#!/bin/bash
# Copyright 2020 The Fuchsia Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

## usage: fx vdl [-a <action>] [-d <device_launcher>] [-c <text>] [-e <directory>] [-H|--headless] [--software-gpu] [-N] [-u <path>]
##   -a <text> action, allowed values: start, kill. Default is start
##   -d <path> device_launcher/vdl binary location. Defaults to looking in prebuilt/vdl/device_launcher
##   -c <text> append item to kernel command line, currently not supported.
##   -ds <size> extends the fvm image size to <size> bytes. Default is 2G
##   -N run with emulated nic via tun/tap
##   -e <directory> location of emulator, defaults to looking in prebuilt/third_party/aemu/PLATFORM
##   -H|--headless run in headless mode
##   -p <text> extra packages to serve to FEMU.
##   -u <path> execute emu if-up script, default: linux: no script, macos: tap ifup script.
##   --host-gpu run with host GPU acceleration, this doesn't work on remote-desktop && headless=false.
##   --software-gpu run without host GPU acceleration, default.

set -e

DEVSHELL_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" >/dev/null 2>&1 && pwd)"
source "${DEVSHELL_DIR}"/lib/image_build_vars.sh || exit $?

# Scans ports from and return the first identified unused port.
function find_unused_tcp_port {
  local server_port="${1}"
  local max_port=59759
  while ss -latn | grep -q :${server_port} && server_port < ${max_port}; do
    server_port=$((${server_port} + 1))
  done
  echo "${server_port}"
}

# Defaults
ACTION="start"
EXTR_KERNEL_FLAGS=""
IMAGE_SIZE="2G"
AEMU_DIR="${PREBUILT_AEMU_DIR}"
VDL="${PREBUILT_VDL_DIR}/device_launcher"
PACKAGES_TO_SERVE=""
GPU="swiftshader_indirect"
HEADLESS=false
TUNTAP=false
UPSCRIPT=""
while [[ $# -ge 1 ]]; do
  case "${1}" in
  -h|--help)
    fx-command-help
    exit 0
    ;;
  -a)
    shift
    ACTION="${1}"
    ;;
  -c)
    shift
    EXTR_KERNEL_FLAGS+="${1} "
    ;;
  -d)
    shift
    VDL="${1}"
    ;;
  -ds)
    shift
    IMAGE_SIZE="${1}"
    ;;
  -e)
    shift
    AEMU_DIR="${1}"
    ;;
  -p)
    shift
    PACKAGES_TO_SERVE="${1}"
    ;;
  -u)
    shift
    UPSCRIPT="${1}"
    ;;
  -H|--headless)
    HEADLESS=true
    ;;
  -N)
    TUNTAP=true
    ;;
  --host-gpu)
    GPU="host"
    ;;
  --software-gpu)
    GPU="swiftshader_indirect"
    ;;
  *)
    break
  esac
  shift
done

# Stores VDL outputs such as pid for package server, and created tmp files.
VDL_PROTO="/tmp/vdl_proto"

if [[ "${ACTION}" == "kill" ]]; then
  "${VDL}" --action=kill \
    --launched_virtual_device_proto="${VDL_PROTO}" \
    --ga=true

  exit_code=$?
  if [[ ${exit_code} == 0 ]]; then
    rm "${VDL_PROTO}"
  fi
  exit ${exit_code}
fi

if [[ -f "${VDL_PROTO}" ]]; then
  rm "${VDL_PROTO}"
fi
touch "${VDL_PROTO}"
chmod 644 "${VDL_PROTO}"

# Host side binaries
AEMU="${AEMU_DIR}/emulator"
FAR="${HOST_OUT_DIR}/far"
FVM="${HOST_OUT_DIR}/fvm"
PM="${HOST_OUT_DIR}/pm"

img_dir="$(mktemp -d)"
if [[ ! -d "${img_dir}" ]]; then
  fx-error "Failed to create temporary directory"
  exit 1
fi
echo "Created tmp dir ${img_dir}"
trap 'rm -Rf "${img_dir}"' EXIT

# System images
# Currently VDL makes some files naming pattern assumptions
# that requires us to provide a list of files matching the naming
# regex. We want to have VDL automatically check these environment
# variables and look for the relevant image files.

