"""
Copyright (C) 2024 Mandiant, Inc. All Rights Reserved.
Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
You may obtain a copy of the License at: [package root]/LICENSE.txt
Unless required by applicable law or agreed to in writing, software distributed under the License
 is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and limitations under the License.
"""

import os
import sys
import logging
import subprocess
from pathlib import Path
from datetime import datetime, timedelta

logger = logging.getLogger(__name__)

start_dir = Path(sys.argv[1])
output_file = Path(sys.argv[2])

assert start_dir.exists(), "start directory must exist"


def get_yml_files_and_dates(start_dir: Path):
    yml_files = []
    for root, _, files in os.walk(start_dir):
        for file in files:
            if file.endswith(".yml") or file.endswith(".yaml"):
                file_path = Path(root) / file

                proc = subprocess.run(
                    [
                        "git",
                        "log",
                        "-1",  # only show most recent commit
                        '--pretty="%ct"',  # unix timestmp, https://git-scm.com/docs/pretty-formats#Documentation/pretty-formats.txt-emctem
                        file,  # just the filename, will run from the containing directory
                    ],
                    cwd=root,  # the directory with the file we're inspecting
                    check=True,
                    capture_output=True,
                )

                last_modified_date = int(proc.stdout.decode("utf-8").partition("\n")[0].strip('"'))

                yml_files.append((file_path, last_modified_date))
    return yml_files


yml_files_and_dates = get_yml_files_and_dates(start_dir)

yml_files_and_dates.sort(key=lambda x: x[1], reverse=True)


current_date = datetime.now()

categories = [
    ("modified in the last day", current_date - timedelta(days=1)),
    ("modified in the last week", current_date - timedelta(days=7)),
    ("modified in the last month", current_date - timedelta(days=30)),
    ("modified in the last three months", current_date - timedelta(days=90)),
    ("modified in the last year", current_date - timedelta(days=365)),
]


def write_category(f, category_name, files):
    f.write(f"=== {category_name} ===\n")
    for file_path, last_modified_date in files:
        last_modified_date_str = datetime.fromtimestamp(last_modified_date).strftime("%Y-%m-%d %H:%M:%S")
        f.write(f"{file_path} {last_modified_date_str}\n")
    f.write("\n")


with output_file.open("wt", encoding="utf-8") as f:
    for title, delta in categories:
        current_files = []
        for file_path, last_modified_date in yml_files_and_dates:
            last_modified_date_dt = datetime.fromtimestamp(last_modified_date)
            if last_modified_date_dt > delta:
                current_files.append((file_path, last_modified_date))

        write_category(f, title, current_files)

        for item in current_files:
            yml_files_and_dates.remove(item)

    write_category(f, "older", yml_files_and_dates)


logger.info("File names and modification dates have been written to %s", output_file)