import { spawn, ChildProcess } from "child_process";
import path from "path";
import fs from "fs";
import { readRcloneConfig, RCLONE_USER, RCLONE_PASS } from "./rcloneConfigService";

const APP_ROOT = process.cwd();
const SYNC_FOLDERS = ["backups", "chat-history", "uploads"];

let serverProcess: ChildProcess | null = null;

export function checkRcloneInstalled(): Promise<boolean> {
  return new Promise((resolve) => {
    const proc = spawn("rclone", ["version"]);
    proc.on("error", () => resolve(false));
    proc.on("close", (code) => resolve(code === 0));
  });
}

function obscurePassword(password: string): Promise<string> {
  return new Promise((resolve, reject) => {
    const proc = spawn("rclone", ["obscure", password]);
    let stdout = "";
    let stderr = "";
    proc.stdout.on("data", (d) => (stdout += d.toString()));
    proc.stderr.on("data", (d) => (stderr += d.toString()));
    proc.on("error", (err) => reject(new Error(`Failed to run rclone obscure: ${err.message}`)));
    proc.on("close", (code) => {
      if (code !== 0) return reject(new Error(`rclone obscure failed: ${stderr}`));
      resolve(stdout.trim());
    });
  });
}

export function isServerRunning(): boolean {
  return serverProcess !== null && serverProcess.exitCode === null;
}

// Source PC: rclone serve webdav ./backups --addr :8080 --user MyDentalApp --pass SuperSecret!@2026
export async function startWebDavServer(): Promise<void> {
  if (isServerRunning()) return;

  const installed = await checkRcloneInstalled();
  if (!installed) {
    throw new Error("rclone is not installed. Run: curl https://rclone.org/install.sh | sudo bash");
  }

  const config = readRcloneConfig();

  const args = [
    "serve", "webdav",
    APP_ROOT,
    "--addr", `:${config.serverPort}`,
    "--user", RCLONE_USER,
    "--pass", RCLONE_PASS,
    "--read-only",
  ];

  serverProcess = spawn("rclone", args, { stdio: "pipe" });

  serverProcess.stdout?.on("data", (d) => console.log(`[rclone-server] ${d.toString().trim()}`));
  serverProcess.stderr?.on("data", (d) => console.log(`[rclone-server] ${d.toString().trim()}`));

  serverProcess.on("error", (err) => {
    console.error("[rclone-server] Failed to start:", err.message);
    serverProcess = null;
  });

  serverProcess.on("close", (code) => {
    console.log(`[rclone-server] Exited with code ${code}`);
    serverProcess = null;
  });

  await new Promise((resolve) => setTimeout(resolve, 1000));

  if (!isServerRunning()) {
    throw new Error("rclone WebDAV server failed to start");
  }

  console.log(`[rclone-server] WebDAV server started on port ${config.serverPort}`);
}

export function stopWebDavServer(): void {
  if (serverProcess && serverProcess.exitCode === null) {
    serverProcess.kill("SIGTERM");
    serverProcess = null;
    console.log("[rclone-server] WebDAV server stopped");
  }
}

// Sync a single folder from the source PC via WebDAV
function syncFolder(folder: string, webdavUrl: string, obscuredPass: string): Promise<void> {
  const localDir = path.join(APP_ROOT, folder);
  if (!fs.existsSync(localDir)) {
    fs.mkdirSync(localDir, { recursive: true });
  }

  const args = [
    "sync",
    `:webdav:/${folder}`,
    localDir,
    "--webdav-url", webdavUrl,
    "--webdav-user", RCLONE_USER,
    "--webdav-pass", obscuredPass,
    "-v",
  ];

  return new Promise((resolve, reject) => {
    const proc = spawn("rclone", args);

    let stderr = "";
    proc.stdout.on("data", (d) => console.log(`[rclone-pull] ${d.toString().trim()}`));
    proc.stderr.on("data", (d) => {
      const line = d.toString().trim();
      stderr += line + "\n";
      console.log(`[rclone-pull] ${line}`);
    });
    proc.on("error", (err) => reject(new Error(`Failed to start rclone: ${err.message}`)));
    proc.on("close", (code) => {
      if (code !== 0) return reject(new Error(`rclone sync ${folder} failed (exit ${code}): ${stderr}`));
      resolve();
    });
  });
}

// Receiver PC: pull backups, chat-history, and uploads from source
export async function runRclonePull(): Promise<void> {
  const config = readRcloneConfig();
  if (!config.sourceIp || !config.sourcePort) {
    throw new Error("Rclone receiver configuration is incomplete — source IP and port are required");
  }

  const installed = await checkRcloneInstalled();
  if (!installed) {
    throw new Error("rclone is not installed. Run: curl https://rclone.org/install.sh | sudo bash");
  }

  const obscuredPass = await obscurePassword(RCLONE_PASS);
  const webdavUrl = `http://${config.sourceIp}:${config.sourcePort}`;

  for (const folder of SYNC_FOLDERS) {
    console.log(`[rclone-pull] Syncing ${folder}...`);
    await syncFolder(folder, webdavUrl, obscuredPass);
  }
}

export async function autoStartServer(): Promise<void> {
  const config = readRcloneConfig();
  if (config.serverEnabled) {
    try {
      await startWebDavServer();
    } catch (err) {
      console.error("[rclone-server] Auto-start failed:", err);
    }
  }
}