import { Lifecycle } from './lifecycle.js';
import { createModelRouter } from './models.js';
import { initMemory } from './memory.js';
import { createMessageRouter } from './routing.js';
import { initAgents } from './agents.js';
import { initTools } from './tools.js';
import { registerChannels } from './channels.js';
import type { Config } from '../config/index.js';
import type { AudioTranscriptionConfig } from '../models/media.js';
import { ModelRouter } from '../models/index.js';
import { AgentOrchestrator } from '../backends/index.js';
import { OutboundAttachmentCollector } from '../backends/native/attachments.js';
import { SessionStore, SessionManager, parseDuration } from '../session/index.js';
import { HookEngine } from '../hooks/index.js';
import type { ToolRegistry, ToolExecutor, BrowserManager } from '../tools/index.js';
import { createSessionTools, createAgentsListTool, createMessageSendTool, createCronTools } from '../tools/index.js';
import { GatewayServer } from '../gateway/index.js';
import { ChannelRegistry, PairingManager } from '../channels/index.js';
import type { CronScheduler } from '../automation/index.js';
import { HeartbeatMonitor } from '../automation/index.js';
import { McpManager } from '../mcp/index.js';
import { SkillRegistry, SkillInstaller, loadAllSkills } from '../skills/index.js';
import { assembleSystemPrompt } from '../prompt/index.js';
import type { AgentConfigRegistry, AgentRouter } from '../agents/index.js';
import type { SandboxManager } from '../sandbox/index.js';
import { resolve } from 'path';
import { homedir } from 'os';
import { mkdirSync } from 'fs';

export interface DaemonContext {
  config: Config;
  lifecycle: Lifecycle;
  sessionStore: SessionStore;
  sessionManager: SessionManager;
  hookEngine: HookEngine;
  modelRouter: ModelRouter;
  toolRegistry: ToolRegistry;
  toolExecutor: ToolExecutor;
  gateway: GatewayServer;
  channelRegistry: ChannelRegistry;
  mcpManager: McpManager;
  skillRegistry: SkillRegistry;
  skillInstaller: SkillInstaller;
  agentConfigRegistry: AgentConfigRegistry;
  agentRouter: AgentRouter;
  sandboxManager?: SandboxManager;
  browserManager?: BrowserManager;
}

function loadSystemPrompt(config: Config): string {
  const searchDirs = [
    process.cwd(),
    resolve(import.meta.dirname, '../..'),
    ...(config.prompt.search_dirs ?? []),
  ];

  const result = assembleSystemPrompt({
    searchDirs,
    extraSections: config.prompt.extra_sections,
  });

  if (result.loadedFiles.length > 0) {
    console.log(`Loaded prompt templates: ${result.loadedFiles.map(f => f.split('/').pop()).join(', ')}`);
  }

  return result.prompt;
}

export async function startDaemon(config: Config): Promise<DaemonContext> {
  const lifecycle = new Lifecycle();

  // Ensure data directory exists (FLYNN_DATA_DIR overrides default for Docker/custom deployments)
  const dataDir = process.env.FLYNN_DATA_DIR ?? resolve(homedir(), '.local/share/flynn');
  mkdirSync(dataDir, { recursive: true });

  // Initialize session store and manager
  const sessionStore = new SessionStore(resolve(dataDir, 'sessions.db'));
  const sessionManager = new SessionManager(sessionStore);

  lifecycle.onShutdown(async () => {
    sessionStore.close();
    console.log('Session store closed');
  });

  // Session pruning timer (TTL-based cleanup)
  const ttlMs = parseDuration(config.sessions?.ttl ?? '30d');
  if (ttlMs) {
    const pruneInterval = setInterval(() => {
      const cutoff = Math.floor((Date.now() - ttlMs) / 1000); // created_at is unix seconds
      const pruned = sessionStore.pruneStale(cutoff);
      if (pruned.length > 0) {
        sessionManager.evictSessions(pruned);
        console.log(`Pruned ${pruned.length} stale session(s) (TTL: ${config.sessions?.ttl ?? '30d'})`);
      }
    }, 3_600_000); // every hour

    lifecycle.onShutdown(async () => {
      clearInterval(pruneInterval);
    });
  }

  // Initialize hook engine
  const hookEngine = new HookEngine(config.hooks);

  // Initialize tool registry, executor, web search, process tools, browser tools, and tool policy
  const { toolRegistry, toolExecutor, browserManager } = initTools({ config, lifecycle, hookEngine });

  // Initialize memory store, vector search, and memory tools
  const { memoryStore, hybridSearch, memoryDir } = await initMemory({ config, dataDir, lifecycle, toolRegistry });

