#!/usr/bin/env python3
"""Add Bare's conditional builtin map to CommonJS packages in node_modules.

Bare resolves package imports at the package boundary. A number of otherwise
portable npm packages (notably dbus-next's XML parser dependency) still use
bare Node builtin specifiers without declaring a map. Applying the official
bare-node-runtime map at build time keeps those packages usable in the shipped
bundle while leaving the source packages untouched.
"""
import json
import sys
from pathlib import Path

root = Path(sys.argv[1] if len(sys.argv) > 1 else "node_modules")
mapping = json.loads(Path(__file__).with_name("bare-imports.json").read_text())
changed = 0
for directory, subdirs, files in __import__("os").walk(root):
    # Native model payloads can be gigabytes. They never contain package
    # manifests, so do not walk them while preparing JavaScript packages.
    subdirs[:] = [d for d in subdirs if d not in {"prebuilds", ".git", ".cache"}]
    if "package.json" not in files:
        continue
    package_json = Path(directory) / "package.json"
    try:
        package = json.loads(package_json.read_text())
    except (OSError, json.JSONDecodeError):
        continue
    imports = package.get("imports")
    if imports is not None and not isinstance(imports, dict):
        continue
    merged = dict(mapping)
    if isinstance(imports, dict):
        merged.update(imports)
    if imports == merged:
        continue
    package["imports"] = merged
    package_json.write_text(json.dumps(package, indent=2) + "\n")
    changed += 1
print(f"prepared {changed} package import maps for Bare")