<?php

namespace App\Services\SchoolYears;

use App\Models\Configuration;
use App\Models\SchoolYear;
use Illuminate\Http\Request;
use Illuminate\Support\Facades\Schema;
use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;
use Symfony\Component\HttpKernel\Exception\UnprocessableEntityHttpException;

class SelectedSchoolYearContextService
{
    public function __construct(private SchoolYearResolver $resolver) {}

    public function fromRequest(Request $request): SelectedSchoolYearContext
    {
        $explicit = false;
        $name = $this->selectedName($request, $explicit);

        if ($name === '') {
            $name = $this->activeSchoolYearName();
        }

        if ($name === '') {
            throw new UnprocessableEntityHttpException('A school_year value is required.');
        }

        if (! Schema::hasTable('school_years')) {
            throw new UnprocessableEntityHttpException('School-year tracking is unavailable.');
        }

        $this->resolver->ensureCurrentTracked();

        $year = SchoolYear::query()->where('name', $name)->first();
        if (! $year) {
            throw new NotFoundHttpException(sprintf('School year %s was not found.', $name));
        }

        return new SelectedSchoolYearContext(
            (int) $year->id,
            (string) $year->name,
            (string) $year->status,
            in_array($year->status, [SchoolYear::STATUS_CLOSED, SchoolYear::STATUS_ARCHIVED], true),
        );
    }

    public function fromName(string $schoolYear): SelectedSchoolYearContext
    {
        $request = Request::create('/', 'GET', ['school_year' => $schoolYear]);

        return $this->fromRequest($request);
    }

    private function selectedName(Request $request, bool &$explicit): string
    {
        $sources = [
            $request->query('school_year'),
            $request->headers->get('X-School-Year'),
            $request->input('school_year'),
        ];

        foreach ($sources as $value) {
            if (is_string($value) && trim($value) !== '') {
                $explicit = true;

                return trim($value);
            }
        }

        return '';
    }

    private function activeSchoolYearName(): string
    {
        $configured = trim((string) (Configuration::getConfig('school_year') ?? ''));
        if ($configured !== '') {
            return $configured;
        }

        if (! Schema::hasTable('school_years')) {
            return '';
        }

        $year = SchoolYear::query()->where('is_current', true)->orderByDesc('id')->first();

        return $year ? trim((string) $year->name) : '';
    }
}