import "package:flutter/foundation.dart";
import "package:flutter/services.dart";
import "package:flutter/widgets.dart";

// macOS side of the eyedropper. Everything else that isnt web lands here too
// and simply reports "no native sampler", which is the honest answer - theres
// no handler registered on windows/linux/ios/android.

const _channel = MethodChannel("garage/eyedropper");

bool? _cachedAvailability;

Future<bool> nativeEyedropperAvailable() async {
  if (_cachedAvailability != null) return _cachedAvailability!;

  if (defaultTargetPlatform != TargetPlatform.macOS) {
    _cachedAvailability = false;
    return false;
  }
  try {
    _cachedAvailability = await _channel.invokeMethod<bool>("isAvailable");
  } catch (error, stack) {
    // an older macOS (or a runner thats never been rebuilt with the swift
    // side in it) - not fatal, we just fall back to in-app sampling.
    debugPrint("eyedropper: isAvailable failed: $error\n$stack");
    _cachedAvailability = false;
  }
  return _cachedAvailability ?? false;
}

Future<Color?> pickNativeScreenColor() async {
  try {
    final picked = await _channel.invokeMapMethod<String, int>("pick");
    if (picked == null) return null;

    final r = picked["r"];
    final g = picked["g"];
    final b = picked["b"];
    if (r == null || g == null || b == null) {
      debugPrint("eyedropper: native pick returned a malformed colour $picked");
      return null;
    }
    return Color.fromARGB(255, r, g, b);
  } catch (error, stack) {
    debugPrint("eyedropper: native pick failed: $error\n$stack");
    return null;
  }
}