import hashlib
import io
import json
import os
import platform
import re
import subprocess
import sys
import tarfile
import tempfile
import urllib.request
from pathlib import Path


ROOT = Path(__file__).resolve().parents[2]
VERSION = "1.7.12"
ARCHIVE_SHA256 = {
  "darwin_amd64": "5b44c3bc2255115c9b69e30efc0fecdf498fdb63c5d58e17084fd5f16324c644",
  "darwin_arm64": "aba9ced2dee8d27fecca3dc7feb1a7f9a52caefa1eb46f3271ea66b6e0e6953f",
  "linux_amd64": "8aca8db96f1b94770f1b0d72b6dddcb1ebb8123cb3712530b08cc387b349a3d8",
  "linux_arm64": "325e971b6ba9bfa504672e29be93c24981eeb1c07576d730e9f7c8805afff0c6",
}
# These two inherited jobs remain explicitly unavailable. No other diagnostic is waived.
DISABLED_JOBS = {
  ".github/workflows/tests.yaml": ("simulator_driving", "    if: false  # FIXME: Started to timeout recently"),
  ".github/workflows/ui_preview.yaml": ("preview", "    if: false # tmp disable due to GH API rate limiting flakiness"),
}


def actionlint() -> Path:
  machine = {"x86_64": "amd64", "aarch64": "arm64"}.get(platform.machine(), platform.machine())
  target = f"{platform.system().lower()}_{machine}"
  if target not in ARCHIVE_SHA256:
    raise RuntimeError(f"Unsupported actionlint platform: {target}")
  cache = ROOT / ".cache" / f"actionlint-{VERSION}-{target}"
  archive = cache / "release.tar.gz"
  binary = cache / "actionlint"
  cache.mkdir(parents=True, exist_ok=True)
  if not archive.exists():
    url = f"https://github.com/rhysd/actionlint/releases/download/v{VERSION}/actionlint_{VERSION}_{target}.tar.gz"
    with urllib.request.urlopen(url, timeout=60) as response:
      data = response.read()
    if hashlib.sha256(data).hexdigest() != ARCHIVE_SHA256[target]:
      raise RuntimeError("actionlint release checksum mismatch")
    with tempfile.NamedTemporaryFile(dir=cache, delete=False) as temporary:
      temporary.write(data)
      name = temporary.name
    os.replace(name, archive)
  data = archive.read_bytes()
  if hashlib.sha256(data).hexdigest() != ARCHIVE_SHA256[target]:
    raise RuntimeError("Cached actionlint release checksum mismatch")
  with tarfile.open(fileobj=io.BytesIO(data), mode="r:gz") as release:
    member = release.extractfile("actionlint")
    if member is None:
      raise RuntimeError("actionlint release has no binary")
    expected = member.read()
  if not binary.exists() or binary.read_bytes() != expected:
    with tempfile.NamedTemporaryFile(dir=cache, delete=False) as temporary:
      temporary.write(expected)
      name = temporary.name
    os.chmod(name, 0o755)
    os.replace(name, binary)
  return binary


def main() -> int:
  binary = actionlint()
  if sys.argv[1:] == ["--install"]:
    return 0
  if sys.argv[1:]:
    raise RuntimeError("Usage: check_workflows.py [--install]")
  workflows = sorted(str(path.relative_to(ROOT)) for path in (ROOT / ".github/workflows").glob("*.yaml"))
  workflows += sorted(str(path.relative_to(ROOT)) for path in (ROOT / ".github/workflows").glob("*.yml"))
  if not workflows:
    raise RuntimeError("No workflows found")
  result = subprocess.run([str(binary), "-shellcheck=", "-pyflakes=", "-format", "{{json .}}", *workflows],
                          cwd=ROOT, text=True, capture_output=True)
  if result.returncode not in (0, 1) or result.stderr:
    raise RuntimeError(result.stderr or result.stdout or f"actionlint exited {result.returncode}")
  errors = json.loads(result.stdout or "[]")
  failed = False
  for error in errors:
    path = error["filepath"]
    lines = (ROOT / path).read_text().splitlines()
    line = lines[error["line"] - 1]
    preceding_jobs = [match.group(1) for text in lines[:error["line"] - 1]
                      if (match := re.fullmatch(r"  ([a-zA-Z_][a-zA-Z0-9_-]*):", text))]
    job = preceding_jobs[-1] if preceding_jobs else None
    if (error["kind"] == "if-cond" and error["message"] == 'constant expression "false" in condition. remove the if: section'
        and path in DISABLED_JOBS and (job, line) == DISABLED_JOBS[path]):
      continue
    print(f'{path}:{error["line"]}:{error["column"]}: {error["message"]}')
    failed = True
  return int(failed)


if __name__ == "__main__":
  try:
    sys.exit(main())
  except (OSError, RuntimeError, ValueError) as error:
    print(error, file=sys.stderr)
    sys.exit(1)