package main

import (
	"context"
	"fmt"
	"time"

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

const (
	dbName  string = "test"
	colName string = "pids"
)

func deal() {
	defer wg.Done()
	var cooked Event
	var ok bool

	var err error
	var mongo *mongo.Client
	var res []bson.M

	mongo, err = connect()
	if err != nil {
		fmt.Printf("Err connecting the mongodb: %v\n", err)
	}
	pidCol := mongo.Database(dbName).Collection(colName)

	err = pidCol.Drop(context.Background())
	if err != nil {
		fmt.Printf("Err drop: %v\n", err)
	}

	_, err = pidCol.InsertOne(context.Background(), bson.M{
		"ppid": 1,
		"pid":  containerdPid,
		"cwd":  "/",
	})
	if err != nil {
		fmt.Printf("Err containerd: %v", err)
		return
	}

	fmt.Printf("Containerd: %d\n", containerdPid)

	for {
		cooked, ok = <-cookedChan
		if !ok {
			break
		}

		switch syscallTable[cooked.syscall] {
		case "fork", "vfork", "clone":
			// 有无父进程在观察中
			res, err = findDocuments(mongo, "test", "pids", bson.M{"pid": cooked.ppid})
			if err != nil || len(res) != 1 {
				break
			}

			// 自身是否已经记录
			res, err = findDocuments(mongo, "test", "pids", bson.M{"pid": cooked.pid})
			if err != nil {
				fmt.Printf("Err finding: %v\n", err)
				break
			} else if len(res) != 0 {
				fmt.Printf("Err inserting pid %v: already in db: %v\n", cooked.pid, res)
				break
			}

			doc := []bson.A{}
			for _, str := range cooked.argv {
				doc = append(doc, bson.A{str})
			}
			_, err := pidCol.InsertOne(context.Background(), bson.M{
				"timestamp": cooked.timestamp,
				"ppid":      cooked.ppid,
				"pid":       cooked.pid,
				"cwd":       cooked.cwd,
				"args":      doc,
				"children":  []bson.M{},
			})
			if err != nil {
				fmt.Printf("Err insert: %v\n", err)
			}

			_, err = pidCol.UpdateOne(context.Background(), bson.M{"pid": cooked.pid}, bson.M{
				"$push": bson.M{
					"children": cooked.pid,
				},
			})
			if err != nil {
				fmt.Printf("Err insert: %v\n", err)
			}
		case "exit", "exit_group":
			// TODO: 记得补全退出逻辑
			// 上哪找exit code呢？
		}
	}
}

func connect() (*mongo.Client, error) {
	client, err := mongo.NewClient(options.Client().ApplyURI("mongodb://localhost:27017"))

	if err != nil {
		return nil, err
	}

	ctx, _ := context.WithTimeout(context.Background(), 10*time.Second)
	err = client.Connect(ctx)

	if err != nil {
		return nil, err
	}

	return client, nil
}

func findDocuments(client *mongo.Client, dbName, colName string, filter bson.M) ([]bson.M, error) {
	collection := client.Database(dbName).Collection(colName)

	cur, err := collection.Find(context.Background(), filter)
	if err != nil {
		return nil, err
	}

	var results []bson.M
	err = cur.All(context.Background(), &results)

	return results, err
}