#!/usr/bin/env node
// Postinstall script for @hanzo/dev

import {
  existsSync,
  mkdirSync,
  createWriteStream,
  chmodSync,
  readFileSync,
  readSync,
  writeFileSync,
  unlinkSync,
  statSync,
  openSync,
  closeSync,
  copyFileSync,
  fsyncSync,
  renameSync,
  realpathSync,
} from "fs";
import { join, dirname, resolve } from "path";
import { fileURLToPath } from "url";
import { get } from "https";
import { platform, arch, tmpdir } from "os";
import { execSync } from "child_process";
import { createRequire } from "module";

const __dirname = dirname(fileURLToPath(import.meta.url));

function getTargetTriple() {
  const platformMap = {
    darwin: "apple-darwin",
    linux: "unknown-linux-musl",
    win32: "pc-windows-msvc",
  };

  const archMap = {
    x64: "x86_64",
    arm64: "aarch64",
  };

  const rustArch = archMap[arch()] || arch();
  const rustPlatform = platformMap[platform()] || platform();

  return `${rustArch}-${rustPlatform}`;
}

function getCacheDir(version) {
  const plt = platform();
  const home = process.env.HOME || process.env.USERPROFILE || "";
  let base = "";
  if (plt === "win32") {
    base = process.env.LOCALAPPDATA || join(home, "AppData", "Local");
  } else if (plt === "darwin") {
    base = join(home, "Library", "Caches");
  } else {
    base = process.env.XDG_CACHE_HOME || join(home, ".cache");
  }
  const dir = join(base, "hanzo", "dev", version);
  if (!existsSync(dir)) mkdirSync(dir, { recursive: true });
  return dir;
}

function getCachedBinaryPath(version, targetTriple, isWindows) {
  const ext = isWindows ? ".exe" : "";
  const cacheDir = getCacheDir(version);
  return join(cacheDir, `dev-${targetTriple}${ext}`);
}

function isWSL() {
  if (platform() !== "linux") return false;
  try {
    const ver = readFileSync("/proc/version", "utf8").toLowerCase();
    return ver.includes("microsoft") || !!process.env.WSL_DISTRO_NAME;
  } catch {
    return false;
  }
}

function isPathOnWindowsFs(p) {
  try {
    const mounts = readFileSync("/proc/mounts", "utf8")
      .split(/\n/)
      .filter(Boolean);
    let best = { mount: "/", type: "unknown", len: 1 };
    for (const line of mounts) {
      const parts = line.split(" ");
      if (parts.length < 3) continue;
      const mnt = parts[1];
      const typ = parts[2];
      if (p.startsWith(mnt) && mnt.length > best.len)
        best = { mount: mnt, type: typ, len: mnt.length };
    }
    return best.type === "drvfs" || best.type === "cifs";
  } catch {
    return false;
  }
}

async function writeCacheAtomic(srcPath, cachePath) {
  try {
    if (existsSync(cachePath)) {
      const ok = validateDownloadedBinary(cachePath).ok;
      if (ok) return;
    }
  } catch {}
  const dir = dirname(cachePath);
  if (!existsSync(dir)) {
    try {
      mkdirSync(dir, { recursive: true });
    } catch {}
  }
  const tmp = cachePath + ".tmp-" + Math.random().toString(36).slice(2, 8);
  copyFileSync(srcPath, tmp);
  try {
    const fd = openSync(tmp, "r");
    try {
      fsyncSync(fd);
    } finally {
      closeSync(fd);
    }
  } catch {}
  const delays = [100, 200, 400, 800, 1200, 1600];
  for (let i = 0; i < delays.length; i++) {
    try {
      if (existsSync(cachePath)) {
        try {
          unlinkSync(cachePath);
        } catch {}
      }
      renameSync(tmp, cachePath);
      return;
    } catch {
      await new Promise((r) => setTimeout(r, delays[i]));
    }
  }
  if (existsSync(cachePath)) {
    try {
      unlinkSync(cachePath);
    } catch {}
  }
  renameSync(tmp, cachePath);
}

