feat(graph): pipeline graph improvements — on_failure, tooltips, bus-bar connectors, skipped colouring, HTML and Mermaid output

- when: on_failure visual distinction: red circle (#d9534f), X-mark icon, dashed
  chip border, and Mermaid classDef; legend entry added
- Job tooltip / detail panel: each chip wrapped in <g data-job="…"><title>…</title>
  <desc>…</desc> so SVG viewers and the HTML sidebar show stage, when, image, needs
- Multi-job connector accuracy: classic mode now uses a bus-bar pattern (vertical
  rail at midpoint + per-job stubs) instead of one center-to-center line per stage pair
- Blocked/skipped state colouring: RenderPipeline and pipelineSVG accept
  *cicontext.Context; skipped jobs rendered in grey (#868686) with dimmed text
- Interactive HTML output (--format html): self-contained .html with inline SVG,
  mouse-wheel zoom, drag-to-pan, double-click reset, and a click-to-open sidebar
- Mermaid pipeline output (--format mermaid): prints existing Pipeline() flowchart
  to stdout; suitable for mermaid.live or Markdown embedding
- imageString() helper to extract image name from string or map form
- 100% statement coverage maintained; 809 tests pass

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

internal/graph/pipeline.go

@@ -27,6 +27,7 @@ func Pipeline(p *model.Pipeline) string {
 	w("    classDef manual fill:#fc6d26,stroke:#e56b1f,color:#fff")
 	w("    classDef trigger fill:#6b4fbb,stroke:#5a3fa0,color:#fff")
 	w("    classDef delayed fill:#fca326,stroke:#d98a1e,color:#333")
+	w("    classDef on_failure fill:#d9534f,stroke:#c0392b,color:#fff")
 	w("")
 
 	// Collect visible (non-template) job names; sort for stable output.
@@ -149,6 +150,8 @@ func jobClass(job model.Job) string {
 		return "manual"
 	case "delayed":
 		return "delayed"
+	case "on_failure":
+		return "on_failure"
 	}
 	return "regular"
 }

internal/graph/pipeline_test.go

@@ -105,10 +105,23 @@ func TestSanitizeID(t *testing.T) {
 func TestJobClass(t *testing.T) {
 	if jobClass(model.Job{When: "manual"}) != "manual" { t.Error("manual") }
 	if jobClass(model.Job{When: "delayed"}) != "delayed" { t.Error("delayed") }
+	if jobClass(model.Job{When: "on_failure"}) != "on_failure" { t.Error("on_failure") }
 	if jobClass(model.Job{Trigger: "x"}) != "trigger" { t.Error("trigger") }
 	if jobClass(model.Job{}) != "regular" { t.Error("regular") }
 }
 
+func TestPipeline_OnFailureClass(t *testing.T) {
+	p := &model.Pipeline{
+		Stages: []string{"cleanup"},
+		Jobs: map[string]model.Job{
+			"cleanup-job": {Name: "cleanup-job", Stage: "cleanup", When: "on_failure"},
+		},
+	}
+	out := Pipeline(p)
+	if !strings.Contains(out, "on_failure") { t.Error("expected on_failure class") }
+	if !strings.Contains(out, "#d9534f") { t.Error("expected on_failure color in classDef") }
+}
+
 // ── needsJobName ──────────────────────────────────────────────────────────────
 
 func TestNeedsJobName(t *testing.T) {

internal/graph/render.go

@@ -10,34 +10,35 @@ import (
 	"strings"
 	"time"
 
+	"git.k3nny.fr/glint/internal/cicontext"
 	"git.k3nny.fr/glint/internal/model"
 )
 
 // Layout constants (pixels) – tuned to resemble GitLab's full pipeline graph view.
 const (
-	chipW     = 178 // job chip width
-	chipH     = 34  // job chip height
-	chipGap   = 6   // vertical gap between chips in a column
-	iconCX    = 14  // status circle: x offset from chip left edge to circle centre
-	iconR     = 7   // status circle radius (14 px diameter)
-	textLeft  = 27  // job name text: x offset from chip left edge
-	labelH    = 30  // stage-name label area height (text + bottom gap)
-	topPad    = 40  // outer top padding
-	sidePad   = 40  // outer left / right padding
-	stageGap  = 50  // horizontal gap between stage columns (connector space)
-	botPad    = 48  // outer bottom padding (legend lives here)
+	chipW    = 178 // job chip width
+	chipH    = 34  // job chip height
+	chipGap  = 6   // vertical gap between chips in a column
+	iconCX   = 14  // status circle: x offset from chip left edge to circle centre
+	iconR    = 7   // status circle radius (14 px diameter)
+	textLeft = 27  // job name text: x offset from chip left edge
+	labelH   = 30  // stage-name label area height (text + bottom gap)
+	topPad   = 40  // outer top padding
+	sidePad  = 40  // outer left / right padding
+	stageGap = 50  // horizontal gap between stage columns (connector space)
+	botPad   = 48  // outer bottom padding (legend lives here)
 )
 
