#!/usr/bin/env node

/**
 * 热启动 mnote-web 单入口，以及按需启用的 FastAPI。
 * Page AI 仅走 Pi Lab（/api/page-ai/pi/*）；不再启动 OpenCode。
 * 可使用以下环境变量调整行为：
 * - ENABLE_BACKEND：设为 "1" or "true" 时启用默认 FastAPI 后端
 * - BACKEND_CMD：覆盖 FastAPI 启动命令；设置后即视为显式启用后端
 * - SKIP_BACKEND：设为 "1" or "true" 可强制跳过 FastAPI 后端
 * - MNOTE_CONTROL_PLANE_BACKEND：控制面后端，默认 libsql-local；可设 turso-remote / turso-local-replica / turso-synced
 * - MNOTE_TURSO_LOCAL_PATH：libsql-local 本地库路径，默认 /mnt/Data1T/Mnote_data/control-plane/control-plane-libsql.db
 * - MNOTE_PAGE_AI_PI_WARMUP：设为 "1" or "true" 时，在 mnote-web 可用后预启动 Pi Lab runtime / MCP cache
 * - MNOTE_PAGE_AI_PI_WARMUP_SEND：设为 "1" or "true" 时，额外发送一次轻量 prompt 预热模型首包（会产生真实模型请求）
 * - PYTHON_BIN：只在 BACKEND_CMD 未覆盖时，设置 Python 可执行文件，默认 "python"
 */

const { spawn, execSync } = require("child_process");
const path = require("path");
const net = require("net");
const fs = require("fs");
const { runPiLabWarmup } = require("./lib/pi-lab-warmup");

const rootDir = path.resolve(__dirname, "..");
const backendDir = path.join(rootDir, "wolai-backend");

function resolveBackendExecutable(envName, fallbackName) {
  const fromEnv = (process.env[envName] || "").trim();
  if (fromEnv) return fromEnv;

  const isWin = process.platform === "win32";
  const candidates = isWin
    ? [
        path.join(backendDir, ".venv", "Scripts", `${fallbackName}.exe`),
        path.join(backendDir, ".venv312", "Scripts", `${fallbackName}.exe`),
        path.join(backendDir, "venv", "Scripts", `${fallbackName}.exe`),
      ]
    : [
        path.join(backendDir, ".venv-linux", "bin", fallbackName),
        path.join(backendDir, ".venv", "bin", fallbackName),
        path.join(backendDir, "venv", "bin", fallbackName),
      ];

  for (const candidate of candidates) {
    if (fs.existsSync(candidate)) {
      return candidate;
    }
  }

  return fallbackName;
}

const pythonBin = resolveBackendExecutable("PYTHON_BIN", "python");
const backendPortFromEnv = Number(process.env.BACKEND_PORT || 8000);
const defaultControlPlaneDir = "/mnt/Data1T/Mnote_data/control-plane";

function hasCommand(command) {
  try {
    execSync(`command -v ${command}`, { stdio: "ignore", shell: "/bin/sh" });
    return true;
  } catch {
    return false;
  }
}

function shouldUseUvBackendRuntime() {
  if (String(process.env.PYTHON_BIN || "").trim()) return false;
  if (!fs.existsSync(path.join(backendDir, "requirements.txt"))) return false;
  return hasCommand("uv");
}

function buildDefaultBackendCommand(port) {
  if (shouldUseUvBackendRuntime()) {
    return `uv run --with-requirements requirements.txt python -m uvicorn app.main:app --reload --port ${port}`;
  }
  return `${pythonBin} -m uvicorn app.main:app --reload --port ${port}`;
}

function isEnabledEnv(value) {
  const normalized = String(value || "").toLowerCase();
  return normalized === "1" || normalized === "true";
}

function shouldStartBackend(env = process.env) {
  if (isEnabledEnv(env.SKIP_BACKEND)) return false;
  if (String(env.BACKEND_CMD || "").trim()) return true;
  return isEnabledEnv(env.ENABLE_BACKEND);
}