function resolveGlobalBinDir() {
  const plt = platform();
  const userAgent = process.env.npm_config_user_agent || "";

  const fromPrefix = (prefixPath) => {
    if (!prefixPath) return "";
    return plt === "win32" ? prefixPath : join(prefixPath, "bin");
  };

  const prefixEnv = process.env.npm_config_prefix || process.env.PREFIX || "";
  const direct = fromPrefix(prefixEnv);
  if (direct) return direct;

  const tryExec = (command) => {
    try {
      return execSync(command, {
        stdio: ["ignore", "pipe", "ignore"],
        shell: true,
      })
        .toString()
        .trim();
    } catch {
      return "";
    }
  };

  const prefixFromNpm = fromPrefix(tryExec("npm prefix -g"));
  if (prefixFromNpm) return prefixFromNpm;

  const binFromNpm = tryExec("npm bin -g");
  if (binFromNpm) return binFromNpm;

  if (userAgent.includes("pnpm")) {
    const pnpmBin = tryExec("pnpm bin --global");
    if (pnpmBin) return pnpmBin;
  }

  if (userAgent.includes("yarn")) {
    const yarnBin = tryExec("yarn global bin");
    if (yarnBin) return yarnBin;
  }

  return "";
}

async function downloadBinary(url, dest, maxRedirects = 5, maxRetries = 3) {
  const sleep = (ms) => new Promise((r) => setTimeout(r, ms));

  const doAttempt = () =>
    new Promise((resolve, reject) => {
      const attempt = (currentUrl, redirectsLeft) => {
        const req = get(currentUrl, (response) => {
          const status = response.statusCode || 0;
          const location = response.headers.location;

          if (
            (status === 301 ||
              status === 302 ||
              status === 303 ||
              status === 307 ||
              status === 308) &&
            location
          ) {
            if (redirectsLeft <= 0) {
              reject(
                new Error(`Too many redirects while downloading ${currentUrl}`),
              );
              return;
            }
            attempt(location, redirectsLeft - 1);
            return;
          }

          if (status === 200) {
            const expected =
              parseInt(response.headers["content-length"] || "0", 10) || 0;
            let bytes = 0;
            let timer;
            const timeoutMs = 30000;

            const resetTimer = () => {
              if (timer) clearTimeout(timer);
              timer = setTimeout(() => {
                req.destroy(new Error("download stalled"));
              }, timeoutMs);
            };

            resetTimer();
            response.on("data", (chunk) => {
              bytes += chunk.length;
              resetTimer();
            });

            const file = createWriteStream(dest);
            response.pipe(file);
            file.on("finish", () => {
              if (timer) clearTimeout(timer);
              file.close();
              if (expected && bytes !== expected) {
                try {
                  unlinkSync(dest);
                } catch {}
                reject(
                  new Error(
                    `incomplete download: got ${bytes} of ${expected} bytes`,
                  ),
                );
              } else if (bytes === 0) {
                try {
                  unlinkSync(dest);
                } catch {}
                reject(new Error("empty download"));
              } else {
                resolve();
              }
            });
            file.on("error", (err) => {
              if (timer) clearTimeout(timer);
              try {
                unlinkSync(dest);
              } catch {}
              reject(err);
            });
          } else {
            reject(new Error(`Failed to download: HTTP ${status}`));
          }
        });

        req.on("error", (err) => {
          try {
            unlinkSync(dest);
          } catch {}
          reject(err);
        });

        req.setTimeout(120000, () => {
          req.destroy(new Error("download timed out"));
        });
      };

      attempt(url, maxRedirects);
    });

  let attemptNum = 0;
  while (true) {
    try {
      return await doAttempt();
    } catch (e) {
      attemptNum += 1;
      if (attemptNum > maxRetries) throw e;
      const backoff = Math.min(2000, 200 * attemptNum);
      await sleep(backoff);
    }
  }
}

