#!/usr/bin/env bash
# 強隔離 on this Mac: macOS can't run gVisor directly, and OrbStack/Docker Desktop's Linux VM
# can't take it. This makes a small Ubuntu VM (Lima, Apple Virtualization) with its OWN Docker
# and gVisor (runsc): Bot 的電腦 runs there on a virtualized kernel, verified by a sandboxed
# Chromium — the Mac's kernel is a whole VM away.
#
#   ./gvisor-vm.sh              create + start the VM (idempotent; re-run to fix/update)
#   ./gvisor-vm.sh --rm         remove the VM (the box's files live in a volume inside it)
#
# Afterwards, in AnyBot 設定 › 電腦 › 在哪裡執行:
#   Docker 主機:  ssh://lima-anybot-gvisor
#   容器隔離:      強隔離（gVisor）
# and press 更新 on the computer card. (AnyBot's Docker host accepts ssh://, the VNC viewer
# forwards through it.)
set -euo pipefail
VM=anybot-gvisor
CPUS=4
MEM=6                    # GiB
DISK=60                  # GiB

if [ "${1:-}" = "--rm" ]; then
  limactl delete --force "$VM" 2>/dev/null || true
  echo "已移除 VM ${VM}。"
  exit 0
fi

command -v limactl >/dev/null 2>&1 || { echo "先裝 Lima：brew install lima"; exit 1; }

STATUS=$(limactl list "$VM" --format '{{.Status}}' 2>/dev/null || true)
if [ "$STATUS" = "Running" ]; then
  echo "VM $VM 已在執行。"
elif [ -n "$STATUS" ]; then
  echo "VM $VM 是 ${STATUS}，啟動中…"
  limactl start --tty=false "$VM"
else
  echo "建立 VM ${VM}（$CPUS CPU / ${MEM}GB / ${DISK}GB，第一次要下載映像檔，幾分鐘）…"
  # template:docker-rootful = Lima's rootful Docker template (runsc wants a plain root daemon;
  # the rootless docker template runs the daemon in a user namespace).
  limactl start --name="$VM" --tty=false --cpus "$CPUS" --memory "$MEM" --disk "$DISK" template:docker-rootful
fi

echo "VM 裡安裝 gVisor（runsc，systrap 平台：不需要 KVM，ARM VM 可用）…"
limactl shell "$VM" -- bash -ec '
set -e
if ! command -v runsc >/dev/null 2>&1; then
  sudo mkdir -p /etc/apt/keyrings
  curl -fsSL https://gvisor.dev/archive.key | sudo gpg --dearmor -o /usr/share/keyrings/gvisor-archive-keyring.gpg
  echo "deb [signed-by=/usr/share/keyrings/gvisor-archive-keyring.gpg] https://storage.googleapis.com/gvisor/releases release main" | sudo tee /etc/apt/sources.list.d/gvisor.list >/dev/null
  sudo apt-get update -qq
  sudo apt-get install -y -qq runsc
fi
# Register the runtime in the VM'\''s Docker daemon (merge, do not clobber other settings).
# Restart Docker only when that changed: a restart stops Bot 的電腦 running in this VM.
CHANGED=$(sudo python3 - <<EOF
import json, os
p = "/etc/docker/daemon.json"
d = json.load(open(p)) if os.path.exists(p) else {}
if d.get("runtimes", {}).get("runsc", {}).get("path") != "runsc":
    d.setdefault("runtimes", {})["runsc"] = {"path": "runsc"}
    os.makedirs("/etc/docker", exist_ok=True)
    json.dump(d, open(p, "w"), indent=2)
    print("changed")
EOF
)
if [ "$CHANGED" = changed ]; then sudo systemctl restart docker; fi
# Prove the wall works: a container whose kernel really is gVisor.
docker run --rm --runtime=runsc --entrypoint sh alpine:3.20 -c "grep -q gVisor /proc/version && uname -r" | sed "s/^/runsc 容器核心: /"
'

# Bot 的電腦 lives in this VM: start it with the Mac, or after a restart the computer is gone
# until someone runs this again.
limactl autostart enable "$VM" >/dev/null 2>&1 || limactl start-at-login "$VM" --enabled >/dev/null 2>&1 || echo "（沒能設定開機自動啟動：Mac 重開機後要再跑一次這個腳本）"

# Lima forwards the VM's Docker socket to the Mac: AnyBot's Docker 主機用這個 unix:// 位址，
# 不用 ssh、不用碰 ~/.ssh/config。
SOCK="$HOME/.lima/$VM/sock/docker.sock"
DOCKER_HOST="unix://$SOCK" docker info --format '{{range $k, $v := .Runtimes}}{{$k}} {{end}}' | grep -qw runsc || { echo "從 Mac 連到 VM 的 Docker 看不到 runsc"; exit 1; }
KERNEL=$(DOCKER_HOST="unix://$SOCK" docker run --rm --runtime=runsc --entrypoint cat alpine:3.20 /proc/version | cut -d' ' -f3)

cat <<EOF

都好了（從 Mac 驗證：runsc 容器的核心是 ${KERNEL}）。AnyBot 設定 › 電腦 › 在哪裡執行：
  Docker 主機：  unix://$SOCK
  容器隔離：      強隔離（gVisor）
然後在電腦卡片按「建立/更新」。要讓舊 box 的檔案與登入跟著走，
先完全退出 AnyBot、跑同資料夾的 gvisor-migrate.sh，再回來開。
EOF