function resolveRuntimePlan(env = process.env) {
  const frontendPort = Number(env.FRONTEND_PORT || 3000);
  const skipGateway = false;
  const publicPort = Number.isFinite(frontendPort) ? Math.floor(frontendPort) : 3000;
  const controlPlaneBackend = String(env.MNOTE_CONTROL_PLANE_BACKEND || "libsql-local").trim() || "libsql-local";
  if (controlPlaneBackend === "sqlite") {
    throw new Error("dev:hot 不再支持 SQLite control-plane fallback；请使用 libsql-local/turso-local-replica/turso-remote/turso-synced");
  }
  const controlPlaneEnv = {
    MNOTE_CONTROL_PLANE_BACKEND: controlPlaneBackend,
  };
  if (controlPlaneBackend === "libsql-local" || controlPlaneBackend === "turso-local" || controlPlaneBackend === "turso") {
    controlPlaneEnv.MNOTE_TURSO_LOCAL_PATH =
      env.MNOTE_TURSO_LOCAL_PATH || path.join(defaultControlPlaneDir, "control-plane-libsql.db");
  } else if (controlPlaneBackend === "turso-local-replica" || controlPlaneBackend === "turso-remote-replica") {
    controlPlaneEnv.MNOTE_TURSO_LOCAL_REPLICA_PATH =
      env.MNOTE_TURSO_LOCAL_REPLICA_PATH || path.join(defaultControlPlaneDir, "control-plane-replica.db");
  } else if (controlPlaneBackend === "turso-synced") {
    controlPlaneEnv.MNOTE_TURSO_SYNCED_PATH =
      env.MNOTE_TURSO_SYNCED_PATH || env.MNOTE_TURSO_LOCAL_REPLICA_PATH || path.join(defaultControlPlaneDir, "control-plane-synced.db");
  }

  const plan = {
    skipGateway,
    publicPort,
    publicUrl: `http://localhost:${publicPort}`,
    mnoteWebCommand: env.MNOTE_WEB_CMD || "cargo run -p mnote-web --bin mnote-web",
    mnoteWebEnv: {
      MNOTE_WEB_BIND: env.MNOTE_WEB_BIND || `0.0.0.0:${publicPort}`,
      MNOTE_WEB_PUBLIC_BIND: env.MNOTE_WEB_PUBLIC_BIND || `127.0.0.1:${publicPort}`,
      MNOTE_KNOWLEDGE_PROVIDER: env.MNOTE_KNOWLEDGE_PROVIDER || "lightrag_legacy",
      ...controlPlaneEnv,
    },
  };
  return plan;
}

const runtimePlan = resolveRuntimePlan(process.env);
const skipMnoteWebGateway = runtimePlan.skipGateway;

const tasks = [
  ...(skipMnoteWebGateway
    ? []
    : [
        {
          name: "mnote-web",
          command:
            process.env.MNOTE_WEB_CMD ||
            runtimePlan.mnoteWebCommand,
          cwd: path.join(rootDir, "rust"),
        },
      ]),
  ...(shouldStartBackend(process.env)
    ? [
        {
          name: "backend",
          command:
            process.env.BACKEND_CMD ||
            buildDefaultBackendCommand(8000),
          cwd: backendDir,
        },
      ]
    : []),
];

function findTask(name) {
  return tasks.find((task) => task.name === name);
}

const children = [];
let shuttingDown = false;

async function isPortFree(host, port, timeoutMs = 400) {
  return await new Promise((resolve) => {
    const socket = net.createConnection({ host, port });
    const timer = setTimeout(() => {
      socket.destroy();
      resolve(true);
    }, timeoutMs);

    socket.once("connect", () => {
      clearTimeout(timer);
      socket.end();
      resolve(false);
    });

    socket.once("error", () => {
      clearTimeout(timer);
      resolve(true);
    });
  });
}

async function findFreePort(startPort) {
  let port = Number.isFinite(startPort) ? Math.floor(startPort) : 3000;
  port = Math.max(1, Math.min(65535, port));

