Add support for d2lang

d2/d2.go

@@ -0,0 +1,107 @@
+package d2
+
+import (
+	"bytes"
+	"context"
+	"encoding/base64"
+	"fmt"
+	"strconv"
+	"time"
+
+	"github.com/chromedp/cdproto/dom"
+	"github.com/chromedp/chromedp"
+
+	"github.com/kovetskiy/mark/attachment"
+	"github.com/reconquest/pkg/log"
+
+	"oss.terrastruct.com/d2/d2graph"
+	"oss.terrastruct.com/d2/d2layouts/d2dagrelayout"
+	"oss.terrastruct.com/d2/d2lib"
+	"oss.terrastruct.com/d2/d2renderers/d2svg"
+	"oss.terrastruct.com/d2/d2themes/d2themescatalog"
+	d2log "oss.terrastruct.com/d2/lib/log"
+	"oss.terrastruct.com/d2/lib/textmeasure"
+	"oss.terrastruct.com/util-go/go2"
+)
+
+var renderTimeout = 120 * time.Second
+
+func ProcessD2(title string, d2Diagram []byte, scale float64) (attachment.Attachment, error) {
+	ctx, cancel := context.WithTimeout(context.TODO(), renderTimeout)
+	ctx = d2log.WithDefault(ctx)
+	defer cancel()
+
+	ruler, err := textmeasure.NewRuler()
+	if err != nil {
+		return attachment.Attachment{}, err
+	}
+	layoutResolver := func(engine string) (d2graph.LayoutGraph, error) {
+		return d2dagrelayout.DefaultLayout, nil
+	}
+	renderOpts := &d2svg.RenderOpts{
+		Pad:     go2.Pointer(int64(5)),
+		ThemeID: &d2themescatalog.GrapeSoda.ID,
+	}
+	compileOpts := &d2lib.CompileOptions{
+		LayoutResolver: layoutResolver,
+		Ruler:          ruler,
+	}
+
+	diagram, _, err := d2lib.Compile(ctx, string(d2Diagram), compileOpts, renderOpts)
+	if err != nil {
+		return attachment.Attachment{}, err
+	}
+
+	out, err := d2svg.Render(diagram, renderOpts)
+	if err != nil {
+		return attachment.Attachment{}, err
+	}
+
+	log.Debugf(nil, "Rendering: %q", title)
+	pngBytes, boxModel, err := convertSVGtoPNG(ctx, out, scale)
+	if err != nil {
+		return attachment.Attachment{}, err
+	}
+
+	checkSum, err := attachment.GetChecksum(bytes.NewReader(d2Diagram))
+	log.Debugf(nil, "Checksum: %q -> %s", title, checkSum)
+
+	if err != nil {
+		return attachment.Attachment{}, err
+	}
+	if title == "" {
+		title = checkSum
+	}
+
+	fileName := title + ".png"
+
+	return attachment.Attachment{
+		ID:        "",
+		Name:      title,
+		Filename:  fileName,
+		FileBytes: pngBytes,
+		Checksum:  checkSum,
+		Replace:   title,
+		Width:     strconv.FormatInt(boxModel.Width, 10),
+		Height:    strconv.FormatInt(boxModel.Height, 10),
+	}, nil
+}
+
+func convertSVGtoPNG(ctx context.Context, svg []byte, scale float64) (png []byte, m *dom.BoxModel, err error) {
+	var (
+		result []byte
+		model  *dom.BoxModel
+	)
+	ctx, cancel := chromedp.NewContext(ctx)
+	defer cancel()
+
+	err = chromedp.Run(ctx,
+		chromedp.Navigate(fmt.Sprintf("data:image/svg+xml;base64,%s", base64.StdEncoding.EncodeToString(svg))),
+		chromedp.ScreenshotScale(`document.querySelector("svg > svg")`, scale, &result, chromedp.ByJSPath),
+		chromedp.Dimensions(`document.querySelector("svg > svg")`, &model, chromedp.ByJSPath),
+	)
+	if err != nil {
+		return nil, nil, err
+	}
+	return result, model, err
+}

d2/d2_test.go

@@ -0,0 +1,102 @@
+package d2
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/kovetskiy/mark/attachment"
+	"github.com/stretchr/testify/assert"
+)
+
+var diagram string = `d2
+vars: {
+  d2-config: {
+    layout-engine: elk
+    # Terminal theme code
+    theme-id: 300
+  } 
+}
+network: {
+  cell tower: {
+    satellites: {
+      shape: stored_data
+      style.multiple: true
+    }
+
+    transmitter
+
+    satellites -> transmitter: send
+    satellites -> transmitter: send
+    satellites -> transmitter: send
+  }
+
+  online portal: {
+    ui: {shape: hexagon}
+  }   
+      
+  data processor: {
+    storage: {
+      shape: cylinder
+      style.multiple: true
+    }
+  }
+
+  cell tower.transmitter -> data processor.storage: phone logs
+}
+
+user: {
+  shape: person
+  width: 130
+}
+
+user -> network.cell tower: make call
+user -> network.online portal.ui: access {
+  style.stroke-dash: 3
+}   
+
+api server -> network.online portal.ui: display
+api server -> logs: persist
+logs: {shape: page; style.multiple: true}
+
+network.data processor -> api server
+`
+
+func TestExtractD2Image(t *testing.T) {
+	tests := []struct {
+		name     string
+		markdown []byte
+		scale    float64
+		want     attachment.Attachment
+		wantErr  assert.ErrorAssertionFunc
+	}{
+		{"example", []byte(diagram), 1.0, attachment.Attachment{
+			// This is only the PNG Magic Header
+			FileBytes: []byte{0x89, 0x50, 0x4e, 0x47, 0xd, 0xa, 0x1a, 0xa},
+			Filename:  "example.png",
+			Name:      "example",
+			Replace:   "example",
+			Checksum:  "58fa387384181445e2d8f90a8c7fda945cb75174f73e8b9853ff59b9e0103ddd",
+			ID:        "",
+			Width:     "198",
+			Height:    "441",
+		},
+			assert.NoError},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got, err := ProcessD2(tt.name, tt.markdown, tt.scale)
+			if !tt.wantErr(t, err, fmt.Sprintf("processD2(%v, %v)", tt.name, string(tt.markdown))) {
+				return
+			}
+			assert.Equal(t, tt.want.Filename, got.Filename, "processD2(%v, %v)", tt.name, string(tt.markdown))
+			// We only test for the header as png changes based on system png library
+			assert.Equal(t, tt.want.FileBytes, got.FileBytes[0:8], "processD2(%v, %v)", tt.name, string(tt.markdown))
+			assert.Equal(t, tt.want.Name, got.Name, "processD2(%v, %v)", tt.name, string(tt.markdown))
+			assert.Equal(t, tt.want.Replace, got.Replace, "processD2(%v, %v)", tt.name, string(tt.markdown))
+			assert.Equal(t, tt.want.Checksum, got.Checksum, "processD2(%v, %v)", tt.name, string(tt.markdown))
+			assert.Equal(t, tt.want.ID, got.ID, "processD2(%v, %v)", tt.name, string(tt.markdown))
+			assert.Equal(t, tt.want.Width, got.Width, "processD2(%v, %v)", tt.name, string(tt.markdown))
+			assert.Equal(t, tt.want.Height, got.Height, "processD2(%v, %v)", tt.name, string(tt.markdown))
+		})
+	}
+}