#!/usr/bin/env bash
# ───────────────────────────────────────────────────────────
# run-qemu.sh — Launch the Ansible Control Node VM
#
# Boots the minimal Alpine Linux VM with:
#   • Machine:  pc-q35-10.0
#   • TTY:      ttyS0, xterm-256color (serial console)
#   • Keyboard: PS/2 (atkbd via QEMU default)
#   • Network:  user-mode NAT with port forwards:
#       localhost:2222 → VM:22  (SSH)
#       localhost:8080 → VM:8080 (custom services)
#   • Disk:     virtio-blk, read from output/
#   • Init:     OpenRC (no systemd)
#
# Usage:
#   ./scripts/run-qemu.sh                     # serial console (default)
#   ./scripts/run-qemu.sh --gui               # graphical (GTK) window
#   ./scripts/run-qemu.sh --vnc :0            # VNC on display :0
#   ./scripts/run-qemu.sh --debug             # verbose kernel boot
#
# Environment:
#   QEMU_MEMORY  — RAM size (default: 1024M)
#   QEMU_SMP     — CPU count (default: 2)
#   SSH_PORT     — host port for SSH forward (default: 2222)
#
# Access the VM:
#   ssh -p 2222 ansible@localhost            # password: ansible
#   ssh -p 2222 root@localhost               # password: ansible
#
# Stop the VM:
#   Press Ctrl-A then X (in -nographic mode)
#   Or: sudo shutdown -h now (inside VM)
# ───────────────────────────────────────────────────────────
set -euo pipefail

SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
OUTPUT_DIR="${OUTPUT_DIR:-$SCRIPT_DIR/../output}"

# ── Configuration (env-overridable) ─────────────────────────
QEMU_BIN="${QEMU_BIN:-qemu-system-x86_64}"
QEMU_MACHINE="${QEMU_MACHINE:-pc-q35-10.0}"
QEMU_MEMORY="${QEMU_MEMORY:-1024M}"
QEMU_SMP="${QEMU_SMP:-2}"
SSH_PORT="${SSH_PORT:-2222}"
EXTRA_PORT="${EXTRA_PORT:-8090}"

# ── Colour helpers ──────────────────────────────────────────
RED='\033[0;31m'; GREEN='\033[0;32m'; YELLOW='\033[1;33m'
BLUE='\033[0;34m'; BOLD='\033[1m'; NC='\033[0m'
info()  { echo -e "${BLUE}[*]${NC} $*"; }
ok()    { echo -e "${GREEN}[✓]${NC} $*"; }
warn()  { echo -e "${YELLOW}[!]${NC} $*"; }

# ── Find build artifacts ────────────────────────────────────
# Prefer qcow2 over raw
if [ -f "$OUTPUT_DIR/ansible-node.qcow2" ]; then
    DISK="$OUTPUT_DIR/ansible-node.qcow2"
    DISK_FMT="qcow2"
elif [ -f "$OUTPUT_DIR/ansible-node.raw" ]; then
    DISK="$OUTPUT_DIR/ansible-node.raw"
    DISK_FMT="raw"
else
    echo -e "${RED}[✗]${NC} No disk image found in ${OUTPUT_DIR}"
    echo "  Run ./scripts/build-qemu.sh first."
    exit 1
fi

KERNEL="$OUTPUT_DIR/vmlinuz-virt"
INITRD="$OUTPUT_DIR/initramfs-virt"

for f in "$DISK" "$KERNEL" "$INITRD"; do
    if [ ! -f "$f" ]; then
        echo -e "${RED}[✗]${NC} Missing: $f"
        exit 1
    fi
done

