using MongoDB.Bson;
using MongoDB.Bson.Serialization.Attributes;

namespace QuestionsApi.Models;

public static class StudyGoalTypes
{
    public const string QuestionCount = "question_count";
    public const string Duration = "duration";
    public const string WeakSystem = "weak_system";
    public const string DueReviews = "due_reviews";
    public const string SimulationBlock = "simulation_block";
    public static readonly HashSet<string> All = [QuestionCount, Duration, WeakSystem, DueReviews, SimulationBlock];
}

public static class StudySessionStates
{
    public const string Active = "active";
    public const string Completed = "completed";
    public const string EndedEarly = "ended_early";
    public const string Interrupted = "interrupted";
}

public sealed class StudySession
{
    [BsonId]
    [BsonRepresentation(BsonType.ObjectId)]
    public string? Id { get; set; }
    public string UserId { get; set; } = "";
    public string ClientSessionId { get; set; } = "";
    public string GoalType { get; set; } = StudyGoalTypes.QuestionCount;
    public string Mode { get; set; } = "Tutor";
    public string Step3System { get; set; } = "";
    public int TargetValue { get; set; } = 10;
    public string State { get; set; } = StudySessionStates.Active;
    public int QuestionsCompleted { get; set; }
    public int Correct { get; set; }
    public int ReviewsCompleted { get; set; }
    public int Recovered { get; set; }
    public int CoinsEarned { get; set; }
    public List<CreditAward> CoinAwards { get; set; } = [];
    public List<string> AppliedEventIds { get; set; } = [];
    public int? InitialMasteryScore { get; set; }
    public string InitialMasteryState { get; set; } = "";
    public int? FinalMasteryScore { get; set; }
    public string FinalMasteryState { get; set; } = "";
    public int? InitialReadiness { get; set; }
    public int? FinalReadiness { get; set; }
    public string SimulationId { get; set; } = "";
    public int? SimulationBlock { get; set; }
    public DateTime CreatedUtc { get; set; }
    public DateTime UpdatedUtc { get; set; }
    public DateTime? TargetEndUtc { get; set; }
    public DateTime? CompletedUtc { get; set; }
}

public sealed class CreateStudySessionRequest
{
    public string ClientSessionId { get; set; } = "";
    public string GoalType { get; set; } = StudyGoalTypes.QuestionCount;
    public int TargetValue { get; set; } = 10;
    public string Mode { get; set; } = "Tutor";
    public string Step3System { get; set; } = "";
}

public sealed class StudySessionProgress
{
    public string Id { get; set; } = "";
    public string State { get; set; } = "";
    public string GoalType { get; set; } = "";
    public int TargetValue { get; set; }
    public int CompletedValue { get; set; }
    public int QuestionsCompleted { get; set; }
    public int SecondsRemaining { get; set; }
    public bool GoalReached { get; set; }
}

public sealed class StudySessionSummary
{
    public string Id { get; set; } = "";
    public string State { get; set; } = "";
    public string GoalType { get; set; } = "";
    public int TargetValue { get; set; }
    public int CompletedValue { get; set; }
    public int QuestionsCompleted { get; set; }
    public int Correct { get; set; }
    public int Accuracy { get; set; }
    public int ReviewsCompleted { get; set; }
    public int Recovered { get; set; }
    public int ElapsedSeconds { get; set; }
    public int CoinsEarned { get; set; }
    public List<CreditAward> CoinAwards { get; set; } = [];
    public string Step3System { get; set; } = "";
    public int? MasteryScoreChange { get; set; }
    public string InitialMasteryState { get; set; } = "";
    public string FinalMasteryState { get; set; } = "";
    public int? ReadinessChange { get; set; }
    public string ReadinessExplanation { get; set; } = "A completed exam simulation is required to update readiness.";
    public bool GoalBonusAwarded { get; set; }
}

public sealed class StudySessionEnvelope
{
    public StudySessionProgress Progress { get; set; } = new();
    public StudySessionSummary? Summary { get; set; }
}