Initial commit

internal/haberdasherserver/server.go

@@ -0,0 +1,179 @@
+package haberdasherserver
+
+import (
+	"context"
+	"encoding/binary"
+	"encoding/json"
+	"fmt"
+	"math/rand"
+	"os"
+
+	"github.com/boltdb/bolt"
+	"github.com/twitchtv/twirp"
+
+	pb "haberdasher-twirp/haberdasher"
+)
+
+const dbBucket = "hats"
+
+type Server struct{}
+
+type Hat struct {
+	Inches int32  `json:"inchues"`
+	Color  string `json:"color"`
+	Name   string `json:"name"`
+}
+
+type HatQuery struct {
+	Limit int32
+}
+
+type Store struct {
+	db *bolt.DB
+}
+
+func HatToHatModel(h *pb.Hat) Hat {
+	return Hat{
+		Inches: h.Inches,
+		Color:  h.Color,
+		Name:   h.Name,
+	}
+}
+
+func HatModelToHat(h Hat) *pb.Hat {
+	return &pb.Hat{
+		Inches: h.Inches,
+		Color:  h.Color,
+		Name:   h.Name,
+	}
+}
+
+func HatsModelToHats(hs []Hat) (hats *pb.Hats) {
+	hats = &pb.Hats{}
+	for _, h := range hs {
+		hat := HatModelToHat(h)
+		hats.Hats = append(hats.Hats, hat)
+	}
+	return hats
+}
+
+func HatQueryToHatQueryModel(q *pb.HatQuery) HatQuery {
+	return HatQuery{
+		Limit: q.Limit,
+	}
+}
+
+func (s *Server) MakeHat(ctx context.Context, size *pb.Size) (hat *pb.Hat, err error) {
+	st, _ := NewStore("hat.db", 0600, nil)
+	defer st.Close()
+
+	if size.Inches <= 0 {
+		return nil, twirp.InvalidArgumentError("inches", "I can't make a hat that small!")
+	}
+
+	h := Hat{
+		Inches: size.Inches,
+		Color:  []string{"white", "black", "red", "blue"}[rand.Intn(4)],
+		Name:   []string{"bowler", "baseball cap", "top hat", "derby"}[rand.Intn(3)],
+	}
+
+	fmt.Printf("made hat: %+v\n", h)
+
+	st.SaveHat(h)
+
+	return HatModelToHat(h), nil
+}
+
+func (s *Server) ListHats(ctx context.Context, q *pb.HatQuery) (hats *pb.Hats, err error) {
+	/*
+		var hat *pb.Hat
+
+		hats = &pb.Hats{}
+
+		for i := 0; i < 10; i++ {
+			hat = &pb.Hat{
+				Inches: int32(rand.Intn(12)),
+				Color:  []string{"white", "black", "red", "blue"}[rand.Intn(4)],
+				Name:   []string{"bowler", "baseball cap", "top hat", "derby"}[rand.Intn(3)],
+			}
+			hats.Hats = append(hats.Hats, hat)
+		}
+	*/
+
+	st, _ := NewStore("hat.db", 0600, nil)
+	defer st.Close()
+
+	hs, err := st.ListHats(HatQueryToHatQueryModel(q))
+
+	return HatsModelToHats(hs), nil
+}
+
+func itob(v uint64) []byte {
+	b := make([]byte, 8)
+	binary.BigEndian.PutUint64(b, uint64(v))
+	return b
+}
+
+func btoi(b []byte) uint64 {
+	return binary.BigEndian.Uint64(b)
+}
+
+func NewStore(path string, mode os.FileMode, options *bolt.Options) (s *Store, err error) {
+	s = &Store{}
+	s.db, err = bolt.Open(path, mode, options)
+	if err != nil {
+		fmt.Printf("bolt open: %s", err)
+	}
+
+	s.db.Update(func(tx *bolt.Tx) error {
+		if _, err := tx.CreateBucket([]byte(dbBucket)); err != nil {
+			return fmt.Errorf("create bucket: %s", err)
+		}
+		return nil
+	})
+
+	return s, err
+}
+
+func (s *Store) SaveHat(h Hat) (err error) {
+	return s.db.Update(func(tx *bolt.Tx) error {
+		b := tx.Bucket([]byte("hats"))
+
+		id, _ := b.NextSequence()
+
+		buf, err := json.Marshal(h)
+		if err != nil {
+			return fmt.Errorf("json marshal: %s", err)
+		}
+
+		return b.Put(itob(id), buf)
+	})
+}
+
+func (s *Store) ListHats(q HatQuery) (hats []Hat, err error) {
+	var hat Hat
+	var i int
+
+	s.db.View(func(tx *bolt.Tx) error {
+		b := tx.Bucket([]byte("hats"))
+
+		c := b.Cursor()
+
+		for k, v := c.Last(); k != nil && i < int(q.Limit); k, v = c.Prev() {
+			if err := json.Unmarshal(v, &hat); err != nil {
+				return fmt.Errorf("json unmarshal: %s", err)
+			}
+			h := hat
+			hats = append(hats, h)
+			i++
+		}
+
+		return nil
+	})
+
+	return hats, nil
+}
+
+func (s *Store) Close() (err error) {
+	return s.db.Close()
+}