"""
Resolve deploy-time tokens in deployed files.

Values come from config/environments.yml and config/services_registry.yml --
the single source of truth. Nothing here knows what '-DEV' is.

    render_subs.py --env dev --service tune /path/to/ioc /path/to/systemd
    render_subs.py --env prod /sls/bd/hla/prod/qt

Without --service only the environment tokens are available, so a file that
needs a per-service token (ioc_port) fails loudly rather than shipping the
placeholder. A path that does not exist is reported and skipped, which is how
services without a systemd unit are handled.
"""

import argparse
import sys
from pathlib import Path

from agebd.subs import SubstitutionError, Substitutions


def render(subs, paths):
    """
    Render every path in place. Returns the files that changed.
    """
    changed = []
    for path in paths:
        if not path.exists():
            print(f"skipped (does not exist): {path}")
            continue
        if path.is_dir():
            changed.extend(subs.render_tree(path))
        elif subs.render_file(path):
            changed.append(path)
    return changed


def main(argv=None):
    parser = argparse.ArgumentParser(
        description=__doc__,
        formatter_class=argparse.RawDescriptionHelpFormatter,
    )
    parser.add_argument("--env", required=True, help="Deployment environment, e.g. dev")
    parser.add_argument(
        "--service",
        default=None,
        help="Service name. Required for files holding per-service tokens.",
    )
    parser.add_argument("paths", nargs="+", type=Path, help="Files or directories to render")
    args = parser.parse_args(argv)

    if args.service:
        subs = Substitutions.for_service(args.env, args.service)
    else:
        subs = Substitutions.for_env(args.env)

    changed = render(subs, args.paths)

    for path in changed:
        print(f"rendered: {path}")
    print(f"{len(changed)} file(s) rendered for env '{args.env}'")
    return 0


if __name__ == "__main__":
    try:
        sys.exit(main())
    except SubstitutionError as e:
        print(f"error: {e}", file=sys.stderr)
        sys.exit(1)