#!/usr/bin/env bash
# Prefetch official Node, Corepack pnpm, and lockfile packages into in-repo caches.
# Run on the same OS/CPU as the later install, while nodejs.org and the npm registry
# are reachable. Node/pnpm cannot use socks5h:// proxies; pass an HTTP proxy via
# DSH_NPM_HTTP_PROXY (example: http://127.0.0.1:3067). That overlay is applied only
# around Corepack/pnpm and is restored before the script returns, so a caller SOCKS
# proxy stays in the current shell. curl keeps the inherited proxy (SOCKS included).
# Optional DSH_NODE_VERSION (no leading v) pins the Node distro; otherwise the
# running Node is used, or the newest v24.x from nodejs.org/dist/index.json.
#
# Usage (repo root):  bash scripts/offline/download-deps.sh
set -euo pipefail

ROOT="$(cd "$(dirname "$0")/../.." && pwd)"
cd "$ROOT"

process_var() {
  local name="$1"
  if [[ -n "${!name+x}" ]]; then
    printf '%s' "${!name}"
  fi
}

inherited_proxy() {
  local name value
  for name in HTTPS_PROXY HTTP_PROXY ALL_PROXY https_proxy http_proxy all_proxy; do
    value="$(process_var "$name")"
    if [[ -n "$value" ]]; then
      printf '%s' "$value"
      return
    fi
  done
}

resolve_node_http_proxy() {
  local override socks name value
  override="$(process_var DSH_NPM_HTTP_PROXY)"
  if [[ -n "$override" ]]; then
    if [[ "$override" == socks5* ]]; then
      echo "DSH_NPM_HTTP_PROXY=$override. Node and pnpm cannot fetch through SOCKS. Use an HTTP proxy (for example http://127.0.0.1:3067)." >&2
      exit 1
    fi
    printf '%s' "$override"
    return
  fi
  socks=
  for name in HTTPS_PROXY HTTP_PROXY ALL_PROXY https_proxy http_proxy all_proxy; do
    value="$(process_var "$name")"
    if [[ -z "$value" ]]; then
      continue
    fi
    if [[ "$value" == socks5* ]]; then
      socks="$name=$value"
      continue
    fi
    printf '%s' "$value"
    return
  done
  if [[ -n "$socks" ]]; then
    echo "$socks. Node and pnpm cannot fetch through SOCKS. Set DSH_NPM_HTTP_PROXY to an HTTP proxy (for example http://127.0.0.1:3067)." >&2
    exit 1
  fi
}

run_with_node_http_proxy() {
  local http status
  http="$(resolve_node_http_proxy)"
  if [[ -z "$http" ]]; then
    "$@"
    return
  fi
  local HTTPS_PROXY_BAK="${HTTPS_PROXY-}" HTTP_PROXY_BAK="${HTTP_PROXY-}" ALL_PROXY_BAK="${ALL_PROXY-}"
  local https_proxy_bak="${https_proxy-}" http_proxy_bak="${http_proxy-}" all_proxy_bak="${all_proxy-}"
  local had_HTTPS_PROXY=0 had_HTTP_PROXY=0 had_ALL_PROXY=0
  local had_https_proxy=0 had_http_proxy=0 had_all_proxy=0
  if [[ -n "${HTTPS_PROXY+x}" ]]; then had_HTTPS_PROXY=1; fi
  if [[ -n "${HTTP_PROXY+x}" ]]; then had_HTTP_PROXY=1; fi
  if [[ -n "${ALL_PROXY+x}" ]]; then had_ALL_PROXY=1; fi
  if [[ -n "${https_proxy+x}" ]]; then had_https_proxy=1; fi
  if [[ -n "${http_proxy+x}" ]]; then had_http_proxy=1; fi
  if [[ -n "${all_proxy+x}" ]]; then had_all_proxy=1; fi
  export HTTPS_PROXY="$http" HTTP_PROXY="$http" ALL_PROXY="$http"
  export https_proxy="$http" http_proxy="$http" all_proxy="$http"
  set +e
  "$@"
  status=$?
  set -e
  if (( had_HTTPS_PROXY )); then export HTTPS_PROXY="$HTTPS_PROXY_BAK"; else unset HTTPS_PROXY; fi
  if (( had_HTTP_PROXY )); then export HTTP_PROXY="$HTTP_PROXY_BAK"; else unset HTTP_PROXY; fi
  if (( had_ALL_PROXY )); then export ALL_PROXY="$ALL_PROXY_BAK"; else unset ALL_PROXY; fi
  if (( had_https_proxy )); then export https_proxy="$https_proxy_bak"; else unset https_proxy; fi
  if (( had_http_proxy )); then export http_proxy="$http_proxy_bak"; else unset http_proxy; fi
  if (( had_all_proxy )); then export all_proxy="$all_proxy_bak"; else unset all_proxy; fi
  return "$status"
}

