#!/bin/bash
# 灰度发布脚本：在生产服务器上启动 canary 版本，通过 Nginx 权重切流
# 用法: ./scripts/gray_deploy.sh <版本号> <灰度百分比>
#
# 前提：
#   - 在生产服务器上执行（或通过 SSH 管道执行）
#   - 当前已有全量运行的 production 容器
#   - Nginx 配置在 /etc/nginx/sites-enabled/00-xiaoxia-saas
#
# 灰度范围：API + Web（Worker 暂时全量升级，队列消费无法按比例切流）

set -euo pipefail

VERSION="${1:-}"
GRAY_PCT="${2:-10}"

if [[ -z "$VERSION" ]]; then
    echo "用法: $0 <版本号> [灰度百分比]"
    echo "示例: $0 v0.1.130 5"
    exit 1
fi

REGISTRY="${REGISTRY:-git.xiaoxiajianji.com/xiaoxia/xiaoxia-saas}"
NGINX_CONF="${NGINX_CONF:-/etc/nginx/sites-enabled/00-xiaoxia-saas}"
ENV_FILE="${ENV_FILE:-/var/lib/xiaoxia-saas-production/.env}"
GENERATED_DIR="${GENERATED_DIR:-/var/lib/xiaoxia-saas-production/generated}"
LEGACY_ASSETS_DIR="${LEGACY_ASSETS_DIR:-/var/lib/xiaoxia-saas-production/legacy-assets}"

# Canary 端口（与 production 错开）
CANARY_API_PORT=18001
CANARY_WEB_PORT=13002

echo "============================================"
echo "  灰度发布"
echo "  新版本: $VERSION"
echo "  灰度比例: ${GRAY_PCT}%"
echo "  Canary API 端口: $CANARY_API_PORT"
echo "  Canary Web 端口: $CANARY_WEB_PORT"
echo "============================================"

# 1. 检查环境
if [[ ! -f "$ENV_FILE" ]]; then
    echo "错误: 环境文件不存在: $ENV_FILE"
    exit 1
fi

if [[ ! -f "$NGINX_CONF" ]]; then
    echo "错误: Nginx 配置不存在: $NGINX_CONF"
    exit 1
fi

# 2. 拉取新版本镜像
echo ""
echo ">>> 拉取新版本镜像..."
for component in api web worker; do
    echo "  拉取 $component:$VERSION ..."
    docker pull "${REGISTRY}-${component}:${VERSION}" 2>&1 | tail -1
done
echo "  ✅ 镜像拉取完成"

# 3. 启动 API Canary
echo ""
echo ">>> 启动 API Canary 容器..."
CANARY_API="xiaoxia-api-canary"
if docker ps -a --format '{{.Names}}' | grep -q "^${CANARY_API}$"; then
    echo "  停止旧 canary..."
    docker rm -f "$CANARY_API" >/dev/null 2>&1
fi

docker run -d \
    --name "$CANARY_API" \
    --env-file "$ENV_FILE" \
    --network xiaoxia-net-production \
    -p "127.0.0.1:${CANARY_API_PORT}:8000" \
    -e APP_ENV=production \
    -e APP_VERSION="$VERSION-canary" \
    -e GENERATED_FILES_DIR=/app/generated \
    -e GENERATED_FILES_URL_PREFIX=/generated-files \
    -e PUBLIC_API_BASE_URL=https://saas-api.xiaoxiajianji.com \
    -v "${GENERATED_DIR}:/app/generated" \
    --restart unless-stopped \
    --cpus 1 \
    --memory 1g \
    --health-cmd "python -c \"import urllib.request; urllib.request.urlopen('http://localhost:8000/health', timeout=5)\"" \
    --health-interval 30s \
    --health-timeout 10s \
    --health-retries 3 \
    --health-start-period 40s \
    --log-driver json-file \
    --log-opt max-size=50m \
    --log-opt max-file=3 \
    "${REGISTRY}-api:${VERSION}" >/dev/null

echo "  ✅ API Canary 已启动（端口 $CANARY_API_PORT）"

# 4. 启动 Web Canary
echo ""
echo ">>> 启动 Web Canary 容器..."
CANARY_WEB="xiaoxia-web-canary"
if docker ps -a --format '{{.Names}}' | grep -q "^${CANARY_WEB}$"; then
    echo "  停止旧 canary..."
    docker rm -f "$CANARY_WEB" >/dev/null 2>&1
fi