function validateDownloadedBinary(p) {
  try {
    const st = statSync(p);
    if (!st.isFile() || st.size === 0) {
      return { ok: false, reason: "empty or not a regular file" };
    }
    const fd = openSync(p, "r");
    try {
      const buf = Buffer.alloc(4);
      const n = readSync(fd, buf, 0, 4, 0);
      if (n < 2) return { ok: false, reason: "too short" };
      const plt = platform();
      if (plt === "win32") {
        if (!(buf[0] === 0x4d && buf[1] === 0x5a))
          return { ok: false, reason: "invalid PE header (missing MZ)" };
      } else if (plt === "linux" || plt === "android") {
        if (
          !(
            buf[0] === 0x7f &&
            buf[1] === 0x45 &&
            buf[2] === 0x4c &&
            buf[3] === 0x46
          )
        )
          return { ok: false, reason: "invalid ELF header" };
      } else if (plt === "darwin") {
        const isMachO =
          (buf[0] === 0xcf &&
            buf[1] === 0xfa &&
            buf[2] === 0xed &&
            buf[3] === 0xfe) ||
          (buf[0] === 0xca &&
            buf[1] === 0xfe &&
            buf[2] === 0xba &&
            buf[3] === 0xbe);
        if (!isMachO) return { ok: false, reason: "invalid Mach-O header" };
      }
      return { ok: true };
    } finally {
      closeSync(fd);
    }
  } catch (e) {
    return { ok: false, reason: e.message };
  }
}

export async function runPostinstall(options = {}) {
  const { skipGlobalAlias = false, invokedByRuntime = false } = options;
  if (process.env.DEV_POSTINSTALL_DRY_RUN === "1") {
    return { skipped: true };
  }

  if (invokedByRuntime) {
    process.env.DEV_RUNTIME_POSTINSTALL =
      process.env.DEV_RUNTIME_POSTINSTALL || "1";
  }

  const ua = process.env.npm_config_user_agent || "";
  const isNpx = ua.includes("npx");
  const isGlobal = process.env.npm_config_global === "true";

  const targetTriple = getTargetTriple();
  const isWindows = platform() === "win32";
  const binaryExt = isWindows ? ".exe" : "";

  const binDir = join(__dirname, "bin");
  if (!existsSync(binDir)) {
    mkdirSync(binDir, { recursive: true });
  }

  const packageJson = JSON.parse(
    readFileSync(join(__dirname, "package.json"), "utf8"),
  );
  const version = packageJson.version;

  // The release produces dev-* binaries directly
  const binaries = ["dev"];

  console.log(`Installing @hanzo/dev v${version} for ${targetTriple}...`);

  for (const binary of binaries) {
    const binaryName = `${binary}-${targetTriple}${binaryExt}`;
    const localPath = join(binDir, binaryName);
    const cachePath = getCachedBinaryPath(version, targetTriple, isWindows);

    // Fast path: if a valid cached binary exists, reuse it
    try {
      if (existsSync(cachePath)) {
        const valid = validateDownloadedBinary(cachePath);
        if (valid.ok) {
          const wsl = isWSL();
          const binDirReal = (() => {
            try {
              return realpathSync(binDir);
            } catch {
              return binDir;
            }
          })();
          const mirrorToLocal = !(
            isWindows ||
            (wsl && isPathOnWindowsFs(binDirReal))
          );
          if (mirrorToLocal) {
            copyFileSync(cachePath, localPath);
            try {
              chmodSync(localPath, 0o755);
            } catch {}
          }
          console.log(`✓ ${binaryName} ready from user cache`);
          continue;
        }
      }
    } catch {
      // Ignore cache errors
    }

    // Try platform package via npm optionalDependencies
    const require = createRequire(import.meta.url);
    const platformPkg = (() => {
      const name = (() => {
        if (isWindows) return "@hanzo/dev-win32-x64";
        const plt = platform();
        const cpu = arch();
        if (plt === "darwin" && cpu === "arm64")
          return "@hanzo/dev-darwin-arm64";
        if (plt === "darwin" && cpu === "x64") return "@hanzo/dev-darwin-x64";
        if (plt === "linux" && cpu === "x64")
          return "@hanzo/dev-linux-x64-musl";
        if (plt === "linux" && cpu === "arm64")
          return "@hanzo/dev-linux-arm64-musl";
        return null;
      })();
      if (!name) return null;
      try {
        const pkgJsonPath = require.resolve(`${name}/package.json`);
        const pkgDir = dirname(pkgJsonPath);
        return { name, dir: pkgDir };
      } catch {
        return null;
      }
    })();

