#!/bin/bash
# ============================================================
# config-protector.sh — 配置保护器
# 作用：在每次修改配置前自动备份
#       修改后健康检查失败 → 自动回滚
#       成功 → 标记为新的稳定点
# 由 health-watchdog.sh 联动触发
# 也支持手动调用：config-protector.sh [snapshot|rollback|status]
# ============================================================
set -e

CONFIG_DIR="$HOME/.hermes"
LOG="$HOME/.hermes/watchdog/config-protector.log"
mkdir -p "$(dirname "$LOG")"

log() { echo "[$(date '+%H:%M:%S')] $*" | tee -a "$LOG"; }

# === 快照：记录当前配置状态 ===
snapshot() {
    cd "$CONFIG_DIR"
    
    # 检查是否有未提交的变更
    if git diff --quiet && git diff --cached --quiet; then
        log "✅ 配置无变更，无需快照"
        return 0
    fi
    
    # 有变更 → 自动 commit
    git add -A 2>/dev/null
    local changed=$(git diff --cached --name-only | head -5)
    git commit -m "auto-snapshot $(date '+%Y-%m-%d %H:%M:%S')" 2>&1 | tail -1 | log
    
    log "📸 快照已保存（变更文件：${changed:-无描述}）"
    
    # 标记最近配置
    git tag -f last-config 2>/dev/null
    
    return 0
}

# === 回滚：恢复到上次稳定点 ===
rollback() {
    cd "$CONFIG_DIR"
    
    local target="${1:-stable}"
    
    if ! git rev-parse --verify "$target" 2>/dev/null; then
        log "❌ 回滚目标 '$target' 不存在"
        return 1
    fi
    
    log "⚠️  开始回滚到 $target..."
    
    # 保存当前状态（回滚前的状态，用于诊断）
    git stash 2>/dev/null || true
    
    # 硬重置到目标
    git checkout --force "$target" 2>&1 | log
    
    log "✅ 已回滚到 $target"
    log "📋 受影响文件：$(git diff --name-only HEAD~1..HEAD 2>/dev/null | head -10 || echo '首次回滚')"
    
    # 创建回滚事件记录
    echo "$(date '+%Y-%m-%dT%H:%M:%S')|rollback|$target" >> "$CONFIG_DIR/watchdog/rollback-history.txt"
    
    return 0
}

# === 标记当前为稳定 ===
mark_stable() {
    cd "$CONFIG_DIR"
    local tag="stable-$(date '+%Y%m%d-%H%M%S')"
    git tag -f "$tag" 2>/dev/null
    git tag -f stable 2>/dev/null
    log "⭐ 已标记 $tag 为稳定点"
    return 0
}

# === 状态：显示配置保护和最近变更 ===
status() {
    cd "$CONFIG_DIR"
    echo "=== 配置保护状态 ==="
    echo "仓库: $CONFIG_DIR/.git"
    echo "最近提交:"
    git log --oneline -5 2>/dev/null || echo "  (无提交)"
    echo ""
    echo "未跟踪文件:"
    git status --short 2>/dev/null | head -10 || echo "  全部已跟踪"
    echo ""
    echo "稳定标签:"
    git tag -l 'stable-*' | sort -r | head -5 2>/dev/null || echo "  (无)"
    echo ""
    if [ -f "$CONFIG_DIR/watchdog/rollback-history.txt" ]; then
        echo "回滚历史:"
        tail -3 "$CONFIG_DIR/watchdog/rollback-history.txt"
    fi
}

# === 与看门狗联动：健康检测失败时自动回滚 ===
auto_rollback_if_unhealthy() {
    # 由 watchdog 调用，检测上次变更后系统是否正常
    cd "$CONFIG_DIR"
    
    # 检查最近是否有配置变更（30分钟内）
    local last_change=$(git log --oneline -1 --format="%ct" HEAD 2>/dev/null || echo 0)
    local now=$(date +%s)
    local age=$(( (now - last_change) / 60 ))
    
    if [ "$age" -gt 30 ]; then
        # 上次变更超过30分钟，不触发自动回滚
        return 0
    fi
    
    # 检查关键进程
    local dead=""
    for p in zhiyid-new new-api hermes bge_embed_server; do
        if ! pgrep -f "$p" > /dev/null 2>&1; then
            dead="$dead $p"
        fi
    done
    
    if [ -n "$dead" ]; then
        log "🚨 检测到自动回滚条件：最近配置变更后进程挂了($dead)"
        log "🔙 自动回滚中..."
        rollback "stable"
        log "🔄 回滚完成，重启服务..."
        
        # 重启关键服务
        systemctl --user restart zhiyid.service bge-embed.service new-api.service 2>/dev/null || true
        sleep 5
        
        log "✅ 回滚自愈完成"
        return 0
    fi
    
    return 0
}

# === 主入口 ===
case "${1:-snapshot}" in
    snapshot)
        snapshot
        ;;
    rollback)
        rollback "$2"
        ;;
    mark-stable)
        mark_stable
        ;;
    status)
        status
        ;;
    auto-heal)
        auto_rollback_if_unhealthy
        ;;
    *)
        echo "用法: config-protector.sh [snapshot|rollback <tag>|mark-stable|status|auto-heal]"
        ;;
esac