 type svgPt struct{ x, y int }
 
 // RenderPipeline writes a PNG (or SVG fallback) file with a GitLab CI-style
 // pipeline layout and returns the path to the generated file.
-func RenderPipeline(p *model.Pipeline, outDir string) (string, error) {
+func RenderPipeline(p *model.Pipeline, outDir string, ctx *cicontext.Context) (string, error) {
 	if err := os.MkdirAll(outDir, 0o755); err != nil {
 		return "", fmt.Errorf("creating output directory %s: %w", outDir, err)
 	}
 
-	svg := pipelineSVG(p)
+	svg := pipelineSVG(p, ctx)
 
 	ts := time.Now().Format("20060102-150405")
 	svgPath := filepath.Join(outDir, "pipeline-"+ts+".svg")
@@ -53,6 +54,24 @@ func RenderPipeline(p *model.Pipeline, outDir string) (string, error) {
 	return svgPath, nil
 }
 
+// RenderHTML writes a self-contained HTML file with the pipeline graph embedded
+// inline with pan/zoom and a job-detail sidebar, then returns the output path.
+func RenderHTML(p *model.Pipeline, outDir string, ctx *cicontext.Context) (string, error) {
+	if err := os.MkdirAll(outDir, 0o755); err != nil {
+		return "", fmt.Errorf("creating output directory %s: %w", outDir, err)
+	}
+
+	svg := pipelineSVG(p, ctx)
+	html := htmlPage(svg)
+
+	ts := time.Now().Format("20060102-150405")
+	htmlPath := filepath.Join(outDir, "pipeline-"+ts+".html")
+	if err := os.WriteFile(htmlPath, []byte(html), 0o644); err != nil {
+		return "", fmt.Errorf("writing HTML: %w", err)
+	}
+	return htmlPath, nil
+}
+
 // convertToPNG tries rsvg-convert, Inkscape, magick, and convert (not on Windows).
 func convertToPNG(svgPath, pngPath string) bool {
 	candidates := [][]string{
@@ -75,7 +94,7 @@ func convertToPNG(svgPath, pngPath string) bool {
 	return false
 }
 
-func pipelineSVG(p *model.Pipeline) string {
+func pipelineSVG(p *model.Pipeline, ctx *cicontext.Context) string {
 	// Collect visible (non-template) job names in sorted order.
 	var visible []string
 	for name := range p.Jobs {
@@ -89,6 +108,16 @@ func pipelineSVG(p *model.Pipeline) string {
 		return svgEmpty()
 	}
 
+	// Precompute which jobs are skipped in the given context.
+	skippedJobs := make(map[string]bool)
+	if ctx != nil {
+		for _, name := range visible {
+			if cicontext.EvalJob(p.Jobs[name], ctx) == cicontext.JobSkipped {
+				skippedJobs[name] = true
+			}
+		}
+	}
+
 	// Group by stage; fall back to "test" (GitLab default) when stage is unset.
 	byStage := make(map[string][]string)
 	for _, name := range visible {
@@ -120,8 +149,6 @@ func pipelineSVG(p *model.Pipeline) string {
 	}
 
 	// Compute per-stage column heights and job anchor points for connectors.
-	colH := make([]int, len(stages))   // height of the chip stack (no label)
-	colCtY := make([]int, len(stages)) // y centre of the chip stack
 	maxColH := 0
 	rightMid := make(map[string]svgPt)
 	leftMid := make(map[string]svgPt)
@@ -131,7 +158,6 @@ func pipelineSVG(p *model.Pipeline) string {
 		sort.Strings(jobs)
 		n := len(jobs)
 		h := n*chipH + max(0, n-1)*chipGap
-		colH[i] = h
 		if h > maxColH {
 			maxColH = h
 		}
@@ -141,7 +167,6 @@ func pipelineSVG(p *model.Pipeline) string {
 			rightMid[name] = svgPt{cx + chipW, chy + chipH/2}
 			leftMid[name] = svgPt{cx, chy + chipH/2}
 		}
-		colCtY[i] = topPad + labelH + h/2
 	}
 
 	svgW := sidePad*2 + len(stages)*chipW + max(0, len(stages)-1)*stageGap
@@ -190,29 +215,73 @@ func pipelineSVG(p *model.Pipeline) string {
 		wf(`  <line x1="%d" y1="%d" x2="%d" y2="%d" stroke="#eaeaea" stroke-width="1"/>`,
 			cx, topPad+21, cx+chipW, topPad+21)
 
