/*
 * Code goes along with the post made at:
 * https://ls3.io/post/ship_cloudwatch_logs_to_logentries/
 */
package main

import (
	"encoding/json"
	"fmt"
	"strings"

	"github.com/aws/aws-lambda-go/events"
	"github.com/aws/aws-lambda-go/lambda"
	"github.com/bsphere/le_go"
)

// CHANGE ME
const LE_LOG_KEY = "INSERT_YOUR_LOG_KEY"

func Handler(request events.CloudwatchLogsEvent) error {
	le, err := le_go.Connect(LE_LOG_KEY)
	if err != nil {
		panic(err)
	}
	defer le.Close()

	cloudwatchLogsData, err := request.AWSLogs.Parse()
	if err != nil {
		fmt.Println(err)
		return nil
	}

	// Remove the prefix to get to the name of the Lambda.
	logGroup := strings.Replace(cloudwatchLogsData.LogGroup, "/aws/lambda/", "", 1)

	// What you want to capture is up to you. BUT, for example:
	type LogEntry struct {
		LogGroup  string `json:"log_group"`
		Timestamp int64  `json:"timestamp"`
		Message   string `json:"message"`
	}

	// Stuff the incoming log lines into the datastructure to serialize to Log Entries.
	for _, event := range cloudwatchLogsData.LogEvents {
		logEntry := LogEntry{LogGroup: logGroup, Timestamp: event.Timestamp, Message: event.Message}
		j, err := json.Marshal(logEntry)
		if err != nil {
			fmt.Println(err)
			return nil
		}
		
		// Send to Logentries, basically.
		le.Print(string(j))
	}

	return nil
}

func main() {
	// Entrypoint that the Lambda will execute.
	lambda.Start(Handler)
}