Initial import.

topic/pht/pht.go

@@ -0,0 +1,62 @@
+package pht
+
+import (
+	"context"
+	"encoding/json"
+
+	"git.wntrmute.dev/kyle/sensenet/topic"
+	"github.com/Masterminds/squirrel"
+)
+
+var psql = squirrel.StatementBuilder.PlaceholderFormat(squirrel.Dollar)
+
+func createTable(ctx context.Context, db topic.Database) error {
+	stmt := `CREATE TABLE pht IF NOT EXISTS (
+	id uuid primary key default gen_random_uuid(),
+	source text,
+	timestamp int,
+	temp real,
+	press real,
+	humid real
+);`
+	_, err := db.Exec(ctx, stmt)
+	return err
+}
+
+type reading struct {
+	Timestamp   int64   `json:"timestamp"`
+	Temperature float64 `json:"temperature"`
+	Pressure    float64 `json:"pressure"`
+	Humidity    float64 `json:"relative_humidity"`
+}
+
+func store(ctx context.Context, db topic.Database, packet *topic.Packet) error {
+	r := &reading{}
+	err := json.Unmarshal(packet.Payload, r)
+	if err != nil {
+		return err
+	}
+	stmt := psql.Insert("pht").Columns(
+		"source",
+		"timestamp",
+		"temp",
+		"press",
+		"humid",
+	).Values(packet.Publisher, r.Timestamp, r.Pressure, r.Humidity)
+	query, args, err := stmt.ToSql()
+	if err != nil {
+		return err
+	}
+
+	_, err = db.Exec(ctx, query, args...)
+	return err
+}
+
+var PHT = &topic.Topic{
+	CreateTable: createTable,
+	Store:       store,
+}
+
+func init() {
+	topic.Register("pht", PHT)
+}

topic/topic.go

@@ -0,0 +1,70 @@
+package topic
+
+import (
+	"context"
+	"fmt"
+	"log"
+	"sync"
+
+	"github.com/jackc/pgconn"
+)
+
+type Database interface {
+	Exec(ctx context.Context, query string, args ...interface{}) (pgconn.CommandTag, error)
+}
+
+type Topic struct {
+	CreateTable func(ctx context.Context, db Database) error
+	Store       func(ctx context.Context, db Database, packet *Packet) error
+}
+
+var registry = struct {
+	topics map[string]*Topic
+	lock   *sync.Mutex
+}{
+	topics: map[string]*Topic{},
+	lock:   new(sync.Mutex),
+}
+
+func Register(topic string, handler *Topic) {
+	registry.lock.Lock()
+	defer registry.lock.Unlock()
+
+	if _, ok := registry.topics[topic]; ok {
+		panic(fmt.Sprintf("attempt to register pht '%s' that has already been registered", topic))
+	}
+
+	registry.topics[topic] = handler
+}
+
+type Packet struct {
+	Topic     string
+	Publisher string
+	Received  int64 // unix timestamp
+	Payload   []byte
+}
+
+// Setup ensures all the required tables are created.
+func Setup(ctx context.Context, db Database) error {
+	registry.lock.Lock()
+	defer registry.lock.Unlock()
+
+	for key, topic := range registry.topics {
+		log.Println("running CreateTable for", key)
+		err := topic.CreateTable(ctx, db)
+		if err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func Publish(ctx context.Context, db Database, packet *Packet) error {
+	topic, ok := registry.topics[packet.Topic]
+	if !ok {
+		return fmt.Errorf("topic: no handler for topic '%s' [%x]", packet.Topic, packet.Payload)
+	}
+
+	return topic.Store(ctx, db, packet)
+}