  // Initialize MCP manager and start configured servers
  const mcpManager = new McpManager(toolRegistry);

  if (config.mcp.servers.length > 0) {
    console.log(`Starting ${config.mcp.servers.length} MCP server(s)...`);
    await mcpManager.startAll(config.mcp.servers);
  }

  lifecycle.onShutdown(async () => {
    await mcpManager.stopAll();
    console.log('MCP servers stopped');
  });

  // Initialize skills system
  const defaultManagedDir = resolve(homedir(), '.flynn/workspace/skills');
  const skillRegistry = new SkillRegistry();
  const skillInstaller = new SkillInstaller(config.skills.managed_dir ?? defaultManagedDir);

  const skills = loadAllSkills({
    bundledDir: config.skills.bundled_dir,
    managedDir: config.skills.managed_dir ?? defaultManagedDir,
    workspaceDir: config.skills.workspace_dir,
  });

  for (const skill of skills) {
    skillRegistry.register(skill);
  }

  if (skills.length > 0) {
    const available = skillRegistry.listAvailable().length;
    console.log(`Loaded ${skills.length} skill(s) (${available} available)`);
  }

  // Initialize agent config registry, router, and sandbox manager
  const { agentConfigRegistry, agentRouter, sandboxManager } = await initAgents({ config, lifecycle });

  // Initialize audio transcription config
  const audioConfig: AudioTranscriptionConfig = {
    endpoint: config.audio.transcription_endpoint,
    apiKey: config.audio.transcription_api_key,
    model: config.audio.transcription_model,
  };

  // Initialize model router
  const modelRouter = createModelRouter(config);

  // Load system prompt and append skill instructions
  let systemPrompt = loadSystemPrompt(config);
  const skillAdditions = skillRegistry.getSystemPromptAdditions();
  if (skillAdditions) {
    systemPrompt = `${systemPrompt}\n\n# Available Skills\n\n${skillAdditions}`;
  }

  // Initialize channel registry (created early so the gateway can reference it)
  const channelRegistry = new ChannelRegistry();

  // Create PairingManager if pairing is enabled
  let pairingManager: PairingManager | undefined;
  if (config.pairing.enabled) {
    // Parse code_ttl: supports '5m', '1h', '30s' → milliseconds
    const ttlMatch = config.pairing.code_ttl.match(/^(\d+)(s|m|h)$/);
    const codeTtlMs = ttlMatch
      ? Number(ttlMatch[1]) * ({ s: 1000, m: 60_000, h: 3_600_000 }[ttlMatch[2] as 's' | 'm' | 'h'])
      : 5 * 60_000; // default 5 minutes

    pairingManager = new PairingManager({
      enabled: true,
      codeTtl: codeTtlMs,
      codeLength: config.pairing.code_length,
    });
    console.log(`Pairing codes enabled (TTL: ${config.pairing.code_ttl}, length: ${config.pairing.code_length})`);
  }

  // Mutable reference to channel agents map — set after createMessageRouter() below.
  // This allows the gateway's getTokenUsage callback to access channel agent usage data.
  let channelAgents: Map<string, { orchestrator: AgentOrchestrator; collector: OutboundAttachmentCollector }> | null = null;

  // Initialize gateway WebSocket server
  const gateway = new GatewayServer({
    port: config.server.port,
    host: config.server.localhost ? '127.0.0.1' : '0.0.0.0',
    sessionManager,
    modelClient: modelRouter,
    systemPrompt,
    toolRegistry,
    toolExecutor,
    auth: {
      token: config.server.token,
      tailscaleIdentity: config.server.tailscale_identity,
    },
    authHttp: config.server.auth_http,
    lock: config.server.lock,
    uiDir: resolve(import.meta.dirname, '../gateway/ui'),
    config,
    channelRegistry,
    pairingManager,
    restart: async () => {
      console.log('Restart requested via gateway');
      await lifecycle.shutdown();
      // Exit with code 75 (EX_TEMPFAIL) — process supervisor should restart
      process.exit(75);
    },
    getTokenUsage: () => {
      const results: Array<{
        sessionId: string;
        primary: { inputTokens: number; outputTokens: number; calls: number };
        delegation: Record<string, { inputTokens: number; outputTokens: number; calls: number }>;
        total: { inputTokens: number; outputTokens: number; calls: number; estimatedCost: number };
      }> = [];

      // Collect usage from gateway WebSocket sessions (NativeAgent-based)
      const sessionBridge = gateway.getSessionBridge();
      for (const entry of sessionBridge.getAllUsage()) {
        results.push(entry);
      }

