/**
 * Agents API Routes
 *
 * 提供 Agent 预设管理的 REST API
 */

import { Hono } from 'hono';
import { getConfig } from './config.js';
import type {
  AgentMode,
  AgentInfo,
  AgentConfigFile,
  AgentModelConfig,
  AgentPermission,
} from '@ai-assistant/core';
import {
  agentRegistry,
  loadAgentConfig,
  saveAgentConfig,
  presetAgents,
  isPresetAgent,
} from '@ai-assistant/core';

// API 响应类型
interface AgentListItem {
  name: string;
  description: string;
  mode: AgentMode;
  isPreset: boolean;
  isCustomized: boolean;
  model?: string;
  maxSteps?: number;
}

interface AgentDefaults {
  maxSteps?: number;
  model?: AgentModelConfig;
  permission?: AgentPermission;
}

export const agentsRouter = new Hono();

// 初始化状态
let initialized = false;

/**
 * 确保 AgentRegistry 已初始化
 */
async function ensureRegistryInitialized(): Promise<boolean> {
  if (!initialized) {
    await agentRegistry.init();
    initialized = true;
  }
  return true;
}

/**
 * 将 AgentInfo 转换为 AgentListItem
 */
function toListItem(agent: AgentInfo, customAgentNames: Set<string>): AgentListItem {
  const isPresetAgent_ = isPresetAgent(agent.name);
  return {
    name: agent.name,
    description: agent.description,
    mode: agent.mode,
    isPreset: isPresetAgent_,
    isCustomized: customAgentNames.has(agent.name),
    model: agent.model?.model,
    maxSteps: agent.maxSteps,
  };
}

/**
 * GET /agents - 获取所有 Agent 列表
 */
agentsRouter.get('/', async (c) => {
  if (!(await ensureRegistryInitialized())) {
    return c.json(
      {
        success: false,
        error: 'Failed to initialize agent registry',
      },
      503
    );
  }

  const config = getConfig();
  const userConfig = await loadAgentConfig(config.workdir);
  const customAgentNames = new Set(Object.keys(userConfig?.agents || {}));

  const agents = agentRegistry.list();
  const items = agents.map((agent) => toListItem(agent, customAgentNames));

  return c.json({
    success: true,
    data: items,
  });
});

/**
 * GET /agents/presets - 获取预设 Agent 列表
 */
agentsRouter.get('/presets', async (c) => {
  const presets = Object.entries(presetAgents).map(([name, agent]) => ({
    name,
    description: agent.description,
    mode: agent.mode,
    isPreset: true,
    isCustomized: false,
    model: agent.model?.model,
    maxSteps: agent.maxSteps,
  }));

  return c.json({
    success: true,
    data: presets,
  });
});

/**
 * GET /agents/defaults - 获取全局默认配置
 */
agentsRouter.get('/defaults', async (c) => {
  const config = getConfig();
  const userConfig = await loadAgentConfig(config.workdir);

  return c.json({
    success: true,
    data: userConfig?.defaults || {},
  });
});

/**
 * PUT /agents/defaults - 更新全局默认配置
 */
agentsRouter.put('/defaults', async (c) => {
  try {
    const newDefaults = await c.req.json<AgentDefaults>();
    const config = getConfig();

    // 加载现有配置
    let userConfig = await loadAgentConfig(config.workdir);
    if (!userConfig) {
      userConfig = {};
    }

    // 更新 defaults
    userConfig.defaults = newDefaults;

    // 保存配置
    await saveAgentConfig(config.workdir, userConfig);

    // 重新初始化 registry 以应用新配置
    initialized = false;
    await ensureRegistryInitialized();

    return c.json({
      success: true,
      data: newDefaults,
    });
  } catch (error) {
    return c.json(
      {
        success: false,
        error: error instanceof Error ? error.message : 'Failed to update defaults',
      },
      500
    );
  }
});

/**
 * GET /agents/:name - 获取单个 Agent 详情
 */
agentsRouter.get('/:name', async (c) => {
  if (!(await ensureRegistryInitialized())) {
    return c.json(
      {
        success: false,
        error: 'Failed to initialize agent registry',
      },
      503
    );
  }

  const name = c.req.param('name');
  const agent = agentRegistry.get(name);

  if (!agent) {
    return c.json(
      {
        success: false,
        error: `Agent '${name}' not found`,
      },
      404
    );
  }

  const config = getConfig();
  const userConfig = await loadAgentConfig(config.workdir);
  const isPresetAgent_ = isPresetAgent(name);
  const isCustomized = !!(userConfig?.agents && name in userConfig.agents);

  return c.json({
    success: true,
    data: {
      ...agent,
      isPreset: isPresetAgent_,
      isCustomized,
    },
  });
});

