"""Convert a `docker run ...` command string into a Compose YAML fragment."""
from __future__ import annotations

import shlex

import yaml


def _service_name_from_image(image: str) -> str:
    name = image.split("/")[-1].split(":")[0]
    return name or "app"


def convert_docker_run(command: str) -> str:
    tokens = shlex.split(command)
    # Drop leading "docker run" / "docker container run".
    while tokens and tokens[0] in ("docker", "run", "container", "sudo"):
        tokens.pop(0)

    service: dict = {}
    name = None
    image = None
    ports: list[str] = []
    volumes: list[str] = []
    environment: list[str] = []
    env_file: list[str] = []
    devices: list[str] = []
    cap_add: list[str] = []
    labels: list[str] = []
    networks: list[str] = []
    command_args: list[str] = []

    i = 0
    n = len(tokens)

    def take_value(idx: int, tok: str):
        if "=" in tok and tok.startswith("--") and not tok.endswith("="):
            return tok.split("=", 1)[1], idx + 1
        return tokens[idx + 1], idx + 2

    while i < n:
        tok = tokens[i]
        if image is not None:
            # Everything after the image is the container command.
            command_args = tokens[i:]
            break
        if not tok.startswith("-"):
            image = tok
            i += 1
            continue

        flag = tok.split("=", 1)[0]
        if flag in ("-d", "--detach", "-i", "--interactive", "-t", "--tty", "--rm", "--init"):
            i += 1
        elif flag in ("--name",):
            name, i = take_value(i, tok)
        elif flag in ("-p", "--publish"):
            val, i = take_value(i, tok)
            ports.append(val)
        elif flag in ("-v", "--volume", "--mount"):
            val, i = take_value(i, tok)
            volumes.append(val)
        elif flag in ("-e", "--env"):
            val, i = take_value(i, tok)
            environment.append(val)
        elif flag in ("--env-file",):
            val, i = take_value(i, tok)
            env_file.append(val)
        elif flag in ("--device",):
            val, i = take_value(i, tok)
            devices.append(val)
        elif flag in ("--cap-add",):
            val, i = take_value(i, tok)
            cap_add.append(val)
        elif flag in ("-l", "--label"):
            val, i = take_value(i, tok)
            labels.append(val)
        elif flag in ("--network", "--net"):
            val, i = take_value(i, tok)
            networks.append(val)
        elif flag in ("--restart",):
            val, i = take_value(i, tok)
            service["restart"] = val
        elif flag in ("--privileged",):
            service["privileged"] = True
            i += 1
        elif flag in ("--hostname", "-h"):
            val, i = take_value(i, tok)
            service["hostname"] = val
        elif flag in ("-u", "--user"):
            val, i = take_value(i, tok)
            service["user"] = val
        elif flag in ("-w", "--workdir"):
            val, i = take_value(i, tok)
            service["working_dir"] = val
        else:
            # Unknown flag — try to consume a value if it looks like it takes one.
            if "=" in tok:
                i += 1
            elif i + 1 < n and not tokens[i + 1].startswith("-"):
                i += 2
            else:
                i += 1

    if not image:
        raise ValueError("Could not find an image in the docker run command")

    service["image"] = image
    if "restart" not in service:
        service["restart"] = "unless-stopped"
    if ports:
        service["ports"] = ports
    if volumes:
        service["volumes"] = volumes
    if environment:
        service["environment"] = environment
    if env_file:
        service["env_file"] = env_file
    if devices:
        service["devices"] = devices
    if cap_add:
        service["cap_add"] = cap_add
    if labels:
        service["labels"] = labels
    if networks:
        service["networks"] = networks
    if command_args:
        service["command"] = command_args

    svc_name = name or _service_name_from_image(image)
    if name:
        service["container_name"] = name

    doc = {"services": {svc_name: service}}
    return yaml.safe_dump(doc, sort_keys=False, default_flow_style=False)