<?php

namespace App\Http\Controllers\Api;

use App\Enums\Api\ApiPeriodEnum;
use App\Http\Controllers\Controller;
use App\Http\Requests\Api\GetStatsRequest;
use App\Http\Resources\UrlCollection;
use App\Http\Resources\UrlHistoryCollection;
use App\Http\Resources\UrlResource;
use App\Models\Url;
use Carbon\Carbon;
use Carbon\CarbonPeriod;
use DateTime;
use Illuminate\Http\Request;

class UrlController extends Controller
{
    /**
     * Returns a listing of the urls.
     *
     * @return \App\Http\Resources\UrlCollection
     */
    public function index()
    {
        return new UrlCollection(Url::paginate(25));
    }

    /**
     * Returns the specified url.
     *
     * @param  Url $url
     * @return \App\Http\Resources\UrlResource
     */
    public function show(Url $url)
    {
        return new UrlResource($url);
    }

    /**
     * Returns the history for a given url.
     *
     * @param Url     $url
     * @param Request $request
     * @return \Illuminate\Http\Response|\App\Http\Resources\UrlHistoryCollection
     */
    public function getHistory(Url $url, Request $request)
    {
        // Set start date with request or now - 1 year.
        if ($request->start) {
            $start = $request->start;
            $start = DateTime::createFromFormat('dmY', $start);
        } else {
            $start = now()->modify('-1 year');
        }
        // Set end date with request or now.
        if ($request->end) {
            $end = $request->end;
            $end = DateTime::createFromFormat('dmY', $end)->modify('+1 day');
        } else {
            $end = now();
        }
        // Check if the difference bewteen end and start is < than 1 year.
        if ($start->diff($end)->days > 366) {
            return response('Date interval too long', 403);
        };
        $history = $url->history()
            ->where('start_date', '>', $start)
            ->where('end_date', '<', $end)
            ->get();
        return new UrlHistoryCollection($history);
    }

    /**
     * Returns the stats for the given url.
     *
     * @param \App\Http\Requests\Api\GetStatsRequest $request
     * @param Url                                    $url
     * @return \Illuminate\Http\Response|\Illuminate\Http\JsonResponse
     */
    public function getStats(GetStatsRequest $request, Url $url)
    {
        $period = ApiPeriodEnum::make($request->period, 'name');
        $start  = Carbon::make($request->start);
        $end    = Carbon::make($request->end);
        // Check if the difference bewteen end and start is < than 1 year.
        if ($start->diff($end)->days > 366) {
            return response('Date interval too long', 403);
        };

        $stats = [];
        switch ($period->label()) {
            case \App\Enums\Api\ApiPeriodEnum::day->label():
                $carbonPeriod = CarbonPeriod::create(
                    $start->format('Y-m-d'),
                    $end->format('Y-m-d')
                )->toArray();
                $dbStats      = $url->stats()
                    ->whereDate('date', '>', $start)
                    ->whereDate('date', '<=', $end)
                    ->get(['date', 'calls']);

                foreach ($carbonPeriod as $day) {
                    $stats[] = $dbStats->where('date', $day)->isNotEmpty() ?
                        $dbStats->where('date', $day)->first()->calls :
                        0;
                }
                break;
            case \App\Enums\Api\ApiPeriodEnum::week->label():
                // Create a Carbon Period for weeks to make only one query per week.
                $carbonPeriod = CarbonPeriod::create(
                    $start->startOfWeek()->format('Y-m-d'),
                    $end->endOfWeek()->format('Y-m-d')
                )->weeks()->toArray();

                foreach ($carbonPeriod as $week) {
                    $stats[] = $url->stats()
                        ->whereIn(
                            'date',
                            CarbonPeriod::create(
                                $week->startOfWeek(Carbon::MONDAY)->format('Y-m-d'),
                                $week->endOfWeek(Carbon::SUNDAY)->format('Y-m-d')
                            )->toArray()
                        )
                        ->sum('calls');
                }
                break;
            case \App\Enums\Api\ApiPeriodEnum::month->label():
                // Create a Carbon Period for months to make only one query per month.
                $carbonPeriod = CarbonPeriod::create(
                    $start->startOfMonth()->format('Y-m-d'),
                    $end->endOfMonth()->format('Y-m-d')
                )->months()->toArray();

                foreach ($carbonPeriod as $month) {
                    $stats[] = $url->stats()
                        ->whereIn(
                            'date',
                            CarbonPeriod::create(
                                $month->startOfMonth()->format('Y-m-d'),
                                $month->endOfMonth()->format('Y-m-d')
                            )->toArray()
                        )
                        ->sum('calls');
                }
                break;
        } //end switch

        return \response()->json($stats);
    }
}