#!/usr/bin/env bash
set -Eeuo pipefail

# Build selected app images and package them as an incremental update.
# Usage:
#   ./build-update.sh admin monitor
#   SERVICES="admin monitor" ./build-update.sh
#   EMP_ROOT=/path/to/emp IMAGE_TAG=20260602153000 ./build-update.sh emp-admin emp-monitor
#
# Output:
#   dist/${DEPLOY_ENV}-update-${IMAGE_TAG}-${services}.tar.gz

SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
DIST_DIR="${DIST_DIR:-$SCRIPT_DIR/dist}"
BUILD_CONTEXT_DIR="$SCRIPT_DIR/.build-context"

DEPLOY_ENV="${DEPLOY_ENV:-emp-test}"
IMAGE_NAMESPACE="${IMAGE_NAMESPACE:-$DEPLOY_ENV}"
IMAGE_TAG="${IMAGE_TAG:-$(date '+%Y%m%d%H%M%S')}"
NPM_REGISTRY="${NPM_REGISTRY:-https://registry.npmjs.org}"
SKIP_BUILD="${SKIP_BUILD:-0}"
COS_UPLOAD="${COS_UPLOAD:-0}"

log() {
  echo "[$(date '+%Y-%m-%d %H:%M:%S')] $*"
}

die() {
  echo "ERROR: $*" >&2
  exit 1
}

need_cmd() {
  command -v "$1" >/dev/null 2>&1 || die "Missing command: $1"
}

has_emp_root() {
  [[ -d "$1/emp_server" && -d "$1/emp_admin" && -d "$1/emp_ws" ]]
}

resolve_root_dir() {
  if [[ -n "${EMP_ROOT:-}" ]]; then
    local root
    root="$(cd "$EMP_ROOT" && pwd)"
    has_emp_root "$root" || die "EMP_ROOT is invalid: $EMP_ROOT"
    printf '%s\n' "$root"
    return
  fi

  local candidates=(
    "$SCRIPT_DIR/../.."
    "$SCRIPT_DIR/../../emp"
    "$SCRIPT_DIR/.."
    "$PWD"
  )
  local candidate root
  for candidate in "${candidates[@]}"; do
    if [[ -d "$candidate" ]]; then
      root="$(cd "$candidate" && pwd)"
      if has_emp_root "$root"; then
        printf '%s\n' "$root"
        return
      fi
    fi
  done

  die "Cannot find EMP root. Set EMP_ROOT=/path/to/emp where emp_server, emp_admin and emp_ws exist."
}

normalize_service() {
  case "$1" in
    gateway|emp-gateway) echo "gateway" ;;
    auth|emp-auth) echo "auth" ;;
    monitor|emp-monitor) echo "monitor" ;;
    data|emp-data) echo "data" ;;
    pdf|emp-pdf) echo "pdf" ;;
    ws|emp-ws) echo "ws" ;;
    admin|emp-admin) echo "admin" ;;
    *) die "Unknown service: $1. Allowed: gateway auth monitor data pdf ws admin" ;;
  esac
}

compose_service_name() {
  echo "emp-$1"
}

image_name() {
  echo "$IMAGE_NAMESPACE/emp-$1"
}

java_module_name() {
  case "$1" in
    gateway) echo "emp_gateway" ;;
    auth) echo "emp_auth" ;;
    monitor) echo "emp_monitor" ;;
    data) echo "emp_data" ;;
    *) return 1 ;;
  esac
}

is_java_service() {
  case "$1" in
    gateway|auth|monitor|data) return 0 ;;
    *) return 1 ;;
  esac
}

read_requested_services() {
  local raw_services=()
  if [[ "$#" -gt 0 ]]; then
    raw_services=("$@")
  elif [[ -n "${SERVICES:-}" ]]; then
    # shellcheck disable=SC2206
    raw_services=($SERVICES)
  else
    die "No services specified. Example: ./build-update.sh admin monitor"
  fi

