using Microsoft.AspNetCore.Authorization;
using Microsoft.AspNetCore.Mvc;
using QuestionsApi.Models;
using QuestionsApi.Services;
using System.Security.Claims;

namespace QuestionsApi.Controllers;

[ApiController]
[Route("api/exam-simulations")]
[Authorize(Roles = "USER,SUPER")]
public class ExamSimulationsController(
    ExamSimulationStore simulations,
    CreditStore credits,
    MasteryAwardService masteryAwards,
    StudySessionStore studySessions,
    ProgressionStore progression) : ControllerBase
{
    [HttpGet("readiness")]
    public async Task<IActionResult> Readiness() => Ok(await simulations.GetReadinessAsync(UserId()));

    [HttpPost]
    public async Task<IActionResult> Create()
    {
        var userId = UserId();
        if (await simulations.FindActiveAsync(userId) is not null)
            return Conflict(new { code = "active_exam", message = "An active Step 3 simulation already exists." });
        var operationId = $"exam-create:{Guid.NewGuid():N}";
        var bypass = User.IsInRole("SUPER");
        if (!bypass && !await credits.TryConsumeExamTokenAsync(userId, operationId))
            return Conflict(new
            {
                code = "exam_token_required",
                message = "An Exam Simulation Token is required.",
                credits = await credits.GetStatusAsync(userId)
            });
        try
        {
            var simulation = await simulations.CreateAsync(userId);
            return Ok(await simulations.ToResponseAsync(simulation));
        }
        catch (InvalidOperationException exception)
        {
            if (!bypass) await credits.RefundExamTokenAsync(userId, operationId);
            return Conflict(new { code = "exam_creation_failed", message = exception.Message });
        }
        catch
        {
            if (!bypass) await credits.RefundExamTokenAsync(userId, operationId);
            throw;
        }
    }

    [HttpGet("preview-results")]
    [Authorize(Roles = "SUPER")]
    public async Task<IActionResult> PreviewResults()
    {
        try { return Ok(await simulations.BuildResultsPreviewAsync(UserId())); }
        catch (InvalidOperationException exception) { return Conflict(exception.Message); }
    }

    [HttpPost("sample-completed")]
    [Authorize(Roles = "SUPER")]
    public async Task<IActionResult> CreateSampleCompleted()
    {
        try { return Ok(ExamSimulationStore.ToHistorySummary(await simulations.CreateSampleCompletedAsync(UserId()))); }
        catch (InvalidOperationException exception) { return Conflict(exception.Message); }
    }

    [HttpGet("active")]
    public async Task<IActionResult> Active()
    {
        var simulation = await simulations.FindActiveAsync(UserId());
        return simulation is null ? NoContent() : Ok(await simulations.ToResponseAsync(simulation));
    }

    [HttpGet("completed")]
    public async Task<IActionResult> Completed([FromQuery] int limit = 20, [FromQuery] string? before = null)
    {
        DateTime? completedBefore = null;
        if (!string.IsNullOrWhiteSpace(before))
        {
            if (!DateTime.TryParse(before, null, System.Globalization.DateTimeStyles.RoundtripKind, out var parsed))
                return BadRequest("The completed-simulation cursor is invalid.");
            completedBefore = parsed;
        }
        return Ok(await simulations.GetCompletedAsync(UserId(), limit, completedBefore));
    }

    [HttpGet("history")]
    public async Task<IActionResult> History(
        [FromQuery] int limit = 20,
        [FromQuery] string status = "all",
        [FromQuery] string sort = "newest",
        [FromQuery] string? cursor = null,
        [FromQuery] string? before = null)
    {
        DateTime? legacyBefore = null;
        if (!string.IsNullOrWhiteSpace(before))
        {
            if (!DateTime.TryParse(before, null, System.Globalization.DateTimeStyles.RoundtripKind, out var parsed))
                return BadRequest("The simulation-history cursor is invalid.");
            legacyBefore = parsed;
        }
        try { return Ok(await simulations.GetHistoryAsync(UserId(), limit, status, sort, cursor, legacyBefore)); }
        catch (ArgumentException exception) { return BadRequest(exception.Message); }
    }

    [HttpGet("{id}")]
    public async Task<IActionResult> Get(string id)
    {
        var simulation = await simulations.GetOwnedAsync(id, UserId());
        return simulation is null ? NotFound() : Ok(await simulations.ToResponseAsync(simulation));
    }

