import 'package:uuid/uuid.dart';

/// What kind of thing this service deploys.
enum ServiceKind { jarService, webApp, generic }

/// Front-end framework for a [ServiceKind.webApp].
enum WebFramework { angular, react, flutterWeb, staticFiles }

/// How a service's health is probed.
enum HealthCheckType { auto, http, tcp, command, none }

extension ServiceKindX on ServiceKind {
  String get label => switch (this) {
    ServiceKind.webApp => 'Web app (nginx)',
    ServiceKind.generic => 'Service (any binary)',
    ServiceKind.jarService => 'Jar service',
  };
}

extension HealthCheckTypeX on HealthCheckType {
  String get label => switch (this) {
    HealthCheckType.auto => 'systemd (auto)',
    HealthCheckType.http => 'HTTP request',
    HealthCheckType.tcp => 'TCP port',
    HealthCheckType.command => 'Command exit 0',
    HealthCheckType.none => 'Disabled',
  };
}

extension WebFrameworkX on WebFramework {
  String get label => switch (this) {
    WebFramework.angular => 'Angular',
    WebFramework.react => 'React',
    WebFramework.flutterWeb => 'Flutter web',
    WebFramework.staticFiles => 'Static files',
  };

  /// Default build command (run through a shell). Blank = no build.
  String get defaultBuild => switch (this) {
    WebFramework.angular => 'npm install && npm run build',
    WebFramework.react => 'npm install && npm run build',
    WebFramework.flutterWeb => 'flutter build web --release',
    WebFramework.staticFiles => '',
  };
}

/// A single deployable service that lives on a [ServerProfile].
/// One server can host many of these — jar services and/or web apps.
class ServiceConfig {
  final String id;
  String name; // friendly label, e.g. "orders-api"

  ServiceKind kind;
  WebFramework framework;

  /// Absolute target directory on the server.
  /// - jar service: where the jar lives, e.g. /opt/orders
  /// - web app: the nginx web root, e.g. /var/www/orders
  String remoteDir;

  /// The filename the uploaded jar should be saved as (jar services only).
  String remoteJarName;

  /// The systemd unit to (re)start for a jar service, e.g. "orders".
  String serviceName;

  /// The nginx unit to reload for a web app (web only). Default "nginx".
  String nginxService;

  /// Optional custom log command (WITHOUT sudo — the deployer adds it).
  String logCommand;

  /// Absolute path to the local source project. When set, PeachDeployments can build
  /// from source before deploying.
  String localProjectPath;

  /// Optional custom build command. Blank auto-detects.
  String buildCommand;

  /// jar services: glob/path for the built jar (blank auto-detects).
  String jarPattern;

  /// web apps: build output directory relative to the project (blank
  /// auto-detects, e.g. dist/, build/, build/web).
  String outputSubdir;

  /// How to probe this service's health.
  HealthCheckType healthType;

  /// Health target: a URL (http), port number (tcp), or shell command.
  String healthTarget;

  ServiceConfig({
    String? id,
    this.name = 'New service',
    this.kind = ServiceKind.jarService,
    this.framework = WebFramework.react,
    this.remoteDir = '/opt/app',
    this.remoteJarName = '',
    this.serviceName = '',
    this.nginxService = 'nginx',
    this.logCommand = '',
    this.localProjectPath = '',
    this.buildCommand = '',
    this.jarPattern = '',
    this.outputSubdir = '',
    this.healthType = HealthCheckType.auto,
    this.healthTarget = '',
  }) : id = id ?? const Uuid().v4();

  bool get isWeb => kind == ServiceKind.webApp;
  bool get isGeneric => kind == ServiceKind.generic;
  bool get canBuild => localProjectPath.trim().isNotEmpty;

  String get effectiveLogCommand {
    if (logCommand.trim().isNotEmpty) return logCommand.trim();
    if (isWeb) {
      final unit = nginxService.trim().isEmpty ? 'nginx' : nginxService.trim();
      return 'journalctl -u $unit -n 200 --no-pager';
    }
    return 'journalctl -u ${serviceName.isEmpty ? 'app' : serviceName} '
        '-n 200 --no-pager';
  }

  /// Normalized remote directory (no trailing slash).
  String get remoteRoot => remoteDir.endsWith('/')
      ? remoteDir.substring(0, remoteDir.length - 1)
      : remoteDir;

  String remotePath(String jarLabelFallback) {
    final name = remoteJarName.trim().isNotEmpty
        ? remoteJarName.trim()
        : jarLabelFallback;
    return '$remoteRoot/$name';
  }

  ServiceConfig copy() => ServiceConfig.fromJson(toJson());

  Map<String, dynamic> toJson() => {
    'id': id,
    'name': name,
    'kind': kind.name,
    'framework': framework.name,
    'remoteDir': remoteDir,
    'remoteJarName': remoteJarName,
    'serviceName': serviceName,
    'nginxService': nginxService,
    'logCommand': logCommand,
    'localProjectPath': localProjectPath,
    'buildCommand': buildCommand,
    'jarPattern': jarPattern,
    'outputSubdir': outputSubdir,
    'healthType': healthType.name,
    'healthTarget': healthTarget,
  };

  factory ServiceConfig.fromJson(Map<String, dynamic> j) => ServiceConfig(
    id: j['id'] as String?,
    name: (j['name'] ?? 'service') as String,
    kind: ServiceKind.values.firstWhere(
      (k) => k.name == j['kind'],
      orElse: () => ServiceKind.jarService,
    ),
    framework: WebFramework.values.firstWhere(
      (f) => f.name == j['framework'],
      orElse: () => WebFramework.react,
    ),
    remoteDir: (j['remoteDir'] ?? '/opt/app') as String,
    remoteJarName: (j['remoteJarName'] ?? '') as String,
    serviceName: (j['serviceName'] ?? '') as String,
    nginxService: (j['nginxService'] ?? 'nginx') as String,
    logCommand: (j['logCommand'] ?? '') as String,
    localProjectPath: (j['localProjectPath'] ?? '') as String,
    buildCommand: (j['buildCommand'] ?? '') as String,
    jarPattern: (j['jarPattern'] ?? '') as String,
    outputSubdir: (j['outputSubdir'] ?? '') as String,
    healthType: HealthCheckType.values.firstWhere(
      (h) => h.name == j['healthType'],
      orElse: () => HealthCheckType.auto,
    ),
    healthTarget: (j['healthTarget'] ?? '') as String,
  );
}