curl_proxy_args=()
curl_proxy="$(inherited_proxy)"
if [[ -z "$curl_proxy" ]]; then
  curl_proxy="$(process_var DSH_NPM_HTTP_PROXY)"
fi
if [[ -n "$curl_proxy" ]]; then
  curl_proxy_args=(--proxy "$curl_proxy")
fi

save_url() {
  local url="$1"
  local dest="$2"
  mkdir -p "$(dirname "$dest")"
  curl -fsSL --retry 3 "${curl_proxy_args[@]}" -o "$dest" "$url"
}

node_platform() {
  local sys arch
  sys="$(uname -s)"
  arch="$(uname -m)"
  case "$sys:$arch" in
    Linux:x86_64) echo linux-x64 ;;
    Linux:aarch64) echo linux-arm64 ;;
    Darwin:x86_64) echo darwin-x64 ;;
    Darwin:arm64) echo darwin-arm64 ;;
    MINGW*|MSYS*|CYGWIN*)
      echo "Use scripts/offline/download-deps.ps1 on Windows." >&2
      exit 1
      ;;
    *)
      echo "Unsupported OS/CPU: $sys $arch" >&2
      exit 1
      ;;
  esac
}

archive_name() {
  local version="$1"
  local platform="$2"
  case "$platform" in
    linux-*) echo "node-v${version}-${platform}.tar.xz" ;;
    darwin-*) echo "node-v${version}-${platform}.tar.gz" ;;
    *) echo "node-v${version}-${platform}.zip" ;;
  esac
}

file_tag() {
  case "$1" in
    linux-x64) echo linux-x64 ;;
    linux-arm64) echo linux-arm64 ;;
    darwin-x64) echo osx-x64-tar ;;
    darwin-arm64) echo osx-arm64-tar ;;
    win-x64) echo win-x64-zip ;;
    win-arm64) echo win-arm64-zip ;;
  esac
}

engines_ok() {
  local version="$1"
  local major minor
  major="${version%%.*}"
  minor="${version#*.}"
  minor="${minor%%.*}"
  if (( major == 22 && minor >= 19 )); then return 0; fi
  if (( major >= 24 )); then return 0; fi
  return 1
}

resolve_node_version() {
  local platform="$1"
  local dist_base="$2"
  if [[ -n "${DSH_NODE_VERSION:-}" ]]; then
    echo "${DSH_NODE_VERSION#v}"
    return
  fi
  if command -v node >/dev/null 2>&1; then
    local running
    running="$(node --version)"
    running="${running#v}"
    if ! engines_ok "$running"; then
      echo "Running Node v$running is outside engines.node (^22.19.0 || >=24.0.0). Set DSH_NODE_VERSION." >&2
      exit 1
    fi
    echo "$running"
    return
  fi
  local index_path tag version
  index_path="$(mktemp)"
  save_url "$dist_base/index.json" "$index_path"
  tag="$(file_tag "$platform")"
  if command -v python3 >/dev/null 2>&1; then
    version="$(python3 -c 'import json,sys
releases=json.load(open(sys.argv[1]))
tag=sys.argv[2]
for r in releases:
    if r["version"].startswith("v24.") and tag in r["files"]:
        print(r["version"][1:])
        break
' "$index_path" "$tag")"
  else
    echo "python3 or node is required to pick a Node v24.x from index.json, or set DSH_NODE_VERSION." >&2
    rm -f "$index_path"
    exit 1
  fi
  rm -f "$index_path"
  if [[ -z "$version" ]]; then
    echo "No Node v24.x archive published for $platform at $dist_base." >&2
    exit 1
  fi
  echo "$version"
}

