#!/usr/bin/env python3
"""Add a label to a pull request (idempotent).

Commonly used to add the ``ready-to-merge`` label after CI passes and
review is complete. The operation is idempotent — if the label is already
attached, it succeeds without error.

Usage::

    # Add ready-to-merge to PR #42
    python -m devx.tools.pr_label --pr 42 --label ready-to-merge

    # Add label to current branch's PR
    python -m devx.tools.pr_label --label ready-to-merge

    # Add multiple labels
    python -m devx.tools.pr_label --pr 42 --label ready-to-merge --label reviewed

The repository is auto-detected from ``DEVX_REPO_OWNER`` /
``DEVX_REPO_NAME`` or ``GITHUB_REPOSITORY`` environment variables.
"""

from __future__ import annotations

import click
from dotenv import load_dotenv

from devx.api_clients import GiteaClient
from devx.config import GITEA_API_URL, REPO_OWNER
from devx.i18n import _
from devx.tokens import get_developer_token
from devx.tools.create_pr import get_repo_name
from devx.tools.pr_status import _get_current_branch_pr

load_dotenv()


@click.command()
@click.option("--pr", "pr_number", type=int, default=None, help="PR number (default: auto-detect from current branch).")
@click.option("--label", "labels", multiple=True, required=True, help="Label name(s) to add (can be repeated).")
@click.option("--owner", default=None, help="Repository owner (default: DEVX_REPO_OWNER).")
@click.option("--repo", default=None, help="Repository name (default: DEVX_REPO_NAME or GITHUB_REPOSITORY).")
def cli(
    pr_number: int | None,
    labels: tuple[str, ...],
    owner: str | None,
    repo: str | None,
) -> None:
    """Add one or more labels to a pull request (idempotent)."""
    try:
        token = get_developer_token()
    except click.ClickException:
        raise click.ClickException(_("CI_GITEA_TOKEN is not set.")) from None

    repo_owner = owner or REPO_OWNER
    if not repo_owner:
        raise click.ClickException(_("Repository owner not set. Use --owner or DEVX_REPO_OWNER env var."))
    repo_name = repo or get_repo_name()

    client = GiteaClient(GITEA_API_URL, token, repo_owner, repo_name)

    if pr_number is None:
        pr_number = _get_current_branch_pr(client)

    label_list = list(labels)
    existing = client.get_pr_label_names(pr_number)
    to_add = [lbl for lbl in label_list if lbl not in existing]
    already = [lbl for lbl in label_list if lbl in existing]

    if already:
        for lbl in already:
            click.echo(_("Label '{label}' already on PR #{pr}.", label=lbl, pr=pr_number))

    if to_add:
        client.add_pr_label(pr_number, to_add)
        for lbl in to_add:
            click.echo(_("Added label '{label}' to PR #{pr}.", label=lbl, pr=pr_number))


if __name__ == "__main__":  # pragma: no cover
    cli()  # pragma: no cover