using QuestionsApi.Models;
using QuestionsApi.Services;
using Xunit;

namespace QuestionsApi.Tests;

public sealed class WeeklyGoalPolicyTests
{
    [Theory]
    [InlineData("2026-08-03", "2026-08-03")]
    [InlineData("2026-08-09", "2026-08-03")]
    [InlineData("2026-08-10", "2026-08-10")]
    public void WeekStartsOnMondayUtc(string value, string expected) =>
        Assert.Equal(DateTime.Parse(expected).Date, WeeklyGoalStore.WeekStart(DateTime.Parse(value)));

    [Fact]
    public void ActiveDaysAreDistinctUtcDates()
    {
        var values = new[]
        {
            new DateTime(2026, 8, 3, 1, 0, 0, DateTimeKind.Utc),
            new DateTime(2026, 8, 3, 22, 0, 0, DateTimeKind.Utc),
            new DateTime(2026, 8, 4, 1, 0, 0, DateTimeKind.Utc)
        };
        Assert.Equal(2, WeeklyGoalStore.CountActiveDays(values));
    }

    [Theory]
    [InlineData(0, WeeklyRemediationTypes.HardCorrect, 5)]
    [InlineData(4, WeeklyRemediationTypes.HardCorrect, 5)]
    [InlineData(5, WeeklyRemediationTypes.Reviews, 5)]
    [InlineData(25, WeeklyRemediationTypes.Reviews, 15)]
    public void RemediationIsFeasibleAndCapped(int available, string type, int target) =>
        Assert.Equal((type, target), WeeklyGoalStore.ChooseRemediation(available));

    [Fact]
    public void HardProgressRequiresCorrectEligibleDifficultyFourAttempt()
    {
        var system = Step3SystemCatalog.All[0];
        var start = new DateTime(2026, 8, 3, 0, 0, 0, DateTimeKind.Utc);
        var goal = new WeeklyGoal { WeekStartUtc = start, ExpiresUtc = start.AddDays(7), EligibleSystems = [system] };
        var attempt = new QuestionAttempt { IsCorrect = true, CreatedUtc = start.AddDays(1) };
        var question = new Question { Step3System = system, Difficulty = 4 };
        Assert.True(WeeklyGoalStore.QualifiesHardAttempt(goal, attempt, question));
        attempt.IsCorrect = false;
        Assert.False(WeeklyGoalStore.QualifiesHardAttempt(goal, attempt, question));
        attempt.IsCorrect = true;
        question.Difficulty = 3;
        Assert.False(WeeklyGoalStore.QualifiesHardAttempt(goal, attempt, question));
    }
}