#!/usr/bin/env python3

import importlib
import os
from pathlib import Path
from typing import Iterator

import click
import git
import toml

from clickusagelib.githook import install_hook, uninstall_hook


def find_git_root(path) -> Path:
    git_repo = git.Repo(path, search_parent_directories=True)
    git_root = git_repo.git.rev_parse("--show-toplevel")
    return Path(git_root)


def iter_commands(
    tool_name: str,
    cmd_chain: list,
    cliobj: click.Group | click.Command,
    depth: int = 1,
) -> Iterator[str]:
    assert isinstance(cliobj, click.Command) or isinstance(cliobj, click.Group)

    if isinstance(cliobj, click.Group):
        if depth > 1:
            yield f"{'#'*depth} {tool_name} {cliobj.name}\n"

        for name in sorted(cliobj.commands):
            yield from iter_commands(
                tool_name, cmd_chain + [name], cliobj.commands[name], depth=depth + 1
            )
    else:
        ctx = click.get_current_context()
        cmd = f"{tool_name} {' '.join(cmd_chain)}"
        help_message = cliobj.get_help(ctx).replace(ctx.command_path, cmd)

        yield f"{'#'*(depth)} {tool_name} {' '.join(cmd_chain)}\n```\n{help_message}\n```"


def generate_usage_md(script: str, version: str):
    script_name, module = script
    assert ":" in module
    module_name, cliobj = module.split(":")

    mod = importlib.import_module(module_name)
    cli = getattr(mod, cliobj)

    with open("USAGE.md", "wt") as fd:
        if "." in module_name:
            module_name = module_name.split(".")[0]

        print(
            f"# {module_name.capitalize()} v{version} - {script_name} - Command Usage Overview\n",
            file=fd,
        )
        for command in iter_commands(script_name, [], cli):
            print(command, file=fd)


@click.group()
def cli():
    pass


@cli.command(help="Generate markdown usage description.")
@click.argument(
    "poetry_project_file",
    type=click.File(),
    default=os.path.join(find_git_root(os.getcwd()), "pyproject.toml"),
)
@click.pass_context
def run(ctx, poetry_project_file):
    contents = toml.loads(poetry_project_file.read())
    try:
        scripts = contents["tool"]["poetry"]["scripts"].items()
        version = contents["tool"]["poetry"]["version"]
        for script in scripts:
            generate_usage_md(script, version)
    except KeyError:
        click.echo("[ERROR] File does not contain 'tool.poetry.scripts' definitions.")
        ctx.exit(1)


@cli.command(help="Install clickusagemd as pre-push hook.")
def install():
    install_hook(find_git_root(os.getcwd()))


@cli.command(help="Uninstall clickusagemd pre-push hook.")
def uninstall():
    uninstall_hook(find_git_root(os.getcwd()))


cli.add_command(run)
cli.add_command(install)
cli.add_command(uninstall)


if __name__ == "__main__":
    cli()