import 'dart:convert';

import 'package:flutter/material.dart';

const double roomGameDesignWidth = 750;

double resolveRoomGameAvailableHeight(
  BuildContext context, {
  double reservedTop = 12,
}) {
  final mediaQuery = MediaQuery.maybeOf(context);
  if (mediaQuery == null) {
    return 0;
  }

  final bottomInset =
      mediaQuery.viewInsets.bottom > mediaQuery.padding.bottom
          ? mediaQuery.viewInsets.bottom
          : mediaQuery.padding.bottom;
  final availableHeight =
      mediaQuery.size.height -
      mediaQuery.padding.top -
      bottomInset -
      reservedTop;
  if (!availableHeight.isFinite || availableHeight <= 0) {
    return mediaQuery.size.height;
  }
  return availableHeight.clamp(0.0, mediaQuery.size.height).toDouble();
}

double clampRoomGameHeight(
  double value,
  double maxHeight, {
  double minHeight = 0,
}) {
  if (!value.isFinite || value <= 0) {
    return maxHeight > 0 ? maxHeight : 0;
  }
  if (!maxHeight.isFinite || maxHeight <= 0) {
    return value;
  }
  if (minHeight > maxHeight) {
    return maxHeight;
  }
  return value.clamp(minHeight, maxHeight).toDouble();
}

String resolveRoomGameScreenMode(
  Map<String, dynamic> launchParams, {
  required bool fullScreen,
}) {
  final candidates = <String>[
    launchParams['screenMode']?.toString() ?? '',
    launchParams['screen_mode']?.toString() ?? '',
    launchParams['displayMode']?.toString() ?? '',
    launchParams['gameScreenMode']?.toString() ?? '',
  ];
  for (final candidate in candidates) {
    final trimmed = candidate.trim();
    if (trimmed.isNotEmpty) {
      return trimmed.toLowerCase();
    }
  }
  return fullScreen ? 'full' : 'half';
}

String buildRoomGameNativeFitScript({
  required double visibleHeight,
  required double expectedHeight,
}) {
  final options = jsonEncode(<String, dynamic>{
    'visibleHeight': _roundMetric(visibleHeight),
    'expectedHeight': _roundMetric(expectedHeight),
  });
  return '''
    (function() {
      const options = $options;
      const fitKey = '__roomGameNativeViewportFit';

      function applyFit() {
        try {
          const visibleHeight = Number(options.visibleHeight) || window.innerHeight || 0;
          const expectedHeight = Number(options.expectedHeight) || 0;
          if (!document.body || !visibleHeight || !expectedHeight) {
            return;
          }

          const rawScale = visibleHeight / expectedHeight;
          const scale = Math.min(1, rawScale);
          window[fitKey] = {
            scale: scale,
            visibleHeight: visibleHeight,
            expectedHeight: expectedHeight,
            compact: scale < 0.999
          };

          if (scale >= 0.999) {
            document.documentElement.style.overflow = '';
            document.body.style.overflow = '';
            document.body.style.transform = '';
            document.body.style.transformOrigin = '';
            document.body.style.width = '';
            document.body.style.minHeight = '';
            document.documentElement.removeAttribute('data-room-game-native-fit');
            return;
          }

          document.documentElement.setAttribute('data-room-game-native-fit', 'true');
          document.documentElement.style.overflow = 'hidden';
          document.body.style.overflow = 'hidden';
          document.body.style.transform = 'scale(' + scale + ')';
          document.body.style.transformOrigin = 'top left';
          document.body.style.width = (100 / scale) + '%';
          document.body.style.minHeight = expectedHeight + 'px';
        } catch (_) {}
      }

      if (document.readyState === 'loading') {
        document.addEventListener('DOMContentLoaded', applyFit, { once: true });
      } else {
        applyFit();
      }
      [50, 250, 800, 1600, 3000].forEach(function(delay) {
        window.setTimeout(applyFit, delay);
      });
      if (!window.__roomGameNativeFitResizeReady) {
        window.__roomGameNativeFitResizeReady = true;
        window.addEventListener('resize', applyFit, true);
        window.addEventListener('orientationchange', function() {
          window.setTimeout(applyFit, 120);
        }, true);
      }
    })();
  ''';
}

double _roundMetric(double value) {
  if (!value.isFinite) {
    return 0;
  }
  return double.parse(value.toStringAsFixed(2));
}