#!/usr/bin/env bash
# ============================================================
# GovAI - Go 补丁版本升级脚本
# 功能：检查 Go 最新补丁版 -> 本地编译 -> 上传部署 -> 重启服务
# 监控：建议通过 cron 定期执行（如每周一次）
# 用法: bash go-upgrade.sh [check|upgrade|status]
#   check   - 仅检查版本（默认）
#   upgrade - 执行完整升级流程
#   status  - 查看当前 Go 版本和服务状态
# ============================================================

set -euo pipefail

SERVER="${SERVER:-govai-root}"
REMOTE_DIR="/opt/govai"
REMOTE_SERVER_BIN="$REMOTE_DIR/server/server"
PROJECT_DIR="$(cd "$(dirname "$0")" && pwd)"
SERVER_GO_VERSION="${SERVER_GO_VERSION:-1.25.0}"

GREEN='\033[0;32m'; BLUE='\033[0;34m'; RED='\033[0;31m'; YELLOW='\033[0;33m'; NC='\033[0m'
log()  { echo -e "${GREEN}[✓]${NC} $1"; }
step() { echo -e "\n${BLUE}==== $1 ====${NC}"; }
warn() { echo -e "${YELLOW}[!]${NC} $1"; }
err()  { echo -e "${RED}[✗]${NC} $1"; exit 1; }

# ---- 当前版本信息 ----
CURRENT_GO_VERSION=$(go version 2>/dev/null | sed 's/go version //' | awk '{print $1}')
MAJOR_MINOR=$(echo "$CURRENT_GO_VERSION" | sed 's/\.[0-9]*$//')

echo "当前本地 Go 版本: $CURRENT_GO_VERSION"
echo "服务器 Go 版本:   $SERVER_GO_VERSION"

# ---- 获取 Go 官方最新补丁版本 ----
fetch_latest_patch() {
    local major_minor="$1"
    # 从 Go 官方 dl 页面解析最新补丁版本
    # 例如: go1.25.11, go1.24.5 等
    local url="https://go.dev/dl/?mode=json&include=all"
    local latest

    latest=$(curl -sL "$url" 2>/dev/null | \
        python3 -c "
import sys, json
data = json.load(sys.stdin)
current = '$major_minor'
for p in data:
    v = p.get('version','')
    if v.startswith('go' + current + '.'):
        print(v)
        break
" 2>/dev/null) || true

    echo "$latest"
}

# ---- 版本比较 ----
# 返回 0 表示有更新，返回 1 表示已是最新
is_update_available() {
    local current="$1"
    local latest="$2"
    [ -n "$latest" ] && [ "$latest" != "$current" ]
}

# ---- 检查模式 ----
do_check() {
    step "检查 Go 版本更新"
    echo ""

    local latest
    latest=$(fetch_latest_patch "$MAJOR_MINOR")
    echo "  本地当前版本:  $CURRENT_GO_VERSION"
    echo "  $MAJOR_MINOR 系列最新: $latest"
    echo ""

    if is_update_available "$CURRENT_GO_VERSION" "$latest"; then
        echo "  发现新版本: $CURRENT_GO_VERSION → $latest"
        echo "  建议执行: bash go-upgrade.sh upgrade"
        return 0
    else
        echo "  ✅ 当前版本已是最新"
        return 1
    fi
}

# ---- 升级模式 ----
do_upgrade() {
    local latest
    latest=$(fetch_latest_patch "$MAJOR_MINOR")

    if ! is_update_available "$CURRENT_GO_VERSION" "$latest"; then
        echo "已是最新版本，无需升级"
        return 0
    fi

    local new_patch="${latest#go}"
    step "Go 升级: $CURRENT_GO_VERSION → go$new_patch"

    # 1. 安装新版本 Go
    echo ""
    log "下载 Go $new_patch..."
    cd /tmp
    local go_archive="go$new_patch.darwin-arm64.tar.gz"
    local download_url="https://go.dev/dl/$go_archive"

    # 检测架构
    local arch
    case "$(uname -m)" in
        x86_64)  arch="darwin-amd64" ;;
        arm64|aarch64) arch="darwin-arm64" ;;
        *) err "不支持的架构: $(uname -m)" ;;
    esac
    go_archive="go$new_patch.$arch.tar.gz"
    download_url="https://go.dev/dl/$go_archive"

    if [ -f "/usr/local/go/bin/go" ]; then
        if /usr/local/go/bin/go version 2>/dev/null | grep -q "$new_patch"; then
            echo "目标版本已安装"
        else
            curl -sL "$download_url" -o "go.tar.gz"
            rm -rf /usr/local/go
            tar -C /usr/local -xzf go.tar.gz
            rm -f go.tar.gz
        fi
    else
        curl -sL "$download_url" -o "go.tar.gz"
        tar -C /usr/local -xzf go.tar.gz
        rm -f go.tar.gz
    fi

    local new_go="/usr/local/go/bin/go"
    echo "  新版本: $($new_go version)"