# TODO(yuanzhi) Remove the `ln` command once VDL can look for these
# files automatically.

# SSH
PRIVATE_KEY="$(get-ssh-privkey)"
AUTHORIZED_KEYS="${PRIVATE_KEY}.pub"
SSH_CONFIG="${FUCHSIA_BUILD_DIR}/ssh-keys/ssh_config"
VDL_PRIVATE_KEY="${img_dir}/id_ed25519"
VDL_AUTHORIZED_KEYS="${img_dir}/id_ed25519.pub"
ln -s "${PRIVATE_KEY}" "${VDL_PRIVATE_KEY}"
ln -s "${AUTHORIZED_KEYS}" "${VDL_AUTHORIZED_KEYS}"
SYSTEM_FILES="${VDL_PRIVATE_KEY},${VDL_AUTHORIZED_KEYS},${SSH_CONFIG},"

# ziron-a.zbi
ZBI_IMAGE="${FUCHSIA_BUILD_DIR}/${IMAGE_ZIRCONA_ZBI}"
VDL_ZBI_IMAGE="${img_dir}/qemu_zircona-ed25519"
fx-zbi -o "${VDL_ZBI_IMAGE}" "${ZBI_IMAGE}" \
  --entry "data/ssh/authorized_keys=${AUTHORIZED_KEYS}"
SYSTEM_FILES+="${VDL_ZBI_IMAGE},"

# Kernel
KERNEL_IMAGE="${FUCHSIA_BUILD_DIR}/${IMAGE_QEMU_KERNEL_RAW}"
VDL_KERNEL_IMAGE="${img_dir}/qemu_kernel"
ln -s "${KERNEL_IMAGE}" "${VDL_KERNEL_IMAGE}"
SYSTEM_FILES+="${VDL_KERNEL_IMAGE},"

# FVM storage
FVM_IMAGE="${FUCHSIA_BUILD_DIR}/${IMAGE_FVM_RAW}"
VDL_FVM_IMAGE="${img_dir}/qemu_fvm"
ln -s "${FVM_IMAGE}" "${VDL_FVM_IMAGE}"
SYSTEM_FILES+="${VDL_FVM_IMAGE},"

# Build Args
BUILD_ARGS="${FUCHSIA_BUILD_DIR}/args.gn"
VDL_BUILD_ARGS="${img_dir}/qemu_buildargs"
ln -s "${BUILD_ARGS}" "${VDL_BUILD_ARGS}"
SYSTEM_FILES+="${VDL_BUILD_ARGS},"

# Fuchsia packages
AMBER_FILES="${FUCHSIA_BUILD_DIR}/amber-files"
SYSTEM_FILES+="${AMBER_FILES}"

# Device Spec
# TODO(yuanzhi) Integrate with FVD
DEVICE_PROTO="${img_dir}/virtual_device.textproto"
echo "device_spec {
  horizontal_resolution: 1280
  vertical_resolution: 800
  vm_heap: 192
  ram: 4096
  cache: 32
  screen_density: 240
}
" >> "${DEVICE_PROTO}"
# This is only relevant when using SLIRP where we manually map ssh port;
# if using Tun/Tap (-N) then we don't need to forward ssh port, and this flag
# will be ignored by VDL.
SSH_PORT=$(find_unused_tcp_port 32761)
readonly PORT_MAP="hostfwd=tcp::${SSH_PORT}-:22"

# Start FEMU using VDL
set -x
if [[ "${ACTION}" == "start" ]]; then
  "${VDL}" --action=start \
      --emulator_binary_path="${AEMU}" \
      --pm_tool="${PM}" \
      --far_tool="${FAR}" \
      --fvm_tool="${FVM}" \
      --resize_fvm="${IMAGE_SIZE}" \
      --gpu="${GPU}" \
      --headless_mode="${HEADLESS}" \
      --tuntap="${TUNTAP}" \
      --upscript="${UPSCRIPT}" \
      --enable_grpc_server=false \
      --enable_grpc_tls=false \
      --system_images="${SYSTEM_FILES}" \
      --proto_file_path="${DEVICE_PROTO}" \
      --host_port_map="${PORT_MAP}" \
      --output_launched_device_proto="${VDL_PROTO}" \
      --ga=true \
      --emu_log="/tmp/emulator_log.log"
fi