subreddit notifications

internal/api/api.go

@@ -24,8 +24,10 @@ type api struct {
 	reddit *reddit.Client
 	apns   *token.Token
 
-	accountRepo domain.AccountRepository
-	deviceRepo  domain.DeviceRepository
+	accountRepo   domain.AccountRepository
+	deviceRepo    domain.DeviceRepository
+	subredditRepo domain.SubredditRepository
+	watcherRepo   domain.WatcherRepository
 }
 
 func NewAPI(ctx context.Context, logger *logrus.Logger, statsd *statsd.Client, pool *pgxpool.Pool) *api {
@@ -52,14 +54,19 @@ func NewAPI(ctx context.Context, logger *logrus.Logger, statsd *statsd.Client, p
 
 	accountRepo := repository.NewPostgresAccount(pool)
 	deviceRepo := repository.NewPostgresDevice(pool)
+	subredditRepo := repository.NewPostgresSubreddit(pool)
+	watcherRepo := repository.NewPostgresWatcher(pool)
 
 	return &api{
-		logger:      logger,
-		statsd:      statsd,
-		reddit:      reddit,
-		apns:        apns,
-		accountRepo: accountRepo,
-		deviceRepo:  deviceRepo,
+		logger: logger,
+		statsd: statsd,
+		reddit: reddit,
+		apns:   apns,
+
+		accountRepo:   accountRepo,
+		deviceRepo:    deviceRepo,
+		subredditRepo: subredditRepo,
+		watcherRepo:   watcherRepo,
 	}
 }
 
@@ -83,6 +90,9 @@ func (a *api) Routes() *mux.Router {
 	r.HandleFunc("/v1/device/{apns}/accounts", a.upsertAccountsHandler).Methods("POST")
 	r.HandleFunc("/v1/device/{apns}/account/{redditID}", a.disassociateAccountHandler).Methods("DELETE")
 
+	r.HandleFunc("/v1/device/{apns}/accounts/{redditID}/watcher", a.createWatcherHandler).Methods("POST")
+	r.HandleFunc("/v1/device/{apns}/accounts/{redditID}/watcher/{watcherID}", a.deleteWatcherHandler).Methods("DELETE")
+
 	r.HandleFunc("/v1/receipt", a.checkReceiptHandler).Methods("POST")
 	r.HandleFunc("/v1/receipt/{apns}", a.checkReceiptHandler).Methods("POST")
 

internal/api/watcher.go

@@ -0,0 +1,127 @@
+package api
+
+import (
+	"context"
+	"encoding/json"
+	"net/http"
+	"strconv"
+
+	"github.com/christianselig/apollo-backend/internal/domain"
+	"github.com/gorilla/mux"
+)
+
+type watcherCriteria struct {
+	Upvotes int64
+	Keyword string
+	Flair   string
+	Domain  string
+}
+
+type createWatcherRequest struct {
+	Subreddit string
+	Criteria  watcherCriteria
+}
+
+func (a *api) createWatcherHandler(w http.ResponseWriter, r *http.Request) {
+	ctx := context.Background()
+
+	vars := mux.Vars(r)
+	apns := vars["apns"]
+	redditID := vars["redditID"]
+
+	cwr := &createWatcherRequest{}
+	if err := json.NewDecoder(r.Body).Decode(cwr); err != nil {
+		a.errorResponse(w, r, 500, err.Error())
+		return
+	}
+
+	dev, err := a.deviceRepo.GetByAPNSToken(ctx, apns)
+	if err != nil {
+		a.errorResponse(w, r, 422, err.Error())
+		return
+	}
+
+	accs, err := a.accountRepo.GetByAPNSToken(ctx, apns)
+	if err != nil || len(accs) == 0 {
+		a.errorResponse(w, r, 422, err.Error())
+		return
+	}
+
+	account := accs[0]
+	found := false
+	for _, acc := range accs {
+		if acc.AccountID == redditID {
+			found = true
+			account = acc
+		}
+	}
+
+	if !found {
+		a.errorResponse(w, r, 422, "yeah nice try")
+		return
+	}
+
+	ac := a.reddit.NewAuthenticatedClient(account.RefreshToken, account.AccessToken)
+	srr, err := ac.SubredditAbout(cwr.Subreddit)
+	if err != nil {
+		a.errorResponse(w, r, 422, err.Error())
+		return
+	}
+
+	sr, err := a.subredditRepo.GetByName(ctx, cwr.Subreddit)
+
+	switch err {
+	case domain.ErrNotFound:
+		// Might be that we don't know about that subreddit yet
+		sr = domain.Subreddit{SubredditID: srr.ID, Name: srr.Name}
+		_ = a.subredditRepo.CreateOrUpdate(ctx, &sr)
+	default:
+		a.errorResponse(w, r, 500, err.Error())
+		return
+	}
+
+	watcher := domain.Watcher{
+		SubredditID: sr.ID,
+		DeviceID:    dev.ID,
+		AccountID:   account.ID,
+		Upvotes:     cwr.Criteria.Upvotes,
+		Keyword:     cwr.Criteria.Keyword,
+		Flair:       cwr.Criteria.Flair,
+		Domain:      cwr.Criteria.Domain,
+	}
+
+	if err := a.watcherRepo.Create(ctx, &watcher); err != nil {
+		a.errorResponse(w, r, 422, err.Error())
+		return
+	}
+
+	w.WriteHeader(http.StatusOK)
+}
+
+func (a *api) deleteWatcherHandler(w http.ResponseWriter, r *http.Request) {
+	ctx := context.Background()
+
+	vars := mux.Vars(r)
+	id, err := strconv.ParseInt(vars["watcherID"], 10, 64)
+	if err != nil {
+		a.errorResponse(w, r, 422, err.Error())
+		return
+	}
+
+	apns := vars["apns"]
+
+	dev, err := a.deviceRepo.GetByAPNSToken(ctx, apns)
+	if err != nil {
+		a.errorResponse(w, r, 422, err.Error())
+		return
+	}
+
+	watcher, err := a.watcherRepo.GetByID(ctx, id)
+	if err != nil || watcher.DeviceID != dev.ID {
+		a.errorResponse(w, r, 422, "nice try")
+		return
+	}
+
+	_ = a.watcherRepo.Delete(ctx, id)
+	w.WriteHeader(http.StatusOK)
+}