    # 2. 备份当前服务器二进制
    step "备份服务器二进制"
    local backup_file="server.bak.$(date '+%Y%m%d%H%M%S')"
    ssh "$SERVER" "cp $REMOTE_SERVER_BIN $REMOTE_DIR/$backup_file"

    # 3. 本地编译
    step "编译新版本二进制"
    local dist_dir="$PROJECT_DIR/dist"
    mkdir -p "$dist_dir"

    log "编译 Go 后端 (linux/amd64)..."
    export PATH="/usr/local/go/bin:$PATH"
    export GOROOT="/usr/local/go"

    cd "$PROJECT_DIR/server"
    CGO_ENABLED=0 GOOS=linux GOARCH=amd64 GOROOT="/usr/local/go" go build \
        -ldflags="-s -w" \
        -o "$dist_dir/server" ./cmd/server/

    local binary_size
    binary_size=$(ls -lh "$dist_dir/server" 2>/dev/null | awk '{print $5}')
    log "编译完成: dist/server ($binary_size)"

    # 4. 上传
    step "上传到服务器"
    ssh $SERVER "systemctl stop govai-api 2>/dev/null || true"
    ssh $SERVER "cp $REMOTE_SERVER_BIN $REMOTE_DIR/server.bak.pre-upgrade"
    cat "$dist_dir/server" | ssh $SERVER "cat > $REMOTE_SERVER_BIN.tmp && mv $REMOTE_SERVER_BIN.tmp $REMOTE_SERVER_BIN && chmod +x $REMOTE_SERVER_BIN"
    log "上传完成"

    # 5. 重启服务
    step "重启服务"
    ssh $SERVER "systemctl start govai-api && sleep 2 && systemctl status govai-api --no-pager | head -5"

    # 6. 验证
    step "验证服务"
    if ssh $SERVER "curl -sf http://localhost:8080/api/v1/store/featured -o /dev/null"; then
        log "API 服务正常"
    else
        err "API 服务异常，请检查: ssh $SERVER 'journalctl -u govai-api -n 30'"
    fi

    # 7. 记录
    local upgrade_log="$PROJECT_DIR/.go-upgrade-log"
    echo "[$(date '+%Y-%m-%d %H:%M:%S')] $CURRENT_GO_VERSION → go$new_patch" >> "$upgrade_log"

    echo ""
    echo -e "${GREEN}════════════════════════════════════════${NC}"
    echo -e "${GREEN}  升级完成！${NC}"
    echo -e "${GREEN}  Go: $CURRENT_GO_VERSION → go$new_patch${NC}"
    echo -e "${GREEN}════════════════════════════════════════${NC}"
}

# ---- 状态模式 ----
do_status() {
    step "版本状态"
    echo "  本地 Go 版本:   $CURRENT_GO_VERSION"
    ssh $SERVER "echo '  服务器 Go 版本: $SERVER_GO_VERSION'; echo '  GovAI 二进制:'; ssh $SERVER 'ls -lh $REMOTE_SERVER_BIN 2>/dev/null || echo 不存在'"
    echo ""

    local latest
    latest=$(fetch_latest_patch "$MAJOR_MINOR" 2>/dev/null)
    echo "  $MAJOR_MINOR 系列最新: ${latest:-无法获取}"
    echo ""

    # 检查 govulncheck
    if command -v ~/go/bin/govulncheck &>/dev/null; then
        echo "  govulncheck 已知漏洞: $(cd "$PROJECT_DIR/server" && ~/go/bin/govulncheck ./... 2>&1 | grep -c '^Vulnerability #' || echo 0) 个"
    fi
}

# ---- 主流程 ----
ACTION="${1:-check}"
case "$ACTION" in
    check)
        do_check
        ;;
    upgrade)
        do_upgrade
        ;;
    status)
        do_status
        ;;
    *)
        echo "用法: bash go-upgrade.sh [check|upgrade|status]"
        echo ""
        echo "  check   - 检查 Go 版本更新（默认）"
        echo "  upgrade - 执行完整升级：下载 -> 编译 -> 上传 -> 重启"
        echo "  status  - 查看当前 Go 版本和补丁状态"
        exit 1
        ;;
esac