<?php

namespace App\Services\Calculators;

use App\Interfaces\ScoreCalculatorInterface;
use App\Models\ProjectModel;

class ProjectCalculator implements ScoreCalculatorInterface
{
    private $projectModel;

    public function __construct(ProjectModel $projectModel)
    {
        $this->projectModel = $projectModel;
    }

    /**
     * Calculate the average project score for a student
     *
     * @param int $studentId
     * @param string $semester
     * @param string $schoolYear
     * @return array Returns ['project_avg' => float|null]
     * @throws \RuntimeException If no project scores are found
     */
    public function calculate(int $studentId, string $semester, string $schoolYear, ?int $classSectionId = null): array
    {
        $average = $this->projectModel->getAverageProjectScore($studentId, $semester, $schoolYear, $classSectionId);
        
        return ['project_avg' => $average !== null ? (float) $average : null];
    }
}