"""Docker service for managing tool instances."""

import logging
import subprocess
import time
from collections import Counter
from pathlib import Path
from typing import Any

logger = logging.getLogger(__name__)


def sort_volumes_by_specificity(volumes: list[str]) -> list[str]:
    """Sort volume strings so parent paths come before child paths.

    Docker Compose mounts volumes in array order. A later mount at a parent
    path hides earlier mounts at child paths. By sorting shallow paths first
    and deep paths last, deeper (more specific) mounts overlay correctly.

    Volume format: source:target or source:target:type

    Args:
        volumes: List of Docker volume mount strings.

    Returns:
        Sorted list with parent paths before child paths.
    """

    def _target_depth(vol: str) -> int:
        parts = vol.split(":")
        if len(parts) < 2:
            return 0
        target = parts[1].rstrip("/")
        if not target or target == "/":
            return 0
        return target.count("/")

    # Detect duplicate targets and warn
    targets = []
    for vol in volumes:
        parts = vol.split(":")
        targets.append(parts[1] if len(parts) > 1 else "")
    dupes = [t for t, c in Counter(targets).items() if c > 1]
    if dupes:
        logger.warning("Duplicate mount targets detected: %s", dupes)

    # Stable sort: parent paths first, child paths last
    return sorted(volumes, key=_target_depth)


def render_compose_template(template: str, variables: dict[str, Any]) -> str:
    """Render a Docker Compose template with variable substitution.

    Args:
        template: The compose template string
        variables: Dictionary of variable names to values

    Returns:
        Rendered compose file content
    """
    result = template
    for key, value in variables.items():
        placeholder = f"{{{{{key}}}}}"
        result = result.replace(placeholder, str(value))
    return result


def ensure_instance_directory(instance_id: str, base_path: str | None = None) -> str:
    """Create and return the instance directory path.

    Args:
        instance_id: Unique instance identifier
        base_path: Base directory for all instances (defaults to Settings.instance_base_path)

    Returns:
        Absolute path to instance directory
    """
    if base_path is None:
        from src.config import Settings

        base_path = Settings().instance_base_path
    instance_dir = Path(base_path) / instance_id
    instance_dir.mkdir(parents=True, exist_ok=True)
    return str(instance_dir.absolute())


def write_compose_file(instance_dir: str, content: str) -> str:
    """Write the rendered compose file to the instance directory.

    Args:
        instance_dir: Path to instance directory
        content: Rendered compose content

    Returns:
        Path to the compose file
    """
    compose_path = Path(instance_dir) / "docker-compose.yml"
    compose_path.write_text(content)
    return str(compose_path)


def write_env_file(instance_dir: str, env_vars: dict[str, str]) -> str:
    """Write environment variables to a .env file.

    Args:
        instance_dir: Path to instance directory
        env_vars: Dictionary of env var names to values

    Returns:
        Path to the env file
    """
    env_path = Path(instance_dir) / ".env"
    lines = [f'{key}="{value}"' for key, value in env_vars.items()]
    env_path.write_text("\n".join(lines) + "\n")
    return str(env_path)


def write_config_files(instance_dir: str, files: dict[str, str]) -> None:
    """Write config files to the instance directory.

    Args:
        instance_dir: Path to instance directory
        files: Dictionary of file paths (relative to instance dir) to content
    """
    instance_path = Path(instance_dir)
    for file_path, content in files.items():
        # Ensure the path is within the instance directory (security)
        full_path = instance_path / file_path
        try:
            full_path.resolve().relative_to(instance_path.resolve())
        except ValueError:
            raise ValueError(f"File path '{file_path}' escapes instance directory")

        full_path.parent.mkdir(parents=True, exist_ok=True)
        full_path.write_text(content)


def execute_compose_command(
    compose_path: str, action: str, timeout: int = 60, env_file: str | None = None
) -> tuple[int, str, str]:
    """Execute a docker compose command.