internal/cmd/scheduler.go

@@ -20,9 +20,11 @@ import (
 )
 
 const (
-	batchSize      = 250
-	checkTimeout   = 60 // how long until we force a check
-	enqueueTimeout = 5  // how long until we try to re-enqueue
+	batchSize    = 250
+	checkTimeout = 60 // how long until we force a check
+
+	accountEnqueueTimeout   = 5      // how frequently we want to check (seconds)
+	subredditEnqueueTimeout = 5 * 60 // how frequently we want to check (seconds)
 
 	staleAccountThreshold = 7200   // 2 hours
 	staleDeviceThreshold  = 604800 // 1 week
@@ -70,8 +72,14 @@ func SchedulerCmd(ctx context.Context) *cobra.Command {
 				return err
 			}
 
+			subredditQueue, err := queue.OpenQueue("subreddits")
+			if err != nil {
+				return err
+			}
+
 			s := gocron.NewScheduler(time.UTC)
 			_, _ = s.Every(200).Milliseconds().SingletonMode().Do(func() { enqueueAccounts(ctx, logger, statsd, db, redis, luaSha, notifQueue) })
+			_, _ = s.Every(200).Milliseconds().SingletonMode().Do(func() { enqueueSubreddits(ctx, logger, statsd, db, subredditQueue) })
 			_, _ = s.Every(1).Second().Do(func() { cleanQueues(ctx, logger, queue) })
 			_, _ = s.Every(1).Minute().Do(func() { reportStats(ctx, logger, statsd, db, redis) })
 			_, _ = s.Every(1).Minute().Do(func() { pruneAccounts(ctx, logger, db) })
@@ -195,6 +203,70 @@ func reportStats(ctx context.Context, logger *logrus.Logger, statsd *statsd.Clie
 	}
 }
 
+func enqueueSubreddits(ctx context.Context, logger *logrus.Logger, statsd *statsd.Client, pool *pgxpool.Pool, queue rmq.Queue) {
+	now := time.Now()
+	ready := now.Unix() - subredditEnqueueTimeout
+
+	ids := []int64{}
+
+	err := pool.BeginFunc(ctx, func(tx pgx.Tx) error {
+		stmt := `
+			WITH subreddit AS (
+			  SELECT id
+				FROM subreddits
+				WHERE last_checked_at < $1
+				ORDER BY last_checked_at
+				LIMIT 100
+			)
+			UPDATE subreddits
+			SET last_checked_at = $2
+			WHERE subreddits.id IN(SELECT id FROM subreddit)
+			RETURNING subreddits.id`
+		rows, err := tx.Query(ctx, stmt, ready, now.Unix())
+		if err != nil {
+			return err
+		}
+		defer rows.Close()
+		for rows.Next() {
+			var id int64
+			_ = rows.Scan(&id)
+			ids = append(ids, id)
+		}
+		return nil
+	})
+
+	if err != nil {
+		logger.WithFields(logrus.Fields{
+			"err": err,
+		}).Error("failed to fetch batch of subreddits")
+		return
+	}
+
+	if len(ids) == 0 {
+		return
+	}
+
+	logger.WithFields(logrus.Fields{
+		"count": len(ids),
+		"start": ready,
+	}).Debug("enqueueing subreddit batch")
+
+	batchIds := make([]string, len(ids))
+	for i, id := range ids {
+		batchIds[i] = strconv.FormatInt(id, 10)
+	}
+
+	if err = queue.Publish(batchIds...); err != nil {
+		logger.WithFields(logrus.Fields{
+			"err": err,
+		}).Error("failed to enqueue subreddit")
+	}
+
+	_ = statsd.Histogram("apollo.queue.subreddits.enqueued", float64(len(ids)), []string{}, 1)
+	_ = statsd.Histogram("apollo.queue.subreddits.runtime", float64(time.Since(now).Milliseconds()), []string{}, 1)
+
+}
+
 func enqueueAccounts(ctx context.Context, logger *logrus.Logger, statsd *statsd.Client, pool *pgxpool.Pool, redisConn *redis.Client, luaSha string, queue rmq.Queue) {
 	start := time.Now()
 