      // Collect usage from channel agents (AgentOrchestrator-based, has full delegation data)
      if (channelAgents) {
        for (const [sessionId, { orchestrator }] of channelAgents) {
          const usage = orchestrator.getUsage();
          results.push({
            sessionId,
            primary: usage.primary,
            delegation: usage.delegation,
            total: usage.total,
          });
        }
      }

      return results;
    },
  });

  if (config.server.token) {
    console.log(`Gateway auth: token required${config.server.tailscale_identity ? ' + Tailscale identity' : ''}`);
  }

  // ── Channel Registry ──────────────────────────────────────────

  // Set up the unified message handler
  const messageRouter = createMessageRouter({
    sessionManager,
    modelRouter,
    systemPrompt,
    toolRegistry,
    toolExecutor,
    config,
    memoryStore,
    agentConfigRegistry,
    agentRouter,
    sandboxManager,
    audioConfig,
  });
  channelRegistry.setMessageHandler(messageRouter.handler);

  // Wire channel agents into the getTokenUsage callback (late binding)
  channelAgents = messageRouter.agents;

  // Register all channel adapters (Telegram, Discord, Slack, WhatsApp, WebChat, cron, webhooks, Gmail)
  const { cronScheduler } = registerChannels({ config, channelRegistry, hookEngine, pairingManager, gateway });

  // ── Register Tier 1 agent tools ─────────────────────────────

  // Session management tools (list, history, create, delete)
  for (const tool of createSessionTools(sessionManager)) {
    toolRegistry.register(tool);
  }

  // Agent discovery tool
  toolRegistry.register(createAgentsListTool(agentConfigRegistry));

  // Cross-channel messaging tool
  toolRegistry.register(createMessageSendTool(channelRegistry));

  // Cron management tools (if scheduler is active)
  if (cronScheduler) {
    for (const tool of createCronTools(cronScheduler)) {
      toolRegistry.register(tool);
    }
  }

  // ── Signal Handlers ───────────────────────────────────────────

  const signalHandler = () => {
    lifecycle.shutdown().then(() => process.exit(0));
  };

  process.on('SIGINT', signalHandler);
  process.on('SIGTERM', signalHandler);

  lifecycle.onShutdown(async () => {
    process.off('SIGINT', signalHandler);
    process.off('SIGTERM', signalHandler);
  });

  // ── Start Services ────────────────────────────────────────────

  // Register shutdown handler for channels (stops Telegram bot etc.)
  lifecycle.onShutdown(async () => {
    await channelRegistry.stopAll();
    console.log('Channel adapters stopped');
  });

  // Start all channel adapters (Telegram long polling, WebChat status)
  await channelRegistry.startAll();

  // Start gateway (HTTP + WS server)
  lifecycle.onShutdown(async () => {
    await gateway.stop();
    console.log('Gateway server stopped');
  });

  await gateway.start();

  // ── Tailscale Serve ────────────────────────────────────────────
  if (config.server.tailscale?.serve) {
    const { startTailscaleServe, stopTailscaleServe } = await import('../gateway/tailscale.js');
    const tsConfig = {
      localPort: config.server.port,
      servePort: config.server.tailscale.port,
      hostname: config.server.tailscale.hostname,
    };
    try {
      await startTailscaleServe(tsConfig);
      lifecycle.onShutdown(async () => {
        await stopTailscaleServe(tsConfig);
      });
    } catch {
      console.warn('Tailscale Serve failed to start — gateway still accessible on local port');
    }
  }

  // ── Heartbeat Monitor ──────────────────────────────────────────
  const heartbeatMonitor = new HeartbeatMonitor({
    config: config.automation.heartbeat,
    getGatewayPort: () => config.server.port,
    modelRouter,
    channelLister: channelRegistry,
    memoryDir: config.memory.enabled ? memoryDir : undefined,
    dataDir,
    channelLookup: channelRegistry,
  });

  heartbeatMonitor.start();

  lifecycle.onShutdown(async () => {
    heartbeatMonitor.stop();
    console.log('Heartbeat monitor stopped');
  });

  console.log('Flynn daemon started');

  return {
    config,
    lifecycle,
    sessionStore,
    sessionManager,
    hookEngine,
    modelRouter,
    toolRegistry,
    toolExecutor,
    gateway,
    channelRegistry,
    mcpManager,
    skillRegistry,
    skillInstaller,
    agentConfigRegistry,
    agentRouter,
    sandboxManager,
    browserManager,
  };
}

export { Lifecycle } from './lifecycle.js';
export { createClientFromConfig, anthropicToGitHubModel, createAutoFallbackClient, createModelRouter } from './models.js';