import 'dart:convert';

enum ConnectionMode { automatic, direct, relay }

enum HostPlatform { linux, windows }

class RemoteHost {
  const RemoteHost({
    required this.id,
    required this.name,
    required this.address,
    required this.user,
    required this.certificateSha256,
    this.platform = HostPlatform.linux,
    this.connectionMode = ConnectionMode.direct,
    this.edgeApiUrl,
    this.agentPublicKey,
  });

  final String id;
  final String name;
  final String address;
  final String user;
  final String certificateSha256;
  final HostPlatform platform;
  final ConnectionMode connectionMode;
  final String? edgeApiUrl;
  final String? agentPublicKey;

  Uri get uri => normalizeAgentUri(address);
  Uri get windowsUri => normalizeWindowsAgentUri(address);

  RemoteHost copyWith({
    String? id,
    String? name,
    String? address,
    String? user,
    String? certificateSha256,
    HostPlatform? platform,
    ConnectionMode? connectionMode,
    String? edgeApiUrl,
    String? agentPublicKey,
  }) => RemoteHost(
    id: id ?? this.id,
    name: name ?? this.name,
    address: address ?? this.address,
    user: user ?? this.user,
    certificateSha256: certificateSha256 ?? this.certificateSha256,
    platform: platform ?? this.platform,
    connectionMode: connectionMode ?? this.connectionMode,
    edgeApiUrl: edgeApiUrl ?? this.edgeApiUrl,
    agentPublicKey: agentPublicKey ?? this.agentPublicKey,
  );

  Map<String, Object?> toJson() => {
    'id': id,
    'name': name,
    'address': address,
    'user': user,
    'certificate_sha256': certificateSha256,
    'platform': platform.name,
    'connection_mode': connectionMode.name,
    'use_relay': connectionMode != ConnectionMode.direct,
    'edge_api_url': edgeApiUrl,
    'agent_public_key': agentPublicKey,
  };

  factory RemoteHost.fromJson(Map<String, dynamic> json) => RemoteHost(
    id: json['id'] as String,
    name: json['name'] as String,
    address: json['address'] as String,
    user: json['user'] as String? ?? '',
    certificateSha256: json['certificate_sha256'] as String? ?? '',
    platform: _hostPlatformFromJson(json['platform']),
    connectionMode: _connectionModeFromJson(json),
    edgeApiUrl: json['edge_api_url'] as String?,
    agentPublicKey: json['agent_public_key'] as String?,
  );

  static List<RemoteHost> decodeList(String value) {
    final decoded = jsonDecode(value) as List<dynamic>;
    return decoded
        .map((item) => RemoteHost.fromJson(item as Map<String, dynamic>))
        .toList(growable: false);
  }

  static String encodeList(List<RemoteHost> hosts) =>
      jsonEncode(hosts.map((host) => host.toJson()).toList());
}

HostPlatform _hostPlatformFromJson(Object? value) {
  if (value is String) {
    for (final platform in HostPlatform.values) {
      if (platform.name == value) return platform;
    }
  }
  return HostPlatform.linux;
}

ConnectionMode _connectionModeFromJson(Map<String, dynamic> json) {
  final value = json['connection_mode'];
  if (value is String) {
    for (final mode in ConnectionMode.values) {
      if (mode.name == value) return mode;
    }
  }
  return json['use_relay'] == true
      ? ConnectionMode.relay
      : ConnectionMode.direct;
}

class AppSettings {
  const AppSettings({
    this.languageCode,
    this.maxWidth = 1280,
    this.maxHeight = 720,
    this.framesPerSecond = 15,
  });

  final String? languageCode;
  final int maxWidth;
  final int maxHeight;
  final int framesPerSecond;

  AppSettings copyWith({
    String? languageCode,
    int? maxWidth,
    int? maxHeight,
    int? framesPerSecond,
  }) => AppSettings(
    languageCode: languageCode ?? this.languageCode,
    maxWidth: maxWidth ?? this.maxWidth,
    maxHeight: maxHeight ?? this.maxHeight,
    framesPerSecond: framesPerSecond ?? this.framesPerSecond,
  );
}

Uri normalizeAgentUri(String input) {
  final value = input.trim();
  if (value.isEmpty) {
    throw const FormatException('empty address');
  }
  final withScheme = value.contains('://') ? value : 'wss://$value';
  final parsed = Uri.parse(withScheme);
  if (parsed.scheme != 'wss' || parsed.host.isEmpty) {
    throw const FormatException('invalid WSS address');
  }
  if (parsed.path.isNotEmpty && parsed.path != '/') {
    throw const FormatException('agent URL must not contain a path');
  }
  return Uri(
    scheme: 'wss',
    host: parsed.host,
    port: parsed.hasPort ? parsed.port : 39500,
    path: '/',
  );
}

Uri normalizeWindowsAgentUri(String input) {
  final value = input.trim();
  if (value.isEmpty) throw const FormatException('empty address');
  final withScheme = value.contains('://') ? value : 'tcp://$value';
  final parsed = Uri.parse(withScheme);
  if (parsed.scheme != 'tcp' ||
      parsed.host.isEmpty ||
      parsed.userInfo.isNotEmpty ||
      parsed.query.isNotEmpty ||
      parsed.fragment.isNotEmpty ||
      (parsed.path.isNotEmpty && parsed.path != '/')) {
    throw const FormatException('invalid Windows Agent address');
  }
  return Uri(
    scheme: 'tcp',
    host: parsed.host,
    port: parsed.hasPort ? parsed.port : 39501,
  );
}

String normalizeFingerprint(String input) =>
    input.trim().replaceAll(':', '').toLowerCase();

bool isValidFingerprint(String input) =>
    RegExp(r'^[0-9a-f]{64}$').hasMatch(normalizeFingerprint(input));

bool isValidAgentPublicKey(String input) =>
    RegExp(r'^[A-Za-z0-9+/]{43}$').hasMatch(input.trim());