-		// Job chips.
+		// Job chips – each wrapped in a <g> with tooltip metadata.
 		for j, name := range jobs {
 			job := p.Jobs[name]
 			chy := topPad + labelH + j*(chipH+chipGap)
+			isSkipped := skippedJobs[name]
+
+			// Build <desc> content: shown in the HTML sidebar and SVG viewer tooltips.
+			desc := "stage: " + stage
+			if job.When != "" {
+				desc += "\nwhen: " + job.When
+			}
+			if img := imageString(job.Image); img != "" {
+				desc += "\nimage: " + img
+			}
+			var needNames []string
+			for _, n := range job.Needs {
+				if s := needsJobName(n); s != "" {
+					needNames = append(needNames, s)
+				}
+			}
+			if len(needNames) > 0 {
+				desc += "\nneeds: " + strings.Join(needNames, ", ")
+			}
+			if isSkipped {
+				desc += "\nstate: skipped"
+			}
+
+			// data-job attribute enables JS click detection in the HTML output.
+			wf(`  <g data-job="%s">`, svgEsc(name))
+			wf(`    <title>%s</title>`, svgEsc(name))
+			wf(`    <desc>%s</desc>`, svgEsc(desc))
+
 			color := chipColor(job)
+			if isSkipped {
+				color = "#868686"
+			}
 
 			// Chip card (white, rounded, subtle border + shadow).
-			wf(`  <rect x="%d" y="%d" width="%d" height="%d" rx="4" `+
-				`fill="#ffffff" stroke="#dde1e7" stroke-width="1" filter="url(#chip-shadow)"/>`,
-				cx, chy, chipW, chipH)
+			// on_failure jobs get a dashed border to signal the failure path.
+			dashAttr := ""
+			if !isSkipped && job.When == "on_failure" {
+				dashAttr = ` stroke-dasharray="4,3"`
+			}
+			wf(`    <rect x="%d" y="%d" width="%d" height="%d" rx="4" `+
+				`fill="#ffffff" stroke="#dde1e7" stroke-width="1"%s filter="url(#chip-shadow)"/>`,
+				cx, chy, chipW, chipH, dashAttr)
 
 			// Colored status indicator circle.
-			wf(`  <circle cx="%d" cy="%d" r="%d" fill="%s"/>`,
+			wf(`    <circle cx="%d" cy="%d" r="%d" fill="%s"/>`,
 				cx+iconCX, chy+chipH/2, iconR, color)
 
-			// Icon symbol inside the circle.
-			drawChipIcon(&sb, job, cx+iconCX, chy+chipH/2)
+			// Icon inside the circle (omitted for skipped — grey circle speaks for itself).
+			if !isSkipped {
+				drawChipIcon(&sb, job, cx+iconCX, chy+chipH/2)
+			}
 
-			// Job name text.
-			wf(`  <text x="%d" y="%d" dominant-baseline="middle" `+
+			// Job name text — dimmed for skipped jobs.
+			textColor := "#303030"
+			if isSkipped {
+				textColor = "#868686"
+			}
+			wf(`    <text x="%d" y="%d" dominant-baseline="middle" `+
 				`font-family="'GitLab Sans','Segoe UI',-apple-system,BlinkMacSystemFont,sans-serif" `+
-				`font-size="13" fill="#303030">%s</text>`,
-				cx+textLeft, chy+chipH/2, svgEsc(svgTrunc(name, 20)))
+				`font-size="13" fill="%s">%s</text>`,
+				cx+textLeft, chy+chipH/2, textColor, svgEsc(svgTrunc(name, 20)))
+
+			wf(`  </g>`)
 		}
 	}
 
