package main

import (
	"context"
	"encoding/json"
	"fmt"
	"log"
	"os"

	"go.mongodb.org/mongo-driver/bson"
	"go.mongodb.org/mongo-driver/mongo"
	"go.mongodb.org/mongo-driver/mongo/options"
)

const (
	oldDBName      = "test"
	oldPidColName  = "pids"
	oldFdColName   = "fds"
	oldFileColName = "files"

	newDBName      = "cooked"
	newPidColName  = "tgids"
	newFileColName = "files"
)

// 进程树信息
var findTgid map[int]int
var helloTree map[int]*tgidNode

// 文件信息
var files []File

func main() {
	// 连接到MongoDB
	client, err := mongo.Connect(context.TODO(), options.Client().ApplyURI("mongodb://192.168.192.136:27017"))
	if err != nil {
		log.Fatal(err)
	}
	defer client.Disconnect(context.TODO())

	oldDB := client.Database(oldDBName)

	/*
	 * Step 1: 进程数据处理
	 */
	oldPidCol := oldDB.Collection(oldPidColName)

	// 数据提取
	var rawPidData []Process
	cursor, err := oldPidCol.Find(context.Background(), bson.M{})
	if err != nil {
		fmt.Fprintf(os.Stderr, "Err: %v\n", err)
		return
	}
	err = cursor.All(context.Background(), &rawPidData)
	if err != nil {
		fmt.Fprintf(os.Stderr, "Err All: %v\n", err)
		return
	}
	cursor.Close(context.Background())

	filtPids(&rawPidData)

	/*
	 * Step 2: 文件数据处理
	 * - 将已经关闭的和未关闭的同等看待
	 * - 未关闭的将关闭时间修改为对应进程退出时间
	 * - 值得注意的是，同一进程各线程共享文件描述符……需要处理吗？
	 */
	// 提取files和fds里的数据
	// TODO:是否可以只筛选被写过的记录?
	var rawFileData []File
	oldFileCol := oldDB.Collection(oldFileColName)
	cursor, err = oldFileCol.Find(context.Background(), bson.M{})
	if err != nil {
		fmt.Fprintf(os.Stderr, "Err: %v\n", err)
		return
	}
	err = cursor.All(context.Background(), &rawFileData)
	if err != nil {
		fmt.Fprintf(os.Stderr, "Err All: %v\n", err)
		return
	}
	cursor.Close(context.Background())

	var rawFdData []File
	oldFdCol := oldDB.Collection(oldFdColName)
	cursor, err = oldFdCol.Find(context.Background(), bson.M{})
	if err != nil {
		fmt.Fprintf(os.Stderr, "Err: %v\n", err)
		return
	}
	err = cursor.All(context.Background(), &rawFdData)
	if err != nil {
		fmt.Fprintf(os.Stderr, "Err All: %v\n", err)
		return
	}
	cursor.Close(context.Background())

	// 合并,处理
	rawFileData = append(rawFileData, rawFdData...)
	filtFiles(&rawFileData)

	// 扔回数据库
	newDB := client.Database(newDBName)
	newDB.Drop(context.Background())
	newPidCol := newDB.Collection(newPidColName)
	for _, pTgidNode := range helloTree {
		newPidCol.InsertOne(context.Background(), *pTgidNode)
	}

	newFileCol := newDB.Collection(newFileColName)
	for _, file := range files {
		newFileCol.InsertOne(context.Background(), file)
	}

	/* Step 3: 输出到文件
	 * - 所有内容输出到logs目录，所有文本存在则覆盖，不存在则创建
	 * - 进程树输出到logs/tree.log
	 * - 每个进程以json格式输出到logs/pids.log
	 * - 文件信息输出到logs/files.log
	 */
	stat, err := os.Stat("logs")
	if err != nil || !stat.IsDir() {
		os.Mkdir("logs", 0755)
	}

	// 进程树
	treeFile, err := os.OpenFile("logs/tree.log", os.O_CREATE|os.O_WRONLY|os.O_TRUNC, 0644)
	if err != nil {
		fmt.Fprintf(os.Stderr, "Err: %v\n", err)
		return
	}
	defer treeFile.Close()
	pidFile, err := os.OpenFile("logs/pid.log", os.O_CREATE|os.O_WRONLY|os.O_TRUNC, 0644)
	if err != nil {
		fmt.Fprintf(os.Stderr, "Err: %v\n", err)
		return
	}
	defer pidFile.Close()
	// 从starTgid开始，按照树的形状输出
	drawTree(treeFile, pidFile, helloTree[starTgid], "", true)

	// 文件信息，json格式
	fileFile, err := os.OpenFile("logs/files.log", os.O_CREATE|os.O_WRONLY|os.O_TRUNC, 0644)
	if err != nil {
		fmt.Fprintf(os.Stderr, "Err: %v\n", err)
		return
	}
	defer fileFile.Close()
	for _, file := range files {
		jsonData, err := json.MarshalIndent(file, "", "    ")
		if err != nil {
			fmt.Fprintf(os.Stderr, "Err: %v\n", err)
			return
		}
		fileFile.Write(jsonData)
		fileFile.WriteString("\n\n")
	}
}