#!/usr/bin/env node

import { spawn } from "node:child_process";
import fs from "node:fs";
import path from "node:path";
import { pathToFileURL } from "node:url";
import { BUNDLED_PLUGIN_PATH_PREFIX } from "./lib/bundled-plugin-paths.mjs";
import { resolvePnpmRunner } from "./pnpm-runner.mjs";
import {
  isSourceCheckoutRoot,
  pruneBundledPluginSourceNodeModules,
} from "./postinstall-bundled-plugins.mjs";

const logLevel = process.env.OPENCLAW_BUILD_VERBOSE ? "info" : "warn";
const extraArgs = process.argv.slice(2);
const INEFFECTIVE_DYNAMIC_IMPORT_MARKER = "[INEFFECTIVE_DYNAMIC_IMPORT]";
const UNRESOLVED_IMPORT_RE = /\[UNRESOLVED_IMPORT\]/;
const ANSI_ESCAPE_RE = new RegExp(String.raw`\u001B\[[0-9;]*m`, "g");
const HASHED_ROOT_JS_RE = /^(?<base>.+)-[A-Za-z0-9_-]+\.js$/u;
const DEFAULT_CAPTURE_BYTES = 8 * 1024 * 1024;
const DEFAULT_HEARTBEAT_MS = 30_000;
const TERMINATION_GRACE_MS = 5_000;
const TSDOWN_OUTPUT_ROOTS = ["dist", "dist-runtime"];

function removeDistPluginNodeModulesSymlinks(rootDir) {
  const extensionsDir = path.join(rootDir, "extensions");
  if (!fs.existsSync(extensionsDir)) {
    return;
  }

  for (const dirent of fs.readdirSync(extensionsDir, { withFileTypes: true })) {
    if (!dirent.isDirectory()) {
      continue;
    }
    const nodeModulesPath = path.join(extensionsDir, dirent.name, "node_modules");
    try {
      if (fs.lstatSync(nodeModulesPath).isSymbolicLink()) {
        fs.rmSync(nodeModulesPath, { force: true, recursive: true });
      }
    } catch {
      // Skip missing or unreadable paths so the build can proceed.
    }
  }
}

function pruneStaleRuntimeSymlinks() {
  const cwd = process.cwd();
  // runtime-postbuild stages plugin-owned node_modules into dist/ and links the
  // dist-runtime overlay back to that tree. Remove only those symlinks up front
  // so tsdown's clean step cannot traverse stale runtime overlays on rebuilds.
  removeDistPluginNodeModulesSymlinks(path.join(cwd, "dist"));
  removeDistPluginNodeModulesSymlinks(path.join(cwd, "dist-runtime"));
}

export function cleanTsdownOutputRoots(params = {}) {
  const cwd = params.cwd ?? process.cwd();
  const fsImpl = params.fs ?? fs;
  for (const root of TSDOWN_OUTPUT_ROOTS) {
    const rootPath = path.join(cwd, root);
    try {
      fsImpl.rmSync(rootPath, { force: true, recursive: true });
    } catch {
      // Best-effort cleanup. tsdown will recreate the output tree it needs.
    }
  }
}

export function pruneStaleRootChunkFiles(params = {}) {
  const cwd = params.cwd ?? process.cwd();
  const fsImpl = params.fs ?? fs;
  const roots = TSDOWN_OUTPUT_ROOTS.map((root) => path.join(cwd, root));
  for (const root of roots) {
    let entries = [];
    try {
      entries = fsImpl.readdirSync(root, { withFileTypes: true });
    } catch {
      continue;
    }

    for (const entry of entries) {
      if (!entry.isFile()) {
        continue;
      }
      if (!HASHED_ROOT_JS_RE.test(entry.name)) {
        continue;
      }
      try {
        fsImpl.rmSync(path.join(root, entry.name), { force: true });
      } catch {
        // Best-effort cleanup. The subsequent build will overwrite any stragglers.
      }
    }
  }
}

