/**
 * Team Board Agent Runner
 * Runs inside a container. Receives prompts via stdin, outputs results to stdout.
 * Supports persistent sessions via Claude Agent SDK.
 *
 * Input: JSON on stdin (ContainerInput)
 * Follow-up messages: JSON files in /workspace/ipc/input/
 * Output: JSON wrapped in markers on stdout
 * Close signal: /workspace/ipc/input/_close
 */

import fs from 'fs';
import path from 'path';
import { query, HookCallback, PreCompactHookInput, PreToolUseHookInput } from '@anthropic-ai/claude-agent-sdk';

// --- Types ---

interface ContainerInput {
  prompt: string;
  sessionId?: string;
  agentSlug: string;
  agentName: string;
  secrets?: Record<string, string>;
}

interface ContainerOutput {
  status: 'success' | 'error';
  result: string | null;
  newSessionId?: string;
  error?: string;
}

interface SDKUserMessage {
  type: 'user';
  message: { role: 'user'; content: string };
  parent_tool_use_id: null;
  session_id: string;
}

// --- Constants ---

const IPC_INPUT_DIR = '/workspace/ipc/input';
const IPC_CLOSE_SENTINEL = path.join(IPC_INPUT_DIR, '_close');
const IPC_POLL_MS = 500;
const OUTPUT_START = '---AGENT_OUTPUT_START---';
const OUTPUT_END = '---AGENT_OUTPUT_END---';

// Secrets to strip from Bash subprocesses
const SECRET_ENV_VARS = ['ANTHROPIC_API_KEY', 'CLAUDE_CODE_OAUTH_TOKEN'];

// --- MessageStream: push-based async iterable for streaming prompts ---

class MessageStream {
  private queue: SDKUserMessage[] = [];
  private waiting: (() => void) | null = null;
  private done = false;

  push(text: string): void {
    this.queue.push({
      type: 'user',
      message: { role: 'user', content: text },
      parent_tool_use_id: null,
      session_id: '',
    });
    this.waiting?.();
  }

  end(): void {
    this.done = true;
    this.waiting?.();
  }

  async *[Symbol.asyncIterator](): AsyncGenerator<SDKUserMessage> {
    while (true) {
      while (this.queue.length > 0) {
        yield this.queue.shift()!;
      }
      if (this.done) return;
      await new Promise<void>(r => { this.waiting = r; });
      this.waiting = null;
    }
  }
}

// --- Helpers ---

function log(msg: string): void {
  console.error(`[agent] ${msg}`);
}

function writeOutput(output: ContainerOutput): void {
  console.log(OUTPUT_START);
  console.log(JSON.stringify(output));
  console.log(OUTPUT_END);
}

async function readStdin(): Promise<string> {
  return new Promise((resolve, reject) => {
    let data = '';
    process.stdin.setEncoding('utf8');
    process.stdin.on('data', chunk => { data += chunk; });
    process.stdin.on('end', () => resolve(data));
    process.stdin.on('error', reject);
  });
}

function shouldClose(): boolean {
  if (fs.existsSync(IPC_CLOSE_SENTINEL)) {
    try { fs.unlinkSync(IPC_CLOSE_SENTINEL); } catch {}
    return true;
  }
  return false;
}

function drainIpcInput(): string[] {
  try {
    fs.mkdirSync(IPC_INPUT_DIR, { recursive: true });
    const files = fs.readdirSync(IPC_INPUT_DIR)
      .filter(f => f.endsWith('.json'))
      .sort();

    const messages: string[] = [];
    for (const file of files) {
      const filePath = path.join(IPC_INPUT_DIR, file);
      try {
        const data = JSON.parse(fs.readFileSync(filePath, 'utf-8'));
        fs.unlinkSync(filePath);
        if (data.type === 'message' && data.text) {
          messages.push(data.text);
        }
      } catch (err) {
        log(`Failed to process IPC file ${file}: ${err}`);
        try { fs.unlinkSync(filePath); } catch {}
      }
    }
    return messages;
  } catch {
    return [];
  }
}

function waitForIpcMessage(): Promise<string | null> {
  return new Promise((resolve) => {
    const poll = () => {
      if (shouldClose()) { resolve(null); return; }
      const msgs = drainIpcInput();
      if (msgs.length > 0) { resolve(msgs.join('\n')); return; }
      setTimeout(poll, IPC_POLL_MS);
    };
    poll();
  });
}

// --- Hooks ---

/** Strip API keys from Bash subprocess environments */
function createSanitizeBashHook(): HookCallback {
  return async (input) => {
    const preInput = input as PreToolUseHookInput;
    const command = (preInput.tool_input as { command?: string })?.command;
    if (!command) return {};
    const unsetPrefix = `unset ${SECRET_ENV_VARS.join(' ')} 2>/dev/null; `;
    return {
      hookSpecificOutput: {
        hookEventName: 'PreToolUse',
        updatedInput: {
          ...(preInput.tool_input as Record<string, unknown>),
          command: unsetPrefix + command,
        },
      },
    };
  };
}

/** Archive transcript before compaction */
function createPreCompactHook(): HookCallback {
  return async (input) => {
    const preCompact = input as PreCompactHookInput;
    const transcriptPath = preCompact.transcript_path;
    if (!transcriptPath || !fs.existsSync(transcriptPath)) return {};

    try {
      const content = fs.readFileSync(transcriptPath, 'utf-8');
      const archiveDir = '/workspace/conversations';
      fs.mkdirSync(archiveDir, { recursive: true });
      const date = new Date().toISOString().split('T')[0];
      const time = new Date().toISOString().replace(/[:.]/g, '-');
      fs.writeFileSync(
        path.join(archiveDir, `${date}-${time}.jsonl`),
        content
      );
      log(`Archived transcript before compaction`);
    } catch (err) {
      log(`Failed to archive: ${err}`);
    }
    return {};
  };
}