@@ -204,7 +276,7 @@ func enqueueAccounts(ctx context.Context, logger *logrus.Logger, statsd *statsd.
 	// and at most 6 seconds ago. Also look for accounts that haven't been checked
 	// in over a minute.
 	ts := start.Unix()
-	ready := ts - enqueueTimeout
+	ready := ts - accountEnqueueTimeout
 	expired := ts - checkTimeout
 
 	ids := []int64{}
@@ -292,9 +364,9 @@ func enqueueAccounts(ctx context.Context, logger *logrus.Logger, statsd *statsd.
 		}
 	}
 
-	_ = statsd.Histogram("apollo.queue.enqueued", float64(enqueued), []string{}, 1)
-	_ = statsd.Histogram("apollo.queue.skipped", float64(skipped), []string{}, 1)
-	_ = statsd.Histogram("apollo.queue.runtime", float64(time.Since(start).Milliseconds()), []string{}, 1)
+	_ = statsd.Histogram("apollo.queue.notifications.enqueued", float64(enqueued), []string{}, 1)
+	_ = statsd.Histogram("apollo.queue.notifications.skipped", float64(skipped), []string{}, 1)
+	_ = statsd.Histogram("apollo.queue.notifications.runtime", float64(time.Since(start).Milliseconds()), []string{}, 1)
 
 	logger.WithFields(logrus.Fields{
 		"count":   enqueued,

internal/cmd/worker.go

@@ -14,6 +14,7 @@ import (
 var (
 	queues = map[string]worker.NewWorkerFn{
 		"notifications": worker.NewNotificationsWorker,
+		"subreddits":    worker.NewSubredditsWorker,
 	}
 )
 

internal/domain/device.go

@@ -15,6 +15,7 @@ type Device struct {
 }
 
 type DeviceRepository interface {
+	GetByID(ctx context.Context, id int64) (Device, error)
 	GetByAPNSToken(ctx context.Context, token string) (Device, error)
 	GetByAccountID(ctx context.Context, id int64) ([]Device, error)
 

internal/domain/subreddit.go

@@ -0,0 +1,25 @@
+package domain
+
+import (
+	"context"
+	"strings"
+)
+
+type Subreddit struct {
+	ID int64
+
+	// Reddit information
+	SubredditID string
+	Name        string
+}
+
+func (sr *Subreddit) NormalizedName() string {
+	return strings.ToLower(sr.Name)
+}
+
+type SubredditRepository interface {
+	GetByID(ctx context.Context, id int64) (Subreddit, error)
+	GetByName(ctx context.Context, name string) (Subreddit, error)
+
+	CreateOrUpdate(ctx context.Context, sr *Subreddit) error
+}

internal/domain/watcher.go

@@ -0,0 +1,25 @@
+package domain
+
+import "context"
+
+type Watcher struct {
+	ID int64
+
+	DeviceID    int64
+	AccountID   int64
+	SubredditID int64
+
+	Upvotes int64
+	Keyword string
+	Flair   string
+	Domain  string
+}
+
+type WatcherRepository interface {
+	GetByID(ctx context.Context, id int64) (Watcher, error)
+	GetBySubredditID(ctx context.Context, id int64) ([]Watcher, error)
+
+	Create(ctx context.Context, watcher *Watcher) error
+	Update(ctx context.Context, watcher *Watcher) error
+	Delete(ctx context.Context, id int64) error
+}

internal/reddit/client.go

@@ -1,6 +1,7 @@
 package reddit
 
 import (
+	"fmt"
 	"io/ioutil"
 	"net/http"
 	"net/http/httptrace"
@@ -179,6 +180,40 @@ func (rac *AuthenticatedClient) RefreshTokens() (*RefreshTokenResponse, error) {
 	return ret, nil
 }
 
