// Copyright 2025 syzkaller project authors. All rights reserved.
// Use of this source code is governed by Apache 2 LICENSE that can be found in the LICENSE file.

// NOTE: This app assumes that only one copy of it is runnning at the same time.

package main

import (
	"context"
	"log"
	"time"

	"github.com/google/syzkaller/pkg/email/lore"
	"github.com/google/syzkaller/syz-cluster/pkg/api"
	"github.com/google/syzkaller/syz-cluster/pkg/app"
	"github.com/google/syzkaller/syz-cluster/pkg/emailclient"
	"golang.org/x/sync/errgroup"
)

// TODO: add extra sanity checks that would prevent flooding the mailing lists:
// - this pod may crash and be restarted by K8S: this complicates accounting,
// - the send operation might return an error, yet an email would be actually sent: back off on errors?

const (
	// How often to check whether there are new emails to be sent.
	senderPollPeriod = 30 * time.Second
	// How often to check whether there are new incoming emails.
	fetcherPollPeriod = 2 * time.Minute
)

func main() {
	ctx := context.Background()
	cfg, err := app.Config()
	if err != nil {
		app.Fatalf("failed to load config: %v", err)
	}
	if cfg.EmailReporting == nil {
		app.Fatalf("reporting is not configured: %v", err)
	}
	sender, err := emailclient.MakeSender(ctx, cfg.EmailReporting)
	if err != nil {
		app.Fatalf("failed to create a sender: %s", err)
	}
	reporterClient := app.DefaultReporterClient()
	handler := &Handler{
		reporter:    api.LKMLReporter,
		apiClient:   reporterClient,
		emailConfig: cfg.EmailReporting,
		sender:      sender,
	}
	msgCh := make(chan *lore.Email, 16)
	eg, loopCtx := errgroup.WithContext(ctx)
	if cfg.EmailReporting.LoreArchiveURL != "" {
		fetcher := NewLKMLEmailStream("/lore-repo/checkout", reporterClient, cfg.EmailReporting, msgCh)
		eg.Go(func() error { return fetcher.Loop(loopCtx, fetcherPollPeriod) })
	}
	eg.Go(func() error {
		for {
			var newEmail *lore.Email
			select {
			case newEmail = <-msgCh:
			case <-loopCtx.Done():
				return nil
			}
			log.Printf("received email %q", newEmail.MessageID)
			err := handler.IncomingEmail(loopCtx, newEmail.Email)
			if err != nil {
				// Note that we just print an error and go on instead of retrying.
				// Some retrying may be reasonable, but it also comes with a risk of flooding
				// the mailing lists.
				app.Errorf("email %q: failed to process: %v", newEmail.MessageID, err)
			}
		}
	})
	eg.Go(func() error {
		handler.PollReportsLoop(loopCtx, senderPollPeriod)
		return nil
	})
	if err = eg.Wait(); err != nil {
		app.Errorf("failed: %s", err)
	}
}