#!/bin/bash
# run-vm.sh — Launch QEMU VM for testing (reusable by other test scripts)
# Usage: ./test/qemu/run-vm.sh <iso-or-img> [options]
#
# Options:
#   --arch <arch>         Architecture: x86_64 (default) or arm64
#   --data-disk <path>    Use existing data disk (default: create temp)
#   --data-size <MB>      Size of temp data disk (default: 1024)
#   --memory <MB>         VM memory (default: 2048)
#   --cpus <n>            VM CPUs (default: 2)
#   --serial-log <path>   Write serial output to file
#   --api-port <port>     Forward K8s API to host port (default: 6443)
#   --ssh-port <port>     Forward SSH to host port (default: 2222)
#   --background          Run in background, print PID
#   --append <args>       Extra kernel append args
#   --kernel <path>       Kernel image (required for arm64)
#   --initrd <path>       Initramfs image (required for arm64)
#
# Outputs (on stdout):
#   QEMU_PID=<pid>
#   DATA_DISK=<path>
#   SERIAL_LOG=<path>
set -euo pipefail

IMAGE="${1:?Usage: $0 <iso-or-img> [options]}"
shift

# Defaults
ARCH="x86_64"
DATA_DISK=""
DATA_SIZE_MB=1024
MEMORY=2048
CPUS=2
SERIAL_LOG=""
API_PORT=6443
SSH_PORT=2222
BACKGROUND=0
EXTRA_APPEND=""
CREATED_DATA_DISK=""
VM_KERNEL=""
VM_INITRD=""

# Parse options
while [ $# -gt 0 ]; do
    case "$1" in
        --arch)         ARCH="$2"; shift 2 ;;
        --data-disk)    DATA_DISK="$2"; shift 2 ;;
        --data-size)    DATA_SIZE_MB="$2"; shift 2 ;;
        --memory)       MEMORY="$2"; shift 2 ;;
        --cpus)         CPUS="$2"; shift 2 ;;
        --serial-log)   SERIAL_LOG="$2"; shift 2 ;;
        --api-port)     API_PORT="$2"; shift 2 ;;
        --ssh-port)     SSH_PORT="$2"; shift 2 ;;
        --background)   BACKGROUND=1; shift ;;
        --append)       EXTRA_APPEND="$2"; shift 2 ;;
        --kernel)       VM_KERNEL="$2"; shift 2 ;;
        --initrd)       VM_INITRD="$2"; shift 2 ;;
        *) echo "Unknown option: $1" >&2; exit 1 ;;
    esac
done

# Create data disk if not provided
if [ -z "$DATA_DISK" ]; then
    DATA_DISK=$(mktemp /tmp/kubesolo-data-XXXXXX.img)
    CREATED_DATA_DISK="$DATA_DISK"
    dd if=/dev/zero of="$DATA_DISK" bs=1M count="$DATA_SIZE_MB" 2>/dev/null
    mkfs.ext4 -q -L KSOLODATA "$DATA_DISK" 2>/dev/null
fi

# Create serial log if not provided
if [ -z "$SERIAL_LOG" ]; then
    SERIAL_LOG=$(mktemp /tmp/kubesolo-serial-XXXXXX.log)
fi

# Build QEMU command based on architecture
if [ "$ARCH" = "arm64" ] || [ "$ARCH" = "aarch64" ]; then
    # ARM64: qemu-system-aarch64 with -machine virt
    # No KVM for cross-arch emulation (TCG only)
    CONSOLE="ttyAMA0"

    # ARM64 requires explicit kernel + initrd (no -cdrom support with -machine virt)
    if [ -z "$VM_KERNEL" ] || [ -z "$VM_INITRD" ]; then
        echo "ERROR: ARM64 mode requires --kernel and --initrd options" >&2
        exit 1
    fi

    QEMU_CMD=(
        qemu-system-aarch64
        -machine virt
        -cpu cortex-a72
        -m "$MEMORY"
        -smp "$CPUS"
        -nographic
        -net "nic,model=virtio"
        -net "user,hostfwd=tcp::${API_PORT}-:6443,hostfwd=tcp::${SSH_PORT}-:22"
        -drive "file=$DATA_DISK,format=raw,if=virtio"
        -serial "file:$SERIAL_LOG"
        -kernel "$VM_KERNEL"
        -initrd "$VM_INITRD"
        -append "console=${CONSOLE} kubesolo.data=/dev/vda kubesolo.debug $EXTRA_APPEND"
    )
else
    # x86_64: standard QEMU
    CONSOLE="ttyS0,115200n8"

    # Detect KVM availability
    KVM_FLAG=""
    if [ -w /dev/kvm ] 2>/dev/null; then
        KVM_FLAG="-enable-kvm"
    fi

    QEMU_CMD=(
        qemu-system-x86_64
        -m "$MEMORY"
        -smp "$CPUS"
        -nographic
        -net "nic,model=virtio"
        -net "user,hostfwd=tcp::${API_PORT}-:6443,hostfwd=tcp::${SSH_PORT}-:22"
        -drive "file=$DATA_DISK,format=raw,if=virtio"
        -serial "file:$SERIAL_LOG"
    )

    [ -n "$KVM_FLAG" ] && QEMU_CMD+=("$KVM_FLAG")

    case "$IMAGE" in
        *.iso)
            QEMU_CMD+=(
                -cdrom "$IMAGE"
                -boot d
                -append "console=${CONSOLE} kubesolo.data=/dev/vda kubesolo.debug $EXTRA_APPEND"
            )
            ;;
        *.img)
            QEMU_CMD+=(
                -drive "file=$IMAGE,format=raw,if=virtio"
            )
            ;;
        *)
            echo "ERROR: Unrecognized image format: $IMAGE" >&2
            exit 1
            ;;
    esac
fi

# Launch
"${QEMU_CMD[@]}" &
QEMU_PID=$!

# Output metadata
echo "QEMU_PID=$QEMU_PID"
echo "DATA_DISK=$DATA_DISK"
echo "SERIAL_LOG=$SERIAL_LOG"
echo "CREATED_DATA_DISK=$CREATED_DATA_DISK"

if [ "$BACKGROUND" = "0" ]; then
    # Foreground mode — wait for QEMU to exit
    wait "$QEMU_PID" || true
    # Clean up temp data disk
    [ -n "$CREATED_DATA_DISK" ] && rm -f "$CREATED_DATA_DISK"
fi