#!/usr/bin/env sh
set -eu

if [ "$#" -ne 7 ]; then
  echo "用法: $0 <环境> <镜像仓库> <镜像标签> <服务> <环境文件> <Compose文件> <项目名>" >&2
  exit 2
fi

DEPLOY_ENV="$1"
IMAGE_REPOSITORY="$2"
IMAGE_TAG="$3"
SERVICE="$4"
ENV_FILE="$5"
COMPOSE_FILE="$6"
BASE_PROJECT="$7"

case "$DEPLOY_ENV" in
  production) ;;
  *) echo "蓝绿执行器仅用于 production，当前: $DEPLOY_ENV" >&2; exit 2 ;;
esac

for file in "$ENV_FILE" "$COMPOSE_FILE"; do
  [ -f "$file" ] || { echo "必需文件不存在: $file" >&2; exit 2; }
done

case "$SERVICE" in
  *[!A-Za-z0-9_-]*|'') echo "非法服务名: $SERVICE" >&2; exit 2 ;;
esac

env_value() {
  sed -n "s/^$1=//p" "$ENV_FILE" | tail -n 1 | tr -d '\r'
}

service_contract() {
  case "$SERVICE:$COMPOSE_FILE" in
    gateway:*) echo "gateway|9000|9000|gateway" ;;
    auth:*) echo "auth|9100|9100|auth-service" ;;
    iam:*) echo "iam|9201|9201|iam-service" ;;
    firstleg:*) echo "business|9202|9202|firstleg-service" ;;
    finance:*) echo "finance|9203|9203|finance-service" ;;
    order:*) echo "order|9204|9204|order-service" ;;
    warehouse:*) echo "warehouse|9205|9205|warehouse-service" ;;
    file:*) echo "file|9206|9206|file-service" ;;
    print:*) echo "print|9207|9207|print-service" ;;
    integration-service:*) echo "integration|9210|9210|integration-service" ;;
    audit-service:*) echo "audit|9700|9700|audit-service" ;;
    gateway-overseas:*) echo "gateway-overseas|9300|9300|gateway-overseas" ;;
    lastleg-service:*) echo "lastleg|9303|9303|lastleg-service" ;;
    warehouse-overseas-service:*) echo "warehouse-overseas|9305|9305|warehouse-overseas-service" ;;
    event-bridge-service:*overseas*) echo "event-bridge-overseas|9312|9313|event-bridge-service" ;;
    event-bridge-service:*) echo "event-bridge|9312|9312|event-bridge-service" ;;
    *) echo "不支持蓝绿部署的服务: $SERVICE" >&2; exit 2 ;;
  esac
}

IFS='|' read -r CONTAINER_STEM INTERNAL_PORT BASE_PORT NACOS_SERVICE <<EOF
$(service_contract)
EOF

STATE_ROOT="${BLUE_GREEN_STATE_ROOT:-/data/firstleg/deploy/blue-green-state}"
STATE_KEY="${BASE_PROJECT}-${SERVICE}"
STATE_FILE="$STATE_ROOT/$STATE_KEY.active"
ROUTING_NETWORK="${BLUE_GREEN_ROUTING_NETWORK:-firstleg-${DEPLOY_ENV}-routing}"
HEALTH_TIMEOUT="${DEPLOY_HEALTH_TIMEOUT_SECONDS:-240}"
HEALTH_POLL="${DEPLOY_HEALTH_POLL_SECONDS:-5}"
STABILIZATION_SECONDS="${BLUE_GREEN_STABILIZATION_SECONDS:-10}"
STOP_TIMEOUT="${BLUE_GREEN_STOP_TIMEOUT_SECONDS:-45}"
IMAGE="$IMAGE_REPOSITORY/$SERVICE:$IMAGE_TAG"

for value in "$HEALTH_TIMEOUT" "$HEALTH_POLL" "$STABILIZATION_SECONDS" "$STOP_TIMEOUT"; do
  case "$value" in ''|*[!0-9]*) echo "蓝绿时间参数必须为非负整数: $value" >&2; exit 2 ;; esac
done

mkdir -p "$STATE_ROOT"
chmod 750 "$STATE_ROOT"
docker network inspect "$ROUTING_NETWORK" >/dev/null 2>&1 || docker network create "$ROUTING_NETWORK" >/dev/null

legacy_container="firstleg-${DEPLOY_ENV}-${CONTAINER_STEM}"
active_slot=""
active_container=""
active_port=""
if [ -s "$STATE_FILE" ]; then
  IFS='|' read -r active_slot active_container active_port active_image < "$STATE_FILE"
elif docker inspect "$legacy_container" >/dev/null 2>&1; then
  active_slot="legacy"
  active_container="$legacy_container"
  active_port="$BASE_PORT"
fi

if [ "$active_slot" = "blue" ]; then
  target_slot="green"
else
  target_slot="blue"
  [ "$active_slot" = "legacy" ] && target_slot="green"
fi

if [ "$target_slot" = "blue" ]; then
  target_port="$BASE_PORT"
else
  target_port=$((BASE_PORT + 10000))
fi
candidate="firstleg-${DEPLOY_ENV}-${CONTAINER_STEM}-${target_slot}"

if docker inspect "$candidate" >/dev/null 2>&1; then
  if [ "$candidate" = "$active_container" ]; then
    echo "活动槽状态异常，候选容器与活动容器相同: $candidate" >&2
    exit 1
  fi
  docker rm -f "$candidate" >/dev/null
fi

compose() {
  docker compose --project-name "$BASE_PROJECT" --env-file "$ENV_FILE" -f "$COMPOSE_FILE" "$@"
}

