import 'dart:convert';

import 'package:ente_auth/ente_theme_data.dart';
import 'package:ente_auth/models/all_icon_data.dart';
import 'package:ente_auth/theme/ente_theme.dart';
import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:flutter_svg/svg.dart';
import 'package:logging/logging.dart';

class IconUtils {
  IconUtils._privateConstructor();

  static final IconUtils instance = IconUtils._privateConstructor();

  // Map of icon-title to the color code in HEX
  final Map<String, String> _simpleIcons = {};
  final Map<String, CustomIconData> _customIcons = {};
  // Map of icon-color to its luminance
  final Map<Color, double> _colorLuminance = {};
  final List<String> _titleSplitCharacters = ['(', '.'];

  Future<void> init() async {
    await _loadJson();
  }

  Map<String, AllIconData> getAllIcons() {
    Set<String> processedIconPaths = {};
    final allIcons = <String, AllIconData>{};

    final simpleIterator = _simpleIcons.entries.iterator;
    final customIterator = _customIcons.entries.iterator;

    var simpleEntry = simpleIterator.moveNext() ? simpleIterator.current : null;
    var customEntry = customIterator.moveNext() ? customIterator.current : null;

    String simpleIconPath, customIconPath;

    while (simpleEntry != null && customEntry != null) {
      if (simpleEntry.key.compareTo(customEntry.key) <= 0) {
        simpleIconPath = "assets/simple-icons/icons/${simpleEntry.key}.svg";
        if (!processedIconPaths.contains(simpleIconPath)) {
          allIcons[simpleEntry.key] = AllIconData(
            title: simpleEntry.key,
            type: IconType.simpleIcon,
            color: simpleEntry.value,
          );
          processedIconPaths.add(simpleIconPath);
        }
        simpleEntry = simpleIterator.moveNext() ? simpleIterator.current : null;
      } else {
        customIconPath =
            "assets/custom-icons/icons/${customEntry.value.slug ?? customEntry.key}.svg";

        if (!processedIconPaths.contains(customIconPath)) {
          allIcons[customEntry.key] = AllIconData(
            title: customEntry.key,
            type: IconType.customIcon,
            color: customEntry.value.color,
            slug: customEntry.value.slug,
          );
          processedIconPaths.add(customIconPath);
        }
        customEntry = customIterator.moveNext() ? customIterator.current : null;
      }
    }

    while (simpleEntry != null) {
      simpleIconPath = "assets/simple-icons/icons/${simpleEntry.key}.svg";

      if (!processedIconPaths.contains(simpleIconPath)) {
        allIcons[simpleEntry.key] = AllIconData(
          title: simpleEntry.key,
          type: IconType.simpleIcon,
          color: simpleEntry.value,
        );
        processedIconPaths.add(simpleIconPath);
      }
      simpleEntry = simpleIterator.moveNext() ? simpleIterator.current : null;
    }

    while (customEntry != null) {
      customIconPath =
          "assets/custom-icons/icons/${customEntry.value.slug ?? customEntry.key}.svg";

      if (!processedIconPaths.contains(customIconPath)) {
        allIcons[customEntry.key] = AllIconData(
          title: customEntry.key,
          type: IconType.customIcon,
          color: customEntry.value.color,
          slug: customEntry.value.slug,
        );
        processedIconPaths.add(customIconPath);
      }
      customEntry = customIterator.moveNext() ? customIterator.current : null;
    }

    return allIcons;
  }

  Widget getIcon(
    BuildContext context,
    String provider, {
    double width = 24,
  }) {
    final providerTitle = _getProviderTitle(provider);
    final List<String> titlesList = [providerTitle];
    titlesList.addAll(
      _titleSplitCharacters
          .where((char) => providerTitle.contains(char))
          .map((char) => providerTitle.split(char)[0]),
    );
    for (final title in titlesList) {
      if (_customIcons.containsKey(title)) {
        return getSVGIcon(
          "assets/custom-icons/icons/${_customIcons[title]!.slug ?? title}.svg",
          title,
          _customIcons[title]!.color,
          width,
          context,
        );
      } else if (_simpleIcons.containsKey(title)) {
        final simpleIconPath = normalizeSimpleIconName(title);
        return getSVGIcon(
          "assets/simple-icons/icons/$simpleIconPath.svg",
          title,
          _simpleIcons[title],
          width,
          context,
        );
      }
    }
    if (providerTitle.isNotEmpty) {
      bool showLargeIcon = width > 24;
      return CircleAvatar(
        radius: width / 2,
        backgroundColor: getEnteColorScheme(context).avatarColors[
            providerTitle.hashCode %
                getEnteColorScheme(context).avatarColors.length],
        child: Text(
          providerTitle.toUpperCase()[0],
          // fixed color
          style: showLargeIcon
              ? getEnteTextTheme(context).h3Bold.copyWith(color: Colors.white)
              : getEnteTextTheme(context).body.copyWith(color: Colors.white),
        ),
      );
    } else {
      return const SizedBox.shrink();
    }
  }

