// =============================================================================
// GB5 Framework — ReportOrchestrationServiceExtensions
// Namespace : FrameworkSL.ReportOrchestration
// Purpose   : DI registration for all orchestration services.
//             Call AddReportOrchestration() once in Program.cs of each
//             module API and once in the Framework API.
//
// =============================================================================
// MIGRATION STANDARD — READ THIS BEFORE MIGRATING A REPORT
// =============================================================================
//
// STEP 1: Add MREPORTCONFIG row for your report
//   - DATASOURCETYPE:      0=OLTP (default), 1=ReportDB, 2=ArchiveDB, 3=Auto
//   - ASYNCMODE:           0=Auto (period-based), 1=AlwaysAsync, 2=AlwaysSync
//   - ASYNCTHRESHOLDDAYS:  90 (default) — adjust per report complexity
//   - QUERYTIMEOUTSECONDS: 30 sync / 300 async (defaults)
//   - PIVOTENGINE:         0=None, 1=Backend, 2=Frontend
//   - ISNOLOCKALLOWED:     0 (true) for ReportDB/Archive MSSQL reads
//   - ALLOWEDEXPORTFORMATS: "0,1,2,3" = Grid,PDF,Excel,CSV (default)
//   - REPORTCATEGORY:      0=Operational, 1=Analytical, 2=KPI, 3=Archive
//
// STEP 2: Add MREPORTDATASOURCERULE rows (optional, for Auto datasource)
//   Example: DateRangeDays > 365 → ArchiveDB
//   RULETYPE=0, THRESHOLDVALUE=365, TARGETDATASOURCE=2, RULEPRIORITY=10
//
// STEP 3: Migrate the endpoint class
//   BEFORE (typical legacy pattern):
//   ─────────────────────────────────
//   public class SalesReportEndpoint : BaseEndpoint
//   {
//       public async Task<IActionResult> GetReport([FromBody] LoginDTO loginDTO)
//       {
//           string connStr = ConfigHelper.GetConnectionString(loginDTO.ServerConfigId);
//           using var conn = new SqlConnection(connStr);
//           var data = await conn.QueryAsync<...>(Sql, new { loginDTO.ClientId, ... });
//           return Ok(data);
//       }
//   }
//
//   AFTER (orchestrated pattern):
//   ─────────────────────────────
//   [ReportEndpoint(ReportCode = "SALES001", PreferredDataSource = DataSourceType.ReportDb)]
//   public class SalesReportEndpoint : ReportEndpointBase
//   {
//       public SalesReportEndpoint(IReportConnectionResolver resolver) : base(resolver) { }
//
//       public override async IAsyncEnumerable<IReadOnlyDictionary<string, object?>>
//           GetReportDataAsync(
//               ReportExecutionContext context,
//               IDbConnection connection,
//               [EnumeratorCancellation] CancellationToken ct = default)
//       {
//           var p = BuildBaseParameters(context);
//           p.Add("FromDate", GetParameter<DateTime?>(context, "FromDate"));
//           p.Add("ToDate",   GetParameter<DateTime?>(context, "ToDate"));
//
//           await foreach (var row in connection.QueryUnbufferedAsync<Dictionary<string, object?>>(
//               Sql, p, commandTimeout: context.QueryTimeoutSeconds).WithCancellation(ct))
//           {
//               yield return row;
//           }
//       }
//
//       private const string Sql = @"
//           SELECT  I.INVOICENO, I.INVOICEDATE, C.CUSTOMERNAME, ...
//           FROM    TINVOICE I
//           JOIN    MCUSTOMER C ON C.CUSTOMERID = I.CUSTOMERID
//           WHERE   I.CLIENTID    = @ClientId
//           AND     I.INVOICEDATE BETWEEN @FromDate AND @ToDate";
//   }
//
// STEP 4: Remove from the endpoint
//   ✗ Connection string construction
//   ✗ SqlConnection / NpgsqlConnection instantiation
//   ✗ Export calls (PivotExcelExport, PivotPdfExport, CsvExporter)
//   ✗ DataPivotEngine calls
//   ✗ SysJob submission
//
// STEP 5: Keep in the endpoint
//   ✓ All SQL (unchanged)
//   ✓ All business parameter extraction
//   ✓ Any pre/post data processing specific to this report
//
// =============================================================================