+func (rac *AuthenticatedClient) SubredditAbout(subreddit string, opts ...RequestOption) (*SubredditResponse, error) {
+	url := fmt.Sprintf("https://oauth.reddit.com/r/%s/about.json", subreddit)
+	opts = append([]RequestOption{
+		WithMethod("GET"),
+		WithToken(rac.accessToken),
+		WithURL(url),
+	}, opts...)
+	req := NewRequest(opts...)
+	sr, err := rac.request(req, NewSubredditResponse, nil)
+
+	if err != nil {
+		return nil, err
+	}
+
+	return sr.(*SubredditResponse), nil
+}
+
+func (rac *AuthenticatedClient) SubredditNew(subreddit string, opts ...RequestOption) (*ListingResponse, error) {
+	url := fmt.Sprintf("https://oauth.reddit.com/r/%s/new.json", subreddit)
+	opts = append([]RequestOption{
+		WithMethod("GET"),
+		WithToken(rac.accessToken),
+		WithURL(url),
+	}, opts...)
+	req := NewRequest(opts...)
+
+	lr, err := rac.request(req, NewListingResponse, EmptyListingResponse)
+	if err != nil {
+		return nil, err
+	}
+
+	return lr.(*ListingResponse), nil
+}
+
 func (rac *AuthenticatedClient) MessageInbox(opts ...RequestOption) (*ListingResponse, error) {
 	opts = append([]RequestOption{
 		WithTags([]string{"url:/api/v1/message/inbox"}),

internal/reddit/types.go

@@ -73,6 +73,11 @@ type Thing struct {
 	LinkTitle   string  `json:"link_title"`
 	Destination string  `json:"dest"`
 	Subreddit   string  `json:"subreddit"`
+	Score       int64   `json:"score"`
+	SelfText    string  `json:"selftext"`
+	Title       string  `json:"title"`
+	URL         string  `json:"url"`
+	Flair       string  `json:"flair"`
 }
 
 func (t *Thing) FullName() string {
@@ -98,6 +103,12 @@ func NewThing(val *fastjson.Value) *Thing {
 	t.Destination = string(data.GetStringBytes("dest"))
 	t.Subreddit = string(data.GetStringBytes("subreddit"))
 
+	t.Score = data.GetInt64("score")
+	t.Title = string(data.GetStringBytes("title"))
+	t.SelfText = string(data.GetStringBytes("selftext"))
+	t.URL = string(data.GetStringBytes("url"))
+	t.Flair = string(data.GetStringBytes("link_flair_text"))
+
 	return t
 }
 
@@ -131,4 +142,22 @@ func NewListingResponse(val *fastjson.Value) interface{} {
 	return lr
 }
 
+type SubredditResponse struct {
+	Thing
+
+	Name string
+}
+
+func NewSubredditResponse(val *fastjson.Value) interface{} {
+	sr := &SubredditResponse{}
+
+	sr.Kind = string(val.GetStringBytes("kind"))
+
+	data := val.Get("data")
+	sr.ID = string(data.GetStringBytes("id"))
+	sr.Name = string(data.GetStringBytes("display_name"))
+
+	return sr
+}
+
 var EmptyListingResponse = &ListingResponse{}

internal/reddit/types_test.go

@@ -43,6 +43,7 @@ func TestRefreshTokenResponseParsing(t *testing.T) {
 }
 
 func TestListingResponseParsing(t *testing.T) {
+	// Message list
 	bb, err := ioutil.ReadFile("testdata/message_inbox.json")
 	assert.NoError(t, err)
 
@@ -74,4 +75,39 @@ func TestListingResponseParsing(t *testing.T) {
 	assert.Equal(t, "t1_h46tec3", thing.ParentID)
 	assert.Equal(t, "hello i am a cat", thing.LinkTitle)
 	assert.Equal(t, "calicosummer", thing.Subreddit)
+
+	// Post list
+	bb, err = ioutil.ReadFile("testdata/subreddit_new.json")
+	assert.NoError(t, err)
+
+	val, err = parser.ParseBytes(bb)
+	assert.NoError(t, err)
+
+	ret = NewListingResponse(val)
+	l = ret.(*ListingResponse)
+	assert.NotNil(t, l)
+
+	assert.Equal(t, 100, l.Count)
+
+	thing = l.Children[1]
+	assert.Equal(t, "Riven boss", thing.Title)
+	assert.Equal(t, "Question", thing.Flair)
+	assert.Contains(t, thing.SelfText, "never done riven")
+	assert.Equal(t, int64(1), thing.Score)
+}
+
+func TestSubredditResponseParsing(t *testing.T) {
+	bb, err := ioutil.ReadFile("testdata/subreddit_about.json")
+	assert.NoError(t, err)
+
+	val, err := parser.ParseBytes(bb)
+	assert.NoError(t, err)
+
+	ret := NewSubredditResponse(val)
+	s := ret.(*SubredditResponse)
+	assert.NotNil(t, s)
+
+	assert.Equal(t, "t5", s.Kind)
+	assert.Equal(t, "2vq0w", s.ID)
+	assert.Equal(t, "DestinyTheGame", s.Name)
 }

