import 'package:flutter/material.dart';
import 'package:provider/provider.dart';
import '../../models/agent_info.dart';
import '../../providers/session_provider.dart';
import '../../theme/app_theme.dart';
import '../../widgets/common/expandable_card.dart';

class AgentsScreen extends StatelessWidget {
  const AgentsScreen({super.key});

  @override
  Widget build(BuildContext context) {
    final provider = context.watch<SessionProvider>();
    final session = provider.session;
    if (session == null) {
      return const Center(
        child: Text('No session loaded',
            style: TextStyle(color: AppColors.textMuted)),
      );
    }

    return Scaffold(
      backgroundColor: AppColors.background,
      body: ListView(
        padding: const EdgeInsets.all(24),
        children: [
          const Text(
            'Agents Overview',
            style: TextStyle(
              fontSize: 20,
              fontWeight: FontWeight.bold,
              color: AppColors.textPrimary,
            ),
          ),
          const SizedBox(height: 8),
          Text(
            '${session.agents.length} agent(s) used in this session',
            style: const TextStyle(fontSize: 13, color: AppColors.textSecondary),
          ),
          const SizedBox(height: 24),

          // Summary cards
          Wrap(
            spacing: 12,
            runSpacing: 12,
            children: [
              _SummaryCard(
                label: 'Total Agents',
                value: '${session.agents.length}',
                icon: Icons.smart_toy_outlined,
                color: AppColors.agent,
              ),
              _SummaryCard(
                label: 'Total Tools Used',
                value: '${session.toolsByName.length}',
                icon: Icons.build_outlined,
                color: AppColors.tool,
              ),
              _SummaryCard(
                label: 'Total Tokens',
                value: _formatTokens(session.totalUsage.totalTokens),
                icon: Icons.data_usage,
                color: AppColors.assistant,
              ),
            ],
          ),
          const SizedBox(height: 24),

          // Agent cards
          for (final agent in session.agents) ...[
            _AgentCard(agent: agent),
            const SizedBox(height: 12),
          ],
        ],
      ),
    );
  }

  String _formatTokens(int tokens) {
    if (tokens >= 1000000) return '${(tokens / 1000000).toStringAsFixed(1)}M';
    if (tokens >= 1000) return '${(tokens / 1000).toStringAsFixed(1)}K';
    return '$tokens';
  }
}

class _SummaryCard extends StatelessWidget {
  final String label;
  final String value;
  final IconData icon;
  final Color color;

  const _SummaryCard({
    required this.label,
    required this.value,
    required this.icon,
    required this.color,
  });

  @override
  Widget build(BuildContext context) {
    return Container(
      width: 200,
      padding: const EdgeInsets.all(16),
      decoration: BoxDecoration(
        color: AppColors.surface,
        borderRadius: BorderRadius.circular(8),
        border: Border.all(color: AppColors.surfaceBorder),
      ),
      child: Column(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          Icon(icon, size: 20, color: color),
          const SizedBox(height: 12),
          Text(
            value,
            style: TextStyle(
              fontSize: 24,
              fontWeight: FontWeight.bold,
              color: color,
            ),
          ),
          const SizedBox(height: 4),
          Text(
            label,
            style: const TextStyle(fontSize: 12, color: AppColors.textMuted),
          ),
        ],
      ),
    );
  }
}

class _AgentCard extends StatelessWidget {
  final AgentInfo agent;

  const _AgentCard({required this.agent});

  @override
  Widget build(BuildContext context) {
    final isMain = agent.id == 'main';
    final color = isMain ? AppColors.assistant : AppColors.agent;

