/// Agent management endpoints for CQRS API
library;

import 'dart:async';
import 'dart:convert';
import 'dart:io';

import 'package:http/http.dart' as http;

import '../client.dart';
import '../types.dart';

// =============================================================================
// Enums
// =============================================================================

/// Specifies the type/purpose of the agent
enum AgentType {
  codeGenerator('CodeGenerator'),
  codeReviewer('CodeReviewer'),
  debugger('Debugger'),
  documenter('Documenter'),
  custom('Custom');

  const AgentType(this.value);
  final String value;

  static AgentType fromString(String value) {
    return AgentType.values.firstWhere(
      (type) => type.value == value,
      orElse: () => AgentType.custom,
    );
  }

  /// Convert from integer value (backend enum representation)
  /// Backend: CodeGenerator=0, CodeReviewer=1, Debugger=2, Documenter=3, Custom=4
  static AgentType fromInt(int value) {
    if (value >= 0 && value < AgentType.values.length) {
      return AgentType.values[value];
    }
    return AgentType.custom;
  }
}

/// Represents the current status of an agent
enum AgentStatus {
  active('Active'),
  inactive('Inactive'),
  error('Error');

  const AgentStatus(this.value);
  final String value;

  static AgentStatus fromString(String value) {
    return AgentStatus.values.firstWhere(
      (status) => status.value == value,
      orElse: () => AgentStatus.inactive,
    );
  }

  /// Convert from integer value (backend enum representation)
  /// Backend: Active=0, Inactive=1, Error=2
  static AgentStatus fromInt(int value) {
    if (value >= 0 && value < AgentStatus.values.length) {
      return AgentStatus.values[value];
    }
    return AgentStatus.inactive;
  }
}

/// Specifies the type of model provider (cloud API or local endpoint)
enum ModelProviderType {
  cloudApi('CloudApi'),
  localEndpoint('LocalEndpoint'),
  custom('Custom');

  const ModelProviderType(this.value);
  final String value;

  static ModelProviderType fromString(String value) {
    return ModelProviderType.values.firstWhere(
      (type) => type.value == value,
      orElse: () => ModelProviderType.custom,
    );
  }

  /// Convert from integer value (backend enum representation)
  /// Backend: CloudApi=0, LocalEndpoint=1, Custom=2
  static ModelProviderType fromInt(int value) {
    if (value >= 0 && value < ModelProviderType.values.length) {
      return ModelProviderType.values[value];
    }
    return ModelProviderType.custom;
  }
}

// =============================================================================
// Commands
// =============================================================================

/// Command to create a new AI agent with configuration
class CreateAgentCommand implements Serializable {
  final String name;
  final String description;
  final AgentType type;
  final String modelProvider;
  final String modelName;
  final ModelProviderType providerType;
  final String? modelEndpoint;
  final String? apiKey;
  final double temperature;
  final int maxTokens;
  final String systemPrompt;
  final bool enableMemory;
  final int conversationWindowSize;

  const CreateAgentCommand({
    required this.name,
    required this.description,
    required this.type,
    required this.modelProvider,
    required this.modelName,
    required this.providerType,
    this.modelEndpoint,
    this.apiKey,
    this.temperature = 0.7,
    this.maxTokens = 4000,
    required this.systemPrompt,
    this.enableMemory = true,
    this.conversationWindowSize = 10,
  });

  @override
  Map<String, Object?> toJson() => {
        'name': name,
        'description': description,
        'type': type.value,
        'modelProvider': modelProvider,
        'modelName': modelName,
        'providerType': providerType.value,
        'modelEndpoint': modelEndpoint,
        'apiKey': apiKey,
        'temperature': temperature,
        'maxTokens': maxTokens,
        'systemPrompt': systemPrompt,
        'enableMemory': enableMemory,
        'conversationWindowSize': conversationWindowSize,
      };
}

/// Command to update an existing agent's configuration
class UpdateAgentCommand implements Serializable {
  final String id;
  final String? name;
  final String? description;
  final AgentType? type;
  final String? modelProvider;
  final String? modelName;
  final ModelProviderType? providerType;
  final String? modelEndpoint;
  final String? apiKey;
  final double? temperature;
  final int? maxTokens;
  final String? systemPrompt;
  final bool? enableMemory;
  final int? conversationWindowSize;
  final AgentStatus? status;

  const UpdateAgentCommand({
    required this.id,
    this.name,
    this.description,
    this.type,
    this.modelProvider,
    this.modelName,
    this.providerType,
    this.modelEndpoint,
    this.apiKey,
    this.temperature,
    this.maxTokens,
    this.systemPrompt,
    this.enableMemory,
    this.conversationWindowSize,
    this.status,
  });

