using QuestionsApi.Models;
using QuestionsApi.Services;
using System.Text.Json;
using MongoDB.Bson;
using Xunit;

namespace QuestionsApi.Tests;

public sealed class CcsCaseTests
{
    [Fact]
    public void NewCcsAttemptsAreTimedOnly()
    {
        Assert.Null(CcsCaseValidator.ValidateCreate(new CreateCcsAttemptRequest()));
        Assert.Equal("new CCS attempts must be timed",
            CcsCaseValidator.ValidateCreate(new CreateCcsAttemptRequest { Mode = CcsAttemptModes.Practice }));
    }

    [Fact]
    public void CcsBatchCommandsAreBoundedAndHomogeneous()
    {
        var valid = new CcsBatchCommandRequest
        {
            CommandId = "batch-1",
            Commands =
            [
                new() { Type = "exam", Code = "general" },
                new() { Type = "exam", Code = "cardiac" }
            ]
        };
        Assert.Null(CcsCaseValidator.ValidateBatch(valid));
        valid.Commands.Add(new() { Type = "order", Code = "bmp" });
        Assert.Contains("cannot be mixed", CcsCaseValidator.ValidateBatch(valid), StringComparison.OrdinalIgnoreCase);
    }

    [Fact]
    public void CcsTimingReservesTwoMinutesWithoutExtendingTheHardDeadline()
    {
        Assert.Equal(18, CcsStore.ActivePhaseMinutes(20));
        Assert.Equal(8, CcsStore.ActivePhaseMinutes(10));
        var now = new DateTime(2026, 7, 23, 12, 0, 0, DateTimeKind.Utc);
        Assert.Equal(now.AddMinutes(2), CcsStore.FinalOrdersDeadline(now, now.AddMinutes(5)));
        Assert.Equal(now.AddMinutes(1), CcsStore.FinalOrdersDeadline(now, now.AddMinutes(1)));
    }

    [Fact]
    public void CcsHistoryCursorRoundTripsTimestampAndId()
    {
        var createdUtc = new DateTime(2026, 7, 19, 12, 34, 56, DateTimeKind.Utc);
        var id = ObjectId.GenerateNewId().ToString();

        var encoded = CcsStore.EncodeHistoryCursor(createdUtc, id);

        Assert.True(CcsStore.TryDecodeHistoryCursor(encoded, out var decoded));
        Assert.Equal(createdUtc, decoded!.CreatedUtc);
        Assert.Equal(id, decoded.Id);
        Assert.False(CcsStore.TryDecodeHistoryCursor("not-a-cursor", out _));
    }

    [Fact]
    public void AppFeedbackValidationAcceptsSafeDiagnostics()
    {
        var request = new CreateAppFeedbackRequest {
            Category = "bug", Details = "The next button stopped responding.",
            Context = new AppFeedbackContext { Screen = "player", Platform = "Web", ViewportWidth = 1280, ViewportHeight = 720 }
        };
        Assert.Null(AppFeedbackValidator.Validate(request));
        request.Category = "content_accuracy";
        Assert.Equal("category is invalid", AppFeedbackValidator.Validate(request));
        request.Category = "bug";
        request.Details = "short";
        Assert.Contains("details", AppFeedbackValidator.Validate(request));
    }

    [Fact]
    public void CcsReportCategoriesAreSpecificAndStable()
    {
        Assert.Contains("case_progression_scoring", CcsCaseReportCategory.All);
        Assert.DoesNotContain("answer_explanation", CcsCaseReportCategory.All);
        Assert.Equal(6, CcsCaseReportCategory.All.Count);
    }

    [Fact]
    public void DkaImportArtifactMatchesTheCaseSchema()
    {
        var path = Path.GetFullPath(Path.Combine(AppContext.BaseDirectory, "../../../../../content/ccs/dka-emergency-001.json"));
        var request = JsonSerializer.Deserialize<CcsImportRequest>(File.ReadAllText(path), new JsonSerializerOptions { PropertyNameCaseInsensitive = true });

        Assert.NotNull(request);
        Assert.Empty(CcsCaseValidator.ValidateImport(request!, new HashSet<string>()));
        Assert.True(request!.Cases.Single().ScoringCriteria.Count >= 12);
    }

    [Fact]
    public void PublishedCaseRequiresReferencesAndKnownOrders()
    {
        var request = ValidImport();
        request.Cases[0].References = [];
        request.Cases[0].OrderResponses.Add(new CcsCaseOrderDefinition { OrderCode = "unknown" });

        var errors = CcsCaseValidator.ValidateImport(request, new HashSet<string>());