@@ -241,27 +310,54 @@ func pipelineSVG(p *model.Pipeline) string {
 			}
 		}
 	} else {
-		// Classic: one connector per adjacent stage pair.
+		// Classic: bus-bar connectors – every job in stage[i] fans to a vertical
+		// bus at the midpoint column gap, then fans out to every job in stage[i+1].
+		// This gives each job pair its own visual connection instead of a single
+		// center-to-center line that misses jobs at the top and bottom of columns.
 		for i := 0; i < len(stages)-1; i++ {
-			x1 := sidePad + i*(chipW+stageGap) + chipW
-			x2 := sidePad + (i+1)*(chipW+stageGap)
-			y1 := colCtY[i]
-			y2 := colCtY[i+1]
+			x1 := sidePad + i*(chipW+stageGap) + chipW // right edge of left column
+			x2 := sidePad + (i+1)*(chipW+stageGap)    // left edge of right column
 			midX := (x1 + x2) / 2
 
-			if y1 == y2 {
-				// Straight horizontal line.
-				wf(`  <line x1="%d" y1="%d" x2="%d" y2="%d" stroke="%s" stroke-width="2"/>`,
-					x1, y1, x2-7, y2, connStroke)
-			} else {
-				// L-shaped elbow: right → vertical → right.
-				wf(`  <polyline points="%d,%d %d,%d %d,%d %d,%d" `+
-					`stroke="%s" stroke-width="2" fill="none" stroke-linejoin="round"/>`,
-					x1, y1, midX, y1, midX, y2, x2-7, y2, connStroke)
+			srcJobs := byStage[stages[i]]
+			sort.Strings(srcJobs)
+			dstJobs := byStage[stages[i+1]]
+			sort.Strings(dstJobs)
+
+			// Collect all Y midpoints to span the vertical bus bar.
+			var allYs []int
+			srcY := make([]int, len(srcJobs))
+			dstY := make([]int, len(dstJobs))
+			for j, name := range srcJobs {
+				srcY[j] = rightMid[name].y
+				allYs = append(allYs, srcY[j])
+			}
+			for j, name := range dstJobs {
+				dstY[j] = leftMid[name].y
+				allYs = append(allYs, dstY[j])
+			}
+			sort.Ints(allYs)
+			busMinY, busMaxY := allYs[0], allYs[len(allYs)-1]
+
+			// Vertical bus bar at midX (only drawn when there are multiple Y levels).
+			if busMinY < busMaxY {
+				wf(`  <line x1="%d" y1="%d" x2="%d" y2="%d" stroke="%s" stroke-width="2"/>`,
+					midX, busMinY, midX, busMaxY, connStroke)
+			}
+
+			// Horizontal stubs from each source job to the bus.
+			for _, y := range srcY {
+				wf(`  <line x1="%d" y1="%d" x2="%d" y2="%d" stroke="%s" stroke-width="2"/>`,
+					x1, y, midX, y, connStroke)
+			}
+
+			// Horizontal stubs from bus to each destination job, with arrowhead.
+			for _, y := range dstY {
+				wf(`  <line x1="%d" y1="%d" x2="%d" y2="%d" stroke="%s" stroke-width="2"/>`,
+					midX, y, x2-7, y, connStroke)
+				wf(`  <polygon points="%d,%d %d,%d %d,%d" fill="%s"/>`,
+					x2-7, y-4, x2, y, x2-7, y+4, connStroke)
 			}
-			// Arrowhead at the destination.
-			wf(`  <polygon points="%d,%d %d,%d %d,%d" fill="%s"/>`,
-				x2-7, y2-4, x2, y2, x2-7, y2+4, connStroke)
 		}
 	}
 