# ── Parse arguments ─────────────────────────────────────────
DISPLAY_MODE="nographic"
KERNEL_APPEND="root=/dev/vda console=ttyS0 TERM=xterm-256color quiet modules=virtio_blk,ext4 rootflags=rw"
EXTRA_QEMU_ARGS=()

while [[ $# -gt 0 ]]; do
    case "$1" in
        --gui|-g)
            DISPLAY_MODE="gtk"
            ;;
        --vnc)
            DISPLAY_MODE="vnc"
            VNC_DISPLAY="${2:-:0}"
            shift
            ;;
        --debug)
            # Remove 'quiet', add verbose/delay for debugging
            KERNEL_APPEND="${KERNEL_APPEND// quiet/} debug_init rootdelay=3"
            ;;
        --help|-h)
            echo "Usage: $0 [--gui|--vnc :N|--debug] [extra qemu args...]"
            echo ""
            echo "Modes:"
            echo "  (default)   Serial console (-nographic), Ctrl-A X to exit"
            echo "  --gui       Graphical GTK window with keyboard support"
            echo "  --vnc :N    VNC server on display N"
            echo "  --debug     Verbose kernel boot messages"
            echo ""
            echo "Environment:"
            echo "  QEMU_MEMORY=1024M   RAM size"
            echo "  QEMU_SMP=2          CPU count"
            echo "  SSH_PORT=2222       Host SSH port"
            exit 0
            ;;
        *)
            EXTRA_QEMU_ARGS+=("$1")
            ;;
    esac
    shift
done

# ── Display mode flags ──────────────────────────────────────
case "$DISPLAY_MODE" in
    nographic)
        DISPLAY_FLAG="-nographic"
        ;;
    gtk)
        DISPLAY_FLAG="-display gtk"
        # QEMU's GTK display includes keyboard support via PS/2 emulation
        # which covers the CONFIG_KEYBOARD_ATKBD kernel requirement
        ;;
    vnc)
        DISPLAY_FLAG="-vnc ${VNC_DISPLAY} -vga virtio"
        KERNEL_APPEND="$KERNEL_APPEND video=1024x768"
        ;;
esac

# ── Launch ──────────────────────────────────────────────────
echo ""
echo -e "${BOLD}══════════════════════════════════════════════${NC}"
echo -e "${BOLD}  Ansible Control Node${NC}"
echo -e "${BOLD}══════════════════════════════════════════════${NC}"
echo ""
echo -e "  Machine:  ${GREEN}${QEMU_MACHINE}${NC}"
echo -e "  Memory:   ${GREEN}${QEMU_MEMORY}${NC}"
echo -e "  CPUs:     ${GREEN}${QEMU_SMP}${NC}"
echo -e "  Disk:     ${GREEN}${DISK_FMT}:${DISK}${NC}"
echo -e "  Display:  ${GREEN}${DISPLAY_MODE}${NC}"
echo -e "  Kernel:   ${KERNEL_APPEND}"
echo ""
echo -e "  SSH:      ${YELLOW}ssh -p ${SSH_PORT} ansible@localhost${NC}"
echo -e "  Password: ${YELLOW}ansible${NC}"
echo ""
echo -e "  ${BOLD}Ctrl-A X${NC} to quit (serial mode)"
echo -e "  ${BOLD}Ctrl-C${NC}   to force-quit (any mode)"
echo ""

# Build netdev string, skipping extra port if already in use
NETDEV_FORWARDS="hostfwd=tcp::${SSH_PORT}-:22"
if ! ss -tlnp 2>/dev/null | grep -q ":${EXTRA_PORT} "; then
    NETDEV_FORWARDS="${NETDEV_FORWARDS},hostfwd=tcp::${EXTRA_PORT}-:8080"
else
    warn "Port ${EXTRA_PORT} already in use — skipping extra forward"
fi

# shellcheck disable=SC2086
exec "$QEMU_BIN" \
    -machine "$QEMU_MACHINE" \
    -m "$QEMU_MEMORY" \
    -smp "$QEMU_SMP" \
    -enable-kvm \
    -kernel "$KERNEL" \
    -initrd "$INITRD" \
    -append "$KERNEL_APPEND" \
    -drive "file=$DISK,if=virtio,format=$DISK_FMT" \
    -netdev "user,id=net0,${NETDEV_FORWARDS}" \
    -device virtio-net,netdev=net0 \
    $DISPLAY_FLAG \
    "${EXTRA_QEMU_ARGS[@]}"