assert_checksum() {
  local sums_path="$1"
  local archive_path="$2"
  local archive="$3"
  local expected actual
  expected="$(awk -v name="$archive" '$2 == name { print $1; exit }' "$sums_path")"
  if [[ -z "$expected" ]]; then
    echo "SHASUMS256.txt has no entry for $archive" >&2
    exit 1
  fi
  if command -v sha256sum >/dev/null 2>&1; then
    actual="$(sha256sum "$archive_path" | awk '{ print $1 }')"
  else
    actual="$(shasum -a 256 "$archive_path" | awk '{ print $1 }')"
  fi
  if [[ "$actual" != "$expected" ]]; then
    echo "SHA256 mismatch for $archive" >&2
    exit 1
  fi
}

extract_node() {
  local archive_path="$1"
  local runtime_dir="$2"
  mkdir -p "$runtime_dir"
  case "$archive_path" in
    *.tar.xz) tar -xJf "$archive_path" -C "$runtime_dir" ;;
    *.tar.gz) tar -xzf "$archive_path" -C "$runtime_dir" ;;
    *.zip) unzip -q "$archive_path" -d "$runtime_dir" ;;
    *)
      echo "Unknown Node archive: $archive_path" >&2
      exit 1
      ;;
  esac
}

PACKAGE_MANAGER="$(sed -n 's/.*"packageManager": "\(pnpm@[0-9.]*\)".*/\1/p' package.json | head -n 1)"
case "$PACKAGE_MANAGER" in
  pnpm@*) ;;
  *)
    echo "package.json packageManager must be pnpm@<version>, got ${PACKAGE_MANAGER:-<empty>}" >&2
    exit 1
    ;;
esac

DIST_BASE="${DSH_NODE_DIST_BASE:-https://nodejs.org/dist}"
DIST_BASE="${DIST_BASE%/}"
PLATFORM="$(node_platform)"
NODE_VERSION="$(resolve_node_version "$PLATFORM" "$DIST_BASE")"
ARCHIVE_NAME="$(archive_name "$NODE_VERSION" "$PLATFORM")"
NODE_CACHE="$ROOT/.offline-cache/node"
ARCHIVE_PATH="$NODE_CACHE/$ARCHIVE_NAME"
SUMS_PATH="$NODE_CACHE/SHASUMS256-v${NODE_VERSION}.txt"
RUNTIME_DIR="$NODE_CACHE/runtime"
NODE_PREFIX="$RUNTIME_DIR/node-v${NODE_VERSION}-${PLATFORM}"

echo "Prefetch Node v$NODE_VERSION ($PLATFORM)"
save_url "$DIST_BASE/v$NODE_VERSION/SHASUMS256.txt" "$SUMS_PATH"
save_url "$DIST_BASE/v$NODE_VERSION/$ARCHIVE_NAME" "$ARCHIVE_PATH"
assert_checksum "$SUMS_PATH" "$ARCHIVE_PATH" "$ARCHIVE_NAME"
if [[ ! -x "$NODE_PREFIX/bin/node" ]]; then
  rm -rf "$RUNTIME_DIR"
  extract_node "$ARCHIVE_PATH" "$RUNTIME_DIR"
fi
if [[ ! -x "$NODE_PREFIX/bin/node" ]]; then
  echo "Unpacked Node is missing: $NODE_PREFIX/bin/node" >&2
  exit 1
fi
printf '%s\n' "{\"version\":\"$NODE_VERSION\",\"archive\":\"$ARCHIVE_NAME\",\"platform\":\"$PLATFORM\"}" > "$NODE_CACHE/runtime.json"

STORE_DIR="$ROOT/.offline-store"
COREPACK_HOME="$ROOT/.offline-cache/corepack"
mkdir -p "$STORE_DIR" "$COREPACK_HOME"
export COREPACK_HOME
export PATH="$NODE_PREFIX/bin:$PATH"

echo "Node $("$NODE_PREFIX/bin/node" --version); prefetch $PACKAGE_MANAGER into $STORE_DIR"
run_with_node_http_proxy corepack prepare "$PACKAGE_MANAGER" --activate
run_with_node_http_proxy corepack pnpm fetch --frozen-lockfile --store-dir "$STORE_DIR"

cat <<EOF
Prefetch complete (Node v$NODE_VERSION archive + pnpm store).
Copy this checkout (including .offline-store and .offline-cache) to the offline machine.
Then run: bash scripts/offline/install-deps.sh
EOF