#!/usr/bin/python3
#
# Merge a separate CVE file (such as data/next-point-update.txt) back into
# the main one.
#
# Copyright © 2020-2023 Emilio Pozuelo Monfort <pochu@debian.org>
# Copyright (c) 2021-2022 Neil Williams <codehelp@debian.org>

import os
import sys

import setup_paths  # noqa
from debian_support import internRelease
from sectracker.parsers import (
    Bug,
    cvelist,
    writecvelist,
    PackageAnnotation,
    FlagAnnotation,
    StringAnnotation,
    XrefAnnotation
)

def merge_notes(annotations, new_annotation):
    """
    Special support for StringAnnotations.

    Merges a note into the bug's annotations, taking care not to
    add duplicate notes.

    new_annotation is a new string annotation for this CVE (bug),
    """
    old_descriptions = [ann.description
                        for ann in annotations
                        if isinstance(ann, StringAnnotation)]

    # prevent adding duplicate notes
    if not new_annotation.description in old_descriptions:
        annotations.append(new_annotation)


def merge_annotations(annotations, new_annotation):
    """
    Adds new_annotation to the annotations list
    """
    if not isinstance(new_annotation, PackageAnnotation):
        raise NotImplementedError(f"unsupported annotation of type {new_annotation.type} (line {new_annotation.line})")

    annotations_for_pkg = [ann for ann in annotations \
                           if isinstance(ann, PackageAnnotation) \
                           and ann.package == new_annotation.package]
    if not annotations_for_pkg:
        if new_annotation.release:
            raise ValueError(f"new annotation for {new_annotation.package}/{new_annotation.release} "
                              "but there is no annotation for sid")
        # new package, add it at the top
        for idx, annotation in enumerate(annotations):
            if isinstance(annotation, FlagAnnotation) \
              or isinstance(annotation, XrefAnnotation):
                continue

            annotations.insert(idx, new_annotation)
            return


    # append/substitute the new one at the right place
    for idx, annotation in enumerate(annotations):
        if not isinstance(annotation, PackageAnnotation) \
          or annotation.package != new_annotation.package:
            continue

        # if the annotation is for the same package/release, replace it
        if annotation.package == new_annotation.package \
          and annotation.release == new_annotation.release:
            annotations[idx] = new_annotation
            break

        # if we found an experimental annotation, it will be followed by a 'sid'
        # one, so next_annotation.release will be None in the next case. That
        # comparison will break, so we avoid it by continuing. If new_annotation
        # was for experimental, we would have already replaced it in the above check.
        if annotation.release == 'experimental':
            continue

        # if the next annotation's release is the same, we continue to replace
        # it in the next iteration. otherwise if we found the right place, we
        # insert the new annotation
        next_annotation = annotations[idx + 1] if len(annotations) > (idx + 1) else None
        if next_annotation and isinstance(next_annotation, PackageAnnotation) \
          and next_annotation.package == new_annotation.package \
          and internRelease(new_annotation.release) <= internRelease(next_annotation.release):
            continue

        annotations.insert(idx + 1, new_annotation)
        break


if len(sys.argv) not in (2, 3):
    print(f"Usage: {os.path.basename(sys.argv[0])} (CVE/list) extra-cve-list")
    sys.exit(1)

if len(sys.argv) == 3:
    main_list = sys.argv[1]
else:
    main_list = os.path.dirname(__file__) + '/../data/CVE/list'

extra_list = sys.argv[-1]

data = cvelist(main_list)
extra_data = cvelist(extra_list)

for extra_bug in extra_data:
    bug = next(bug for bug in data if bug.header.name == extra_bug.header.name)

    for extra_annotation in extra_bug.annotations:
        if isinstance(extra_annotation, FlagAnnotation):
            continue
        if isinstance(extra_annotation, StringAnnotation):
            merge_notes(bug.annotations, extra_annotation)
            continue

        merge_annotations(bug.annotations, extra_annotation)

with open(main_list, 'w') as f:
    writecvelist(data, f)

# check for and erase an .xpck file built from the merge
xpck = f"{extra_list}.xpck"
if os.path.exists(xpck):
    os.unlink(xpck)