    [HttpPost("{id}/blocks/start")]
    public async Task<IActionResult> StartBlock(string id)
    {
        var simulation = await simulations.GetOwnedAsync(id, UserId());
        if (simulation is null) return NotFound();
        try
        {
            simulation = await simulations.StartNextBlockAsync(simulation);
            await studySessions.EnsureSimulationBlockAsync(UserId(), simulation.Id ?? id, simulation.CurrentBlock);
            return Ok(await simulations.ToResponseAsync(simulation));
        }
        catch (InvalidOperationException exception) { return Conflict(exception.Message); }
    }

    [HttpPut("{id}/responses")]
    public async Task<IActionResult> SaveResponse(string id, SaveSimulationResponseRequest request)
    {
        var simulation = await simulations.GetOwnedAsync(id, UserId());
        if (simulation is null) return NotFound();
        try { return Ok(await simulations.ToResponseAsync(await simulations.SaveResponseAsync(simulation, request))); }
        catch (ArgumentException exception) { return BadRequest(exception.Message); }
        catch (InvalidOperationException exception) { return Conflict(exception.Message); }
    }

    [HttpPost("{id}/blocks/submit")]
    public async Task<IActionResult> SubmitBlock(string id)
    {
        var simulation = await simulations.GetOwnedAsync(id, UserId());
        if (simulation is null) return NotFound();
        try
        {
            var userId = UserId();
            await masteryAwards.PrepareAsync(userId);
            await progression.PrepareAsync(userId);
            simulation = await simulations.SubmitBlockAsync(simulation);
            var response = await simulations.ToResponseAsync(simulation);
            var session = await studySessions.CompleteSimulationBlockAsync(userId, simulation.Id ?? id, simulation.CurrentBlock);
            response.StudySessionProgress = session.Progress;
            response.SessionSummary = session.Summary;
            if (session.Summary is not null)
                response.CreditAwards.AddRange(session.Summary.CoinAwards.Where(value =>
                    value.ReasonCode == CreditReasonCodes.SessionGoalComplete));
            if (simulation.State == ExamSimulationStates.Completed && !simulation.IsSample)
            {
                var result = await credits.AwardAsync(userId, new CreditAwardRequest(
                    $"simulation:{simulation.Id}", 10, CreditReasonCodes.ExamSimulationComplete,
                    "Completed a Step 3 exam simulation", "exam_simulation", simulation.Id ?? "", false));
                if (result.Award is not null) response.CreditAwards.Add(result.Award);
                response.CreditAwards.AddRange(await masteryAwards.AwardPromotionsAsync(userId));
                response.Credits = await credits.GetStatusAsync(userId);
            }
            else if (session.Summary is not null)
                response.Credits = await credits.GetStatusAsync(userId);
            var progressionResult = await progression.RefreshAsync(userId);
            response.Progression = progressionResult.State;
            response.CreditAwards.AddRange(progressionResult.Awards);
            if (progressionResult.Awards.Count > 0) response.Credits = await credits.GetStatusAsync(userId);
            return Ok(response);
        }
        catch (InvalidOperationException exception) { return Conflict(exception.Message); }
    }

    [HttpPost("{id}/abandon")]
    public async Task<IActionResult> Abandon(string id)
    {
        var simulation = await simulations.GetOwnedAsync(id, UserId());
        if (simulation is null) return NotFound();
        await simulations.AbandonAsync(simulation);
        return NoContent();
    }

    private string UserId() => User.FindFirstValue(ClaimTypes.NameIdentifier)
        ?? User.FindFirstValue(ClaimTypes.Name)
        ?? User.Identity?.Name
        ?? throw new UnauthorizedAccessException();
}

[ApiController]
[Route("api/step3-outcomes")]
[Authorize(Roles = "USER,SUPER")]
public class Step3OutcomesController(ExamSimulationStore simulations) : ControllerBase
{
    [HttpGet("me")]
    public async Task<IActionResult> Get()
    {
        var outcome = await simulations.GetOutcomeAsync(UserId());
        return outcome is null ? NoContent() : Ok(outcome);
    }

    [HttpPut("me")]
    public async Task<IActionResult> Put(UpsertStep3OutcomeRequest request)
    {
        try { return Ok(await simulations.UpsertOutcomeAsync(UserId(), request)); }
        catch (ArgumentException exception) { return BadRequest(exception.Message); }
    }

    [HttpDelete("me")]
    public async Task<IActionResult> Delete()
    {
        await simulations.DeleteOutcomeAsync(UserId());
        return NoContent();
    }

    private string UserId() => User.FindFirstValue(ClaimTypes.NameIdentifier)
        ?? User.FindFirstValue(ClaimTypes.Name)
        ?? User.Identity?.Name
        ?? throw new UnauthorizedAccessException();
}