginalDocument
{
    /**
     *
     * @throws \Exception
     */
    public function start($document, $searchers)
    {
        $storeResultAtPath = '';

        if ($document instanceof UploadedFile) {
            $fileName = pathinfo($document->getClientOriginalName(), PATHINFO_FILENAME);
        } else {
            // From CLI.

            $document = new File($document);

            $fileName = str_replace('.' . $document->getExtension(), '', $document->getFilename());

            $storeResultAtPath = $document->getPath();
        }

        $id = time() . '_' . $fileName;

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

        return $id;
    }

    /**
     * @param $id
     * @param $contents
     * @param $documentFormat
     * @throws \GuzzleHttp\Exception\GuzzleException
     */
    public function applySD($id, $contents, $documentFormat)
    {
        $data = json_decode($contents['document'], true);

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

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

            $result = $searchAndDisplace->execute();

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

            $data['document_format'] = $documentFormat;

            $this->sendDataToIngestToRebuild($id, $data);
        } catch (\Exception $exception) {
            \Illuminate\Support\Facades\Log::info('========================');
            \Illuminate\Support\Facades\Log::info('Exception - SearchAndDisplaceOriginalDocument@applySD');
            \Illuminate\Support\Facades\Log::info($exception->getMessage());
            \Illuminate\Support\Facades\Log::info($exception->getTraceAsString());
            \Illuminate\Support\Facades\Log::info('========================');
        }
    }

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

        $storage->deleteDirectory($directory);
    }

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

        if ($storage->exists($basePath)) {
            return false;
        }

        if ($this->findDocumentById($id) !== null) {
            return false;
        }

        return true;
    }

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

        return $storage->exists($basePath) && $this->findDocumentById($id) === null;
    }

    /**
     * @param $id
     * @return string
     * @throws \Exception
     */
    public function getDownloadPath($id)
    {
        $storage = Storage::disk('local');

        // @TODO Improve this. Right now we are calling 'findDocumentById' multiple times.

        if ($this->hasFailed($id)) {
            throw new \Exception('Document has failed.');
        }

        if ($this->isInProgress($id)) {
            throw new \Exception('Document is still processing.');
        }

        return $storage->path($this->findDocumentById($id));
    }

    protected function findDocumentById($id)
    {
        $storage = Storage::disk('local');

        $documentPartialPath = "contracts/$id-document";

        $contractFiles = $storage->files('contracts');

        foreach ($contractFiles as $contractFile) {
            if (substr($contractFile, 0, strlen($documentPartialPath)) === $documentPartialPath) {
                return $contractFile;
            }
        }

        return null;
    }

    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;
            }
        }

        $lastOffset = 0;

        foreach ($ingestData['elements'] as $elementIndex => $element) {
            $currentOffset = 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'] - $index['original_end']) -
                        ($index['start'] - $index['original_start']);

                    $ingestData['elements'][$elementIndex]['range_end'] += $endDifference;
                    $currentOffset += $endDifference;

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

            $ingestData['elements'][$elementIndex]['range_start'] += $lastOffset;
            $ingestData['elements'][$elementIndex]['range_end'] += $lastOffset;

            $lastOffset += $currentOffset;
        }

        return $ingestData;
    }

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

        $storage->put("$directory/searchers.json", json_encode([
            'searchers' => $searchers,
            'document_path' => $storeResultAtPath ?? '',
        ]));
    }

    /**
     *
     * @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)['searchers'];
    }

    public function getStoreAtPathFromJsonFile($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)['document_path'];
    }

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

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

    /**
     *
     * @param $id
     * @param $data
     * @throws \GuzzleHttp\Exception\GuzzleException
     */
    protected function sendDataToIngestToRebuild($id, $data)
    {
        $handler = new SendDataToRecreateDocument();

        $handler->execute($id, $data);
    }
}