  // 最多尝试 20 个端口，避免无限循环。
  for (let i = 0; i < 20; i += 1) {
    // eslint-disable-next-line no-await-in-loop
    const free = await isPortFree("127.0.0.1", port);
    if (free) return port;
    port += 1;
  }

  return startPort;
}

function getListeningPidsByPort(port) {
  const pids = new Set();

  if (process.platform !== "win32") {
    try {
      const out = execSync(`ss -ltnp 'sport = :${port}'`, { encoding: "utf8" });
      for (const match of out.matchAll(/pid=(\d+)/g)) {
        const pid = Number(match[1]);
        if (Number.isFinite(pid) && pid > 0) {
          pids.add(pid);
        }
      }
    } catch {
      // ignore
    }

    if (pids.size > 0) {
      return [...pids];
    }

    try {
      const out = execSync(`lsof -nP -iTCP:${port} -sTCP:LISTEN -t`, { encoding: "utf8" });
      for (const line of out.split(/\r?\n/)) {
        const pid = Number(line.trim());
        if (Number.isFinite(pid) && pid > 0) {
          pids.add(pid);
        }
      }
    } catch {
      // ignore
    }

    return [...pids];
  }

  try {
    // 说明：netstat 输出示例：
    // TCP    0.0.0.0:3000   0.0.0.0:0   LISTENING   12345
    const out = execSync("netstat -ano -p tcp", { encoding: "utf8" });
    for (const line of out.split(/\r?\n/)) {
      if (!line.includes(`:${port}`)) continue;
      if (!/LISTENING/i.test(line)) continue;
      const parts = line.trim().split(/\s+/);
      const pid = Number(parts[parts.length - 1]);
      if (Number.isFinite(pid) && pid > 0) {
        pids.add(pid);
      }
    }
    return [...pids];
  } catch {
    return [];
  }
}

function getProcessNameByPid(pid) {
  if (process.platform !== "win32") {
    try {
      return execSync(`ps -p ${pid} -o comm=`, { encoding: "utf8" }).trim();
    } catch {
      return "";
    }
  }

  try {
    // 输出为 CSV，示例：
    // "Image Name","PID","Session Name","Session#","Mem Usage"
    // "python.exe","12345","Console","1","12,345 K"
    const out = execSync(`tasklist /FI "PID eq ${pid}" /FO CSV /NH`, {
      encoding: "utf8",
    }).trim();
    if (!out || /No tasks are running/i.test(out)) return "";
    const firstLine = out.split(/\r?\n/)[0].trim();
    if (!firstLine) return "";
    const cells = firstLine
      .split('","')
      .map((s) => s.replace(/^"/, "").replace(/"$/, ""));
    return (cells[0] || "").trim();
  } catch {
    return "";
  }
}

function getProcessCommandByPid(pid) {
  if (process.platform === "win32") {
    try {
      const out = execSync(`wmic process where ProcessId=${pid} get CommandLine /value`, {
        encoding: "utf8",
      });
      return out.replace(/^CommandLine=/m, "").trim();
    } catch {
      return "";
    }
  }

  try {
    return execSync(`ps -p ${pid} -o args=`, { encoding: "utf8" }).trim();
  } catch {
    return "";
  }
}

function getProcessGroupByPid(pid) {
  if (process.platform === "win32") return pid;
  try {
    const pgid = Number(execSync(`ps -p ${pid} -o pgid=`, { encoding: "utf8" }).trim());
    return Number.isFinite(pgid) && pgid > 0 ? pgid : pid;
  } catch {
    return pid;
  }
}

function terminatePid(pid) {
  if (process.platform === "win32") {
    execSync(`taskkill /PID ${pid} /T /F`, { stdio: "ignore" });
    return;
  }

  try {
    process.kill(pid, "SIGTERM");
  } catch {
    return;
  }
}

function forceKillPid(pid) {
  if (process.platform === "win32") {
    execSync(`taskkill /PID ${pid} /T /F`, { stdio: "ignore" });
    return;
  }

