#!/usr/bin/env bash
# Build HTKnow on a server without installing Node.js or Rust on the host.
#
# Examples:
#   ./build-docker.sh
#   ./build-docker.sh --tag gwknow:v0.0.2
#   ./build-docker.sh --skip-frontend --tag gwknow:v0.0.3
#   IMAGE_TAG=v0.0.3 ./build-docker.sh

set -Eeuo pipefail

ROOT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
cd "$ROOT_DIR"

NODE_IMAGE="${NODE_IMAGE:-docker.1ms.run/node:22}"
RUST_BUILDER_IMAGE="${RUST_BUILDER_IMAGE:-htknow-rust-builder:bookworm}"
SKIP_FRONTEND=false
REBUILD_BUILDER=false
IMAGE_TAG="${IMAGE_TAG:-}"

usage() {
    cat <<'EOF'
Usage: ./build-docker.sh [options]

Options:
  --tag IMAGE          Target image tag, for example gwknow:v0.0.2.
  --skip-frontend      Do not rebuild frontend/dist (safe for Rust-only changes).
  --rebuild-builder    Rebuild the cached Rust + protoc builder image.
  -h, --help           Show this help.

Environment overrides:
  IMAGE_TAG, NODE_IMAGE, RUST_BUILDER_IMAGE

If --tag and IMAGE_TAG are omitted, a new gwknow:YYYYmmdd-HHMMSS tag is used.
EOF
}

while [[ $# -gt 0 ]]; do
    case "$1" in
        --tag)
            [[ $# -ge 2 ]] || { echo "--tag requires an image tag" >&2; exit 2; }
            IMAGE_TAG="$2"
            shift 2
            ;;
        --skip-frontend|--backend-only)
            SKIP_FRONTEND=true
            shift
            ;;
        --rebuild-builder)
            REBUILD_BUILDER=true
            shift
            ;;
        -h|--help)
            usage
            exit 0
            ;;
        *)
            echo "Unknown option: $1" >&2
            usage >&2
            exit 2
            ;;
    esac
done

command -v docker >/dev/null || { echo "docker is not installed or is not in PATH" >&2; exit 1; }
docker info >/dev/null 2>&1 || { echo "Docker daemon is unavailable" >&2; exit 1; }

if [[ -z "$IMAGE_TAG" ]]; then
    IMAGE_TAG="gwknow:$(date +%Y%m%d-%H%M%S)"
elif [[ "$IMAGE_TAG" != *:* ]]; then
    IMAGE_TAG="gwknow:${IMAGE_TAG}"
fi

HOST_UID="$(id -u)"
HOST_GID="$(id -g)"
mkdir -p .cargo-cache .npm-cache

if [[ "$REBUILD_BUILDER" == true ]] || ! docker image inspect "$RUST_BUILDER_IMAGE" >/dev/null 2>&1; then
    echo "==> Building Rust builder image: $RUST_BUILDER_IMAGE"
    docker build -t "$RUST_BUILDER_IMAGE" -f Dockerfile.rust-builder .
fi

if [[ "$SKIP_FRONTEND" == false ]]; then
    echo "==> Building frontend with $NODE_IMAGE"
    docker run --rm \
        --user "${HOST_UID}:${HOST_GID}" \
        -e HOME=/tmp \
        -e npm_config_cache=/npm-cache \
        -v "$ROOT_DIR":/app \
        -v "$ROOT_DIR/.npm-cache":/npm-cache \
        -w /app/frontend \
        "$NODE_IMAGE" \
        sh -c 'npm ci && npm run build'
else
    echo "==> Skipping frontend build (--skip-frontend)"
fi

echo "==> Building Rust release binary with $RUST_BUILDER_IMAGE"
docker run --rm \
    --user "${HOST_UID}:${HOST_GID}" \
    -e HOME=/tmp \
    -e CARGO_HOME=/cargo-cache \
    -v "$ROOT_DIR":/app \
    -v "$ROOT_DIR/.cargo-cache":/cargo-cache \
    -w /app \
    "$RUST_BUILDER_IMAGE" \
    bash -c 'cargo build --locked --release'

echo "==> Building runtime image: $IMAGE_TAG"
docker build -f Dockerfile -t "$IMAGE_TAG" .

echo
echo "Build complete: $IMAGE_TAG"
echo "To deploy, update the compose image tag and recreate only the intended service."