#!/usr/bin/env python3
"""Rewrite HTML script tags to point at Vite's hashed production bundle.

Usage:
  inject-hashed-filenames.py CONFIG_JSON [BUILD_DIR]

CONFIG_JSON is a path to a JSON file listing the entries to rewrite. The
schema mirrors the two hard-coded entries fewo-webapp had baked into an
earlier version of this script:

    [
      {
        "manifest":   "static/dist/.vite/manifest.json",
        "html":       "static/index.html",
        "old_src":    "/static/dist/app.js"
      },
      {
        "manifest":   "static/guest/dist/.vite/manifest.json",
        "html":       "static/guest/index.html",
        "old_src":    "/guest/dist/guest-app.js"
      }
    ]

All paths are resolved relative to BUILD_DIR (defaults to the repo root
containing the config file's parent chain → `$PWD`).
"""
import json
import os
import re
import sys


def _build_pattern(old_src: str) -> "re.Pattern[str]":
    # Match `src` on <script> and `href` on <link>, single- or double-quoted.
    # We anchor to the tag name so an `old_src` substring sitting inside an
    # HTML comment, a JSON literal, or a `data-…` attribute is not rewritten.
    return re.compile(
        r'(<(?:script|link)\b[^>]*?\b(?:src|href)\s*=\s*["\'])'
        + re.escape(old_src)
        + r'(["\'])',
        re.IGNORECASE,
    )


def rewrite(html: str, old_src: str, new_src: str) -> "tuple[str, int]":
    """Return (new_html, count). Tag-aware: only rewrites <script src> /
    <link href> attributes, never substring matches in comments or JSON."""
    pattern = _build_pattern(old_src)
    return pattern.subn(lambda m: m.group(1) + new_src + m.group(2), html)


def inject(manifest_path: str, html_path: str, old_src: str) -> None:
    if not os.path.exists(manifest_path):
        print(f"skip: no manifest at {manifest_path}")
        return
    if not os.path.exists(html_path):
        print(f"skip: no html at {html_path}")
        return
    with open(manifest_path) as f:
        manifest = json.load(f)
    for entry in manifest.values():
        if not entry.get("isEntry"):
            continue
        hashed = entry["file"]
        new_src = f"{os.path.dirname(old_src)}/{hashed}"
        with open(html_path) as f:
            html = f.read()
        new_html, count = rewrite(html, old_src, new_src)
        if count == 0:
            # Loud warning — silent skip used to mask typos in `old_src`.
            print(
                f"WARN: no <script src> or <link href> matching {old_src!r} "
                f"in {html_path} — leaving file unchanged",
                file=sys.stderr,
            )
            return
        with open(html_path, "w") as f:
            f.write(new_html)
        print(f"{old_src} -> {new_src} ({count} occurrence{'s' if count != 1 else ''})")
        return
    print(f"skip: no isEntry row in {manifest_path}")


def main() -> int:
    if len(sys.argv) < 2:
        print("usage: inject-hashed-filenames.py CONFIG_JSON [BUILD_DIR]", file=sys.stderr)
        return 2
    cfg_path = sys.argv[1]
    build_dir = sys.argv[2] if len(sys.argv) > 2 else os.getcwd()
    with open(cfg_path) as f:
        entries = json.load(f)
    for e in entries:
        inject(
            os.path.join(build_dir, e["manifest"]),
            os.path.join(build_dir, e["html"]),
            e["old_src"],
        )
    return 0


if __name__ == "__main__":
    sys.exit(main())