<?php

namespace App\Services;

use App\Models\SchoolYearModel;
use App\Support\SchoolYear\SchoolYearContext;
use CodeIgniter\HTTP\IncomingRequest;
use RuntimeException;

final class SchoolYearContextService
{
    public function __construct(
        private readonly SchoolYearModel $schoolYearModel,
    ) {
    }

    public function resolve(
        IncomingRequest $request,
        ?int $routeSchoolYearId = null
    ): SchoolYearContext {
        $requestedId = $routeSchoolYearId
            ?? $this->normalizeInt($request->getGet('school_year_id'));

        $requestedName = trim((string) $request->getGet('school_year'));

        if ($requestedId !== null && $requestedName !== '') {
            $row = $this->schoolYearModel->find($requestedId);

            if ($row === null || (string) ($row['name'] ?? '') !== $requestedName) {
                throw new RuntimeException('Selected school-year parameters conflict.');
            }

            return $this->fromRow($row, true);
        }

        if ($requestedId !== null) {
            $row = $this->schoolYearModel->find($requestedId);

            if ($row === null) {
                throw new RuntimeException('Selected school year was not found.');
            }

            return $this->fromRow($row, true);
        }

        if ($requestedName !== '') {
            $row = $this->schoolYearModel
                ->where('name', $requestedName)
                ->first();

            if ($row === null) {
                throw new RuntimeException('Selected school year was not found.');
            }

            return $this->fromRow($row, true);
        }

        $sessionYearId = session('selected_school_year_id');

        if (is_numeric($sessionYearId)) {
            $row = $this->schoolYearModel->find((int) $sessionYearId);

            if ($row !== null) {
                return $this->fromRow($row, false);
            }
        }

        $active = $this->schoolYearModel->active();

        if ($active === null) {
            throw new RuntimeException('No active school year is configured.');
        }

        return $this->fromRow($active, false);
    }

    private function normalizeInt(mixed $value): ?int
    {
        if ($value === null || $value === '' || ! ctype_digit((string) $value)) {
            return null;
        }

        return (int) $value;
    }

    private function fromRow(array $row, bool $explicit): SchoolYearContext
    {
        return new SchoolYearContext(
            id: (int) $row['id'],
            yearName: (string) $row['name'],
            status: (string) $row['status'],
            explicitSelection: $explicit,
        );
    }
}