    return ExpandableCard(
      initiallyExpanded: isMain,
      backgroundColor: isMain ? AppColors.assistantBg : AppColors.agentBg,
      borderColor: color.withAlpha(40),
      header: Row(
        children: [
          Icon(
            isMain ? Icons.smart_toy : Icons.smart_toy_outlined,
            size: 16,
            color: color,
          ),
          const SizedBox(width: 8),
          Expanded(
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                Text(
                  agent.name,
                  style: TextStyle(
                    fontSize: 13,
                    fontWeight: FontWeight.w600,
                    color: color,
                  ),
                ),
                if (agent.subagentType != null)
                  Text(
                    agent.subagentType!,
                    style: const TextStyle(
                        fontSize: 11, color: AppColors.textMuted),
                  ),
              ],
            ),
          ),
          if (agent.model != null)
            Container(
              padding: const EdgeInsets.symmetric(horizontal: 6, vertical: 2),
              decoration: BoxDecoration(
                color: AppColors.surfaceLight,
                borderRadius: BorderRadius.circular(3),
              ),
              child: Text(
                agent.model!,
                style: const TextStyle(
                    fontSize: 10,
                    color: AppColors.textSecondary,
                    fontFamily: 'JetBrains Mono'),
              ),
            ),
        ],
      ),
      child: Column(
        crossAxisAlignment: CrossAxisAlignment.stretch,
        children: [
          // Stats row
          Row(
            children: [
              _StatChip('Messages', '${agent.messageCount}'),
              const SizedBox(width: 8),
              _StatChip('Tool Calls', '${agent.toolsUsed.length}'),
              const SizedBox(width: 8),
              _StatChip(
                'Input Tokens',
                _formatTokens(agent.aggregatedUsage.inputTokens),
              ),
              const SizedBox(width: 8),
              _StatChip(
                'Output Tokens',
                _formatTokens(agent.aggregatedUsage.outputTokens),
              ),
            ],
          ),
          const SizedBox(height: 12),

          // Description
          if (agent.description != null) ...[
            const Text(
              'DESCRIPTION',
              style: TextStyle(
                fontSize: 10,
                fontWeight: FontWeight.w600,
                color: AppColors.textMuted,
                letterSpacing: 1,
              ),
            ),
            const SizedBox(height: 4),
            Text(
              agent.description!,
              style: const TextStyle(
                  fontSize: 12, color: AppColors.textSecondary),
            ),
            const SizedBox(height: 12),
          ],

          // Prompt
          if (agent.prompt != null) ...[
            ExpandableCard(
              backgroundColor: AppColors.surface,
              borderColor: AppColors.surfaceBorder,
              header: const Text(
                'Agent Prompt',
                style: TextStyle(fontSize: 11, color: AppColors.textMuted),
              ),
              child: SelectableText(
                agent.prompt!,
                style: const TextStyle(
                  fontSize: 12,
                  color: AppColors.textSecondary,
                  height: 1.5,
                ),
              ),
            ),
            const SizedBox(height: 8),
          ],

          // Toolbelt
          if (agent.uniqueToolNames.isNotEmpty) ...[
            const Text(
              'TOOLBELT',
              style: TextStyle(
                fontSize: 10,
                fontWeight: FontWeight.w600,
                color: AppColors.textMuted,
                letterSpacing: 1,
              ),
            ),
            const SizedBox(height: 6),
            Wrap(
              spacing: 6,
              runSpacing: 6,
              children: agent.toolUsageCounts.entries.map((e) {
                return Container(
                  padding:
                      const EdgeInsets.symmetric(horizontal: 8, vertical: 4),
                  decoration: BoxDecoration(
                    color: AppColors.toolBg,
                    borderRadius: BorderRadius.circular(4),
                    border: Border.all(color: AppColors.tool.withAlpha(40)),
                  ),
                  child: Text(
                    '${e.key} (${e.value})',
                    style: const TextStyle(
                      fontSize: 11,
                      color: AppColors.tool,
                      fontFamily: 'JetBrains Mono',
                    ),
                  ),
                );
              }).toList(),
            ),
          ],
        ],
      ),
    );
  }

  String _formatTokens(int tokens) {
    if (tokens >= 1000000) return '${(tokens / 1000000).toStringAsFixed(1)}M';
    if (tokens >= 1000) return '${(tokens / 1000).toStringAsFixed(1)}K';
    return '$tokens';
  }
}

class _StatChip extends StatelessWidget {
  final String label;
  final String value;

  const _StatChip(this.label, this.value);

  @override
  Widget build(BuildContext context) {
    return Container(
      padding: const EdgeInsets.symmetric(horizontal: 8, vertical: 4),
      decoration: BoxDecoration(
        color: AppColors.surfaceLight,
        borderRadius: BorderRadius.circular(4),
      ),
      child: Row(
        mainAxisSize: MainAxisSize.min,
        children: [
          Text(
            '$label: ',
            style: const TextStyle(fontSize: 11, color: AppColors.textMuted),
          ),
          Text(
            value,
            style: const TextStyle(
              fontSize: 11,
              fontWeight: FontWeight.w600,
              color: AppColors.textPrimary,
            ),
          ),
        ],
      ),
    );
  }
}