  @override
  Map<String, Object?> toJson() => {
        'id': id,
        if (name != null) 'name': name,
        if (description != null) 'description': description,
        if (type != null) 'type': type!.value,
        if (modelProvider != null) 'modelProvider': modelProvider,
        if (modelName != null) 'modelName': modelName,
        if (providerType != null) 'providerType': providerType!.value,
        if (modelEndpoint != null) 'modelEndpoint': modelEndpoint,
        if (apiKey != null) 'apiKey': apiKey,
        if (temperature != null) 'temperature': temperature,
        if (maxTokens != null) 'maxTokens': maxTokens,
        if (systemPrompt != null) 'systemPrompt': systemPrompt,
        if (enableMemory != null) 'enableMemory': enableMemory,
        if (conversationWindowSize != null)
          'conversationWindowSize': conversationWindowSize,
        if (status != null) 'status': status!.value,
      };
}

/// Command to soft-delete an agent
class DeleteAgentCommand implements Serializable {
  final String id;

  const DeleteAgentCommand({required this.id});

  @override
  Map<String, Object?> toJson() => {'id': id};
}

// =============================================================================
// Queries
// =============================================================================

/// Query to get a single agent by ID
class GetAgentQuery implements Serializable {
  final String id;

  const GetAgentQuery({required this.id});

  @override
  Map<String, Object?> toJson() => {'id': id};
}

// =============================================================================
// DTOs
// =============================================================================

/// Response containing agent details
class AgentDto {
  final String id;
  final String name;
  final String description;
  final AgentType type;
  final String modelProvider;
  final String modelName;
  final ModelProviderType providerType;
  final String? modelEndpoint;
  final double? temperature;
  final int? maxTokens;
  final String? systemPrompt;
  final bool? enableMemory;
  final int? conversationWindowSize;
  final AgentStatus status;
  final DateTime createdAt;
  final DateTime updatedAt;

  const AgentDto({
    required this.id,
    required this.name,
    required this.description,
    required this.type,
    required this.modelProvider,
    required this.modelName,
    required this.providerType,
    this.modelEndpoint,
    this.temperature,
    this.maxTokens,
    this.systemPrompt,
    this.enableMemory,
    this.conversationWindowSize,
    required this.status,
    required this.createdAt,
    required this.updatedAt,
  });

  factory AgentDto.fromJson(Map<String, Object?> json) {
    // Helper to parse enum from either int or string
    AgentType parseAgentType(Object? value) {
      if (value is int) return AgentType.fromInt(value);
      if (value is String) return AgentType.fromString(value);
      return AgentType.custom;
    }

    AgentStatus parseAgentStatus(Object? value) {
      if (value is int) return AgentStatus.fromInt(value);
      if (value is String) return AgentStatus.fromString(value);
      return AgentStatus.inactive;
    }

    ModelProviderType parseProviderType(Object? value) {
      if (value is int) return ModelProviderType.fromInt(value);
      if (value is String) return ModelProviderType.fromString(value);
      return ModelProviderType.custom;
    }

    return AgentDto(
      id: json['id'] as String,
      name: json['name'] as String,
      description: json['description'] as String,
      type: parseAgentType(json['type']),
      modelProvider: json['modelProvider'] as String,
      modelName: json['modelName'] as String,
      providerType: parseProviderType(json['providerType']),
      modelEndpoint: json['modelEndpoint'] as String?,
      temperature: json['temperature'] != null ? (json['temperature'] as num).toDouble() : null,
      maxTokens: json['maxTokens'] as int?,
      systemPrompt: json['systemPrompt'] as String?,
      enableMemory: json['enableMemory'] as bool?,
      conversationWindowSize: json['conversationWindowSize'] as int?,
      status: parseAgentStatus(json['status']),
      createdAt: DateTime.parse(json['createdAt'] as String),
      updatedAt: DateTime.parse(json['updatedAt'] as String),
    );
  }