  try {
    process.kill(pid, "SIGKILL");
  } catch {
    // 进程可能已经退出。
  }
}

function terminateProcessGroup(pgid) {
  if (process.platform === "win32") {
    terminatePid(pgid);
    return;
  }
  try {
    process.kill(-pgid, "SIGTERM");
  } catch {
    terminatePid(pgid);
  }
}

function forceKillProcessGroup(pgid) {
  if (process.platform === "win32") {
    forceKillPid(pgid);
    return;
  }
  try {
    process.kill(-pgid, "SIGKILL");
  } catch {
    forceKillPid(pgid);
  }
}

function collectStaleMnoteWebCargoPids() {
  if (process.platform === "win32") return [];
  const currentPgid = getProcessGroupByPid(process.pid);
  try {
    const out = execSync("pgrep -f 'cargo (watch|run).*mnote-web|cargo-watch watch.*mnote-web'", {
      encoding: "utf8",
    });
    return out
      .split(/\r?\n/)
      .map((line) => Number(line.trim()))
      .filter((pid) => Number.isFinite(pid) && pid > 0 && pid !== process.pid)
      .filter((pid) => getProcessGroupByPid(pid) !== currentPgid)
      .filter((pid) => {
        const command = getProcessCommandByPid(pid);
        return !command.includes("pgrep -f");
      });
  } catch {
    return [];
  }
}

async function stopStaleMnoteWebCargoProcesses() {
  const pids = collectStaleMnoteWebCargoPids();
  if (pids.length === 0) return true;

  const safePids = pids.filter((pid) => {
    const command = getProcessCommandByPid(pid);
    return (
      command.includes("mnote-web") &&
      command.includes("cargo") &&
      (command.includes("cargo watch") ||
        command.includes("cargo-watch watch") ||
        command.includes("cargo run -p mnote-web"))
    );
  });
  if (safePids.length === 0) return true;

  const pgids = [...new Set(safePids.map(getProcessGroupByPid).filter((pgid) => pgid > 0))];
  logPrefix("mnote-web", `检测到陈旧 cargo-watch/cargo run，先清理进程组：${pgids.join(", ")}`);
  pgids.forEach(terminateProcessGroup);

  for (let i = 0; i < 20; i += 1) {
    // eslint-disable-next-line no-await-in-loop
    await new Promise((r) => setTimeout(r, 150));
    const remaining = collectStaleMnoteWebCargoPids().filter((pid) =>
      safePids.includes(pid) || pgids.includes(getProcessGroupByPid(pid)),
    );
    if (remaining.length === 0) return true;
  }

  pgids.forEach(forceKillProcessGroup);
  return true;
}

async function ensurePortFree(port, nameForLog) {
  const free = await isPortFree("127.0.0.1", port);
  if (free) return true;

  const pids = getListeningPidsByPort(port);
  if (pids.length === 0) {
    logPrefix(nameForLog, `检测到端口 ${port} 被占用，但无法定位 PID。`);
    return false;
  }

  let killPids = pids;
  // 安全策略：后端默认只结束 python 进程（避免误杀其他服务）。
  if (nameForLog === "backend") {
    killPids = pids.filter((pid) => {
      const procName = getProcessNameByPid(pid).toLowerCase();
      return procName.includes("python");
    });
    if (killPids.length === 0) {
      logPrefix(
        nameForLog,
        `检测到端口 ${port} 被占用，但没有可安全结束的 python 进程（PIDs=${pids.join(", ")}）。请手动释放端口后重试。`,
      );
      return false;
    }
  }

  logPrefix(nameForLog, `检测到端口 ${port} 被占用，准备重启（结束旧进程）：${killPids.join(", ")}`);
  for (const pid of killPids) {
    try {
      terminatePid(pid);
    } catch {
      // ignore
    }
  }