// --- Main query loop ---

async function runQuery(
  prompt: string,
  sessionId: string | undefined,
  input: ContainerInput,
  sdkEnv: Record<string, string | undefined>,
  mcpServerPath: string,
  resumeAt?: string,
): Promise<{ newSessionId?: string; lastAssistantUuid?: string; closedDuringQuery: boolean }> {
  const stream = new MessageStream();
  stream.push(prompt);

  // Poll IPC during query
  let ipcPolling = true;
  let closedDuringQuery = false;
  const pollIpc = () => {
    if (!ipcPolling) return;
    if (shouldClose()) {
      closedDuringQuery = true;
      stream.end();
      ipcPolling = false;
      return;
    }
    const msgs = drainIpcInput();
    for (const text of msgs) {
      log(`IPC message piped (${text.length} chars)`);
      stream.push(text);
    }
    setTimeout(pollIpc, IPC_POLL_MS);
  };
  setTimeout(pollIpc, IPC_POLL_MS);

  let newSessionId: string | undefined;
  let lastAssistantUuid: string | undefined;

  // Load system prompt from CLAUDE.md if exists
  const claudeMdPath = '/workspace/CLAUDE.md';
  let systemPromptAppend: string | undefined;
  if (fs.existsSync(claudeMdPath)) {
    systemPromptAppend = fs.readFileSync(claudeMdPath, 'utf-8');
  }

  for await (const message of query({
    prompt: stream,
    options: {
      cwd: '/workspace',
      resume: sessionId,
      resumeSessionAt: resumeAt,
      systemPrompt: systemPromptAppend
        ? { type: 'preset' as const, preset: 'claude_code' as const, append: systemPromptAppend }
        : undefined,
      allowedTools: [
        'Bash', 'Read', 'Write', 'Edit', 'Glob', 'Grep',
        'WebSearch', 'WebFetch',
        'Task', 'TaskOutput', 'TaskStop',
        'TeamCreate', 'TeamDelete', 'SendMessage',
        'TodoWrite', 'NotebookEdit',
        'mcp__tracker__*',
      ],
      env: sdkEnv,
      permissionMode: 'bypassPermissions',
      allowDangerouslySkipPermissions: true,
      mcpServers: {
        tracker: {
          command: 'node',
          args: [mcpServerPath],
          env: {
            AGENT_SLUG: input.agentSlug,
            AGENT_NAME: input.agentName,
          },
        },
      },
      hooks: {
        PreCompact: [{ hooks: [createPreCompactHook()] }],
        PreToolUse: [{ matcher: 'Bash', hooks: [createSanitizeBashHook()] }],
      },
    },
  })) {
    if (message.type === 'system' && message.subtype === 'init') {
      newSessionId = message.session_id;
      log(`Session: ${newSessionId}`);
    }
    if (message.type === 'assistant' && 'uuid' in message) {
      lastAssistantUuid = (message as { uuid: string }).uuid;
    }
    if (message.type === 'result') {
      const text = 'result' in message ? (message as { result?: string }).result : null;
      if (text) {
        const clean = text.replace(/<internal>[\s\S]*?<\/internal>/g, '').trim();
        if (clean) {
          writeOutput({ status: 'success', result: clean, newSessionId });
        }
      }
    }
  }

  ipcPolling = false;
  return { newSessionId, lastAssistantUuid, closedDuringQuery };
}

// --- Entry point ---

async function main(): Promise<void> {
  let input: ContainerInput;
  try {
    const raw = await readStdin();
    input = JSON.parse(raw);
    try { fs.unlinkSync('/tmp/input.json'); } catch {}
    log(`Agent '${input.agentName}' (${input.agentSlug}) starting`);
  } catch (err) {
    writeOutput({ status: 'error', result: null, error: `Bad input: ${err}` });
    process.exit(1);
  }

  // Build SDK env with secrets (never exposed to Bash)
  const sdkEnv: Record<string, string | undefined> = { ...process.env };
  for (const [key, value] of Object.entries(input.secrets || {})) {
    sdkEnv[key] = value;
  }

  const mcpServerPath = path.join(
    path.dirname(new URL(import.meta.url).pathname),
    'mcp.js'
  );

  let sessionId = input.sessionId;
  fs.mkdirSync(IPC_INPUT_DIR, { recursive: true });
  try { fs.unlinkSync(IPC_CLOSE_SENTINEL); } catch {}

  // Drain pending IPC
  let prompt = input.prompt;
  const pending = drainIpcInput();
  if (pending.length > 0) {
    prompt += '\n' + pending.join('\n');
  }

  // Query loop: run → wait for IPC → run again (persistent session)
  let resumeAt: string | undefined;
  try {
    while (true) {
      log(`Query start (session: ${sessionId || 'new'})`);
      const result = await runQuery(prompt, sessionId, input, sdkEnv, mcpServerPath, resumeAt);

      if (result.newSessionId) sessionId = result.newSessionId;
      if (result.lastAssistantUuid) resumeAt = result.lastAssistantUuid;
      if (result.closedDuringQuery) { log('Closed during query'); break; }

      // Session update marker
      writeOutput({ status: 'success', result: null, newSessionId: sessionId });

      log('Waiting for next message...');
      const next = await waitForIpcMessage();
      if (next === null) { log('Close signal received'); break; }

      log(`New message (${next.length} chars)`);
      prompt = next;
    }
  } catch (err) {
    writeOutput({ status: 'error', result: null, newSessionId: sessionId, error: String(err) });
    process.exit(1);
  }
}

main();