import 'package:flutter/material.dart';
import 'package:iconsax/iconsax.dart';
import 'package:animate_do/animate_do.dart';
import 'package:getwidget/getwidget.dart';
import '../api/api.dart';
import '../dialogs/create_agent_dialog.dart';

/// Agents management page
///
/// Displays all AI agents with ability to create, view, edit, and delete agents.
/// Integrates with backend CQRS API for agent management.
class AgentsPage extends StatefulWidget {
  const AgentsPage({super.key});

  @override
  State<AgentsPage> createState() => _AgentsPageState();
}

class _AgentsPageState extends State<AgentsPage> {
  final CqrsApiClient _apiClient = CqrsApiClient(
    config: ApiClientConfig.development,
  );

  List<AgentDto>? _agents;
  bool _isLoading = true;
  String? _errorMessage;

  @override
  void initState() {
    super.initState();
    _loadAgents();
  }

  @override
  void dispose() {
    _apiClient.dispose();
    super.dispose();
  }

  Future<void> _loadAgents() async {
    setState(() {
      _isLoading = true;
      _errorMessage = null;
    });

    // TODO: Implement list agents endpoint when available
    // For now, show empty state
    await Future<void>.delayed(const Duration(milliseconds: 500));

    setState(() {
      _agents = [];
      _isLoading = false;
    });
  }

  Future<void> _createAgent(CreateAgentCommand command) async {
    final Result<void> result = await _apiClient.createAgent(command);

    result.when(
      success: (_) {
        if (mounted) {
          ScaffoldMessenger.of(context).showSnackBar(
            SnackBar(
              content: Text('Agent "${command.name}" created successfully'),
              backgroundColor: Theme.of(context).colorScheme.primary,
            ),
          );
          _loadAgents();
        }
      },
      error: (ApiErrorInfo error) {
        if (mounted) {
          ScaffoldMessenger.of(context).showSnackBar(
            SnackBar(
              content: Text('Failed to create agent: ${error.message}'),
              backgroundColor: Theme.of(context).colorScheme.error,
            ),
          );
        }
      },
    );
  }

  @override
  Widget build(BuildContext context) {
    final ColorScheme colorScheme = Theme.of(context).colorScheme;

    return Container(
      padding: const EdgeInsets.all(24),
      child: Column(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          // Header Section
          _buildHeader(colorScheme),
          const SizedBox(height: 24),

          // Content Section
          Expanded(
            child: _buildContent(colorScheme),
          ),
        ],
      ),
    );
  }

  Widget _buildHeader(ColorScheme colorScheme) {
    return Row(
      mainAxisAlignment: MainAxisAlignment.spaceBetween,
      children: [
        // Title & Description
        Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            Text(
              'AI Agents',
              style: TextStyle(
                fontSize: 28,
                fontWeight: FontWeight.bold,
                color: colorScheme.onSurface,
              ),
            ),
            const SizedBox(height: 4),
            Text(
              'Manage your AI agents and their configurations',
              style: TextStyle(
                fontSize: 14,
                color: colorScheme.onSurfaceVariant,
              ),
            ),
          ],
        ),

        // Create Agent Button
        FadeInRight(
          duration: const Duration(milliseconds: 400),
          child: ElevatedButton.icon(
            onPressed: () => _showCreateAgentDialog(),
            icon: const Icon(Iconsax.add, size: 20),
            label: const Text('Create Agent'),
            style: ElevatedButton.styleFrom(
              backgroundColor: colorScheme.primary,
              foregroundColor: Colors.white,
              padding: const EdgeInsets.symmetric(horizontal: 24, vertical: 16),
              shape: RoundedRectangleBorder(
                borderRadius: BorderRadius.circular(12),
              ),
            ),
          ),
        ),
      ],
    );
  }

