namespace XP.ImageProcessing.Core.Alignment;

/// <summary>
/// 从旋转模板匹配算子（键 <see cref="ProcessorKey"/>）的 OutputData 读取测量位姿。
/// </summary>
public static class TemplateMatchOutputReader
{
    public const string ProcessorKey = "RotatedTemplateMatching";

    public static bool TryReadMeasuredPose(
        IReadOnlyDictionary<string, object>? outputData,
        out Pose2D measuredPose,
        out string? errorMessage,
        int matchIndex = 0)
    {
        measuredPose = default;
        errorMessage = null;

        if (outputData == null || outputData.Count == 0)
        {
            errorMessage = "Template match output is empty.";
            return false;
        }

        if (outputData.TryGetValue("Matched", out var matchedObj)
            && matchedObj is bool matched
            && !matched)
        {
            if (outputData.TryGetValue("Message", out var msgObj) && msgObj is string msg && !string.IsNullOrWhiteSpace(msg))
                errorMessage = msg;
            else
                errorMessage = "Template match failed (Matched=false).";
            return false;
        }

        if (outputData.TryGetValue("MatchCount", out var countObj))
        {
            int count = Convert.ToInt32(countObj);
            if (count <= 0)
            {
                errorMessage = "Template match count is zero.";
                return false;
            }

            if (matchIndex < 0 || matchIndex >= count)
            {
                errorMessage = $"Match index {matchIndex} is out of range (MatchCount={count}).";
                return false;
            }
        }

        string prefix = matchIndex == 0 ? string.Empty : $"[{matchIndex}]";

        if (!TryReadDouble(outputData, "CenterX" + prefix, out double cx)
            || !TryReadDouble(outputData, "CenterY" + prefix, out double cy)
            || !TryReadDouble(outputData, "Angle" + prefix, out double angle))
        {
            errorMessage = "Template match output is missing CenterX/CenterY/Angle.";
            return false;
        }

        measuredPose = new Pose2D(cx, cy, angle);
        return true;
    }

    private static bool TryReadDouble(IReadOnlyDictionary<string, object> data, string key, out double value)
    {
        value = 0;
        if (!data.TryGetValue(key, out var obj) || obj == null)
            return false;

        try
        {
            value = Convert.ToDouble(obj);
            return true;
        }
        catch
        {
            return false;
        }
    }
}