# Copyright 2023 The Chromium Authors
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.
"""Methods to run tools over jars and cache their output."""

import logging
import pathlib
import zipfile
from typing import List, Optional, Union

from util import build_utils

_SRC_PATH = pathlib.Path(__file__).resolve().parents[4]
_JDEPS_PATH = _SRC_PATH / 'third_party/jdk/current/bin/jdeps'

_IGNORED_JAR_PATHS = [
    # This matches org_ow2_asm_asm_commons and org_ow2_asm_asm_analysis, both of
    # which fail jdeps (not sure why).
    'third_party/android_deps/libs/org_ow2_asm_asm',
]


def _is_relative_to(path: pathlib.Path, other_path: pathlib.Path):
  """This replicates pathlib.Path.is_relative_to.

    Since bots still run python3.8, they do not have access to is_relative_to,
    which was introduced in python3.9.
    """
  try:
    path.relative_to(other_path)
    return True
  except ValueError:
    # This error is expected when path is not a subpath of other_path.
    return False


def _should_ignore(jar_path: pathlib.Path) -> bool:
  for ignored_jar_path in _IGNORED_JAR_PATHS:
    if ignored_jar_path in str(jar_path):
      return True
  return False


def run_jdeps(filepath: pathlib.Path,
              *,
              jdeps_path: pathlib.Path = _JDEPS_PATH) -> Optional[str]:
  """Runs jdeps on the given filepath and returns the output."""
  if not filepath.exists() or _should_ignore(filepath):
    # Some __compile_java targets do not generate a .jar file, skipping these
    # does not affect correctness.
    return None

  return build_utils.CheckOutput([
      str(jdeps_path),
      '-verbose:class',
      '--multi-release',  # Some jars support multiple JDK releases.
      'base',
      str(filepath),
  ])


def extract_full_class_names_from_jar(
    jar_path: Union[str, pathlib.Path]) -> List[str]:
  """Returns set of fully qualified class names in passed-in jar."""
  out = set()
  with zipfile.ZipFile(jar_path) as z:
    for zip_entry_name in z.namelist():
      if not zip_entry_name.endswith('.class'):
        continue
      # Remove .class suffix
      full_java_class = zip_entry_name[:-6]

      # Remove inner class names after the first $.
      full_java_class = full_java_class.replace('/', '.')
      dollar_index = full_java_class.find('$')
      if dollar_index >= 0:
        full_java_class = full_java_class[0:dollar_index]

      out.add(full_java_class)
  return sorted(out)


def parse_full_java_class(source_path: pathlib.Path) -> str:
  """Guess the fully qualified class name from the path to the source file."""
  if source_path.suffix not in ('.java', '.kt'):
    logging.warning('"%s" does not end in .java or .kt.', source_path)
    return ''

  directory_path = source_path.parent
  package_list_reversed = []
  for part in reversed(directory_path.parts):
    if part == 'java':
      break
    package_list_reversed.append(part)
    if part in ('com', 'org'):
      break
  else:
    logging.debug(
        'File %s not in a subdir of "org" or "com", cannot detect '
        'package heuristically.', source_path)
    return ''

  package = '.'.join(reversed(package_list_reversed))
  class_name = source_path.stem
  return f'{package}.{class_name}'