export function pruneSourceCheckoutBundledPluginNodeModules(params = {}) {
  const cwd = params.cwd ?? process.cwd();
  const logger = params.logger ?? console;
  if (!isSourceCheckoutRoot({ packageRoot: cwd, existsSync: fs.existsSync })) {
    return;
  }
  try {
    pruneBundledPluginSourceNodeModules({
      extensionsDir: path.join(cwd, "extensions"),
      existsSync: fs.existsSync,
      readdirSync: fs.readdirSync,
      rmSync: fs.rmSync,
    });
  } catch (error) {
    logger.warn(`tsdown: could not prune bundled plugin source node_modules: ${String(error)}`);
  }
}

function findFatalUnresolvedImport(lines) {
  for (const line of lines) {
    if (!UNRESOLVED_IMPORT_RE.test(line)) {
      continue;
    }

    const normalizedLine = line.replace(ANSI_ESCAPE_RE, "");
    if (
      !normalizedLine.includes(BUNDLED_PLUGIN_PATH_PREFIX) &&
      !normalizedLine.includes("node_modules/")
    ) {
      return normalizedLine;
    }
  }

  return null;
}

function parsePositiveInteger(value) {
  if (typeof value !== "string" || value.trim() === "") {
    return null;
  }
  const parsed = Number(value);
  if (!Number.isFinite(parsed) || parsed <= 0) {
    return null;
  }
  return Math.trunc(parsed);
}

function parseNonNegativeInteger(value) {
  if (typeof value !== "string" || value.trim() === "") {
    return null;
  }
  const parsed = Number(value);
  if (!Number.isFinite(parsed) || parsed < 0) {
    return null;
  }
  return Math.trunc(parsed);
}

export function createTsdownOutputScanner(params = {}) {
  const maxCaptureBytes = params.maxCaptureBytes ?? DEFAULT_CAPTURE_BYTES;
  let captured = "";
  let pendingLine = "";
  let hasIneffectiveDynamicImport = false;
  let fatalUnresolvedImport = null;

  function scanLines(text) {
    const combined = pendingLine + text;
    const lines = combined.split(/\r?\n/u);
    pendingLine = lines.pop() ?? "";
    for (const line of lines) {
      fatalUnresolvedImport ??= findFatalUnresolvedImport([line]);
    }
  }

  return {
    append(chunk) {
      const text = Buffer.isBuffer(chunk) ? chunk.toString("utf8") : String(chunk);
      if (text.includes(INEFFECTIVE_DYNAMIC_IMPORT_MARKER)) {
        hasIneffectiveDynamicImport = true;
      }
      scanLines(text);
      captured += text;
      if (captured.length > maxCaptureBytes) {
        captured = captured.slice(-maxCaptureBytes);
      }
    },
    finish() {
      if (pendingLine) {
        fatalUnresolvedImport ??= findFatalUnresolvedImport([pendingLine]);
        pendingLine = "";
      }
      return {
        captured,
        hasIneffectiveDynamicImport,
        fatalUnresolvedImport,
      };
    },
  };
}

export function resolveTsdownBuildInvocation(params = {}) {
  const env = params.env ?? process.env;
  const runner = resolvePnpmRunner({
    pnpmArgs: [
      "exec",
      "tsdown",
      "--config-loader",
      "unrun",
      "--logLevel",
      logLevel,
      "--no-clean",
      ...extraArgs,
    ],
    nodeExecPath: params.nodeExecPath ?? process.execPath,
    npmExecPath: params.npmExecPath ?? env.npm_execpath,
    comSpec: params.comSpec ?? env.ComSpec,
    platform: params.platform ?? process.platform,
  });
  return {
    command: runner.command,
    args: runner.args,
    options: {
      stdio: ["ignore", "pipe", "pipe"],
      shell: runner.shell,
      windowsVerbatimArguments: runner.windowsVerbatimArguments,
      env,
    },
  };
}

