#!/usr/bin/env python3
#
# Use BeautifulSoup to deduplicate functions in a grov XML (cobertura)
# output file.

import sys

try:
    from bs4 import BeautifulSoup

    _ = __import__("lxml")
except ImportError:
    print("Sorry, BeautifulSoup 4 or lxml is not installed.", file=sys.stderr)
    sys.exit(1)

if len(sys.argv) != 2:
    print(f"Usage: {sys.argv[0]} <cobertura_file>")
    print("    Post-process a grcov cobertura.xml file")
    sys.exit(1)

# Parse the coverage file
with open(sys.argv[1]) as f:
    document = BeautifulSoup(f, "lxml")


def get_or_fail(obj, field):
    """
    Like obj.field, but raise a KeyError if obj.field is None.

    Insisting on an exception in this case helps mypy typecheck this code.
    """
    val = getattr(obj, field)
    if val is None:
        raise KeyError(field)
    return val


# Iterate over source files
coverage = get_or_fail(document, "coverage")
packages = get_or_fail(coverage, "packages")
for file in packages.findAll("package"):
    already_seen = set()
    # Iterate over function
    for func in file.classes.findChild("class").methods.findAll("method"):
        name = func["name"]
        if name in already_seen:
            # Remove duplicate function
            func.extract()
        else:
            already_seen.add(name)

with open(sys.argv[1], "w") as out:
    out.write(document.prettify())