<?php

namespace App\Http\Controllers;

use App\Services\ApiService;
use Illuminate\Http\Request;

class StatisticController extends Controller
{
    protected ApiService $api;

    public function __construct(ApiService $api)
    {
        $this->api = $api;
    }

    public function index()
    {
        $groups = $this->api->get('/employee/groups')->json();
        $directions = $this->api->get('/employee/directions')->json();
        $teachers = $this->api->get('/employee/teachers')->json();

        return view('statistics.index', [
            'groups' => $groups,
            'directions' => $directions,
            'teachers' => $teachers,
            'statistics' => request()->has('type') ? $this->getStatistics(request()) : null
        ]);
    }

    public function generate(Request $request)
    {
        $validated = $request->validate([
            'type' => 'required|string|in:group,direction,teacher',
            'id' => 'required|integer',
            'start_date' => 'required|date',
            'end_date' => 'required|date|after_or_equal:start_date',
        ]);

        if ($validated['type'] === 'teacher') {
            $teachersResponse = $this->api->get('/employee/teachers');

            if (!$teachersResponse->successful()) {
                return back()->withErrors('Не удалось получить список преподавателей');
            }

            $teachers = $teachersResponse->json()['data'] ?? [];

            $teacher = collect($teachers)->firstWhere('teacher_id', $validated['id']);

            if (!$teacher) {
                return back()->withErrors('Преподаватель не найден');
            }

            $validated['id'] = $teacher['user_id'];
        }

        $response = $this->api->get('/employee/statements/statistics', $validated);

        if ($response->successful()) {
            $content = $response->body();
            $contentType = $response->header('Content-Type');
            $contentDisposition = $response->header('Content-Disposition');

            return response($content)
                ->header('Content-Type', $contentType)
                ->header('Content-Disposition', $contentDisposition);
        }

        return back()->withErrors($response->json()['error'] ?? 'Ошибка при генерации статистики');
    }

    /**
     * Получает статистику через API на основе параметров запроса.
     */
    protected function getStatistics(Request $request): array
    {
        $validated = $request->validate([
            'type' => 'required|string|in:group,direction,teacher',
            'id' => 'required|integer',
            'start_date' => 'required|date',
            'end_date' => 'required|date|after_or_equal:start_date',
        ]);

        $response = $this->api->get('/employee/statistics', $validated);

        if ($response->successful()) {
            return $response->json();
        }

        return [
            'error' => $response->json()['error'] ?? 'Не удалось загрузить статистику'
        ];
    }
}