  local -A seen=()
  local service normalized
  for service in "${raw_services[@]}"; do
    normalized="$(normalize_service "$service")"
    if [[ -z "${seen[$normalized]:-}" ]]; then
      seen[$normalized]=1
      echo "$normalized"
    fi
  done
}

join_by_comma() {
  local IFS=,
  echo "$*"
}

run_step() {
  local workdir="$1"
  shift
  (cd "$workdir" && "$@")
}

build_java_images() {
  local services=("$@")
  [[ "${#services[@]}" -gt 0 ]] || return 0

  local server_dir="$ROOT_DIR/emp_server"
  local modules=()
  local service module jar target_dir

  for service in "${services[@]}"; do
    modules+=("$(java_module_name "$service")")
  done

  log "Build backend jars: ${modules[*]}"
  run_step "$server_dir" mvn package -DskipTests -B -pl "$(join_by_comma "${modules[@]}")" -am

  for service in "${services[@]}"; do
    module="$(java_module_name "$service")"
    target_dir="$server_dir/$module/target"
    jar="$(find "$target_dir" -maxdepth 1 -name '*.jar' ! -name '*original*' ! -name 'app.jar' | head -1)"
    [[ -n "$jar" ]] || die "Jar not found for $module"
    cp "$jar" "$target_dir/app.jar"

    log "Build image: $(image_name "$service"):$IMAGE_TAG"
    run_step "$server_dir" docker build \
      -f Dockerfile.service \
      --build-arg "MODULE=$module" \
      -t "$(image_name "$service"):$IMAGE_TAG" \
      -t "$(image_name "$service"):latest" \
      .
  done
}

build_pdf_image() {
  local server_dir="$ROOT_DIR/emp_server"
  log "Build image: $(image_name pdf):$IMAGE_TAG"
  run_step "$server_dir" docker build \
    -f emp_pdf/Dockerfile \
    -t "$(image_name pdf):$IMAGE_TAG" \
    -t "$(image_name pdf):latest" \
    emp_pdf
}

build_ws_image() {
  log "Build image: $(image_name ws):$IMAGE_TAG"
  run_step "$ROOT_DIR" docker build \
    -f "$SCRIPT_DIR/dockerfiles/emp-ws.Dockerfile" \
    --build-arg "NPM_REGISTRY=$NPM_REGISTRY" \
    -t "$(image_name ws):$IMAGE_TAG" \
    -t "$(image_name ws):latest" \
    .
}

build_admin_image() {
  local admin_dir="$ROOT_DIR/emp_admin"
  local context_dir="$BUILD_CONTEXT_DIR/emp-admin"

  log "Build frontend dist"
  run_step "$admin_dir" pnpm install --frozen-lockfile
  run_step "$admin_dir" pnpm run build:shunfeng

  log "Prepare frontend image context"
  rm -rf "$context_dir"
  mkdir -p "$context_dir"
  cp -R "$admin_dir/dist" "$context_dir/dist"
  cp "$SCRIPT_DIR/nginx/admin.conf" "$context_dir/admin.conf"

  log "Build image: $(image_name admin):$IMAGE_TAG"
  run_step "$context_dir" docker build \
    -f "$SCRIPT_DIR/dockerfiles/emp-admin.Dockerfile" \
    -t "$(image_name admin):$IMAGE_TAG" \
    -t "$(image_name admin):latest" \
    .
}

prepare_package() {
  local services_slug="$1"
  PACKAGE_NAME="${PACKAGE_NAME:-${DEPLOY_ENV}-update-${IMAGE_TAG}-${services_slug}}"
  PACKAGE_DIR="$DIST_DIR/$PACKAGE_NAME"
  PACKAGE_ARCHIVE="$DIST_DIR/${PACKAGE_NAME}.tar.gz"

  rm -rf "$PACKAGE_DIR"
  mkdir -p "$PACKAGE_DIR"

  cp "$SCRIPT_DIR/apply-update.sh" "$PACKAGE_DIR/apply-update.sh"
  chmod +x "$PACKAGE_DIR/apply-update.sh"

  local service
  for service in "${REQUESTED_SERVICES[@]}"; do
    compose_service_name "$service"
  done > "$PACKAGE_DIR/services.txt"

