#!/bin/bash
# =============================================================================
# 企微IT智能服务台 — 蓝绿部署切换脚本
# =============================================================================
# 用法：
#   ./switch-blue-green.sh status     # 查看当前环境
#   ./switch-blue-green.sh to-blue    # 切换到 Blue 环境
#   ./switch-blue-green.sh to-green   # 切换到 Green 环境
#   ./switch-blue-green.sh deploy     # 部署到 Green 环境（先构建再启动）
#   ./switch-blue-green.sh rollback   # 回滚（切换到另一环境）
# =============================================================================

set -e

# 配置
COMPOSE_FILE="docker-compose.yml"
COMPOSE_FILE_GREEN="docker-compose-green.yml"
ACTIVE_FILE="/tmp/active_environment"
ENV_FILE=".env"

# 颜色
RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
BLUE='\033[0;34m'
NC='\033[0m'

log_info() { echo -e "${GREEN}[INFO]${NC} $1"; }
log_warn() { echo -e "${YELLOW}[WARN]${NC} $1"; }
log_error() { echo -e "${RED}[ERROR]${NC} $1"; }

# 获取当前环境
get_active() {
    if [ -f "$ACTIVE_FILE" ]; then
        cat "$ACTIVE_FILE"
    else
        echo "blue"  # 默认 blue
    fi
}

# 切换到指定环境
switch_to() {
    local env=$1
    local current=$(get_active)

    if [ "$env" = "$current" ]; then
        log_warn "当前已是 $env 环境，无需切换"
        return
    fi

    # 切换 Nginx upstream
    log_info "切换 Nginx upstream 到 $env..."

    # 这里需要根据实际情况修改 Nginx 配置
    # 简化版：直接通过端口切换

    echo "$env" > "$ACTIVE_FILE"
    log_info "已切换到 $env 环境"
}

# 部署到 Green 环境
deploy_green() {
    log_info "开始部署到 Green 环境..."

    # 检查 docker-compose-green.yml 是否存在
    if [ ! -f "$COMPOSE_FILE_GREEN" ]; then
        log_error "配置文件不存在: $COMPOSE_FILE_GREEN"
        exit 1
    fi

    # 停止现有 Green 容器（如果存在）
    log_info "停止现有 Green 容器..."
    docker compose -f "$COMPOSE_FILE_GREEN" down 2>/dev/null || true

    # 构建并启动
    log_info "构建 Green 环境镜像..."
    docker compose -f "$COMPOSE_FILE_GREEN" build

    log_info "启动 Green 环境服务..."
    docker compose -f "$COMPOSE_FILE_GREEN" up -d

    # 等待健康检查
    log_info "等待服务就绪..."
    sleep 15

    # 检查状态
    if docker compose -f "$COMPOSE_FILE_GREEN" ps | grep -q "healthy"; then
        log_info "Green 环境部署成功！"
    else
        log_warn "部分服务可能未完全就绪，请手动检查"
    fi
}

# 查看状态
show_status() {
    local active=$(get_active)
    echo ""
    echo "========================================"
    echo "  蓝绿部署状态"
    echo "========================================"
    echo "  当前活动环境: $active"
    echo ""
    echo "  Blue 环境: $(docker ps --filter name=wecom_it_backend --format '{{.Status}}' 2>/dev/null || echo '未运行')"
    echo "  Green 环境: $(docker ps --filter name=wecom_it_backend_green --format '{{.Status}}' 2>/dev/null || echo '未运行')"
    echo "========================================"
    echo ""
}

# 主命令
case "${1:-status}" in
    status)
        show_status
        ;;
    to-blue)
        switch_to blue
        ;;
    to-green)
        switch_to green
        ;;
    deploy)
        deploy_green
        ;;
    rollback)
        current=$(get_active)
        if [ "$current" = "blue" ]; then
            switch_to green
        else
            switch_to blue
        fi
        ;;
    *)
        echo "用法: $0 {status|to-blue|to-green|deploy|rollback}"
        exit 1
        ;;
esac