  // 等待端口释放
  for (let i = 0; i < 20; i += 1) {
    // eslint-disable-next-line no-await-in-loop
    const ok = await isPortFree("127.0.0.1", port, 250);
    if (ok) return true;
    // eslint-disable-next-line no-await-in-loop
    await new Promise((r) => setTimeout(r, 150));
  }

  if (process.platform !== "win32") {
    for (const pid of killPids) {
      forceKillPid(pid);
    }

    for (let i = 0; i < 10; i += 1) {
      // eslint-disable-next-line no-await-in-loop
      const ok = await isPortFree("127.0.0.1", port, 250);
      if (ok) return true;
      // eslint-disable-next-line no-await-in-loop
      await new Promise((r) => setTimeout(r, 150));
    }
  }

  logPrefix(nameForLog, `端口 ${port} 仍未释放，可能有其他程序占用。`);
  return false;
}

async function isHttpHealthy(url) {
  if (!url) return false;
  try {
    const controller = new AbortController();
    const timer = setTimeout(() => controller.abort(), 1200);
    const response = await fetch(url, {
      method: "GET",
      headers: { accept: "application/json,text/plain,*/*" },
      signal: controller.signal,
    });
    clearTimeout(timer);
    return response.ok;
  } catch {
    return false;
  }
}

function loadEnvFile(filePath) {
  if (!fs.existsSync(filePath)) return {};
  const content = fs.readFileSync(filePath, "utf8");
  return content
    .split(/\r?\n/)
    .filter((line) => line.trim() && !line.trim().startsWith("#"))
    .reduce((acc, line) => {
      const idx = line.indexOf("=");
      if (idx === -1) return acc;
      const key = line.slice(0, idx).trim();
      const value = line.slice(idx + 1).trim();
      acc[key] = value;
      return acc;
    }, {});
}

// 约定：全局仅使用仓库根目录的 .env.all 作为配置来源（生产优先）。
const envAllPath = path.join(rootDir, ".env.all");
if (!fs.existsSync(envAllPath)) {
  console.error("[system] 缺少 .env.all：请在仓库根目录创建全局唯一 env 文件后重试。");
  process.exit(1);
}
const envFromAll = loadEnvFile(envAllPath);
const mergedEnv = {
  ...process.env,
  ...envFromAll,
};

function logPrefix(name, message) {
  console.log(`[${name}] ${message}`);
}

function startTask(task) {
  logPrefix(task.name, `启动命令：${task.command}`);
  const child = spawn(task.command, {
    cwd: task.cwd,
    stdio: "inherit",
    shell: true,
    env: mergedEnv,
  });

  child.on("exit", (code, signal) => {
    if (shuttingDown) {
      return;
    }
    const status =
      signal !== null ? `因信号 ${signal} 退出` : `退出码 ${code ?? "null"}`;
    logPrefix(task.name, `进程结束（${status}），准备清理其它任务。`);
    shutdown(code ?? 0);
  });

  child.on("error", (err) => {
    logPrefix(task.name, `启动失败：${err.message}`);
    shutdown(1);
  });

  children.push(child);
}

function schedulePiLabWarmup(frontendUrl) {
  if (!isEnabledEnv(mergedEnv.MNOTE_PAGE_AI_PI_WARMUP)) return;
  const warmupEnv = {
    ...mergedEnv,
    MNOTE_PAGE_AI_PI_WARMUP_BASE_URL: mergedEnv.MNOTE_PAGE_AI_PI_WARMUP_BASE_URL || frontendUrl,
  };
  runPiLabWarmup(warmupEnv, {
    rootDir,
    log: (message) => logPrefix("pi-warmup", message),
  }).then((result) => {
    if (result.skipped) {
      logPrefix("pi-warmup", `已跳过：${result.reason || "disabled"}`);
      return;
    }
    logPrefix(
      "pi-warmup",
      `完成：session=${result.sessionId} send=${result.sendEnabled ? "1" : "0"} elapsedMs=${result.elapsedMs}`,
    );
  }).catch((error) => {
    logPrefix("pi-warmup", `失败但不阻塞 dev-hot：${error.message}`);
  });
}

function shutdown(code) {
  if (shuttingDown) {
    return;
  }
  shuttingDown = true;
  logPrefix("system", "收到终止信号，正在关闭所有子进程…");

  for (const child of children) {
    if (!child.pid) continue;