  Widget _buildContent(ColorScheme colorScheme) {
    if (_isLoading) {
      return Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            CircularProgressIndicator(
              valueColor: AlwaysStoppedAnimation<Color>(colorScheme.primary),
            ),
            const SizedBox(height: 16),
            Text(
              'Loading agents...',
              style: TextStyle(
                color: colorScheme.onSurfaceVariant,
                fontSize: 14,
              ),
            ),
          ],
        ),
      );
    }

    if (_errorMessage != null) {
      return _buildErrorState(colorScheme);
    }

    if (_agents == null || _agents!.isEmpty) {
      return _buildEmptyState(colorScheme);
    }

    return _buildAgentsList(colorScheme);
  }

  Widget _buildEmptyState(ColorScheme colorScheme) {
    return Center(
      child: FadeIn(
        duration: const Duration(milliseconds: 600),
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            Icon(
              Iconsax.cpu,
              size: 80,
              color: colorScheme.onSurfaceVariant.withValues(alpha: 0.5),
            ),
            const SizedBox(height: 24),
            Text(
              'No Agents Yet',
              style: TextStyle(
                fontSize: 24,
                fontWeight: FontWeight.bold,
                color: colorScheme.onSurface,
              ),
            ),
            const SizedBox(height: 12),
            Text(
              'Create your first AI agent to get started',
              style: TextStyle(
                fontSize: 14,
                color: colorScheme.onSurfaceVariant,
              ),
              textAlign: TextAlign.center,
            ),
            const SizedBox(height: 32),
            ElevatedButton.icon(
              onPressed: () => _showCreateAgentDialog(),
              icon: const Icon(Iconsax.add),
              label: const Text('Create Your First Agent'),
              style: ElevatedButton.styleFrom(
                backgroundColor: colorScheme.primary,
                foregroundColor: Colors.white,
                padding: const EdgeInsets.symmetric(
                  horizontal: 32,
                  vertical: 16,
                ),
                shape: RoundedRectangleBorder(
                  borderRadius: BorderRadius.circular(12),
                ),
              ),
            ),
          ],
        ),
      ),
    );
  }

  Widget _buildErrorState(ColorScheme colorScheme) {
    return Center(
      child: FadeIn(
        duration: const Duration(milliseconds: 400),
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            Icon(
              Iconsax.danger,
              size: 64,
              color: colorScheme.error,
            ),
            const SizedBox(height: 16),
            Text(
              'Error Loading Agents',
              style: TextStyle(
                fontSize: 20,
                fontWeight: FontWeight.bold,
                color: colorScheme.onSurface,
              ),
            ),
            const SizedBox(height: 8),
            Text(
              _errorMessage ?? 'Unknown error',
              style: TextStyle(
                fontSize: 14,
                color: colorScheme.onSurfaceVariant,
              ),
              textAlign: TextAlign.center,
            ),
            const SizedBox(height: 24),
            ElevatedButton.icon(
              onPressed: _loadAgents,
              icon: const Icon(Iconsax.refresh),
              label: const Text('Retry'),
              style: ElevatedButton.styleFrom(
                backgroundColor: colorScheme.primary,
                foregroundColor: Colors.white,
              ),
            ),
          ],
        ),
      ),
    );
  }

  Widget _buildAgentsList(ColorScheme colorScheme) {
    return GridView.builder(
      gridDelegate: const SliverGridDelegateWithMaxCrossAxisExtent(
        maxCrossAxisExtent: 400,
        childAspectRatio: 1.5,
        crossAxisSpacing: 16,
        mainAxisSpacing: 16,
      ),
      itemCount: _agents!.length,
      itemBuilder: (BuildContext context, int index) {
        return FadeInUp(
          duration: Duration(milliseconds: 300 + (index * 100)),
          child: _buildAgentCard(_agents![index], colorScheme),
        );
      },
    );
  }