    Args:
        compose_path: Path to docker-compose.yml
        action: The compose action (up, down, start, stop, restart)
        timeout: Command timeout in seconds
        env_file: Optional path to .env file for environment variables

    Returns:
        Tuple of (returncode, stdout, stderr)
    """
    instance_dir = Path(compose_path).parent

    cmd = ["docker", "compose", "-f", compose_path]

    if env_file:
        cmd.extend(["--env-file", env_file])

    if action == "up":
        cmd.extend(["up", "-d", "--force-recreate"])
    elif action == "down":
        cmd.extend(["down", "-v"])
    elif action in ("start", "stop", "restart"):
        cmd.append(action)
    else:
        raise ValueError(f"Unknown compose action: {action}")

    result = subprocess.run(
        cmd,
        cwd=str(instance_dir),
        capture_output=True,
        text=True,
        timeout=timeout,
    )

    return result.returncode, result.stdout, result.stderr


def get_container_id(instance_name: str) -> str | None:
    """Get the container ID for a compose service.

    Uses exact name matching via docker inspect to avoid substring collisions
    with tunnel containers (e.g. tunnel-code-server-... matching code-server-...).

    Args:
        instance_name: The exact container name (case-insensitive for Docker).

    Returns:
        Container ID or None if not found.
    """
    result = subprocess.run(
        ["docker", "inspect", "-f", "{{.Id}}", instance_name.lower()],
        capture_output=True,
        text=True,
    )
    if result.returncode == 0 and result.stdout.strip():
        return result.stdout.strip()
    return None


def get_container_name(instance_name: str) -> str | None:
    """Get the full container name for a compose service.

    Uses exact name matching via docker inspect to avoid substring collisions.

    Args:
        instance_name: The exact container name (case-insensitive for Docker).

    Returns:
        Container name or None if not found.
    """
    result = subprocess.run(
        ["docker", "inspect", "-f", "{{.Name}}", instance_name.lower()],
        capture_output=True,
        text=True,
    )
    if result.returncode == 0 and result.stdout.strip():
        return result.stdout.strip().lstrip("/")
    return None


def get_backend_network_name() -> str:
    """Auto-detect the actual Docker network name for the backend network.

    Docker Compose prefixes network names with the project directory name
    (e.g. 'headquarter_backend' instead of 'backend'). We inspect the API
    container itself to find the real network name it's connected to.

    Returns:
        The actual Docker network name, or 'backend' as fallback.
    """
    # Try to find the API container by its known name
    api_container = "hq-api"
    result = subprocess.run(
        [
            "docker",
            "inspect",
            "-f",
            "{{range $k, $v := .NetworkSettings.Networks}}{{$k}} {{end}}",
            api_container,
        ],
        capture_output=True,
        text=True,
    )
    if result.returncode == 0 and result.stdout.strip():
        networks = result.stdout.strip().split()
        for net in networks:
            if "backend" in net.lower():
                return net
        # API container is on some network — return the first one
        return networks[0]
    return "backend"


def connect_container_to_network(
    container_name: str, network_name: str | None = None
) -> bool:
    """Connect a Docker container to an existing network.

    Args:
        container_name: Name or ID of the container
        network_name: Name of the Docker network. If None, auto-detects
            from the API container's own network membership.

    Returns:
        True if successful, False otherwise
    """
    if network_name is None:
        network_name = get_backend_network_name()
    result = subprocess.run(
        ["docker", "network", "connect", network_name, container_name],
        capture_output=True,
        text=True,
    )
    return result.returncode == 0


def get_container_ip_on_network(
    container_id: str, network_name: str | None = None
) -> str | None:
    """Get a container's IP address on a specific Docker network.

    Args:
        container_id: Docker container ID or name.
        network_name: Network name. If None, auto-detects from the API container.

    Returns:
        IP address string, or None if the container is not on that network.
    """
    if network_name is None:
        network_name = get_backend_network_name()
    result = subprocess.run(
        [
            "docker",
            "inspect",
            "-f",
            f"{{{{.NetworkSettings.Networks.{network_name}.IPAddress}}}}",
            container_id,
        ],
        capture_output=True,
        text=True,
    )
    if result.returncode == 0:
        ip = result.stdout.strip()
        if ip and ip != "<no value>":
            return ip
    return None


def is_container_on_network(container_id: str, network_name: str | None = None) -> bool:
    """Check whether a container is already attached to a Docker network.