internal/repository/postgres_device.go

@@ -40,6 +40,23 @@ func (p *postgresDeviceRepository) fetch(ctx context.Context, query string, args
 	return devs, nil
 }
 
+func (p *postgresDeviceRepository) GetByID(ctx context.Context, id int64) (domain.Device, error) {
+	query := `
+		SELECT id, apns_token, sandbox, active_until
+		FROM devices
+		WHERE id = $1`
+
+	devs, err := p.fetch(ctx, query, id)
+
+	if err != nil {
+		return domain.Device{}, err
+	}
+	if len(devs) == 0 {
+		return domain.Device{}, domain.ErrNotFound
+	}
+	return devs[0], nil
+}
+
 func (p *postgresDeviceRepository) GetByAPNSToken(ctx context.Context, token string) (domain.Device, error) {
 	query := `
 		SELECT id, apns_token, sandbox, active_until

internal/repository/postgres_subreddit.go

@@ -0,0 +1,90 @@
+package repository
+
+import (
+	"context"
+	"strings"
+
+	"github.com/christianselig/apollo-backend/internal/domain"
+	"github.com/jackc/pgx/v4/pgxpool"
+)
+
+type postgresSubredditRepository struct {
+	pool *pgxpool.Pool
+}
+
+func NewPostgresSubreddit(pool *pgxpool.Pool) domain.SubredditRepository {
+	return &postgresSubredditRepository{pool: pool}
+}
+
+func (p *postgresSubredditRepository) fetch(ctx context.Context, query string, args ...interface{}) ([]domain.Subreddit, error) {
+	rows, err := p.pool.Query(ctx, query, args...)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+
+	var srs []domain.Subreddit
+	for rows.Next() {
+		var sr domain.Subreddit
+		if err := rows.Scan(
+			&sr.ID,
+			&sr.SubredditID,
+			&sr.Name,
+		); err != nil {
+			return nil, err
+		}
+		srs = append(srs, sr)
+	}
+	return srs, nil
+}
+
+func (p *postgresSubredditRepository) GetByID(ctx context.Context, id int64) (domain.Subreddit, error) {
+	query := `
+		SELECT id, subreddit_id, name
+		FROM subreddits
+		WHERE id = $1`
+
+	srs, err := p.fetch(ctx, query, id)
+
+	if err != nil {
+		return domain.Subreddit{}, err
+	}
+	if len(srs) == 0 {
+		return domain.Subreddit{}, domain.ErrNotFound
+	}
+	return srs[0], nil
+}
+
+func (p *postgresSubredditRepository) GetByName(ctx context.Context, name string) (domain.Subreddit, error) {
+	query := `
+		SELECT id, subreddit_id, name
+		FROM subreddits
+		WHERE name = $1`
+
+	name = strings.ToLower(name)
+
+	srs, err := p.fetch(ctx, query, name)
+
+	if err != nil {
+		return domain.Subreddit{}, err
+	}
+	if len(srs) == 0 {
+		return domain.Subreddit{}, domain.ErrNotFound
+	}
+	return srs[0], nil
+}
+
+func (p *postgresSubredditRepository) CreateOrUpdate(ctx context.Context, sr *domain.Subreddit) error {
+	query := `
+		INSERT INTO subreddits (subreddit_id, name)
+		VALUES ($1, $2)
+		ON CONFLICT(subreddit_id) DO NOTHING
+		RETURNING id`
+
+	return p.pool.QueryRow(
+		ctx,
+		query,
+		sr.SubredditID,
+		sr.NormalizedName(),
+	).Scan(&sr.ID)
+}