    // Windows 下，shell 子进程常常无法可靠传播 SIGINT/SIGTERM 到孙进程（例如 uvicorn --reload）。
    // 这里优先用 taskkill /T /F 确保整个进程树被结束，避免残留占用端口导致下次启动失败。
    if (process.platform === "win32") {
      try {
        execSync(`taskkill /PID ${child.pid} /T /F`, { stdio: "ignore" });
        continue;
      } catch {
        // fallback to signals
      }
    }

    if (!child.killed) {
      child.kill("SIGINT");
      setTimeout(() => {
        if (!child.killed) {
          child.kill("SIGTERM");
        }
      }, 5000);
    }
  }

  setTimeout(() => process.exit(code), 200);
}

process.on("SIGINT", () => shutdown(0));
process.on("SIGTERM", () => shutdown(0));

async function main() {
  // 说明：你外网绑定了 3000 端口，这里默认强制使用 3000。
  // 如果检测到 3000 被占用，则自动结束旧进程后重启，以保证始终跑在 3000。
  const desiredFrontendPort = runtimePlan.publicPort;
  const frontendOwnerName = "mnote-web";
  await stopStaleMnoteWebCargoProcesses();
  const frontendPortOk = await ensurePortFree(desiredFrontendPort, frontendOwnerName);
  if (!frontendPortOk) {
    console.error(`前端端口 ${desiredFrontendPort} 无法释放，已中止启动。`);
    process.exit(1);
  }
  const frontendPort = desiredFrontendPort;
  const frontendUrl = `http://localhost:${frontendPort}`;

  if (skipMnoteWebGateway) {
    logPrefix("frontend", `前端地址：${frontendUrl}`);
  } else {
    logPrefix("mnote-web", `Rust gateway 公开入口：${frontendUrl}`);
    const gatewayTask = tasks.find((task) => task.name === "mnote-web");
    if (gatewayTask) {
      gatewayTask.command = runtimePlan.mnoteWebCommand;
    }
    Object.assign(mergedEnv, runtimePlan.mnoteWebEnv);
  }

  const desiredBackendPort = backendPortFromEnv;
  if (shouldStartBackend(process.env) && !process.env.BACKEND_CMD) {
    const backendPortOk = await ensurePortFree(desiredBackendPort, "backend");
    if (!backendPortOk) {
      console.error(`后端端口 ${desiredBackendPort} 无法释放，已中止启动。`);
      process.exit(1);
    }
    const backendTask = findTask("backend");
    if (!backendTask) {
      throw new Error("缺少后端任务配置");
    }
    backendTask.command = buildDefaultBackendCommand(desiredBackendPort);
  } else if (isEnabledEnv(process.env.SKIP_BACKEND)) {
    logPrefix("backend", "已跳过 FastAPI 后端（SKIP_BACKEND=1）。");
  } else if (!shouldStartBackend(process.env)) {

  }

  if (tasks.length === 0) {
    console.error("未配置任何可运行的任务，检查环境变量设置。");
    process.exit(1);
  }

  for (const task of tasks) {
    startTask(task);
  }
  schedulePiLabWarmup(frontendUrl);
}

if (require.main === module) {
  main().catch((error) => {
    logPrefix("system", `启动失败：${error.message}`);
    process.exit(1);
  });
}

module.exports = {
  collectStaleMnoteWebCargoPids,
  ensurePortFree,
  getListeningPidsByPort,
  getProcessCommandByPid,
  getProcessGroupByPid,
  getProcessNameByPid,
  isHttpHealthy,
  isPortFree,
  resolveRuntimePlan,
  resolveBackendExecutable,
  schedulePiLabWarmup,
  shouldStartBackend,
  stopStaleMnoteWebCargoProcesses,
  terminatePid,
};