@@ -271,6 +367,7 @@ func pipelineSVG(p *model.Pipeline) string {
 		{"#fc6d26", "manual"},
 		{"#6b4fbb", "trigger"},
 		{"#fca326", "delayed"},
+		{"#d9534f", "on_failure"},
 	}
 	const legendItemW = 82
 	legendY := topPad + labelH + maxColH + botPad/2
@@ -293,7 +390,7 @@ func pipelineSVG(p *model.Pipeline) string {
 func drawChipIcon(sb *strings.Builder, job model.Job, cx, cy int) {
 	if job.Trigger != nil {
 		// Right-pointing chevron for trigger jobs.
-		fmt.Fprintf(sb, "  <polyline points=\"%d,%d %d,%d %d,%d\" "+
+		fmt.Fprintf(sb, "    <polyline points=\"%d,%d %d,%d %d,%d\" "+
 			"stroke=\"#fff\" stroke-width=\"1.5\" fill=\"none\" stroke-linecap=\"round\" stroke-linejoin=\"round\"/>\n",
 			cx-3, cy-3, cx+3, cy, cx-3, cy+3)
 		return
@@ -301,18 +398,24 @@ func drawChipIcon(sb *strings.Builder, job model.Job, cx, cy int) {
 	switch job.When {
 	case "manual":
 		// Filled play triangle.
-		fmt.Fprintf(sb, "  <polygon points=\"%d,%d %d,%d %d,%d\" fill=\"#fff\"/>\n",
+		fmt.Fprintf(sb, "    <polygon points=\"%d,%d %d,%d %d,%d\" fill=\"#fff\"/>\n",
 			cx-3, cy-4, cx+5, cy, cx-3, cy+4)
 	case "delayed":
-		// Clock hands: vertical + horizontal.
-		fmt.Fprintf(sb, "  <circle cx=\"%d\" cy=\"%d\" r=\"5\" stroke=\"#fff\" stroke-width=\"1.2\" fill=\"none\"/>\n", cx, cy)
-		fmt.Fprintf(sb, "  <line x1=\"%d\" y1=\"%d\" x2=\"%d\" y2=\"%d\" stroke=\"#fff\" stroke-width=\"1.2\" stroke-linecap=\"round\"/>\n",
+		// Clock: circle + hands.
+		fmt.Fprintf(sb, "    <circle cx=\"%d\" cy=\"%d\" r=\"5\" stroke=\"#fff\" stroke-width=\"1.2\" fill=\"none\"/>\n", cx, cy)
+		fmt.Fprintf(sb, "    <line x1=\"%d\" y1=\"%d\" x2=\"%d\" y2=\"%d\" stroke=\"#fff\" stroke-width=\"1.2\" stroke-linecap=\"round\"/>\n",
 			cx, cy, cx, cy-3)
-		fmt.Fprintf(sb, "  <line x1=\"%d\" y1=\"%d\" x2=\"%d\" y2=\"%d\" stroke=\"#fff\" stroke-width=\"1.2\" stroke-linecap=\"round\"/>\n",
+		fmt.Fprintf(sb, "    <line x1=\"%d\" y1=\"%d\" x2=\"%d\" y2=\"%d\" stroke=\"#fff\" stroke-width=\"1.2\" stroke-linecap=\"round\"/>\n",
 			cx, cy, cx+2, cy+1)
+	case "on_failure":
+		// X mark for failure-path jobs.
+		fmt.Fprintf(sb, "    <line x1=\"%d\" y1=\"%d\" x2=\"%d\" y2=\"%d\" stroke=\"#fff\" stroke-width=\"1.5\" stroke-linecap=\"round\"/>\n",
+			cx-3, cy-3, cx+3, cy+3)
+		fmt.Fprintf(sb, "    <line x1=\"%d\" y1=\"%d\" x2=\"%d\" y2=\"%d\" stroke=\"#fff\" stroke-width=\"1.5\" stroke-linecap=\"round\"/>\n",
+			cx+3, cy-3, cx-3, cy+3)
 	default:
-		// Regular job: small white checkmark outline.
-		fmt.Fprintf(sb, "  <polyline points=\"%d,%d %d,%d %d,%d\" "+
+		// Regular job: small white checkmark.
+		fmt.Fprintf(sb, "    <polyline points=\"%d,%d %d,%d %d,%d\" "+
 			"stroke=\"#fff\" stroke-width=\"1.5\" fill=\"none\" stroke-linecap=\"round\" stroke-linejoin=\"round\"/>\n",
 			cx-3, cy, cx-1, cy+3, cx+4, cy-3)
 	}
@@ -327,10 +430,25 @@ func chipColor(job model.Job) string {
 		return "#fc6d26"
 	case "delayed":
 		return "#fca326"
+	case "on_failure":
+		return "#d9534f"
 	}
 	return "#1f75cb"
 }
 
