#!/usr/bin/env bash
set -euo pipefail
# POS: docker vbox — Disposable Docker-based VMs (create/enter/start/stop/rm/ls)
# POS_SUBCMDS: create enter stop start rm ls
source "$(dirname "$0")/../lib/common.sh" 2>/dev/null || source "$(dirname "$0")/common.sh"

usage() {
    cat <<EOF
Usage:
  pos docker vbox create <name> [image] [--dir <path>]
  pos docker vbox enter  <name>
  pos docker vbox stop   <name>
  pos docker vbox start  <name>
  pos docker vbox rm     <name>
  pos docker vbox ls

Manage disposable Docker containers as lightweight VMs.

Each container gets a bind-mounted host directory so files persist
on the host even after the container is removed.

Options:
  --dir <path>   Use custom directory instead of default ~/<name>
                 Use "." for current directory

Examples:
  pos docker vbox create lab1
  pos docker vbox create lab1 --dir .
  pos docker vbox create lab1 --dir /mnt/data/lab1
  pos docker vbox create kali kalilinux/kali-rolling
  pos docker vbox enter lab1
  pos docker vbox stop lab1
  pos docker vbox start lab1
  pos docker vbox rm lab1
  pos docker vbox ls
EOF
    exit 0
}

case "${1:-}" in
    -h|--help) usage ;;
esac

cmd="${1:-}"
[ -z "$cmd" ] && usage

container_exists() {
    docker container inspect "$1" &>/dev/null
}

container_running() {
    [[ "$(docker inspect -f '{{.State.Running}}' "$1" 2>/dev/null)" == "true" ]]
}

case "$cmd" in
    create)
        name="${2:-}"
        [ -z "$name" ] && usage

        # Parse remaining args: [image] [--dir <path>]
        image="ubuntu:22.04"
        custom_dir=""
        shift 2 || true
        while [ $# -gt 0 ]; do
            case "$1" in
                --dir)
                    [ -z "${2:-}" ] && { echo "Missing value for --dir"; exit 1; }
                    custom_dir="$2"
                    shift 2
                    ;;
                *)
                    image="$1"
                    shift
                    ;;
            esac
        done

        if container_exists "$name"; then
            echo "[!] Container already exists: $name"
            exit 0
        fi

        if [ -n "$custom_dir" ]; then
            lab_dir="$(cd "$custom_dir" 2>/dev/null && pwd)" || { echo "[!] Directory not found: $custom_dir"; exit 1; }
        else
            lab_dir="$HOME/$name"
        fi
        mkdir -p "$lab_dir"
        echo "[+] Lab directory: $lab_dir"

        echo "[+] Pulling image: $image"
        docker pull "$image"

        echo "[+] Creating: $name"
        docker create \
            -it \
            --name "$name" \
            --label linux_post_install.vbox=true \
            -v "$lab_dir:$lab_dir" \
            -w "$lab_dir" \
            "$image" \
            bash >/dev/null
        echo "[+] Done"

        if confirm "Enter now?"; then
            docker start "$name" >/dev/null
            exec docker exec -it -w "$lab_dir" "$name" bash
        fi
        ;;

    enter)
        name="${2:-}"
        [ -z "$name" ] && usage

        if ! container_exists "$name"; then
            echo "[!] Container not found: $name"
            exit 1
        fi

        if ! container_running "$name"; then
            docker start "$name" >/dev/null
        fi

        # Detect working dir from container mounts
        lab_dir=$(docker inspect -f '{{range .Mounts}}{{if eq .Destination .Destination}}{{.Source}}{{end}}{{end}}' "$name" 2>/dev/null | head -1)
        if [ -n "$lab_dir" ] && [ -d "$lab_dir" ]; then
            exec docker exec -it -w "$lab_dir" "$name" bash
        else
            exec docker exec -it "$name" bash
        fi
        ;;

    start)
        name="${2:-}"
        [ -z "$name" ] && usage
        docker start "$name"
        ;;

    stop)
        name="${2:-}"
        [ -z "$name" ] && usage
        docker stop "$name"
        ;;

    rm)
        name="${2:-}"
        [ -z "$name" ] && usage
        docker rm -f "$name"
        ;;

    ls)
        docker ps -a --filter label=linux_post_install.vbox=true --format "table {{.Names}}\t{{.Image}}\t{{.Status}}"
        ;;

    *)
        usage
        ;;
esac