using System.Reflection;
using FrameworkBLL.ReportOrchestration;
using GB5Shared.DTO.Framework.Login;
using GB5Shared.Enums.ReportOrchestration;
using Microsoft.Extensions.DependencyInjection;

namespace FrameworkSL.ReportOrchestration
{
    /// <summary>
    /// DI registration for the report orchestration infrastructure.
    /// Call once per module API and once in the Framework API.
    /// </summary>
    public static class ReportOrchestrationServiceExtensions
    {
        /// <summary>
        /// Registers all orchestration services with appropriate lifetimes.
        /// </summary>
        /// <param name="services">The service collection.</param>
        /// <param name="reportAssemblies">
        /// One or more assemblies containing <see cref="ReportEndpointBase"/>
        /// implementations for this module. Pass <c>typeof(YourEndpoint).Assembly</c>.
        /// The registry scans these for <see cref="ReportEndpointAttribute"/>.
        /// </param>
        public static IServiceCollection AddReportOrchestration(
            this IServiceCollection services,
            params Assembly[] reportAssemblies)
        {
            // -----------------------------------------------------------------
            // Singleton: registry and configuration (built once at startup)
            // -----------------------------------------------------------------
            services.AddSingleton<IReportEndpointRegistry>(sp =>
            {
                var logger   = sp.GetRequiredService<Microsoft.Extensions.Logging.ILogger<ReportEndpointRegistry>>();
                var registry = new ReportEndpointRegistry(sp, logger);
                foreach (var assembly in reportAssemblies)
                    registry.ScanAssembly(assembly);
                return registry;
            });

            // -----------------------------------------------------------------
            // Scoped: one instance per HTTP request
            // -----------------------------------------------------------------

            // Connection resolution — reads MSERVERCONFIG via scoped cache
            services.AddScoped<IReportConnectionResolver, ReportConnectionResolver>();
            services.AddScoped<IServerConfigCache, ServerConfigCache>();

            // Orchestration pipeline
            services.AddScoped<IQueryOrchestrator, QueryOrchestrator>();
            services.AddScoped<IDataSourceRuleEvaluator, DataSourceRuleEvaluator>();
            services.AddScoped<IAsyncDecisionEngine, AsyncDecisionEngine>();

            // -----------------------------------------------------------------
            // Register each discovered ReportEndpointBase as Scoped
            // (Scoped so they can inject Scoped services like DAL, BLL etc.)
            // -----------------------------------------------------------------
            foreach (var assembly in reportAssemblies)
            {
                var endpointTypes = assembly.GetTypes()
                    .Where(t => !t.IsAbstract
                             && t.IsClass
                             && t.IsSubclassOf(typeof(ReportEndpointBase))
                             && t.GetCustomAttributes(
                                 typeof(ReportEndpointAttribute), true).Length > 0);

                foreach (var type in endpointTypes)
                {
                    services.AddScoped(type);
                    services.AddScoped(
                        typeof(IReportEndpoint),
                        sp => sp.GetRequiredService(type));
                }
            }

            return services;
        }
    }

    // =========================================================================
    // ReportRequestDTO — the standard request body for all report HTTP actions
    // =========================================================================

    /// <summary>
    /// Standard request body posted by the Angular frontend for any report call.
    /// The module's HTTP action method receives this and passes it to the
    /// orchestrator builder.
    /// </summary>
    public sealed class ReportRequestDTO
    {
        /// <summary>The authenticated session.</summary>
        public LoginDTO LoginDTO { get; init; } = null!;

        /// <summary>MREPORT.REPORTID. -1 for analysis reports (use AnalysisId).</summary>
        public int ReportId { get; init; } = -1;

        /// <summary>MANALYSIS.ANALYSISID. -1 for standard reports.</summary>
        public int AnalysisId { get; init; } = -1;

        /// <summary>MREPORTVIEW.REPORTVIEWID. -1 = use default view.</summary>
        public int ViewId { get; init; } = -1;

        /// <summary>Report-specific filter parameters (FromDate, ToDate, etc.).</summary>
        public Dictionary<string, object?> Parameters { get; init; } = new();

        /// <summary>The export format requested by the user. Default: Grid.</summary>
        public ExportFormat ExportFormat { get; init; } = ExportFormat.Grid;
    }
}