internal/repository/postgres_watcher.go

@@ -0,0 +1,126 @@
+package repository
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/jackc/pgx/v4/pgxpool"
+
+	"github.com/christianselig/apollo-backend/internal/domain"
+)
+
+type postgresWatcherRepository struct {
+	pool *pgxpool.Pool
+}
+
+func NewPostgresWatcher(pool *pgxpool.Pool) domain.WatcherRepository {
+	return &postgresWatcherRepository{pool: pool}
+}
+
+func (p *postgresWatcherRepository) fetch(ctx context.Context, query string, args ...interface{}) ([]domain.Watcher, error) {
+	rows, err := p.pool.Query(ctx, query, args...)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+
+	var watchers []domain.Watcher
+	for rows.Next() {
+		var watcher domain.Watcher
+		if err := rows.Scan(
+			&watcher.ID,
+			&watcher.DeviceID,
+			&watcher.AccountID,
+			&watcher.SubredditID,
+			&watcher.Upvotes,
+			&watcher.Keyword,
+			&watcher.Flair,
+			&watcher.Domain,
+		); err != nil {
+			return nil, err
+		}
+		watchers = append(watchers, watcher)
+	}
+	return watchers, nil
+}
+
+func (p *postgresWatcherRepository) GetByID(ctx context.Context, id int64) (domain.Watcher, error) {
+	query := `
+		SELECT id, device_id, account_id, subreddit_id, upvotes, keyword, flair, domain
+		FROM watchers
+		WHERE id = $1`
+
+	watchers, err := p.fetch(ctx, query, id)
+
+	if err != nil {
+		return domain.Watcher{}, err
+	}
+	if len(watchers) == 0 {
+		return domain.Watcher{}, domain.ErrNotFound
+	}
+	return watchers[0], nil
+}
+
+func (p *postgresWatcherRepository) GetBySubredditID(ctx context.Context, id int64) ([]domain.Watcher, error) {
+	query := `
+		SELECT id, device_id, account_id, subreddit_id, upvotes, keyword, flair, domain
+		FROM watchers
+		WHERE subreddit_id = $1`
+
+	return p.fetch(ctx, query, id)
+}
+
+func (p *postgresWatcherRepository) Create(ctx context.Context, watcher *domain.Watcher) error {
+	query := `
+		INSERT INTO watchers
+			(device_id, account_id, subreddit_id, upvotes, keyword, flair, domain)
+		VALUES ($1, $2, $3, $4, $5, $6, $7)
+		RETURNING id`
+
+	return p.pool.QueryRow(
+		ctx,
+		query,
+		&watcher.DeviceID,
+		&watcher.AccountID,
+		&watcher.SubredditID,
+		&watcher.Upvotes,
+		&watcher.Keyword,
+		&watcher.Flair,
+		&watcher.Domain,
+	).Scan(&watcher.ID)
+}
+
+func (p *postgresWatcherRepository) Update(ctx context.Context, watcher *domain.Watcher) error {
+	query := `
+		UPDATE watchers
+		SET upvotes = $2,
+			keyword = $3,
+			flair = $4,
+			domain = $5,
+		WHERE id = $1`
+
+	res, err := p.pool.Exec(
+		ctx,
+		query,
+		watcher.ID,
+		watcher.Upvotes,
+		watcher.Keyword,
+		watcher.Flair,
+		watcher.Domain,
+	)
+
+	if res.RowsAffected() != 1 {
+		return fmt.Errorf("weird behaviour, total rows affected: %d", res.RowsAffected())
+	}
+	return err
+}
+
+func (p *postgresWatcherRepository) Delete(ctx context.Context, id int64) error {
+	query := `DELETE FROM watchers WHERE id = $1`
+	res, err := p.pool.Exec(ctx, query, id)
+
+	if res.RowsAffected() != 1 {
+		return fmt.Errorf("weird behaviour, total rows affected: %d", res.RowsAffected())
+	}
+	return err
+}

internal/worker/notifications.go

@@ -165,8 +165,7 @@ func (nc *notificationsConsumer) Consume(delivery rmq.Delivery) {
 	account, err := nc.accountRepo.GetByID(ctx, id)
 	if err != nil {
 		nc.logger.WithFields(logrus.Fields{
-			"account#username": account.NormalizedUsername(),
-			"err":              err,
+			"err": err,
 		}).Error("failed to fetch account from database")
 		return
 	}