export async function runTsdownBuildInvocation(invocation, params = {}) {
  const stdout = params.stdout ?? process.stdout;
  const stderr = params.stderr ?? process.stderr;
  const env = params.env ?? process.env;
  const scanner = params.scanner ?? createTsdownOutputScanner();
  const timeoutMs = parsePositiveInteger(env.OPENCLAW_TSDOWN_TIMEOUT_MS);
  const heartbeatMs =
    parseNonNegativeInteger(env.OPENCLAW_TSDOWN_HEARTBEAT_MS) ?? DEFAULT_HEARTBEAT_MS;
  let timedOut = false;
  let settled = false;
  let lastOutputAt = Date.now();

  const child = spawn(invocation.command, invocation.args, invocation.options);
  const pidText = child.pid ? ` pid=${child.pid}` : "";

  function markOutput() {
    lastOutputAt = Date.now();
  }

  child.stdout?.on("data", (chunk) => {
    markOutput();
    scanner.append(chunk);
    stdout.write(chunk);
  });
  child.stderr?.on("data", (chunk) => {
    markOutput();
    scanner.append(chunk);
    stderr.write(chunk);
  });

  const heartbeat =
    heartbeatMs > 0
      ? setInterval(() => {
          if (settled) {
            return;
          }
          const silentForMs = Date.now() - lastOutputAt;
          if (silentForMs < heartbeatMs) {
            return;
          }
          stderr.write(
            `[tsdown-build] still running${pidText}; no output for ${Math.round(
              silentForMs / 1000,
            )}s\n`,
          );
          lastOutputAt = Date.now();
        }, heartbeatMs).unref()
      : null;

  const timeout =
    timeoutMs !== null
      ? setTimeout(() => {
          timedOut = true;
          stderr.write(`[tsdown-build] timeout after ${timeoutMs}ms${pidText}; sending SIGTERM\n`);
          child.kill("SIGTERM");
          setTimeout(() => {
            if (!settled) {
              stderr.write(`[tsdown-build] forcing SIGKILL${pidText}\n`);
              child.kill("SIGKILL");
            }
          }, TERMINATION_GRACE_MS).unref();
        }, timeoutMs).unref()
      : null;

  return new Promise((resolve) => {
    child.once("error", (error) => {
      settled = true;
      clearInterval(heartbeat);
      clearTimeout(timeout);
      stderr.write(`[tsdown-build] failed to start: ${String(error)}\n`);
      resolve({
        status: 1,
        signal: null,
        timedOut,
        error,
        ...scanner.finish(),
      });
    });
    child.once("close", (status, signal) => {
      settled = true;
      clearInterval(heartbeat);
      clearTimeout(timeout);
      resolve({
        status,
        signal,
        timedOut,
        error: null,
        ...scanner.finish(),
      });
    });
  });
}

function isMainModule() {
  const argv1 = process.argv[1];
  if (!argv1) {
    return false;
  }
  return import.meta.url === pathToFileURL(argv1).href;
}

if (isMainModule()) {
  pruneSourceCheckoutBundledPluginNodeModules();
  pruneStaleRuntimeSymlinks();
  cleanTsdownOutputRoots();
  const invocation = resolveTsdownBuildInvocation();
  const result = await runTsdownBuildInvocation(invocation);

  if (result.status === 0 && result.hasIneffectiveDynamicImport) {
    console.error(
      "Build emitted [INEFFECTIVE_DYNAMIC_IMPORT]. Replace transparent runtime re-export facades with real runtime boundaries.",
    );
    process.exit(1);
  }

  if (result.status === 0 && result.fatalUnresolvedImport) {
    console.error(
      `Build emitted [UNRESOLVED_IMPORT] outside extensions: ${result.fatalUnresolvedImport}`,
    );
    process.exit(1);
  }

  if (result.timedOut) {
    process.exit(124);
  }

  if (typeof result.status === "number") {
    process.exit(result.status);
  }

  process.exit(1);
}