+// imageString extracts the image name from a job Image field (string or map form).
+func imageString(img any) string {
+	switch v := img.(type) {
+	case string:
+		return v
+	case map[string]any:
+		if name, ok := v["name"].(string); ok {
+			return name
+		}
+	}
+	return ""
+}
+
 func svgEsc(s string) string {
 	s = strings.ReplaceAll(s, "&", "&amp;")
 	s = strings.ReplaceAll(s, "<", "&lt;")
@@ -356,3 +474,179 @@ func svgEmpty() string {
 			`</svg>`,
 		w, h, w, h, w/2, h/2)
 }
+
+// htmlPage wraps an SVG pipeline graph in a self-contained HTML page with
+// mouse pan/zoom and a job-detail sidebar that appears on chip click.
+func htmlPage(svgContent string) string {
+	var sb strings.Builder
+	sb.WriteString(`<!DOCTYPE html>
+<html lang="en">
+<head>
+<meta charset="UTF-8">
+<meta name="viewport" content="width=device-width,initial-scale=1">
+<title>Pipeline Graph</title>
+<style>
+*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
+body {
+  font-family: 'Segoe UI', Arial, sans-serif;
+  background: #f5f5f5;
+  display: flex;
+  height: 100vh;
+  overflow: hidden;
+}
+#sidebar {
+  width: 260px;
+  flex-shrink: 0;
+  background: #fff;
+  border-right: 1px solid #e0e0e0;
+  display: none;
+  flex-direction: column;
+  overflow-y: auto;
+}
+#sidebar.open { display: flex; }
+#sidebar-header {
+  display: flex;
+  align-items: center;
+  justify-content: space-between;
+  padding: .6rem .8rem;
+  border-bottom: 1px solid #e0e0e0;
+  background: #fafafa;
+  flex-shrink: 0;
+}
+#sidebar-header h3 {
+  font-size: .9rem;
+  color: #303030;
+  word-break: break-all;
+}
+#close-btn {
+  background: none;
+  border: none;
+  cursor: pointer;
+  font-size: 1rem;
+  color: #868686;
+  padding: .2rem .4rem;
+  margin-left: .4rem;
+  flex-shrink: 0;
+}
+#close-btn:hover { color: #303030; }
+#sidebar-body { padding: .8rem; flex: 1; }
+#sidebar-body pre {
+  font-size: .82rem;
+  color: #555;
+  white-space: pre-wrap;
+  line-height: 1.6;
+}
+#viewport {
+  flex: 1;
+  overflow: hidden;
+  cursor: grab;
+  position: relative;
+  background: #f5f5f5;
+}
+#viewport.dragging { cursor: grabbing; }
+#svg-wrap {
+  display: inline-block;
+  transform-origin: 0 0;
+  padding: 20px;
+}
+g[data-job] { cursor: pointer; }
+g[data-job]:hover > rect { stroke: #1f75cb; stroke-width: 2; }
+</style>
+</head>
+<body>
+<div id="sidebar">
+  <div id="sidebar-header">
+    <h3 id="sidebar-title">Job details</h3>
+    <button id="close-btn" title="Close">&#x2715;</button>
+  </div>
+  <div id="sidebar-body">
+    <pre id="sidebar-details"></pre>
+  </div>
+</div>
+<div id="viewport">
+  <div id="svg-wrap">
+`)
+	sb.WriteString(svgContent)
+	sb.WriteString(`
+  </div>
+</div>
+<script>
+(function() {
+  'use strict';
+  var vp = document.getElementById('viewport');
+  var wrap = document.getElementById('svg-wrap');
+  var sidebar = document.getElementById('sidebar');
+  var titleEl = document.getElementById('sidebar-title');
+  var detailsEl = document.getElementById('sidebar-details');
+  var tx = 0, ty = 0, scale = 1;
+
+  function applyTransform() {
+    wrap.style.transform = 'translate(' + tx + 'px,' + ty + 'px) scale(' + scale + ')';
+  }
+
+  // Zoom toward the cursor position.
+  vp.addEventListener('wheel', function(e) {
+    e.preventDefault();
+    var factor = e.deltaY < 0 ? 1.1 : 1 / 1.1;
+    var r = vp.getBoundingClientRect();
+    var mx = e.clientX - r.left;
+    var my = e.clientY - r.top;
+    tx = mx - (mx - tx) * factor;
+    ty = my - (my - ty) * factor;
+    scale *= factor;
+    applyTransform();
+  }, { passive: false });
+
+  // Drag to pan (skip if clicking on a job chip).
+  var dragging = false, ox = 0, oy = 0;
+  vp.addEventListener('mousedown', function(e) {
+    if (e.target.closest('g[data-job]')) return;
+    dragging = true;
+    ox = e.clientX - tx;
+    oy = e.clientY - ty;
+    vp.classList.add('dragging');
+  });
+  window.addEventListener('mousemove', function(e) {
+    if (!dragging) return;
+    tx = e.clientX - ox;
+    ty = e.clientY - oy;
+    applyTransform();
+  });
+  window.addEventListener('mouseup', function() {
+    dragging = false;
+    vp.classList.remove('dragging');
+  });
+
+  // Double-click on the background to reset the view.
+  vp.addEventListener('dblclick', function(e) {
+    if (e.target.closest('g[data-job]')) return;
+    tx = 0; ty = 0; scale = 1;
+    applyTransform();
+  });
+
+  // Click a job chip to show its details in the sidebar.
+  document.addEventListener('click', function(e) {
+    var g = e.target.closest('g[data-job]');
+    if (!g) return;
+    var jobName = g.dataset.job;
+    var descEl = g.querySelector('desc');
+    var desc = descEl ? descEl.textContent : '';
+    titleEl.textContent = jobName;
+    detailsEl.textContent = desc;
+    sidebar.classList.add('open');
+  });
+
+  // Close the sidebar.
+  document.getElementById('close-btn').addEventListener('click', function() {
+    sidebar.classList.remove('open');
+  });
+  document.addEventListener('keydown', function(e) {
+    if (e.key === 'Escape') sidebar.classList.remove('open');
+  });
+})();
+</script>
+</body>
+</html>
+`)
+	return sb.String()
+}