internal/worker/subreddits.go

@@ -0,0 +1,329 @@
+package worker
+
+import (
+	"context"
+	"fmt"
+	"math/rand"
+	"os"
+	"strconv"
+	"strings"
+	"time"
+
+	"github.com/DataDog/datadog-go/statsd"
+	"github.com/adjust/rmq/v4"
+	"github.com/go-redis/redis/v8"
+	"github.com/jackc/pgx/v4/pgxpool"
+	"github.com/sideshow/apns2"
+	"github.com/sideshow/apns2/payload"
+	"github.com/sideshow/apns2/token"
+	"github.com/sirupsen/logrus"
+
+	"github.com/christianselig/apollo-backend/internal/domain"
+	"github.com/christianselig/apollo-backend/internal/reddit"
+	"github.com/christianselig/apollo-backend/internal/repository"
+)
+
+type subredditsWorker struct {
+	logger *logrus.Logger
+	statsd *statsd.Client
+	db     *pgxpool.Pool
+	redis  *redis.Client
+	queue  rmq.Connection
+	reddit *reddit.Client
+	apns   *token.Token
+
+	consumers int
+
+	accountRepo   domain.AccountRepository
+	deviceRepo    domain.DeviceRepository
+	subredditRepo domain.SubredditRepository
+	watcherRepo   domain.WatcherRepository
+}
+
+func NewSubredditsWorker(logger *logrus.Logger, statsd *statsd.Client, db *pgxpool.Pool, redis *redis.Client, queue rmq.Connection, consumers int) Worker {
+	reddit := reddit.NewClient(
+		os.Getenv("REDDIT_CLIENT_ID"),
+		os.Getenv("REDDIT_CLIENT_SECRET"),
+		statsd,
+		consumers,
+	)
+
+	var apns *token.Token
+	{
+		authKey, err := token.AuthKeyFromFile(os.Getenv("APPLE_KEY_PATH"))
+		if err != nil {
+			panic(err)
+		}
+
+		apns = &token.Token{
+			AuthKey: authKey,
+			KeyID:   os.Getenv("APPLE_KEY_ID"),
+			TeamID:  os.Getenv("APPLE_TEAM_ID"),
+		}
+	}
+
+	return &subredditsWorker{
+		logger,
+		statsd,
+		db,
+		redis,
+		queue,
+		reddit,
+		apns,
+		consumers,
+
+		repository.NewPostgresAccount(db),
+		repository.NewPostgresDevice(db),
+		repository.NewPostgresSubreddit(db),
+		repository.NewPostgresWatcher(db),
+	}
+}
+
+func (sw *subredditsWorker) Start() error {
+	queue, err := sw.queue.OpenQueue("subreddits")
+	if err != nil {
+		return err
+	}
+
+	sw.logger.WithFields(logrus.Fields{
+		"numConsumers": sw.consumers,
+	}).Info("starting up subreddits worker")
+
+	prefetchLimit := int64(sw.consumers * 2)
+
+	if err := queue.StartConsuming(prefetchLimit, pollDuration); err != nil {
+		return err
+	}
+
+	host, _ := os.Hostname()
+
+	for i := 0; i < sw.consumers; i++ {
+		name := fmt.Sprintf("consumer %s-%d", host, i)
+
+		consumer := NewSubredditsConsumer(sw, i)
+		if _, err := queue.AddConsumer(name, consumer); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func (sw *subredditsWorker) Stop() {
+	<-sw.queue.StopAllConsuming() // wait for all Consume() calls to finish
+}
+
+type subredditsConsumer struct {
+	*subredditsWorker
+	tag int
+
+	apnsSandbox    *apns2.Client
+	apnsProduction *apns2.Client
+}
+
+func NewSubredditsConsumer(sw *subredditsWorker, tag int) *subredditsConsumer {
+	return &subredditsConsumer{
+		sw,
+		tag,
+		apns2.NewTokenClient(sw.apns),
+		apns2.NewTokenClient(sw.apns).Production(),
+	}
+}
+
+func (sc *subredditsConsumer) Consume(delivery rmq.Delivery) {
+	ctx := context.Background()
+
+	sc.logger.WithFields(logrus.Fields{
+		"subreddit#id": delivery.Payload(),
+	}).Debug("starting job")
+
+	id, err := strconv.ParseInt(delivery.Payload(), 10, 64)
+	if err != nil {
+		sc.logger.WithFields(logrus.Fields{
+			"subreddit#id": delivery.Payload(),
+			"err":          err,
+		}).Error("failed to parse subreddit ID")
+
+		_ = delivery.Reject()
+		return
+	}
+
+	defer func() { _ = delivery.Ack() }()
+
+	subreddit, err := sc.subredditRepo.GetByID(ctx, id)
+	if err != nil {
+		sc.logger.WithFields(logrus.Fields{
+			"err": err,
+		}).Error("failed to fetch subreddit from database")
+		return
+	}
+
+	watchers, err := sc.watcherRepo.GetBySubredditID(ctx, subreddit.ID)
+	if err != nil {
+		sc.logger.WithFields(logrus.Fields{
+			"subreddit#id": subreddit.ID,
+			"err":          err,
+		}).Error("failed to fetch watchers from database")
+		return
+	}
+
+	if len(watchers) == 0 {
+		sc.logger.WithFields(logrus.Fields{
+			"subreddit#id": subreddit.ID,