    if (platformPkg) {
      try {
        const src = join(platformPkg.dir, "bin", binaryName);
        if (!existsSync(src)) {
          throw new Error(
            `platform package missing binary: ${platformPkg.name}`,
          );
        }
        await writeCacheAtomic(src, cachePath);
        const wsl = isWSL();
        const binDirReal = (() => {
          try {
            return realpathSync(binDir);
          } catch {
            return binDir;
          }
        })();
        const mirrorToLocal = !(
          isWindows ||
          (wsl && isPathOnWindowsFs(binDirReal))
        );
        if (mirrorToLocal) {
          copyFileSync(cachePath, localPath);
          try {
            chmodSync(localPath, 0o755);
          } catch {}
        }
        console.log(
          `✓ Installed ${binaryName} from ${platformPkg.name} (cached)`,
        );
        continue;
      } catch (e) {
        console.warn(
          `⚠ Failed platform package install (${e.message}), falling back to GitHub download`,
        );
      }
    }

    // Download from GitHub release
    const isWin = isWindows;
    const detectedWSL = isWSL();
    const binDirReal = (() => {
      try {
        return realpathSync(binDir);
      } catch {
        return binDir;
      }
    })();
    const mirrorToLocal = !(
      isWin ||
      (detectedWSL && isPathOnWindowsFs(binDirReal))
    );
    let useZst = false;
    if (!isWin) {
      try {
        execSync("zstd --version", { stdio: "ignore", shell: true });
        useZst = true;
      } catch {
        useZst = false;
      }
    }
    const archiveName = isWin
      ? `${binaryName}.zip`
      : useZst
        ? `${binaryName}.zst`
        : `${binaryName}.tar.gz`;
    const downloadUrl = `https://github.com/hanzoai/dev/releases/download/v${version}/${archiveName}`;

    console.log(`Downloading ${archiveName}...`);
    try {
      const needsIsolation = isWin || (!isWin && !mirrorToLocal);
      let safeTempDir = needsIsolation
        ? join(tmpdir(), "hanzo", "dev", version)
        : binDir;
      if (needsIsolation) {
        try {
          if (!existsSync(safeTempDir))
            mkdirSync(safeTempDir, { recursive: true });
        } catch {
          try {
            safeTempDir = getCacheDir(version);
            if (!existsSync(safeTempDir))
              mkdirSync(safeTempDir, { recursive: true });
          } catch {}
        }
      }
      const tmpPath = join(
        needsIsolation ? safeTempDir : binDir,
        `.${archiveName}.part`,
      );
      await downloadBinary(downloadUrl, tmpPath);