internal/graph/render_test.go

@@ -5,6 +5,7 @@ import (
 	"strings"
 	"testing"
 
+	"git.k3nny.fr/glint/internal/cicontext"
 	"git.k3nny.fr/glint/internal/model"
 )
 
@@ -59,9 +60,20 @@ func TestChipColor(t *testing.T) {
 	if chipColor(model.Job{Trigger: "x"}) != "#6b4fbb" { t.Error("trigger color") }
 	if chipColor(model.Job{When: "manual"}) != "#fc6d26" { t.Error("manual color") }
 	if chipColor(model.Job{When: "delayed"}) != "#fca326" { t.Error("delayed color") }
+	if chipColor(model.Job{When: "on_failure"}) != "#d9534f" { t.Error("on_failure color") }
 	if chipColor(model.Job{}) != "#1f75cb" { t.Error("regular color") }
 }
 
+// ── imageString ───────────────────────────────────────────────────────────────
+
+func TestImageString(t *testing.T) {
+	if imageString("alpine") != "alpine" { t.Error("string form") }
+	if imageString(map[string]any{"name": "golang:1.21"}) != "golang:1.21" { t.Error("map form") }
+	if imageString(map[string]any{"other": "x"}) != "" { t.Error("map without name key") }
+	if imageString(nil) != "" { t.Error("nil") }
+	if imageString(42) != "" { t.Error("unexpected type") }
+}
+
 // ── drawChipIcon ──────────────────────────────────────────────────────────────
 
 func TestDrawChipIcon(t *testing.T) {
@@ -72,6 +84,7 @@ func TestDrawChipIcon(t *testing.T) {
 		{model.Job{Trigger: "x"}, "<polyline"},
 		{model.Job{When: "manual"}, "<polygon"},
 		{model.Job{When: "delayed"}, "<circle"},
+		{model.Job{When: "on_failure"}, "<line"},
 		{model.Job{}, "<polyline"},
 	}
 	for _, tc := range cases {
@@ -86,7 +99,7 @@ func TestDrawChipIcon(t *testing.T) {
 // ── pipelineSVG ───────────────────────────────────────────────────────────────
 
 func TestPipelineSVG_Empty(t *testing.T) {
-	svg := pipelineSVG(&model.Pipeline{})
+	svg := pipelineSVG(&model.Pipeline{}, nil)
 	if !strings.Contains(svg, "no jobs defined") {
 		t.Errorf("expected 'no jobs defined', got:\n%s", svg)
 	}
@@ -100,13 +113,32 @@ func TestPipelineSVG_ClassicMode(t *testing.T) {
 			"test-job":  {Name: "test-job", Stage: "test"},
 		},
 	}
-	svg := pipelineSVG(p)
+	svg := pipelineSVG(p, nil)
 	if !strings.Contains(svg, "<svg") { t.Error("expected <svg") }
 	if !strings.Contains(svg, "build-job") { t.Error("expected build-job") }
 	if !strings.Contains(svg, "test-job") { t.Error("expected test-job") }
-	// Classic mode connector
-	if !strings.Contains(svg, "<polyline") && !strings.Contains(svg, "<line") {
-		t.Error("expected connector in classic mode")
+	// Classic mode bus-bar draws <line> elements for connectors
+	if !strings.Contains(svg, "<line") {
+		t.Error("expected <line> connector in classic mode")
+	}
+}
+
+func TestPipelineSVG_ClassicMode_MultiJob(t *testing.T) {
+	// Two source jobs, two destination jobs → bus-bar with vertical segment
+	p := &model.Pipeline{
+		Stages: []string{"build", "test"},
+		Jobs: map[string]model.Job{
+			"build-a": {Name: "build-a", Stage: "build"},
+			"build-b": {Name: "build-b", Stage: "build"},
+			"test-a":  {Name: "test-a", Stage: "test"},
+			"test-b":  {Name: "test-b", Stage: "test"},
+		},
+	}
+	svg := pipelineSVG(p, nil)
+	// Bus bar: horizontal stubs from each src + dst, plus a vertical bus line
+	// and an arrowhead polygon for each dst job.
+	if !strings.Contains(svg, "<polygon") {
+		t.Error("expected arrowhead <polygon> in multi-job classic mode")
 	}
 }
 