  Widget _buildAgentCard(AgentDto agent, ColorScheme colorScheme) {
    return Card(
      elevation: 0,
      color: colorScheme.surfaceContainerLow,
      shape: RoundedRectangleBorder(
        borderRadius: BorderRadius.circular(16),
        side: BorderSide(
          color: colorScheme.outline.withValues(alpha: 0.2),
          width: 1,
        ),
      ),
      child: InkWell(
        onTap: () => _showAgentDetails(agent),
        borderRadius: BorderRadius.circular(16),
        child: Padding(
          padding: const EdgeInsets.all(20),
          child: Column(
            crossAxisAlignment: CrossAxisAlignment.start,
            children: [
              // Header Row
              Row(
                children: [
                  // Agent Type Icon
                  Container(
                    padding: const EdgeInsets.all(10),
                    decoration: BoxDecoration(
                      color: colorScheme.primary.withValues(alpha: 0.2),
                      borderRadius: BorderRadius.circular(12),
                    ),
                    child: Icon(
                      _getAgentTypeIcon(agent.type),
                      color: colorScheme.primary,
                      size: 24,
                    ),
                  ),
                  const SizedBox(width: 12),
                  // Agent Name & Status
                  Expanded(
                    child: Column(
                      crossAxisAlignment: CrossAxisAlignment.start,
                      children: [
                        Text(
                          agent.name,
                          style: TextStyle(
                            fontSize: 16,
                            fontWeight: FontWeight.bold,
                            color: colorScheme.onSurface,
                          ),
                          maxLines: 1,
                          overflow: TextOverflow.ellipsis,
                        ),
                        const SizedBox(height: 4),
                        _buildStatusBadge(agent.status, colorScheme),
                      ],
                    ),
                  ),
                  // More Options
                  IconButton(
                    icon: Icon(
                      Iconsax.more,
                      color: colorScheme.onSurfaceVariant,
                    ),
                    onPressed: () => _showAgentMenu(agent),
                  ),
                ],
              ),
              const SizedBox(height: 16),
              // Description
              Text(
                agent.description,
                style: TextStyle(
                  fontSize: 13,
                  color: colorScheme.onSurfaceVariant,
                ),
                maxLines: 2,
                overflow: TextOverflow.ellipsis,
              ),
              const Spacer(),
              // Footer
              Row(
                children: [
                  Icon(
                    Iconsax.cpu,
                    size: 14,
                    color: colorScheme.onSurfaceVariant,
                  ),
                  const SizedBox(width: 6),
                  Expanded(
                    child: Text(
                      '${agent.modelProvider}/${agent.modelName}',
                      style: TextStyle(
                        fontSize: 12,
                        color: colorScheme.onSurfaceVariant,
                      ),
                      maxLines: 1,
                      overflow: TextOverflow.ellipsis,
                    ),
                  ),
                ],
              ),
            ],
          ),
        ),
      ),
    );
  }

  Widget _buildStatusBadge(AgentStatus status, ColorScheme colorScheme) {
    Color badgeColor;
    IconData icon;

    switch (status) {
      case AgentStatus.active:
        badgeColor = Colors.green;
        icon = Iconsax.tick_circle5;
      case AgentStatus.inactive:
        badgeColor = Colors.orange;
        icon = Iconsax.pause_circle5;
      case AgentStatus.error:
        badgeColor = colorScheme.error;
        icon = Iconsax.danger5;
    }

    return Row(
      mainAxisSize: MainAxisSize.min,
      children: [
        Icon(icon, size: 12, color: badgeColor),
        const SizedBox(width: 4),
        Text(
          status.value,
          style: TextStyle(
            fontSize: 11,
            color: badgeColor,
            fontWeight: FontWeight.w500,
          ),
        ),
      ],
    );
  }

  IconData _getAgentTypeIcon(AgentType type) {
    switch (type) {
      case AgentType.codeGenerator:
        return Iconsax.code;
      case AgentType.codeReviewer:
        return Iconsax.search_zoom_in;
      case AgentType.debugger:
        return Iconsax.shield_search;
      case AgentType.documenter:
        return Iconsax.document_text;
      case AgentType.custom:
        return Iconsax.setting_2;
    }
  }

  void _showCreateAgentDialog() {
    showDialog<void>(
      context: context,
      builder: (BuildContext context) {
        return CreateAgentDialog(
          onCreateAgent: _createAgent,
        );
      },
    );
  }

  void _showAgentDetails(AgentDto agent) {
    // TODO: Implement agent details view
    ScaffoldMessenger.of(context).showSnackBar(
      SnackBar(
        content: Text('Viewing agent: ${agent.name}'),
      ),
    );
  }

  void _showAgentMenu(AgentDto agent) {
    // TODO: Implement agent menu (edit, delete, etc.)
    ScaffoldMessenger.of(context).showSnackBar(
      SnackBar(
        content: Text('Agent menu for: ${agent.name}'),
      ),
    );
  }
}