feat: exporter api, json exporter

internal/adapters/exporter/exporter.go

@@ -0,0 +1,43 @@
+package exporter
+
+import (
+	"context"
+	"fmt"
+	"github.com/abelith/spellbook/internal/models"
+	"io"
+	"sync"
+)
+
+type Exporter interface {
+	Export(ctx context.Context, ch <-chan models.Spell, w io.Writer) error
+}
+
+var (
+	exporters = make(map[string]Exporter)
+	mu        sync.Mutex
+)
+
+func Register(name string, exp Exporter) {
+	mu.Lock()
+	defer mu.Unlock()
+
+	if exp == nil {
+		panic("exporter: Exporter cannot be nil")
+	}
+	if _, ok := exporters[name]; ok {
+		panic("exporter: Register called twice for " + name)
+	}
+	exporters[name] = exp
+}
+
+func Export(ctx context.Context, name string, ch <-chan models.Spell, w io.Writer) error {
+	mu.Lock()
+	exp, ok := exporters[name]
+	mu.Unlock()
+
+	if !ok {
+		return fmt.Errorf("exporter %s not found", name)
+	}
+
+	return exp.Export(ctx, ch, w)
+}

internal/adapters/json/json.go

@@ -0,0 +1,34 @@
+package json
+
+import (
+	"context"
+	"encoding/json"
+	"github.com/abelith/spellbook/internal/adapters/exporter"
+	"github.com/abelith/spellbook/internal/models"
+	"io"
+)
+
+func init() {
+	exporter.Register("jsonl", &JsonlExporter{})
+}
+
+type JsonlExporter struct{}
+
+func (je *JsonlExporter) Export(ctx context.Context, ch <-chan models.Spell, w io.Writer) error {
+	encoder := json.NewEncoder(w)
+
+	for {
+		select {
+		case <-ctx.Done():
+			return ctx.Err()
+		case spell, ok := <-ch:
+			if !ok {
+				return nil
+			}
+
+			if err := encoder.Encode(&spell); err != nil {
+				return err
+			}
+		}
+	}
+}

internal/models/models.go

@@ -6,12 +6,12 @@ import (
 )
 
 type Spell struct {
-	Id          int
-	Name        string
-	Spell       string
-	ShortDesc   string
-	Description string
-	Tags        []string
+	Id          int      `json:"-"`
+	Name        string   `json:"name,omitempty"`
+	Spell       string   `json:"spell,omitempty"`
+	ShortDesc   string   `json:"short_desc,omitempty"`
+	Description string   `json:"description,omitempty"`
+	Tags        []string `json:"tags,omitempty"`
 }
 
 type SpellCast struct {