using Managing.Application.Abstractions.Services;
using Managing.Domain.Backtests;
using Microsoft.Extensions.Logging;

namespace Managing.Application.Backtests;

/// <summary>
/// Service for executing genetic algorithm requests without Orleans dependencies.
/// Extracted from GeneticBacktestGrain to be reusable in compute workers.
/// </summary>
public class GeneticExecutor
{
    private readonly ILogger<GeneticExecutor> _logger;
    private readonly IGeneticService _geneticService;
    private readonly IAccountService _accountService;
    private readonly IWebhookService _webhookService;

    public GeneticExecutor(
        ILogger<GeneticExecutor> logger,
        IGeneticService geneticService,
        IAccountService accountService,
        IWebhookService webhookService)
    {
        _logger = logger;
        _geneticService = geneticService;
        _accountService = accountService;
        _webhookService = webhookService;
    }

    /// <summary>
    /// Executes a genetic algorithm request.
    /// </summary>
    /// <param name="geneticRequestId">The genetic request ID to process</param>
    /// <param name="progressCallback">Optional callback for progress updates (0-100)</param>
    /// <param name="cancellationToken">Cancellation token</param>
    /// <returns>The genetic algorithm result</returns>
    public async Task<GeneticAlgorithmResult> ExecuteAsync(
        string geneticRequestId,
        Func<int, Task> progressCallback = null,
        CancellationToken cancellationToken = default)
    {
        try
        {
            // Load the request by status lists and filter by ID (Pending first, then Failed for retries)
            var pending = await _geneticService.GetGeneticRequestsAsync(GeneticRequestStatus.Pending);
            var failed = await _geneticService.GetGeneticRequestsAsync(GeneticRequestStatus.Failed);
            var request = pending.Concat(failed).FirstOrDefault(r => r.RequestId == geneticRequestId);

            if (request == null)
            {
                _logger.LogWarning("[GeneticExecutor] Request {RequestId} not found among pending/failed.",
                    geneticRequestId);
                throw new InvalidOperationException($"Genetic request {geneticRequestId} not found");
            }

            _logger.LogInformation("[GeneticExecutor] Processing genetic request {RequestId} for user {UserId}",
                request.RequestId, request.User.Id);

            // Mark running
            request.Status = GeneticRequestStatus.Running;
            await _geneticService.UpdateGeneticRequestAsync(request);

            // Load user accounts if not already loaded
            if (request.User.Accounts == null || !request.User.Accounts.Any())
            {
                request.User.Accounts = (await _accountService.GetAccountsByUserAsync(request.User)).ToList();
            }

            // Create progress wrapper if callback provided
            Func<int, Task> wrappedProgressCallback = null;
            if (progressCallback != null)
            {
                wrappedProgressCallback = async (percentage) =>
                {
                    try
                    {
                        await progressCallback(percentage);
                    }
                    catch (Exception ex)
                    {
                        _logger.LogWarning(ex, "Error in progress callback for genetic request {RequestId}", geneticRequestId);
                    }
                };
            }

            // Run GA
            var result = await _geneticService.RunGeneticAlgorithm(request, cancellationToken);

            // Update final state
            request.Status = GeneticRequestStatus.Completed;
            request.CompletedAt = DateTime.UtcNow;
            request.BestFitness = result.BestFitness;
            request.BestIndividual = result.BestIndividual;
            request.ProgressInfo = result.ProgressInfo;
            await _geneticService.UpdateGeneticRequestAsync(request);

            _logger.LogInformation("[GeneticExecutor] Completed genetic request {RequestId}. Best Fitness: {BestFitness}",
                request.RequestId, result.BestFitness);

            // Send webhook notification if user has telegram channel
            if (!string.IsNullOrEmpty(request.User?.TelegramChannel))
            {
                var message = $"✅ Genetic algorithm optimization completed for {request.Ticker} on {request.Timeframe}. " +
                             $"Request ID: {request.RequestId}. " +
                             $"Best Fitness: {result.BestFitness:F4}. " +
                             $"Generations: {request.Generations}, Population: {request.PopulationSize}.";
                
                await _webhookService.SendMessage(message, request.User.TelegramChannel);
            }

            return result;
        }
        catch (Exception ex)
        {
            _logger.LogError(ex, "[GeneticExecutor] Error processing genetic request {RequestId}", geneticRequestId);
            
            // Try to mark as failed
            try
            {
                var running = await _geneticService.GetGeneticRequestsAsync(GeneticRequestStatus.Running);
                var req = running.FirstOrDefault(r => r.RequestId == geneticRequestId);
                if (req != null)
                {
                    req.Status = GeneticRequestStatus.Failed;
                    req.ErrorMessage = ex.Message;
                    req.CompletedAt = DateTime.UtcNow;
                    await _geneticService.UpdateGeneticRequestAsync(req);

                    // Send webhook notification for failed genetic request
                    if (!string.IsNullOrEmpty(req.User?.TelegramChannel))
                    {
                        var message = $"❌ Genetic algorithm optimization failed for {req.Ticker} on {req.Timeframe}. " +
                                     $"Request ID: {req.RequestId}. " +
                                     $"Error: {ex.Message}";
                        
                        await _webhookService.SendMessage(message, req.User.TelegramChannel);
                    }
                }
            }
            catch (Exception updateEx)
            {
                _logger.LogError(updateEx, "[GeneticExecutor] Failed to update request status to Failed for {RequestId}", geneticRequestId);
            }

            throw;
        }
    }
}