main.go

package main

import (
	"context"
	"fmt"
	"log"
	"net/http"
	"runtime"
	"strconv"
	"strings"
	"time"

	"github.com/bradleyfalzon/ghinstallation"
	"github.com/google/go-github/v31/github"
	"github.com/slack-go/slack"
)

var slackAPI *slack.Client
var config = Config{}

func arrayHasOverlap(list1 []string, list2 []string) bool {
	for _, a := range list1 {
		for _, b := range list2 {
			if a == b {
				return true
			}
		}
	}
	return false
}

func main() {
	configure(&config)

	itr, err := ghinstallation.NewKeyFromFile(http.DefaultTransport, config.GitHub.AppID, config.GitHub.InstallationID, config.GitHub.PrivateKey)
	if err != nil {
		panic(err)
	}

	timeUntilUnassigned := time.Hour * 24 * time.Duration(config.Unassign.DaysUntilUnassign)
	timeUntilNotified := time.Hour * 24 * time.Duration(config.Unassign.DaysUntilWarning)

	gh := github.NewClient(&http.Client{Transport: itr})
	slackAPI = slack.New(config.Slack.Token)

	if err != nil {
		panic(err)
	}

	opts := &github.IssueListByRepoOptions{Assignee: "*", State: "open"}

	for _, repo := range config.GitHub.Repos {
		issues, _, err := gh.Issues.ListByRepo(context.Background(), config.GitHub.Organization, repo, opts)
		if err != nil {
			logError("[FATAL] Getting issues", err)
			panic(err)
		}

		for _, issue := range issues {
			labels := []string{}
			for _, label := range issue.Labels {
				labels = append(labels, *label.Name)
			}

			if arrayHasOverlap(config.GitHub.IgnoreLabels, labels) {
				continue
			}

			assignees := []string{}
			for _, assignee := range issue.Assignees {
				assignees = append(assignees, *assignee.Login)
			}
			if issue.UpdatedAt.Add(timeUntilUnassigned).Before(time.Now()) {
				// the issue hasn't been updated in a week
				message := "Hi! I've removed @" + strings.Join(assignees, ", @") + " from this issue due to a lack of activity. If this is a mistake, feel free to reassign yourself. If you would like to work on this issue, feel free to assign yourself."
				_, _, err = gh.Issues.RemoveAssignees(context.Background(), config.GitHub.Organization, repo, *issue.Number, assignees)
				if err != nil {
					logError("Removing issue assignees", err)
					continue
				}
				_, _, err = gh.Issues.CreateComment(context.Background(), config.GitHub.Organization, repo, *issue.Number, &github.IssueComment{
					Body: github.String(message),
				})
				// fmt.Println(message)
				if err != nil {
					logError("Creating issue comment", err)
				}
			} else if issue.UpdatedAt.Add(timeUntilNotified).Before(time.Now()) {
				for _, assignee := range assignees {
					message := "Hi! This is a warning that due to a lack of activity on <" + *issue.HTMLURL + "|" + config.GitHub.Organization + "/" + repo + "#" + strconv.Itoa(*issue.Number) + ">, you will be unassigned soon. Comment on the issue if you want to stay assigned (A simple \"bump\" will suffice)."
					_, _, _, err := slackAPI.SendMessage(config.Users[assignee], slack.MsgOptionText(message, false))
					if err != nil {
						logError("Posting message to slack", err)
					}
				}
			}
		}
	}
}

func logError(desc string, err error) {
	buf := make([]byte, 1<<16)
	stackSize := runtime.Stack(buf, false)
	stackTrace := string(buf[0:stackSize])

	log.Println("======================================")

	log.Printf("Error occurred while '%s'!", desc)
	errDesc := ""
	if err != nil {
		errDesc = err.Error()
	} else {
		errDesc = "(err == nil)"
	}
	log.Println(errDesc)
	log.Println(stackTrace)

	log.Println("======================================")

	title := fmt.Sprintf("An error occurred - %s", desc)
	_, _, _, postingErr := slackAPI.SendMessage(config.Slack.ErrlogChannel, slack.MsgOptionAttachments(slack.Attachment{
		Fallback:   title,
		Color:      "danger",
		Title:      title,
		Text:       "```" + stackTrace + "```",
		MarkdownIn: []string{"fields"},
		Fields: []slack.AttachmentField{
			{
				Title: "Host",
				Value: "PlanBot :robot_face:",
				Short: true,
			},
			{
				Title: "Message",
				Value: err.Error(),
				Short: true,
			},
		},
	}))
	if postingErr != nil {
		log.Println("An error occurred while reporting the previous error to Slack")
		log.Println(postingErr)
	}
}