/**
 * POST /agents - 创建新 Agent
 */
agentsRouter.post('/', async (c) => {
  try {
    const body = await c.req.json<{ name: string } & Omit<AgentInfo, 'name'>>();
    const { name, ...agentConfig } = body;

    if (!name || typeof name !== 'string') {
      return c.json(
        {
          success: false,
          error: 'Agent name is required',
        },
        400
      );
    }

    // 检查名称是否与预设冲突
    if (isPresetAgent(name)) {
      return c.json(
        {
          success: false,
          error: `Cannot create agent with preset name '${name}'. Use PUT to customize a preset.`,
        },
        400
      );
    }

    const config = getConfig();
    let userConfig = await loadAgentConfig(config.workdir);
    if (!userConfig) {
      userConfig = {};
    }
    if (!userConfig.agents) {
      userConfig.agents = {};
    }

    // 检查是否已存在
    if (name in userConfig.agents) {
      return c.json(
        {
          success: false,
          error: `Agent '${name}' already exists`,
        },
        409
      );
    }

    // 添加新 Agent
    userConfig.agents[name] = agentConfig;

    // 保存配置
    await saveAgentConfig(config.workdir, userConfig);

    // 重新初始化 registry
    initialized = false;
    await ensureRegistryInitialized();

    const createdAgent = agentRegistry.get(name);

    return c.json({
      success: true,
      data: createdAgent
        ? {
            ...createdAgent,
            isPreset: false,
            isCustomized: false,
          }
        : { name, ...agentConfig, isPreset: false, isCustomized: false },
    });
  } catch (error) {
    return c.json(
      {
        success: false,
        error: error instanceof Error ? error.message : 'Failed to create agent',
      },
      500
    );
  }
});

/**
 * PUT /agents/:name - 更新 Agent
 */
agentsRouter.put('/:name', async (c) => {
  try {
    const name = c.req.param('name');
    const agentConfig = await c.req.json<Omit<AgentInfo, 'name'>>();

    const config = getConfig();
    let userConfig = await loadAgentConfig(config.workdir);
    if (!userConfig) {
      userConfig = {};
    }
    if (!userConfig.agents) {
      userConfig.agents = {};
    }

    // 更新 Agent（支持覆盖预设）
    userConfig.agents[name] = agentConfig;

    // 保存配置
    await saveAgentConfig(config.workdir, userConfig);

    // 重新初始化 registry
    initialized = false;
    await ensureRegistryInitialized();

    const updatedAgent = agentRegistry.get(name);
    const isPresetAgent_ = isPresetAgent(name);

    return c.json({
      success: true,
      data: updatedAgent
        ? {
            ...updatedAgent,
            isPreset: isPresetAgent_,
            isCustomized: true,
          }
        : { name, ...agentConfig, isPreset: isPresetAgent_, isCustomized: true },
    });
  } catch (error) {
    return c.json(
      {
        success: false,
        error: error instanceof Error ? error.message : 'Failed to update agent',
      },
      500
    );
  }
});

/**
 * DELETE /agents/:name - 删除 Agent
 */
agentsRouter.delete('/:name', async (c) => {
  try {
    const name = c.req.param('name');
    const config = getConfig();
    const userConfig = await loadAgentConfig(config.workdir);

    if (!userConfig?.agents || !(name in userConfig.agents)) {
      // 如果是预设 Agent，返回特定错误
      if (isPresetAgent(name)) {
        return c.json(
          {
            success: false,
            error: `Cannot delete preset agent '${name}'`,
          },
          400
        );
      }

      return c.json(
        {
          success: false,
          error: `Agent '${name}' not found in user configuration`,
        },
        404
      );
    }

    // 删除 Agent
    delete userConfig.agents[name];

    // 保存配置
    await saveAgentConfig(config.workdir, userConfig);

    // 重新初始化 registry
    initialized = false;
    await ensureRegistryInitialized();

    return c.json({
      success: true,
      data: null,
    });
  } catch (error) {
    return c.json(
      {
        success: false,
        error: error instanceof Error ? error.message : 'Failed to delete agent',
      },
      500
    );
  }
});