#!/usr/bin/env python3

"""
This module generates a draft_notes.md to be attached to a Gitea release and
a CHANGELOG.md to be committed into the repo.

It is the python version of this https://stackoverflow.com/a/46033999
"""

import subprocess
import argparse

def full():
    with open("CHANGELOG.md", "w+") as fw:
        try:
            # Get all the tags sorted in decreasing order (the -creatordate is what sorts in decreasing order)
            tags = subprocess.check_output(["git", "tag", "--sort=-creatordate"], text=True)
            tags = [tag for tag in tags.split("\n") if tag]
            # Get the remote url
            remote_url = subprocess.check_output(["git", "remote", "get-url", "origin"], text=True)
            # Remove the first occurence of the word git starting from the end of the string
            remote_url = remote_url[0:remote_url.rfind(".git")]
            previous_tag = ""
            for tag in tags:
                if previous_tag:
                    # Extract the date of the commit
                    tag_date = subprocess.check_output(["git", "log", "-1", f"--pretty=format:'%ad'", "--date=short", f"{tag}"], text=True)
                    tag_date = tag_date.replace("'", "")

                    # Get each commit of a tag formatted
                    formatted_lines = subprocess.check_output(["git", "log", f"{tag}...{previous_tag}", f'--pretty=format:"*  %s [View]({remote_url}/commits/%H)"'], text=True)
                    if formatted_lines:
                        fw.write(f"## {tag} ({tag_date})\n\n")
                        # Remove merge commits or Changelog commits
                        lines = "\n".join([line.replace("\"", "") for line in formatted_lines.split("\n") if all(["merge" not in line.lower(), "changelog.md" not in line.lower()])])
                        fw.write(lines)
                        fw.write("\n\n")
                previous_tag = tag
        except subprocess.CalledProcessError as e:
            print(f"Command failed with return code {e.returncode}")

def draft():
    with open("draft_notes.md", "w+") as fw:
        try:
            # Get the remote url
            remote_url = subprocess.check_output(["git", "remote", "get-url", "origin"], text=True)
            # Remove the first occurence of the word git starting from the end of the string
            remote_url = remote_url[0:remote_url.rfind(".git")]

            # Get the current and previous tags
            tags = subprocess.check_output(["git", "tag", "--sort=creatordate"], text=True)
            tags = [tag for tag in tags.split("\n") if tag]
            tags.reverse()
            current_tag, previous_tag, *_ = tags
            formatted_lines = subprocess.check_output(["git", "log", f"{current_tag}...{previous_tag}", f'--pretty=format:"*  %s"'], text=True)
            lines = "\n".join([line.replace("\"", "") for line in formatted_lines.split("\n") if all(["merge" not in line.lower(), "changelog.md" not in line.lower()])])
            fw.write(lines)
            fw.write("\n\n")
            fw.write(f"Compare between recent changes: [{previous_tag[1:]}...{current_tag[1:]}]({remote_url}/compare/{previous_tag}...{current_tag})")
        except subprocess.CalledProcessError as e:
            print(f"Command failed with return code {e.returncode}")

def run():
    parser = argparse.ArgumentParser(description='Generate changelogs....')
    group = parser.add_mutually_exclusive_group(required=True)
    group.add_argument("--full", help="Generate full changelog", action="store_true")
    group.add_argument("--draft", help="Generate notes with tag", action="store_true")
    args = parser.parse_args()
    if args.full:
        full()
    elif args.draft:
        draft()

if __name__ == "__main__":
    run()