using Jiaowu.Api.Domain.Academic;

namespace Jiaowu.Api.Infrastructure.Teaching;

public static class TeachingTaskHours
{
    public static int Calculate(int startWeek, int endWeek, int weeklyHours) =>
        endWeek < startWeek ? 0 : (endWeek - startWeek + 1) * weeklyHours;

    public static string? Validate(
        Course course,
        int startWeek,
        int endWeek,
        int weeklyHours)
    {
        var plannedHours = Calculate(startWeek, endWeek, weeklyHours);
        return plannedHours == course.TotalHours
            ? null
            : $"课程“{course.Name}”总学时为 {course.TotalHours}；当前第 {startWeek}—{endWeek} 周、每周 {weeklyHours} 学时，共 {plannedHours} 学时。请调整授课周次或周学时。";
    }
}