  {
    echo "deploy_env=$DEPLOY_ENV"
    echo "image_namespace=$IMAGE_NAMESPACE"
    echo "image_tag=$IMAGE_TAG"
    echo "services=${REQUESTED_SERVICES[*]}"
    echo "compose_services=$(tr '\n' ' ' < "$PACKAGE_DIR/services.txt")"
    echo "created_at=$(date '+%Y-%m-%d %H:%M:%S')"
  } > "$PACKAGE_DIR/manifest.txt"
}

save_images() {
  local images=()
  local service image
  for service in "${REQUESTED_SERVICES[@]}"; do
    image="$(image_name "$service")"
    images+=("$image:$IMAGE_TAG" "$image:latest")
  done

  log "Save images: ${images[*]}"
  docker save -o "$PACKAGE_DIR/images.tar" "${images[@]}"
}

archive_package() {
  mkdir -p "$DIST_DIR"
  rm -f "$PACKAGE_ARCHIVE"
  tar -czf "$PACKAGE_ARCHIVE" -C "$DIST_DIR" "$PACKAGE_NAME"
  log "Update package created: $PACKAGE_ARCHIVE"
}

publish_package() {
  if [[ "$COS_UPLOAD" != "1" ]]; then
    return
  fi

  log "Upload update package to COS"
  DEPLOY_ENV="$DEPLOY_ENV" PACKAGE_KIND=update bash "$SCRIPT_DIR/publish-cos.sh" "$PACKAGE_ARCHIVE"
}

need_cmd docker
need_cmd tar

mapfile -t REQUESTED_SERVICES < <(read_requested_services "$@")
[[ "${#REQUESTED_SERVICES[@]}" -gt 0 ]] || die "No services to update."

ROOT_DIR="$(resolve_root_dir)"
SERVICES_SLUG="$(IFS=-; echo "${REQUESTED_SERVICES[*]}")"

log "EMP root: $ROOT_DIR"
log "Deploy root: $SCRIPT_DIR"
log "Deploy env: $DEPLOY_ENV"
log "Update services: ${REQUESTED_SERVICES[*]}"
log "Image tag: $IMAGE_TAG"

if [[ "$SKIP_BUILD" != "1" ]]; then
  JAVA_SERVICES=()
  NEED_PNPM=0
  for service in "${REQUESTED_SERVICES[@]}"; do
    if is_java_service "$service"; then
      JAVA_SERVICES+=("$service")
    fi
    if [[ "$service" == "admin" ]]; then
      NEED_PNPM=1
    fi
  done

  if [[ "${#JAVA_SERVICES[@]}" -gt 0 ]]; then
    need_cmd mvn
  fi
  if [[ "$NEED_PNPM" == "1" ]]; then
    need_cmd pnpm
  fi

  build_java_images "${JAVA_SERVICES[@]}"

  for service in "${REQUESTED_SERVICES[@]}"; do
    case "$service" in
      pdf) build_pdf_image ;;
      ws) build_ws_image ;;
      admin) build_admin_image ;;
    esac
  done
else
  log "Skip build, package existing local images only"
fi

prepare_package "$SERVICES_SLUG"
save_images
archive_package
publish_package

cat <<EOF

Next steps on target server:
  DEPLOY_ENV=$DEPLOY_ENV bash deploy-from-url.sh "<COS signed URL>"

Manual fallback:
  mkdir -p /tmp/emp-update
  tar -xzf $(basename "$PACKAGE_ARCHIVE") -C /tmp/emp-update --strip-components=1
  cd /tmp/emp-update
  bash apply-update.sh

EOF