using System.Text.Json;
using Autodesk.AutoCAD.ApplicationServices;
using Autodesk.AutoCAD.DatabaseServices;
using Autodesk.AutoCAD.Geometry;
using PRecAnnot.Abstractions;

namespace PRecAnnot.Plant3D2026;

// This file is deliberately runtime-only.  Core receives only the anonymised
// permit and canonical operation; no AutoCAD handle, database or project path
// crosses the adapter boundary.
internal sealed record FirstLimitedApplyRuntimePermit
{
    public required bool AllowApply { get; init; }
    public required string FixtureMarkerPath { get; init; }
    public required string TargetSnapshotId { get; init; }
    public required string ExpectedPlanId { get; init; }
    public required string VisibilityState { get; init; }
}

internal static class FirstLimitedApplyPermitReader
{
    private const string MarkerContent = "P_REC_ANNOT_TEST_FIXTURE=FIRST_LIMITED_APPLY";

    public static FirstLimitedApplyRuntimePermit ReadFor(Document document)
    {
        var path = Environment.GetEnvironmentVariable("P_REC_ANNOT_APPLY_PERMIT_PATH");
        if (string.IsNullOrWhiteSpace(path) || !Path.IsPathFullyQualified(path) || path.StartsWith("\\\\", StringComparison.Ordinal))
            throw new InvalidOperationException("APPLY_PERMIT_PATH_REQUIRED");
        if (!File.Exists(path)) throw new InvalidOperationException("APPLY_PERMIT_MISSING");

        var permit = JsonSerializer.Deserialize<FirstLimitedApplyRuntimePermit>(File.ReadAllText(path), new JsonSerializerOptions { PropertyNameCaseInsensitive = true });
        if (permit is null || !permit.AllowApply || string.IsNullOrWhiteSpace(permit.TargetSnapshotId) || string.IsNullOrWhiteSpace(permit.ExpectedPlanId) || string.IsNullOrWhiteSpace(permit.VisibilityState))
            throw new InvalidOperationException("APPLY_TEST_FIXTURE_OR_PERMIT_REQUIRED");
        if (!Path.IsPathFullyQualified(permit.FixtureMarkerPath) || permit.FixtureMarkerPath.StartsWith("\\\\", StringComparison.Ordinal) || !File.Exists(permit.FixtureMarkerPath))
            throw new InvalidOperationException("APPLY_TEST_FIXTURE_OR_PERMIT_REQUIRED");
        if (!string.Equals(File.ReadAllText(permit.FixtureMarkerPath).Trim(), MarkerContent, StringComparison.Ordinal))
            throw new InvalidOperationException("APPLY_TEST_FIXTURE_OR_PERMIT_REQUIRED");

        var root = Path.GetDirectoryName(Path.GetFullPath(permit.FixtureMarkerPath))!;
        var drawing = Path.GetFullPath(document.Name);
        if (!drawing.StartsWith(root + Path.DirectorySeparatorChar, StringComparison.OrdinalIgnoreCase))
            throw new InvalidOperationException("APPLY_TEST_FIXTURE_OR_PERMIT_REQUIRED");
        return permit;
    }
}

internal enum PipeAnnotationWriteOutcome { Created, AlreadyExists }

internal sealed class FirstLimitedPipeAnnotationWriter
{
    private const string BlockName = "PIPE";
    private const string XdataApplication = "PXP-OA";

    public PipeAnnotationWriteOutcome Write(Document document, CreatePipeAnnotationOperation operation, string visibilityState)
    {
        var database = document.Database;
        using var transaction = database.TransactionManager.StartTransaction();
        var table = (BlockTable)transaction.GetObject(database.BlockTableId, OpenMode.ForRead);
        if (!table.Has(BlockName)) throw new InvalidOperationException("ANNOTATION_TEMPLATE_BLOCK_MISSING");

        var paper = (BlockTableRecord)transaction.GetObject(table[BlockTableRecord.PaperSpace], OpenMode.ForWrite);
        if (HasOwnedAnnotation(transaction, paper, operation.DuplicateKey)) return PipeAnnotationWriteOutcome.AlreadyExists;
        EnsureRegApp(transaction, database);

        using var annotation = new BlockReference(
            new Point3d(operation.Placement.X, operation.Placement.Y, operation.Placement.Z),
            table[BlockName]);
        paper.AppendEntity(annotation);
        transaction.AddNewlyCreatedDBObject(annotation, true);
        SetConfirmedVisibility(annotation, visibilityState);
        annotation.XData = new ResultBuffer(
            new TypedValue((int)DxfCode.ExtendedDataRegAppName, XdataApplication),
            new TypedValue((int)DxfCode.ExtendedDataAsciiString, operation.DuplicateKey),
            new TypedValue((int)DxfCode.ExtendedDataAsciiString, operation.RuleId));
        transaction.Commit();
        return PipeAnnotationWriteOutcome.Created;
    }

    private static bool HasOwnedAnnotation(Transaction transaction, BlockTableRecord paper, string duplicateKey)
    {
        foreach (ObjectId id in paper)
        {
            if (transaction.GetObject(id, OpenMode.ForRead) is not BlockReference reference) continue;
            using var xdata = reference.GetXDataForApplication(XdataApplication);
            if (xdata?.AsArray().Any(value => value.TypeCode == (int)DxfCode.ExtendedDataAsciiString && string.Equals(value.Value as string, duplicateKey, StringComparison.Ordinal)) == true)
                return true;
        }
        return false;
    }

    private static void EnsureRegApp(Transaction transaction, Database database)
    {
        var apps = (RegAppTable)transaction.GetObject(database.RegAppTableId, OpenMode.ForRead);
        if (apps.Has(XdataApplication)) return;
        apps.UpgradeOpen();
        using var record = new RegAppTableRecord { Name = XdataApplication };
        apps.Add(record);
        transaction.AddNewlyCreatedDBObject(record, true);
    }

    // The "V" property and allowed values are the confirmed legacy PXP-OA
    // dynamic-block contract.  Failure is pre-commit and leaves no entity.
    private static void SetConfirmedVisibility(BlockReference annotation, string visibilityState)
    {
        var property = annotation.DynamicBlockReferencePropertyCollection
            .Cast<DynamicBlockReferenceProperty>()
            .SingleOrDefault(value => string.Equals(value.PropertyName, "V", StringComparison.Ordinal));
        if (property is null || !property.GetAllowedValues().OfType<string>().Contains(visibilityState, StringComparer.Ordinal))
            throw new InvalidOperationException("ANNOTATION_VISIBILITY_STATE_UNSUPPORTED");
        property.Value = visibilityState;
    }
}