#!/bin/bash
set -euo pipefail

echo "[INFO] Starting Fluent Bit uninstallation..."

# 检查是否为 root 用户
if [[ $EUID -ne 0 ]]; then
    echo "[ERROR] This script requires root privileges"
    echo "[INFO] Please use: sudo $0"
    exit 1
fi

echo "[WARNING] This operation will completely uninstall Fluent Bit"
read -p "Confirm to continue? (y/N): " confirm

if [[ "$confirm" != "y" && "$confirm" != "Y" ]]; then
    echo "[INFO] Uninstallation cancelled"
    exit 0
fi

# 停止运行中的进程
echo "[INFO] Stopping Fluent Bit processes..."
install_record="/opt/argus-metric/current/.install_record"
stopped=false

# 首先尝试通过安装记录文件停止服务
if [[ -f "$install_record" ]]; then
    # 尝试使用jq解析JSON格式的安装记录文件
    pid=""
    if command -v jq &> /dev/null; then
        pid=$(jq -r '.components."fluent-bit".pid // empty' "$install_record" 2>/dev/null || echo "")
    else
        # 如果没有jq，使用简单的文本解析方法
        pid=$(grep -A 10 '"fluent-bit"' "$install_record" | grep '"pid"' | cut -d'"' -f4 | head -1)
    fi
    
    if [[ -n "$pid" && "$pid" =~ ^[0-9]+$ ]]; then
        if kill -0 "$pid" 2>/dev/null; then
            echo "[INFO] Stopping service via installation record (PID: $pid)..."
            kill "$pid"
            sleep 3
            
            # 检查进程是否已停止
            if kill -0 "$pid" 2>/dev/null; then
                echo "[WARNING] Process unresponsive, force killing..."
                kill -9 "$pid" 2>/dev/null || true
            fi
            echo "[SUCCESS] Fluent Bit process stopped"
            stopped=true
        else
            echo "[WARNING] PID in installation record no longer exists"
        fi
    fi
fi

# 查找并杀死所有 fluent-bit 进程
pids=$(pgrep -f "fluent-bit" 2>/dev/null || true)
if [[ -n "$pids" ]]; then
    echo "[INFO] Found fluent-bit processes, stopping..."
    for pid in $pids; do
        echo "[INFO] Stopping process PID: $pid"
        kill "$pid" 2>/dev/null || true
    done
    sleep 2
    
    # 检查是否还有进程在运行，如果有则强制终止
    remaining_pids=$(pgrep -f "fluent-bit" 2>/dev/null || true)
    if [[ -n "$remaining_pids" ]]; then
        echo "[WARNING] Processes unresponsive, force killing..."
        for pid in $remaining_pids; do
            echo "[INFO] Force killing process PID: $pid"
            kill -9 "$pid" 2>/dev/null || true
        done
        sleep 1
    fi
    
    # 最终检查
    if pgrep -f "fluent-bit" > /dev/null; then
        echo "[ERROR] Unable to stop all fluent-bit processes"
    else
        echo "[SUCCESS] All Fluent Bit processes stopped"
        stopped=true
    fi
else
    echo "[INFO] No Fluent Bit processes running"
fi

if [[ "$stopped" == "false" ]]; then
    echo "[WARNING] No Fluent Bit processes found to stop"
fi

# 卸载 Fluent Bit 包
echo "[INFO] Uninstalling Fluent Bit package..."
if dpkg -l | grep -q "fluent-bit"; then
    echo "[INFO] Found fluent-bit package installed via dpkg, uninstalling..."
    dpkg --remove --force-remove-reinstreq fluent-bit || true
    echo "[SUCCESS] Fluent Bit package uninstalled"
else
    echo "[INFO] No fluent-bit package found via package manager"
fi

# 删除二进制文件
echo "[INFO] Removing Fluent Bit binary files..."
binary_dir="/opt/fluent-bit"
if [[ -d "$binary_dir" ]]; then
    rm -rf "$binary_dir"
    echo "[SUCCESS] Binary directory removed: $binary_dir"
else
    echo "[INFO] Binary directory does not exist"
fi

# 删除配置文件
echo "[INFO] Removing configuration files..."
config_dir="/etc/fluent-bit"
if [[ -d "$config_dir" ]]; then
    rm -rf "$config_dir"
    echo "[SUCCESS] Configuration directory removed"
else
    echo "[INFO] Configuration directory does not exist"
fi

# 删除数据目录
echo "[INFO] Removing data directories..."
data_dirs=("/logs" "/buffers")
deleted=false
for data_dir in "${data_dirs[@]}"; do
    if [[ -d "$data_dir" ]]; then
        rm -rf "$data_dir"
        echo "[SUCCESS] Data directory removed: $data_dir"
        deleted=true
    fi
done

if [[ "$deleted" == "false" ]]; then
    echo "[INFO] No data directories found"
fi

# 清理安装记录
echo "[INFO] Cleaning up installation record..."
if [[ -f "$install_record" ]]; then
    # 从安装记录中移除 fluent-bit 条目
    sed -i '/^fluent-bit:/d' "$install_record"
    echo "[SUCCESS] Installation record cleaned"
else
    echo "[INFO] Installation record file does not exist"
fi

# 检查用户状态
echo "[INFO] Checking fluent-bit user status..."
if id "fluent-bit" &>/dev/null; then
    echo "[INFO] fluent-bit user exists"
    echo "[WARNING] fluent-bit is a system user, may be used by other services"
    echo "[INFO] fluent-bit user will be preserved for system stability"
    echo "[INFO] To manually remove, run: sudo userdel fluent-bit"
else
    echo "[INFO] fluent-bit user does not exist"
fi

echo "[SUCCESS] Fluent Bit uninstallation completed!"
echo
echo "Removed content:"
echo "  - Binary directory: /opt/fluent-bit"
echo "  - Configuration directory: /etc/fluent-bit"
echo "  - Application log directory: /logs"
echo "  - Buffer directory: /buffers"
echo
echo "Note:"
echo "  - fluent-bit user preserved (system user, may be used by other services)"
echo "  - For complete cleanup, manually check and remove related files"