from pathlib import Path

import yaml

from utils.docker.manager import find_docker_compose


def _get_service_port(mapping: str) -> int | None:
    match mapping.split(":"):
        case [""]:
            return None
        case [port] | [port, _]:
            return int(port)
        case ["localhost" | "127.0.0.1", _, _]:
            return None
        case [_, port, _]:
            return int(port)
        case _:
            return None


def _replace_port_in_mapping(mapping: str, port_from: int, port_to: int) -> str:
    parts = str(mapping).split(":")
    match parts:
        case [_]:
            # "8080" -> "9090"
            return str(port_to)
        case [_, container_port]:
            # "8080:80" -> "9090:80"
            return f"{port_to}:{container_port}"
        case [ip, _, container_port]:
            # "127.0.0.1:8080:80" -> "127.0.0.1:9090:80"
            return f"{ip}:{port_to}:{container_port}"
        case _:
            return str(port_to)


def _get_port_index(mappings: list[str], port: int) -> int | None:
    for i, mapping in enumerate(mappings):
        if _get_service_port(mapping) == port:
            return i
    return None


def change_port(
        folder: Path,
        service_name: str,
        port_from: int,
        port_to: int,
):
    docker_compose, filename = find_docker_compose(folder)
    if not docker_compose or not docker_compose.get('services'):
        return

    compose_path = folder / filename
    backup_compose_path = folder / filename.replace(".yml", ".bak.yml")

    compose_path.copy(backup_compose_path)

    for service, config in docker_compose["services"].items():
        if service != service_name:
            continue
        idx = _get_port_index(config["ports"], port_from)
        if idx is None:
            return
        config["ports"][idx] = _replace_port_in_mapping(config["ports"][idx], port_from, port_to)

    compose_path.write_text(yaml.dump(docker_compose, default_flow_style=False))

    # TODO: run docker compose commands