        Assert.Contains(errors, value => value.Contains("reference", StringComparison.OrdinalIgnoreCase));
        Assert.Contains(errors, value => value.Contains("unknown order code unknown"));
    }

    [Fact]
    public void ScoringCreditsTimelySequencedCareAndPenalizesHarm()
    {
        var definition = ValidImport().Cases[0];
        definition.ScoringCriteria =
        [
            new() { Id = "lab", Title = "Check electrolytes", ActionType = "order", TargetCode = "bmp", Points = 5, LatestMinute = 10, Rationale = "Check potassium." },
            new() { Id = "insulin", Title = "Start insulin safely", ActionType = "order", TargetCode = "insulin", AfterTargetCode = "bmp", Points = 10, Rationale = "Start after potassium assessment." },
            new() { Id = "bicarb", Title = "Avoid bicarbonate", ActionType = "order", TargetCode = "bicarb", Points = -4, Rationale = "Avoid routine bicarbonate." }
        ];
        var attempt = new CcsAttempt { Actions =
        [
            new() { Type = "order", Code = "bmp", SimulatedMinute = 2 },
            new() { Type = "order", Code = "insulin", SimulatedMinute = 4 },
            new() { Type = "order", Code = "bicarb", SimulatedMinute = 5 }
        ]};

        var score = CcsStore.CalculateScore(attempt, definition);

        Assert.Equal(11, score.EarnedPoints);
        Assert.Equal(15, score.PossiblePoints);
        Assert.Equal(73.3, score.Percent);
        Assert.Contains(score.Criteria, value => value.CriterionId == "bicarb" && value.Status == "harmful");
    }

    [Fact]
    public void ValidVersionedCasePassesValidation()
    {
        Assert.Empty(CcsCaseValidator.ValidateImport(ValidImport(), new HashSet<string>()));
    }

    [Fact]
    public void CcsExpectedScoreUsesSeparateUserAndCaseElo()
    {
        Assert.Equal(0.5, CcsRatingStore.ExpectedScore(1000, 1000), 6);
        Assert.True(CcsRatingStore.ExpectedScore(1200, 1000) > 0.75);
        Assert.True(CcsRatingStore.ExpectedScore(800, 1000) < 0.25);
    }

    [Fact]
    public void ScoringReviewIncludesExpectedAndObservedEvidence()
    {
        var definition = ValidImport().Cases[0];
        var attempt = new CcsAttempt
        {
            Actions = [new() { Type = "order", Code = "bmp", SimulatedMinute = 4 }]
        };

        var criterion = CcsStore.CalculateScore(attempt, definition).Criteria.Single();

        Assert.Equal("Check electrolytes", criterion.Title);
        Assert.Contains("Bmp", criterion.ExpectedAction, StringComparison.OrdinalIgnoreCase);
        Assert.Equal("bmp", criterion.ObservedAction);
        Assert.Equal(4, criterion.ObservedMinute);
    }

    private static CcsImportRequest ValidImport() => new()
    {
        Orders =
        [
            new() { Code = "bmp", CanonicalName = "Basic metabolic panel", Category = "laboratory" },
            new() { Code = "insulin", CanonicalName = "Insulin infusion", Category = "medication" },
            new() { Code = "bicarb", CanonicalName = "Sodium bicarbonate", Category = "medication" }
        ],
        Cases =
        [
            new()
            {
                ExternalId = "ccs-test-dka-001", Title = "Diabetic ketoacidosis", System = "Endocrine System",
                PresentingLocation = "emergency_department", AllowedLocations = ["emergency_department", "icu"],
                IsPublished = true, RealTimeMinutes = 20, Difficulty = 2,
                InitialChart = new() { PatientSummary = "Adult with diabetes", ReasonForEncounter = "Vomiting" },
                OrderResponses = [new() { OrderCode = "bmp", Result = "Potassium 4.9 mEq/L" }],
                ScoringCriteria = [new() { Id = "lab", Title = "Check electrolytes", ActionType = "order", TargetCode = "bmp", Points = 5 }],
                References = [new() { Title = "Consensus report", Publisher = "Example Society", Url = "https://example.org/consensus", Supports = "Case management and scoring", AccessedOn = "2026-07-15", Reviewer = "Question bank editorial review" }]
            }
        ]
    };
}