using System.Text;

namespace Sick.ColaB.Commands;

/// <summary>
/// Command to call a method on the scanner (sMN - Method by Name)
/// </summary>
public sealed class MethodCommand(string methodName, params string[] parameters) : CommandBase($"sMN {methodName} {string.Join(" ", parameters)}")
{
    public string MethodName { get; } = methodName;
    public string[] Parameters { get; } = parameters;

    public string? ReplyValue { get; private set; }

    public override bool ProcessReply(ReadOnlyMemory<byte> replyData)
    {
        // Parse reply: "sAN <methodName> <result>" or "sMA <methodName> <result>" or "sFA <errorCode>" (Error)
        var replyString = Encoding.ASCII.GetString(replyData.Span);
        
        // Check if reply starts with "sFA" (Error) - scanner rejected the command
        if (replyString.StartsWith("sFA", StringComparison.Ordinal))
        {
            // Extract error code if present
            var errorParts = replyString.Split(' ', StringSplitOptions.RemoveEmptyEntries);
            var errorInfo = errorParts.Length > 1 ? $" (error code: {string.Join(" ", errorParts.Skip(1))})" : "";
            WasSuccessful = false;
            ReplyValue = null;
            return false;
        }

        // Check if reply starts with "sAN" (Answer) or "sMA" (Method Answer)
        if (!replyString.StartsWith("sAN", StringComparison.Ordinal) &&
            !replyString.StartsWith("sMA", StringComparison.Ordinal))
        {
            WasSuccessful = false;
            return false;
        }

        // Extract result after method name
        var parts = replyString.Split(' ', StringSplitOptions.RemoveEmptyEntries);
        
        if (parts.Length >= 2 && parts[1] == MethodName)
        {
            if (parts.Length > 2)
            {
                ReplyValue = string.Join(" ", parts.Skip(2));
            }
            else
            {
                ReplyValue = string.Empty;
            }
            WasSuccessful = true;
            return true;
        }

        WasSuccessful = false;
        return false;
    }
}