LEGACY_VOLUME=""
if [[ -d "$LEGACY_ASSETS_DIR" ]] && [[ -n "$(ls -A "$LEGACY_ASSETS_DIR" 2>/dev/null)" ]]; then
    LEGACY_VOLUME="-v ${LEGACY_ASSETS_DIR}:/usr/share/nginx/html/assets-legacy/assets:ro"
fi

docker run -d \
    --name "$CANARY_WEB" \
    --network xiaoxia-net-production \
    -p "127.0.0.1:${CANARY_WEB_PORT}:80" \
    --restart unless-stopped \
    --cpus 0.5 \
    --memory 256m \
    $LEGACY_VOLUME \
    --health-cmd "wget --spider -q http://127.0.0.1:80" \
    --health-interval 30s \
    --health-timeout 5s \
    --health-retries 3 \
    --health-start-period 10s \
    --log-driver json-file \
    --log-opt max-size=50m \
    --log-opt max-file=3 \
    "${REGISTRY}-web:${VERSION}" >/dev/null

echo "  ✅ Web Canary 已启动（端口 $CANARY_WEB_PORT）"

# 5. 等待健康检查
echo ""
echo ">>> 等待 Canary 容器健康..."
for i in $(seq 1 40); do
    api_healthy=$(docker inspect --format='{{.State.Health.Status}}' "$CANARY_API" 2>/dev/null || echo "starting")
    web_healthy=$(docker inspect --format='{{.State.Health.Status}}' "$CANARY_WEB" 2>/dev/null || echo "starting")
    
    if [[ "$api_healthy" == "healthy" && "$web_healthy" == "healthy" ]]; then
        echo "  ✅ API + Web Canary 均健康（用时 ${i}s）"
        break
    fi
    
    if [[ "$api_healthy" == "unhealthy" ]]; then
        echo "  ❌ API Canary 健康检查失败"
        docker logs --tail 30 "$CANARY_API"
        exit 1
    fi
    if [[ "$web_healthy" == "unhealthy" ]]; then
        echo "  ❌ Web Canary 健康检查失败"
        docker logs --tail 20 "$CANARY_WEB"
        exit 1
    fi
    
    sleep 3
done

# 6. 更新 Nginx 配置 - 添加 upstream 权重
echo ""
echo ">>> 更新 Nginx 权重（稳定: $((100-GRAY_PCT))% / 灰度: ${GRAY_PCT}%）..."

# 备份
BAK_FILE="${NGINX_CONF}.bak.gray.$(date +%Y%m%d%H%M%S)"
cp "$NGINX_CONF" "$BAK_FILE"
echo "  已备份: $BAK_FILE"

# 生成 upstream 块
UPSTREAM_BLOCK="
# Gray release upstreams（自动生成 - gray_deploy.sh）
upstream saas_api_backend {
    server 127.0.0.1:8001 weight=$((100-GRAY_PCT));
    server 127.0.0.1:${CANARY_API_PORT} weight=${GRAY_PCT};
}

upstream saas_web_backend {
    server 127.0.0.1:3002 weight=$((100-GRAY_PCT));
    server 127.0.0.1:${CANARY_WEB_PORT} weight=${GRAY_PCT};
}
"

# 在文件最前面插入 upstream 块
TMP_CONF=$(mktemp)
{
    echo "$UPSTREAM_BLOCK"
    cat "$NGINX_CONF"
} > "$TMP_CONF"

# 替换 proxy_pass 指向 upstream
# API: proxy_pass http://127.0.0.1:8001 -> proxy_pass http://saas_api_backend
sed -i 's|proxy_pass http://127\.0\.0\.1:8001|proxy_pass http://saas_api_backend|g' "$TMP_CONF"
# Web: proxy_pass http://127.0.0.1:3002/ -> proxy_pass http://saas_web_backend/
sed -i 's|proxy_pass http://127\.0\.0\.1:3002/|proxy_pass http://saas_web_backend/|g' "$TMP_CONF"

# 测试配置
mv "$TMP_CONF" "$NGINX_CONF"
if ! nginx -t 2>&1; then
    echo "  ❌ Nginx 配置测试失败，回滚..."
    cp "$BAK_FILE" "$NGINX_CONF"
    nginx -t
    exit 1
fi

nginx -s reload
echo "  ✅ Nginx 已 reload，灰度生效"

# 7. 验证灰度流量
echo ""
echo ">>> 验证灰度流量..."
gray_hits=0
total_hits=20
for i in $(seq 1 $total_hits); do
    resp=$(curl -s -o /dev/null -w "%{http_code}" -H "X-Gray-Test: 1" http://127.0.0.1:${CANARY_API_PORT}/health 2>/dev/null || echo "000")
    if [[ "$resp" == "200" ]]; then
        gray_hits=$((gray_hits + 1))
    fi
    sleep 0.1
done
echo "  Canary 健康验证: $gray_hits/$total_hits 请求成功"

echo ""
echo "============================================"
echo "  ✅ 灰度发布完成"
echo "  版本: $VERSION (${GRAY_PCT}%流量)"
echo "  API: 127.0.0.1:$CANARY_API_PORT"
echo "  Web: 127.0.0.1:$CANARY_WEB_PORT"
echo "  Nginx 备份: $BAK_FILE"
echo "  回滚: ./scripts/rollback.sh"
echo "  Worker: 暂不灰度（队列消费无法按比例切流）"
echo "============================================"