  Map<String, Object?> toJson() => {
        'id': id,
        'name': name,
        'description': description,
        'type': type.value,
        'modelProvider': modelProvider,
        'modelName': modelName,
        'providerType': providerType.value,
        'modelEndpoint': modelEndpoint,
        'temperature': temperature,
        'maxTokens': maxTokens,
        'systemPrompt': systemPrompt,
        'enableMemory': enableMemory,
        'conversationWindowSize': conversationWindowSize,
        'status': status.value,
        'createdAt': createdAt.toIso8601String(),
        'updatedAt': updatedAt.toIso8601String(),
      };
}

// =============================================================================
// Extension Methods
// =============================================================================

/// Agent management endpoints
extension AgentEndpoint on CqrsApiClient {
  /// Create a new AI agent
  ///
  /// Example:
  /// ```dart
  /// final result = await client.createAgent(
  ///   CreateAgentCommand(
  ///     name: 'Code Generator',
  ///     description: 'AI agent for code generation',
  ///     type: AgentType.codeGenerator,
  ///     modelProvider: 'ollama',
  ///     modelName: 'phi',
  ///     providerType: ModelProviderType.localEndpoint,
  ///     modelEndpoint: 'http://localhost:11434',
  ///     systemPrompt: 'You are a code generation assistant',
  ///   ),
  /// );
  /// ```
  Future<Result<void>> createAgent(CreateAgentCommand command) async {
    return executeCommand(
      endpoint: 'createAgent',
      command: command,
    );
  }

  /// Update an existing agent's configuration
  ///
  /// Example:
  /// ```dart
  /// final result = await client.updateAgent(
  ///   UpdateAgentCommand(
  ///     id: 'agent-uuid',
  ///     name: 'Updated Name',
  ///     status: AgentStatus.active,
  ///   ),
  /// );
  /// ```
  Future<Result<void>> updateAgent(UpdateAgentCommand command) async {
    return executeCommand(
      endpoint: 'updateAgent',
      command: command,
    );
  }

  /// Soft-delete an agent
  ///
  /// Example:
  /// ```dart
  /// final result = await client.deleteAgent(
  ///   DeleteAgentCommand(id: 'agent-uuid'),
  /// );
  /// ```
  Future<Result<void>> deleteAgent(DeleteAgentCommand command) async {
    return executeCommand(
      endpoint: 'deleteAgent',
      command: command,
    );
  }

  /// Get a single agent by ID
  ///
  /// Example:
  /// ```dart
  /// final result = await client.getAgent('agent-uuid');
  ///
  /// result.when(
  ///   success: (agent) => print('Agent: ${agent.name}'),
  ///   error: (error) => print('Error: ${error.message}'),
  /// );
  /// ```
  Future<Result<AgentDto>> getAgent(String id) async {
    return executeQuery<AgentDto>(
      endpoint: 'getAgent',
      query: GetAgentQuery(id: id),
      fromJson: (json) => AgentDto.fromJson(json as Map<String, Object?>),
    );
  }

  /// List all agents
  ///
  /// Returns a list of all active agents from the backend.
  /// Backend endpoint: GET /api/agents
  ///
  /// Example:
  /// ```dart
  /// final result = await client.listAgents();
  ///
  /// result.when(
  ///   success: (agents) => print('Found ${agents.length} agents'),
  ///   error: (error) => print('Error: ${error.message}'),
  /// );
  /// ```
  Future<Result<List<AgentDto>>> listAgents() async {
    try {
      final Uri url = Uri.parse('${config.baseUrl}/api/agents');
      final http.Response response = await http
          .get(url, headers: config.defaultHeaders)
          .timeout(config.timeout);

      if (response.statusCode >= 200 && response.statusCode < 300) {
        final Object? jsonData = jsonDecode(response.body);
        if (jsonData is! List) {
          return ApiError<List<AgentDto>>(ApiErrorInfo(
            message: 'Expected array response, got ${jsonData.runtimeType}',
            type: ApiErrorType.serialization,
          ));
        }

        final List<AgentDto> agents = jsonData
            .map((item) => AgentDto.fromJson(item as Map<String, Object?>))
            .toList();

        return ApiSuccess<List<AgentDto>>(agents);
      }

      // Handle error responses
      return ApiError<List<AgentDto>>(ApiErrorInfo(
        message: 'Failed to load agents',
        type: ApiErrorType.http,
        statusCode: response.statusCode,
      ));
    } on TimeoutException {
      return ApiError<List<AgentDto>>(ApiErrorInfo(
        message: 'Request timed out',
        type: ApiErrorType.timeout,
      ));
    } on SocketException {
      return ApiError<List<AgentDto>>(ApiErrorInfo(
        message: 'No internet connection',
        type: ApiErrorType.network,
      ));
    } catch (e) {
      return ApiError<List<AgentDto>>(ApiErrorInfo(
        message: 'Unexpected error: $e',
        type: ApiErrorType.unknown,
      ));
    }
  }

