namespace XP.ImageProcessing.Core.Alignment;

/// <summary>
/// 示教 ROI + 基准/测量位姿 → 运行图多边形；供 <c>RoiAlignment</c> 算子与流水线胶水调用。
/// </summary>
public static class RoiAlignmentApplier
{
    public static RoiAlignmentResult Apply(AlignmentRecipe recipe, Pose2D measuredPose)
    {
        if (recipe == null)
            return Fail(default, measuredPose, "Alignment recipe is null.");

        return Apply(recipe.ReferencePose, recipe.RoiPoints, measuredPose);
    }

    public static RoiAlignmentResult Apply(
        Pose2D referencePose,
        IReadOnlyList<Point2D> teachPoints,
        Pose2D measuredPose)
    {
        if (teachPoints == null || teachPoints.Count < 3)
            return Fail(referencePose, measuredPose, "Teach polygon must have at least 3 points.");

        var transformed = RoiAlignment.TransformPolygon(teachPoints, referencePose, measuredPose);
        var transformedInt = RoiAlignment.TransformPolygonToInt(teachPoints, referencePose, measuredPose);

        return new RoiAlignmentResult
        {
            Success = true,
            ReferencePose = referencePose,
            MeasuredPose = measuredPose,
            TransformedPoints = transformed,
            TransformedPointsInt = transformedInt
        };
    }

    public static RoiAlignmentResult ApplyFromTemplateMatchOutput(
        AlignmentRecipe recipe,
        IReadOnlyDictionary<string, object>? templateMatchOutput,
        int matchIndex = 0)
    {
        if (recipe == null)
            return Fail(default, default, "Alignment recipe is null.");

        if (!TemplateMatchOutputReader.TryReadMeasuredPose(templateMatchOutput, out var measured, out var error, matchIndex))
            return Fail(recipe.ReferencePose, default, error);

        return Apply(recipe, measured);
    }

    public static IReadOnlyList<Point2D> ReadTeachPolygon(IReadOnlyDictionary<string, object> parameters)
    {
        if (parameters == null)
            return Array.Empty<Point2D>();

        if (!parameters.TryGetValue(RoiPolygonParameterNames.PolyCount, out var countObj))
            return Array.Empty<Point2D>();

        int count = Convert.ToInt32(countObj);
        if (count < 3)
            return Array.Empty<Point2D>();

        count = Math.Min(count, RoiPolygonParameterNames.MaxPoints);
        var points = new List<Point2D>(count);
        for (int i = 0; i < count; i++)
        {
            if (!parameters.TryGetValue(RoiPolygonParameterNames.PolyX(i), out var xObj)
                || !parameters.TryGetValue(RoiPolygonParameterNames.PolyY(i), out var yObj))
                continue;

            points.Add(new Point2D(Convert.ToDouble(xObj), Convert.ToDouble(yObj)));
        }

        return points;
    }

    /// <summary>
    /// 将变换结果写入参数字典（PolyCount、PolyX/PolyY、RoiMode），供下游 VoidMeasurement 等算子使用。
    /// </summary>
    public static void WriteToParameters(
        IDictionary<string, object> parameters,
        RoiAlignmentResult result,
        bool setRoiModePolygon = true)
    {
        if (parameters == null)
            throw new ArgumentNullException(nameof(parameters));

        parameters[RoiAlignmentOutputKeys.Success] = result.Success;
        if (!string.IsNullOrEmpty(result.ErrorMessage))
            parameters[RoiAlignmentOutputKeys.Message] = result.ErrorMessage!;

        if (!result.Success)
            return;

        int count = result.TransformedPointsInt.Count;
        parameters[RoiPolygonParameterNames.PolyCount] = count;

        for (int i = 0; i < RoiPolygonParameterNames.MaxPoints; i++)
        {
            if (i < count)
            {
                parameters[RoiPolygonParameterNames.PolyX(i)] = result.TransformedPointsInt[i].X;
                parameters[RoiPolygonParameterNames.PolyY(i)] = result.TransformedPointsInt[i].Y;
            }
            else
            {
                parameters[RoiPolygonParameterNames.PolyX(i)] = 0;
                parameters[RoiPolygonParameterNames.PolyY(i)] = 0;
            }
        }

        if (setRoiModePolygon)
            parameters[RoiPolygonParameterNames.RoiMode] = "Polygon";
    }

    /// <summary>
    /// 将变换结果写入算子 OutputData（与 <see cref="WriteToParameters"/> 键名一致，便于流水线拷贝）。
    /// </summary>
    public static void WriteToOutputData(IDictionary<string, object> outputData, RoiAlignmentResult result)
    {
        if (outputData == null)
            throw new ArgumentNullException(nameof(outputData));

        WriteToParameters(outputData, result);

        if (result.Success)
        {
            outputData["ReferenceCenterX"] = result.ReferencePose.X;
            outputData["ReferenceCenterY"] = result.ReferencePose.Y;
            outputData["ReferenceAngle"] = result.ReferencePose.AngleDegrees;
            outputData["MeasuredCenterX"] = result.MeasuredPose.X;
            outputData["MeasuredCenterY"] = result.MeasuredPose.Y;
            outputData["MeasuredAngle"] = result.MeasuredPose.AngleDegrees;
            outputData["TransformedPointCount"] = result.TransformedPointsInt.Count;
        }
    }

    private static RoiAlignmentResult Fail(Pose2D reference, Pose2D measured, string? message)
        => new()
        {
            Success = false,
            ErrorMessage = message,
            ReferencePose = reference,
            MeasuredPose = measured
        };
}