using ECMJobRunner.Application.Common.Constants;
using ECMJobRunner.Application.Common.Dtos;
using ECMJobRunner.Application.Common.Exceptions;
using ECMJobRunner.Application.Common.Interfaces;
using ECMJobRunner.Application.Common.Options;
using ECMJobRunner.Domain.Entities;
using MediatR;
using Microsoft.Extensions.Options;
using ReC.Client;
using ReC.Client.Api;
using System;
using System.Text.RegularExpressions;
using System.Threading;
using System.Threading.Tasks;

namespace ECMJobRunner.Application.DEXJob
{
    /// <summary>
    /// Command to trigger a single DEX job execution
    /// Executes main query, check query, and ReC request in sequence
    /// </summary>
    public class TriggeringDEXJobCommand : IRequest<Unit>
    {
        /// <summary>
        /// The SQL job to execute
        /// </summary>
        public ProfileSqlJob Job { get; set; } = null!;

        /// <summary>
        /// Unique batch identifier for this execution
        /// </summary>
        public string BatchId { get; set; } = null!;
    }

    /// <summary>
    /// Handler for TriggeringDEXJobCommand
    /// Orchestrates execution of main query, check query, and ReC HTTP request
    /// </summary>
    public class TriggeringDEXJobCommandHandler(
        ISQLExecutor executor, 
        IOptions<DexJobOptions> options, 
        ReCClient reCClient) 
        : IRequestHandler<TriggeringDEXJobCommand, Unit>
    {
        private readonly DexJobOptions _options = options.Value;

        /// <summary>
        /// Handles the TriggeringDEXJobCommand
        /// Executes main query, check query, and ReC request according to configuration
        /// </summary>
        /// <param name="request">The command containing job and batch ID</param>
        /// <param name="cancel">Cancellation token</param>
        /// <returns>Unit value indicating completion</returns>
        public async Task<Unit> Handle(TriggeringDEXJobCommand request, CancellationToken cancel)
        {
            #region Main Query
            if (!string.IsNullOrWhiteSpace(request.Job.SqlMainQuery))
            {
                var sqlMainQuery = Regex.Replace(
                    request.Job.SqlMainQuery!,
                    _options.Placeholders.BatchId.Pattern,
                    request.BatchId,
                    _options.Placeholders.BatchId.RegexOptions);

                try
                {
                    var result = await executor.ExecuteQueryAsync<MainQueryResult>(sqlMainQuery, cancel);
                    if (_options.Error.MainQuery.OnUnexpectedResult == ErrorAction.Stop)
                    {
                        if (result is null)
                            throw new DEXJobException("SQL Main Query", request.BatchId, sqlMainQuery, "Main Query returned nothing.");
                        else if (result.ReturnValue is not null)
                            throw new DEXJobException("SQL Main Query", request.BatchId, sqlMainQuery, $"The query unexpectedly returned the value {result.ReturnValue}. The expected value was null.");
                    }
                }
                catch (Exception ex)
                {
                    if (_options.Error.MainQuery.OnExecution == ErrorAction.Stop)
                        throw new DEXJobException("SQL Main Query", request.BatchId, sqlMainQuery, ex);
                }
            }
            else if (_options.Error.MainQuery.IfNullOrWhiteSpace == ErrorAction.Stop)
            {
                throw new DEXJobException("SQL Main Query", request.BatchId, null, "SQL Main Query is null or empty");
            }
            #endregion

            #region Check Query
            if (!string.IsNullOrWhiteSpace(request.Job.SqlCheckQuery))
            {
                var sqlCheckQuery = Regex.Replace(
                    request.Job.SqlCheckQuery!,
                    _options.Placeholders.BatchId.Pattern,
                    request.BatchId,
                    _options.Placeholders.BatchId.RegexOptions);

                try
                {
                    var result = await executor.ExecuteQueryAsync<CheckQueryResult>(sqlCheckQuery, cancel);
                    if (_options.Error.CheckQuery.OnUnexpectedResult == ErrorAction.Stop)
                    {
                        if (result is null)
                            throw new DEXJobException("SQL Check Query", request.BatchId, sqlCheckQuery, "Check Query returned nothing.");
                        else if (result.ReturnValue <= 0)
                            throw new DEXJobException("SQL Check Query", request.BatchId, sqlCheckQuery, $"The query unexpectedly returned the value {result.ReturnValue}. The expected value was any value greater than 0.");
                    }
                }
                catch (Exception ex)
                {
                    if (_options.Error.CheckQuery.OnExecution == ErrorAction.Stop)
                        throw new DEXJobException("SQL Check Query", request.BatchId, sqlCheckQuery, ex);
                }
            }
            else if (_options.Error.CheckQuery.IfNullOrWhiteSpace == ErrorAction.Stop)
            {
                throw new DEXJobException("SQL Check Query", request.BatchId, null, "SQL Check Query is null or empty");
            }
            #endregion

            #region ReC Request
            long profileId = request.Job.ProfileId;
            await reCClient.RecActions.InvokeAsync(profileId, new InvokeReferences()
            {
                BatchId = request.BatchId,  // Fixed: Use request.BatchId instead of profileId.ToString()
            }, cancel);
            #endregion

            return Unit.Value;  // Fixed: Added missing return statement
        }
    }
}