  /// Get conversations for a specific agent
  ///
  /// Returns all conversations associated with the specified agent.
  /// Backend endpoint: GET /api/agents/{id}/conversations
  ///
  /// Example:
  /// ```dart
  /// final result = await client.getAgentConversations('agent-uuid');
  ///
  /// result.when(
  ///   success: (conversations) {
  ///     print('Found ${conversations.length} conversations for agent');
  ///   },
  ///   error: (error) => print('Error: ${error.message}'),
  /// );
  /// ```
  Future<Result<List<dynamic>>> getAgentConversations(String agentId) async {
    try {
      final Uri url =
          Uri.parse('${config.baseUrl}/api/agents/$agentId/conversations');
      final http.Response response = await http
          .get(url, headers: config.defaultHeaders)
          .timeout(config.timeout);

      if (response.statusCode >= 200 && response.statusCode < 300) {
        final Object? jsonData = jsonDecode(response.body);
        if (jsonData is! List) {
          return ApiError<List<dynamic>>(ApiErrorInfo(
            message: 'Expected array response, got ${jsonData.runtimeType}',
            type: ApiErrorType.serialization,
          ));
        }

        return ApiSuccess<List<dynamic>>(jsonData);
      }

      return ApiError<List<dynamic>>(ApiErrorInfo(
        message: 'Failed to load agent conversations',
        type: ApiErrorType.http,
        statusCode: response.statusCode,
      ));
    } on TimeoutException {
      return ApiError<List<dynamic>>(ApiErrorInfo(
        message: 'Request timed out',
        type: ApiErrorType.timeout,
      ));
    } on SocketException {
      return ApiError<List<dynamic>>(ApiErrorInfo(
        message: 'No internet connection',
        type: ApiErrorType.network,
      ));
    } catch (e) {
      return ApiError<List<dynamic>>(ApiErrorInfo(
        message: 'Unexpected error: $e',
        type: ApiErrorType.unknown,
      ));
    }
  }

  /// Get execution history for a specific agent
  ///
  /// Returns the 100 most recent executions for the specified agent.
  /// Backend endpoint: GET /api/agents/{id}/executions
  ///
  /// Example:
  /// ```dart
  /// final result = await client.getAgentExecutions('agent-uuid');
  ///
  /// result.when(
  ///   success: (executions) {
  ///     print('Found ${executions.length} executions for agent');
  ///   },
  ///   error: (error) => print('Error: ${error.message}'),
  /// );
  /// ```
  Future<Result<List<dynamic>>> getAgentExecutions(String agentId) async {
    try {
      final Uri url =
          Uri.parse('${config.baseUrl}/api/agents/$agentId/executions');
      final http.Response response = await http
          .get(url, headers: config.defaultHeaders)
          .timeout(config.timeout);

      if (response.statusCode >= 200 && response.statusCode < 300) {
        final Object? jsonData = jsonDecode(response.body);
        if (jsonData is! List) {
          return ApiError<List<dynamic>>(ApiErrorInfo(
            message: 'Expected array response, got ${jsonData.runtimeType}',
            type: ApiErrorType.serialization,
          ));
        }

        return ApiSuccess<List<dynamic>>(jsonData);
      }

      return ApiError<List<dynamic>>(ApiErrorInfo(
        message: 'Failed to load agent executions',
        type: ApiErrorType.http,
        statusCode: response.statusCode,
      ));
    } on TimeoutException {
      return ApiError<List<dynamic>>(ApiErrorInfo(
        message: 'Request timed out',
        type: ApiErrorType.timeout,
      ));
    } on SocketException {
      return ApiError<List<dynamic>>(ApiErrorInfo(
        message: 'No internet connection',
        type: ApiErrorType.network,
      ));
    } catch (e) {
      return ApiError<List<dynamic>>(ApiErrorInfo(
        message: 'Unexpected error: $e',
        type: ApiErrorType.unknown,
      ));
    }
  }
}