+			"err":          err,
+		}).Info("no watchers for subreddit, skipping")
+		return
+	}
+
+	threshold := float64(time.Now().AddDate(0, 0, -1).UTC().Unix())
+	posts := []*reddit.Thing{}
+	before := ""
+	finished := false
+
+	for pages := 0; pages < 5; pages++ {
+		i := rand.Intn(len(watchers))
+		watcher := watchers[i]
+
+		dev, err := sc.deviceRepo.GetByID(ctx, watcher.DeviceID)
+		if err != nil {
+			sc.logger.WithFields(logrus.Fields{
+				"subreddit#id": subreddit.ID,
+				"watcher#id":   watcher.ID,
+				"err":          err,
+			}).Error("failed to fetch device for watcher from database")
+			continue
+		}
+
+		accs, err := sc.accountRepo.GetByAPNSToken(ctx, dev.APNSToken)
+		if err != nil {
+			sc.logger.WithFields(logrus.Fields{
+				"subreddit#id": subreddit.ID,
+				"watcher#id":   watcher.ID,
+				"device#id":    dev.ID,
+				"err":          err,
+			}).Error("failed to fetch accounts for device from database")
+			continue
+		}
+
+		i = rand.Intn(len(accs))
+		acc := accs[i]
+
+		rac := sc.reddit.NewAuthenticatedClient(acc.RefreshToken, acc.AccessToken)
+
+		sps, err := rac.SubredditNew(
+			subreddit.Name,
+			reddit.WithQuery("before", before),
+			reddit.WithQuery("limit", "100"),
+		)
+
+		if err != nil {
+			sc.logger.WithFields(logrus.Fields{
+				"subreddit#id": subreddit.ID,
+				"watcher#id":   watcher.ID,
+				"device#id":    dev.ID,
+				"err":          err,
+			}).Error("failed to fetch posts")
+			continue
+		}
+
+		// If it's empty, we're done
+		if sps.Count == 0 {
+			break
+		}
+
+		// If we don't have 100 posts, we're going to be done
+		if sps.Count < 100 {
+			finished = true
+		}
+
+		for _, post := range sps.Children {
+			if post.CreatedAt < threshold {
+				finished = true
+				break
+			}
+
+			posts = append(posts, post)
+		}
+
+		if finished {
+			break
+		}
+	}
+
+	for _, post := range posts {
+		ids := []int64{}
+
+		for _, watcher := range watchers {
+			matched := (watcher.Upvotes == 0 || (watcher.Upvotes > 0 && post.Score > watcher.Upvotes)) &&
+				(watcher.Keyword == "" || strings.Contains(post.SelfText, watcher.Keyword)) &&
+				(watcher.Flair == "" || strings.Contains(post.Flair, watcher.Flair)) &&
+				(watcher.Domain == "" || strings.Contains(post.URL, watcher.Domain))
+
+			if !matched {
+				continue
+			}
+
+			lockKey := fmt.Sprintf("watcher:%d:%s", watcher.ID, post.ID)
+			notified, _ := sc.redis.Get(ctx, lockKey).Bool()
+
+			if notified {
+				continue
+			}
+
+			sc.redis.SetEX(ctx, lockKey, true, 24*time.Hour)
+			ids = append(ids, watcher.DeviceID)
+		}
+
+		if len(ids) == 0 {
+			continue
+		}
+
+		notification := &apns2.Notification{}
+		notification.Topic = "com.christianselig.Apollo"
+		notification.Payload = payloadFromPost(post)
+
+		for _, id := range ids {
+			device, _ := sc.deviceRepo.GetByID(ctx, id)
+			notification.DeviceToken = device.APNSToken
+
+			client := sc.apnsProduction
+			if device.Sandbox {
+				client = sc.apnsSandbox
+			}
+
+			res, err := client.Push(notification)
+			if err != nil {
+				_ = sc.statsd.Incr("apns.notification.errors", []string{}, 1)
+				sc.logger.WithFields(logrus.Fields{
+					"subreddit#id": subreddit.ID,
+					"device#id":    device.ID,
+					"err":          err,
+					"status":       res.StatusCode,
+					"reason":       res.Reason,
+				}).Error("failed to send notification")
+			} else {
+				_ = sc.statsd.Incr("apns.notification.sent", []string{}, 1)
+				sc.logger.WithFields(logrus.Fields{
+					"subreddit#id": subreddit.ID,
+					"device#id":    device.ID,
+					"device#token": device.APNSToken,
+				}).Info("sent notification")
+			}
+		}
+	}
+}
+
+func payloadFromPost(post *reddit.Thing) *payload.Payload {
+	payload := payload.
+		NewPayload().
+		AlertTitle("DING DONG").
+		AlertBody("I got you something").
+		AlertSummaryArg(post.Subreddit).
+		Category("post-watch").
+		Custom("post_title", post.Title).
+		Custom("post_id", post.ID).
+		Custom("author", post.Author).
+		Custom("post_age", post.CreatedAt)
+
+	return payload
+}