      if (isWin) {
        const unzipDest = safeTempDir;
        try {
          const sysRoot =
            process.env.SystemRoot || process.env.windir || "C:\\Windows";
          const psFull = join(
            sysRoot,
            "System32",
            "WindowsPowerShell",
            "v1.0",
            "powershell.exe",
          );
          const psCmd = `Expand-Archive -Path '${tmpPath}' -DestinationPath '${unzipDest}' -Force`;
          let ok = false;
          try {
            execSync(
              `"${psFull}" -NoProfile -NonInteractive -Command "${psCmd}"`,
              { stdio: "ignore" },
            );
            ok = true;
          } catch {}
          if (!ok) {
            try {
              execSync(
                `powershell -NoProfile -NonInteractive -Command "${psCmd}"`,
                { stdio: "ignore" },
              );
              ok = true;
            } catch {}
          }
          if (!ok) {
            try {
              execSync(`pwsh -NoProfile -NonInteractive -Command "${psCmd}"`, {
                stdio: "ignore",
              });
              ok = true;
            } catch {}
          }
          if (!ok) {
            execSync(`tar -xf "${tmpPath}" -C "${unzipDest}"`, {
              stdio: "ignore",
              shell: true,
            });
          }
        } catch (e) {
          throw new Error(`failed to unzip archive: ${e.message}`);
        } finally {
          try {
            unlinkSync(tmpPath);
          } catch {}
        }
        try {
          const extractedPath = join(unzipDest, binaryName);
          await writeCacheAtomic(extractedPath, cachePath);
          try {
            unlinkSync(extractedPath);
          } catch {}
        } catch (e) {
          throw new Error(`failed to move binary to cache: ${e.message}`);
        }
      } else {
        const downloadedPath = join(binDir, binaryName);
        if (useZst) {
          try {
            execSync(`zstd -d '${tmpPath}' -o '${downloadedPath}'`, {
              stdio: "ignore",
              shell: true,
            });
          } catch (e) {
            try {
              unlinkSync(tmpPath);
            } catch {}
            throw new Error(
              `failed to decompress .zst (need zstd CLI): ${e.message}`,
            );
          }
          try {
            unlinkSync(tmpPath);
          } catch {}
        } else {
          try {
            execSync(`tar -xzf '${tmpPath}' -C '${binDir}'`, {
              stdio: "ignore",
              shell: true,
            });
          } catch (e) {
            try {
              unlinkSync(tmpPath);
            } catch {}
            throw new Error(`failed to extract .tar.gz: ${e.message}`);
          }
          try {
            unlinkSync(tmpPath);
          } catch {}
        }
        if (existsSync(downloadedPath) && !mirrorToLocal) {
          await writeCacheAtomic(downloadedPath, cachePath);
          try {
            unlinkSync(downloadedPath);
          } catch {}
        }
      }

      const valid = validateDownloadedBinary(
        isWin ? cachePath : mirrorToLocal ? localPath : cachePath,
      );
      if (!valid.ok) {
        try {
          isWin || !mirrorToLocal
            ? unlinkSync(cachePath)
            : unlinkSync(localPath);
        } catch {}
        throw new Error(`invalid binary (${valid.reason})`);
      }

      if (!isWin && mirrorToLocal) {
        chmodSync(localPath, 0o755);
      }

      console.log(
        `✓ Installed ${binaryName}${isWin || !mirrorToLocal ? " (cached)" : ""}`,
      );
      if (!isWin && mirrorToLocal) {
        try {
          await writeCacheAtomic(localPath, cachePath);
        } catch {}
      }
    } catch (error) {
      console.error(`✗ Failed to install ${binaryName}: ${error.message}`);
      console.error(`  Downloaded from: ${downloadUrl}`);
    }
  }

  const mainBinary = `dev-${targetTriple}${binaryExt}`;
  const mainBinaryPath = join(binDir, mainBinary);

  if (
    existsSync(mainBinaryPath) ||
    existsSync(
      getCachedBinaryPath(version, targetTriple, platform() === "win32"),
    )
  ) {
    try {
      const probePath = existsSync(mainBinaryPath)
        ? mainBinaryPath
        : getCachedBinaryPath(version, targetTriple, platform() === "win32");
      const stats = statSync(probePath);
      if (!stats.size)
        throw new Error("binary is empty (download likely failed)");
      const valid = validateDownloadedBinary(probePath);
      if (!valid.ok) {
        console.warn(`⚠ Main dev binary appears invalid: ${valid.reason}`);
        console.warn(
          "  Try reinstalling or check your network/proxy settings.",
        );
      }
    } catch (e) {
      console.warn(`⚠ Main dev binary appears invalid: ${e.message}`);
      console.warn("  Try reinstalling or check your network/proxy settings.");
    }
    console.log("✓ Installation complete!");
  } else {
    console.warn(
      "⚠ Main dev binary not found. You may need to build from source.",
    );
  }
}

function isExecutedDirectly() {
  const entry = process.argv[1];
  if (!entry) return false;
  try {
    return resolve(entry) === fileURLToPath(import.meta.url);
  } catch {
    return false;
  }
}

if (isExecutedDirectly()) {
  runPostinstall().catch((error) => {
    console.error("Installation failed:", error);
    process.exit(1);
  });
}