    Args:
        container_id: Docker container ID or name.
        network_name: Network name. If None, auto-detects from the API container.

    Returns:
        True if the container is on the network.
    """
    if network_name is None:
        network_name = get_backend_network_name()
    result = subprocess.run(
        [
            "docker",
            "inspect",
            "-f",
            f"{{{{.NetworkSettings.Networks.{network_name}}}}}",
            container_id,
        ],
        capture_output=True,
        text=True,
    )
    return result.returncode == 0 and "<no value>" not in result.stdout


def get_container_status(container_id: str) -> dict[str, Any]:
    """Get the status of a Docker container.

    Args:
        container_id: Docker container ID

    Returns:
        Dict with 'status' (running, exited, restarting, not_found),
        'exit_code' (int or None), and 'health' (health status or None)
    """
    result = subprocess.run(
        [
            "docker",
            "inspect",
            "-f",
            "{{.State.Status}}|{{.State.ExitCode}}|{{if .State.Health}}{{.State.Health.Status}}{{else}}none{{end}}",
            container_id,
        ],
        capture_output=True,
        text=True,
    )

    if result.returncode != 0:
        return {"status": "not_found", "exit_code": None, "health": None}

    parts = result.stdout.strip().split("|")
    status = parts[0] if parts else "unknown"
    exit_code = int(parts[1]) if len(parts) > 1 and parts[1].isdigit() else None
    health = parts[2] if len(parts) > 2 and parts[2] != "none" else None

    return {"status": status, "exit_code": exit_code, "health": health}


def wait_for_container_running(
    container_id: str, timeout: int = 30, interval: float = 2.0
) -> dict[str, Any]:
    """Wait for a container to reach the running state.

    Polls docker inspect until the container status is "running" or timeout.

    Args:
        container_id: Docker container ID
        timeout: Maximum seconds to wait
        interval: Seconds between polls

    Returns:
        Dict with 'success' (bool), 'status' (str), 'exit_code' (int or None),
        and 'waited_seconds' (float)
    """

    start_time = time.time()

    while time.time() - start_time < timeout:
        info = get_container_status(container_id)

        if info["status"] == "running":
            return {
                "success": True,
                "status": "running",
                "exit_code": None,
                "waited_seconds": time.time() - start_time,
            }

        if info["status"] == "exited":
            return {
                "success": False,
                "status": "exited",
                "exit_code": info["exit_code"],
                "waited_seconds": time.time() - start_time,
            }

        if info["status"] == "not_found":
            return {
                "success": False,
                "status": "not_found",
                "exit_code": None,
                "waited_seconds": time.time() - start_time,
            }

        time.sleep(interval)

    # Timeout reached
    info = get_container_status(container_id)
    return {
        "success": False,
        "status": info["status"],
        "exit_code": info["exit_code"],
        "waited_seconds": time.time() - start_time,
    }


def get_container_logs(container_id: str, tail: int = 100) -> str:
    """Get the logs of a Docker container.

    Args:
        container_id: Docker container ID
        tail: Number of lines to return

    Returns:
        Container logs
    """
    result = subprocess.run(
        ["docker", "logs", "--tail", str(tail), container_id],
        capture_output=True,
        text=True,
    )

    if result.returncode == 0:
        return result.stdout
    return f"Failed to get logs: {result.stderr}"


def find_free_port(start: int = 10000, end: int = 20000) -> int:
    """Find a free TCP port in the given range.

    Args:
        start: Start of port range
        end: End of port range

    Returns:
        Free port number
    """
    import socket

    for port in range(start, end):
        with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:
            if s.connect_ex(("localhost", port)) != 0:
                return port

    raise RuntimeError(f"No free port found in range {start}-{end}")