  Widget getSVGIcon(
    String path,
    String title,
    String? color,
    double width,
    BuildContext context,
  ) {
    final iconColor = _getAdaptiveColor(color, context);
    return SvgPicture.asset(
      path,
      width: width,
      semanticsLabel: title,
      colorFilter: iconColor != null
          ? ColorFilter.mode(
              iconColor,
              BlendMode.srcIn,
            )
          : null,
    );
  }

  Color? _getAdaptiveColor(String? hexColor, BuildContext context) {
    if (hexColor == null) return null;
    final theme = Theme.of(context).brightness;
    final color = Color(int.parse("0xFF$hexColor"));
    // Color is close to neutral-grey and it's too light or dark for theme
    if (_isCloseToNeutralGrey(color) &&
        ((theme == Brightness.light && _getColorLuminance(color) > 0.70) ||
            (theme == Brightness.dark && _getColorLuminance(color) < 0.05))) {
      return Theme.of(context).colorScheme.iconColor;
    }
    return color;
  }

  double _getColorLuminance(Color color) {
    return _colorLuminance.putIfAbsent(color, () => color.computeLuminance());
  }

  bool _isCloseToNeutralGrey(Color color, {double tolerance = 3}) {
    return (color.red - color.green).abs() <= tolerance &&
        (color.green - color.blue).abs() <= tolerance &&
        (color.blue - color.red).abs() <= tolerance;
  }

  Future<void> _loadJson() async {
    try {
      final simpleIconData = await rootBundle
          .loadString('assets/simple-icons/_data/simple-icons.json');
      final simpleIcons = json.decode(simpleIconData);
      for (final icon in simpleIcons) {
        _simpleIcons[icon["title"]
            .toString()
            .replaceAll(' ', '')
            .toLowerCase()] = icon["hex"];
      }
      final customIconData = await rootBundle
          .loadString('assets/custom-icons/_data/custom-icons.json');
      final customIcons = json.decode(customIconData);
      for (final icon in customIcons["icons"]) {
        _customIcons[icon["title"]
            .toString()
            .replaceAll(' ', '')
            .toLowerCase()] = CustomIconData(
          icon["slug"],
          icon["hex"],
        );
        if (icon["altNames"] != null) {
          for (final name in icon["altNames"]) {
            _customIcons[name.toString().replaceAll(' ', '').toLowerCase()] =
                CustomIconData(
              icon["slug"] ?? ((icon["title"] as String).toLowerCase()),
              icon["hex"],
            );
          }
        }
      }
    } catch (e, s) {
      Logger("IconUtils").severe("Error loading icons", e, s);
      if (kDebugMode) {
        rethrow;
      }
    }
  }

  String _getProviderTitle(String provider) {
    return provider.replaceAll(' ', '').toLowerCase();
  }
}

class CustomIconData {
  final String? slug;
  final String? color;

  CustomIconData(this.slug, this.color);
}

final charMap = {
  'á': 'a',
  'à': 'a',
  'â': 'a',
  'ä': 'a',
  'é': 'e',
  'è': 'e',
  'ê': 'e',
  'ë': 'e',
  'í': 'i',
  'ì': 'i',
  'î': 'i',
  'ï': 'i',
  'ó': 'o',
  'ò': 'o',
  'ô': 'o',
  'ö': 'o',
  'ú': 'u',
  'ù': 'u',
  'û': 'u',
  'ü': 'u',
  'ç': 'c',
  'ñ': 'n',
  '.': 'dot',
  '-': '',
  '&': 'and',
  '+': 'plus',
  ':': '',
  "'": '',
  '/': '',
  '!': '',
};
String normalizeSimpleIconName(String input) {
  final buffer = StringBuffer();
  for (var char in input.characters) {
    buffer.write(charMap[char] ?? char);
  }
  return buffer.toString().trim();
}