<?php

namespace App\Http\Controllers;

use App\Experiment;
use App\Result;
use App\Logic\IPAnonymizer;

use League\Csv\Writer;

use Illuminate\Http\Request;
use Str;
use Log;


use ZipStream\Option\Archive as ZipOptions;
use ZipStream\ZipStream;


class ResultController extends Controller
{
    /**
     * Fields provided to the index view.
     *
     * Needed to avoid including the 'data' field, which can get very large.
     */
    const ROWS_FOR_INDEX = [
        "id",
        "created_at",
        "ip",
        "session_id",
    ];

    /**
     * Display a listing of the resource.
     *
     * @return \Illuminate\Http\Response
     */
    public function index() {
        $results = Result::select(self::ROWS_FOR_INDEX)
            ->where('partial', false)
            ->get();

        return view('results.index', ['results' => $results]);
    }

    public function indexPartial() {
        $results = Result::select(self::ROWS_FOR_INDEX)
            ->where('partial', true)
            ->get();

        return view('results.index', ['results' => $results]);
    }

    /**
     * Show the form for creating a new resource.
     *
     * @return \Illuminate\Http\Response
     */
    public function create()
    {
        //
    }

    /**
     * Store a newly created resource in storage.
     *
     * @param  \Illuminate\Http\Request  $request
     * @return \Illuminate\Http\Response
     */
    public function store(Request $request)
    {
        //
    }

    /**
     * Display the specified resource.
     *
     * @param  int  $id
     * @return \Illuminate\Http\Response
     */
    public function show(Result $result) {
        $header = collect($result->data ?? [])
            ->map(function($entry) {
                return array_keys($entry);
            })
            ->flatten()
            ->unique();

        $rows = collect($result->data ?? [])
            ->map(function($row) use ($header) {
                foreach ($header as $key) {
                    // Fill empty columns with N/A
                    $row[$key] = $row[$key] ?? config('experiment.n-a-text');

                    // Replace arrays with json
                    if (is_array($row[$key]))
                        $row[$key] = json_encode($row[$key]);
                }

                return $row;
            });

        return view('results.show', [
            'header' => $header,
            'rows' => $rows,
        ]);
    }

    // Returns object obj with obj->header: array with header info
    //                         obj->rows: arrays with data.
    //
    // @param $results Collection of Result
    private function getResults($results) {
        $header = collect($results->first()->data ?? [])
            ->map(function($entry) {
                return array_keys($entry);
            })
            ->flatten()
            ->unique();

        $all_rows = collect();

        $id = config('experiment.csv-id-header-start');
        $id_format = config('experiment.csv-id-header-format');
        $id_header = config('experiment.csv-id-header');

        foreach ($results as $result) {
            $rows = collect($result->data ?? [])
                ->map(function($row) use ($header, $id_header, $id_format, $id) {
                    foreach ($header as $key) {
                        // Fill empty columns with N/A
                        $row[$key] = $row[$key] ?? config('experiment.n-a-text');

                        // Replace arrays with json
                        if (is_array($row[$key]))
                            $row[$key] = json_encode($row[$key]);
                    }

                    if ($id_header)
                        return array_merge(
                            [$id_header => sprintf($id_format, $id)], $row);
                    else
                        return $row;

                });

            $all_rows = $all_rows->concat($rows);
            $id += 1;
        }

        if ($id_header) {
            $header->prepend($id_header);
        }

        return (object) [
            'header' => $header->toArray(),
            'rows' => $all_rows->toArray(),
        ];
    }

    public function showAllCSV() {
        header('Content-Type: text/csv; charset=utf-8');
        header('Content-Type: application/force-download');
        header('Content-Disposition: attachment; filename=results.csv');

        $data = $this->getResults(Result::all());

        $csv = Writer::createFromString('');
        $csv->insertOne($data->header);
        $csv->insertAll($data->rows);

        return $csv->getContent();
    }

    public function downloadZip() {
        $options = new ZipOptions();
        $options->setSendHttpHeaders(true);

        $zip = new ZipStream('results.zip', $options);

        Result::chunk(5, function($results) use ($zip) {
            foreach ($results as $result) {
                $filename = $result->created_at . ".json";
                $zip->addFile($filename, $result->getOriginal("data"));
            }
        });

        $zip->finish();
    }

    /**
     * Display the result as json.
     */
    public function showJson(Result $result) {
        return $result->data;
    }

    /**
     * Show the form for editing the specified resource.
     *
     * @param  int  $id
     * @return \Illuminate\Http\Response
     */
    public function edit($id)
    {
        //
    }

    /**
     * Update the specified resource in storage.
     *
     * @param  \Illuminate\Http\Request  $request
     * @param  int  $id
     * @return \Illuminate\Http\Response
     */
    public function update(Request $request, $id)
    {
        //
    }

    /**
     * Remove the specified resource from storage.
     *
     * @param  int  $id
     * @return \Illuminate\Http\Response
     */
    public function destroy(Result $result) {
        $result->delete();
        return back();
    }

    /**
     * API route for submitting results for the experiment.
     */
    public function submit(Request $request) {
        try {
            $data = $request->data;
            $run_id = $request->id;
            $isPartial = $request->partial ? true : false;

            // In case the client didn't provide a id, we add a new one.
            $run_id = $run_id ?? Str::random(60);

            if ($data === null)
                return [
                    'code' => 3,
                    'message' => 'Invalid data format. Please provide valid JSON.'
                ];

            // Mark the experiment as done, if this is final data.
            $experiment = Experiment::firstWhere('run_id', $run_id);

            if ($experiment && ! $isPartial) {
                $experiment->status = Experiment::STATUS_DONE;
                if (! config('experiment.store-session-id'))
                    $experiment->session_id = null;

                $experiment->save();
            }

            // Check, if we already have partial data lying around.
            // NOTE: Result::firstOrNew() somehow doesn't work here...
            $result = Result::where('run_id', $run_id)
                ->where('partial', true)
                ->first();

            $result = $result ?? Result::make([
                'run_id' => $run_id,
            ]);

            $result->partial = $isPartial;
            $result->data = $data;

            if (config('experiment.store-ip')) {
                $result->ip = IPAnonymizer::anonymize($request->ip());
                Log::info("Storing data from (anonymized) ip '{$result->ip}'.");
            }
            else
                $result->ip = null;

            if ($experiment && $isPartial) {
                $result->session_id = $experiment->session_id;
            }
            else if (! config('experiment.store-session-id')) {
                $result->session_id = null;
            }

            // Note: even though results can reference there Experiments
            // via the experiment_id key, we don't set it here, because
            // results should probably keep existing, when the Experiment
            // is deleted, but we configured the database to cascade delete.
            // I think, the 'experiment_id' key maybe should be removed.
            $result->save();

            return [
                'code' => 0,
                'message' => 'Result submitted.',
                'session' => $run_id,
            ];
        }
        catch (\Throwable $e) {
            Log::error("Submit request failed:\n{$request}\nError was:\n{$e}");
            return [
                'code' => 500,
                'message' => 'Your request caused a server error. It has been logged.'
            ];
        }
    }

    public function results() {
        return Result::all()->values();
    }
}