candidate_health() {
  docker inspect --format '{{if .State.Health}}{{.State.Health.Status}}{{else}}{{.State.Status}}{{end}}' \
    "$candidate" 2>/dev/null || echo missing
}

cleanup_candidate() {
  docker rm -f "$candidate" >/dev/null 2>&1 || true
}

wait_for_candidate() {
  elapsed=0
  while [ "$elapsed" -lt "$HEALTH_TIMEOUT" ]; do
    state="$(candidate_health)"
    echo "候选槽 $target_slot 健康状态: $state（已等待 ${elapsed}s）"
    case "$state" in
      healthy) return 0 ;;
      unhealthy|exited|dead|missing) return 1 ;;
    esac
    sleep "$HEALTH_POLL"
    elapsed=$((elapsed + HEALTH_POLL))
  done
  return 1
}

connect_routing_alias() {
  alias_name="$1"
  container="$2"
  docker network inspect "$ROUTING_NETWORK" --format '{{json .Containers}}' | grep -q "\"$container\"" \
    && return 0
  docker network connect --alias "$alias_name" "$ROUTING_NETWORK" "$container"
}

bootstrap_legacy_routes() {
  for pair in \
    gateway:gateway auth:auth iam:iam firstleg:business finance:finance order:order \
    warehouse:warehouse file:file print:print integration-service:integration audit-service:audit \
    gateway-overseas:gateway-overseas lastleg-service:lastleg \
    warehouse-overseas-service:warehouse-overseas event-bridge-cn:event-bridge \
    event-bridge-overseas:event-bridge-overseas
  do
    alias_name="${pair%%:*}"
    stem="${pair#*:}"
    container="firstleg-${DEPLOY_ENV}-${stem}"
    if docker inspect "$container" >/dev/null 2>&1; then
      connect_routing_alias "$alias_name" "$container" || true
    fi
  done
}

switch_gateway_proxy() {
  [ "$SERVICE" = "gateway" ] || [ "$SERVICE" = "gateway-overseas" ] || return 0
  if [ "$SERVICE" = "gateway" ]; then
    config="$(env_value GATEWAY_BLUE_GREEN_NGINX_CONFIG)"
  else
    config="$(env_value GATEWAY_OVERSEAS_BLUE_GREEN_NGINX_CONFIG)"
  fi
  if [ -z "$config" ] || [ ! -f "$config" ]; then
    echo "$SERVICE 蓝绿切换要求环境文件配置有效的 Nginx 配置路径" >&2
    return 1
  fi
  backup="$config.blue-green-backup"
  cp -f "$config" "$backup"
  if ! sed -i "s#127\.0\.0\.1:${active_port:-$BASE_PORT}#127.0.0.1:$target_port#g" "$config" \
    || cmp -s "$config" "$backup"; then
    cp -f "$backup" "$config"
    echo "未能在 Nginx 配置中切换 $SERVICE 上游端口" >&2
    return 1
  fi
  if ! nginx -t || ! nginx -s reload; then
    cp -f "$backup" "$config"
    nginx -t && nginx -s reload || true
    return 1
  fi
  rm -f "$backup"
}

bootstrap_legacy_routes

export DEPLOY_ENV IMAGE_REPOSITORY IMAGE_TAG
echo "启动候选槽: service=$SERVICE slot=$target_slot port=$target_port image=$IMAGE"
if ! compose run -d --no-deps --name "$candidate" \
    -e "BAIYUE_DEPLOY_SLOT=$target_slot" -e "BAIYUE_RELEASE_ID=$IMAGE_TAG" \
    -p "${PUBLISHED_BIND_ADDRESS:-0.0.0.0}:$target_port:$INTERNAL_PORT" "$SERVICE" >/dev/null; then
  cleanup_candidate
  exit 1
fi

if ! wait_for_candidate; then
  echo "候选槽未通过健康检查，保留旧实例" >&2
  docker logs --tail 200 "$candidate" 2>&1 || true
  cleanup_candidate
  exit 1
fi

running_image="$(docker inspect --format '{{.Config.Image}}' "$candidate")"
if [ "$running_image" != "$IMAGE" ]; then
  echo "候选镜像不一致: expected=$IMAGE actual=$running_image" >&2
  cleanup_candidate
  exit 1
fi

connect_routing_alias "$SERVICE" "$candidate"
[ "$NACOS_SERVICE" = "$SERVICE" ] || connect_routing_alias "$NACOS_SERVICE" "$candidate"

if [ "$STABILIZATION_SECONDS" -gt 0 ]; then
  echo "候选槽稳定观察 ${STABILIZATION_SECONDS}s"
  sleep "$STABILIZATION_SECONDS"
  [ "$(candidate_health)" = "healthy" ] || { cleanup_candidate; exit 1; }
fi

if ! switch_gateway_proxy; then
  cleanup_candidate
  exit 1
fi

if [ -n "$active_container" ] && docker inspect "$active_container" >/dev/null 2>&1; then
  echo "优雅停止旧实例: $active_container"
  docker stop --time "$STOP_TIMEOUT" "$active_container" >/dev/null
  docker rm "$active_container" >/dev/null
fi

printf '%s|%s|%s|%s\n' "$target_slot" "$candidate" "$target_port" "$IMAGE" > "$STATE_FILE.tmp"
chmod 640 "$STATE_FILE.tmp"
mv -f "$STATE_FILE.tmp" "$STATE_FILE"
echo "蓝绿切换完成: service=$SERVICE active=$target_slot container=$candidate port=$target_port"