@@ -118,7 +150,7 @@ func TestPipelineSVG_DAGMode(t *testing.T) {
 			"test-job":  {Name: "test-job", Stage: "test", Needs: []any{"build-job"}},
 		},
 	}
-	svg := pipelineSVG(p)
+	svg := pipelineSVG(p, nil)
 	// DAG mode draws <path> bezier curves
 	if !strings.Contains(svg, "<path") {
 		t.Error("expected <path> connector in DAG mode")
@@ -126,7 +158,7 @@ func TestPipelineSVG_DAGMode(t *testing.T) {
 }
 
 func TestPipelineSVG_DAGMode_StraightConnector(t *testing.T) {
-	// Two stages at same height → straight <line> connector in classic mode
+	// Two stages at same height → straight connector in classic mode
 	p := &model.Pipeline{
 		Stages: []string{"a", "b"},
 		Jobs: map[string]model.Job{
@@ -134,7 +166,7 @@ func TestPipelineSVG_DAGMode_StraightConnector(t *testing.T) {
 			"j2": {Name: "j2", Stage: "b"},
 		},
 	}
-	svg := pipelineSVG(p)
+	svg := pipelineSVG(p, nil)
 	if !strings.Contains(svg, "<svg") { t.Error("expected <svg") }
 }
 
@@ -142,16 +174,21 @@ func TestPipelineSVG_AllJobTypes(t *testing.T) {
 	p := &model.Pipeline{
 		Stages: []string{"deploy"},
 		Jobs: map[string]model.Job{
-			"manual-job":  {Name: "manual-job", Stage: "deploy", When: "manual"},
-			"delayed-job": {Name: "delayed-job", Stage: "deploy", When: "delayed"},
-			"trigger-job": {Name: "trigger-job", Stage: "deploy", Trigger: "other/project"},
+			"manual-job":     {Name: "manual-job", Stage: "deploy", When: "manual"},
+			"delayed-job":    {Name: "delayed-job", Stage: "deploy", When: "delayed"},
+			"trigger-job":    {Name: "trigger-job", Stage: "deploy", Trigger: "other/project"},
+			"onfailure-job":  {Name: "onfailure-job", Stage: "deploy", When: "on_failure"},
 		},
 	}
-	svg := pipelineSVG(p)
-	// Each type has its own color in the SVG
+	svg := pipelineSVG(p, nil)
 	if !strings.Contains(svg, "#fc6d26") { t.Error("expected manual color") }
 	if !strings.Contains(svg, "#fca326") { t.Error("expected delayed color") }
 	if !strings.Contains(svg, "#6b4fbb") { t.Error("expected trigger color") }
+	if !strings.Contains(svg, "#d9534f") { t.Error("expected on_failure color") }
+	// on_failure chips have a dashed border
+	if !strings.Contains(svg, `stroke-dasharray="4,3"`) {
+		t.Error("expected dashed border on on_failure chip")
+	}
 }
 
 func TestPipelineSVG_JobNoStage(t *testing.T) {
@@ -160,7 +197,7 @@ func TestPipelineSVG_JobNoStage(t *testing.T) {
 			"myjob": {Name: "myjob"},
 		},
 	}
-	svg := pipelineSVG(p)
+	svg := pipelineSVG(p, nil)
 	if !strings.Contains(svg, "myjob") { t.Error("expected myjob") }
 }
 
@@ -172,10 +209,85 @@ func TestPipelineSVG_CrossPipelineNeed(t *testing.T) {
 				Needs: []any{map[string]any{"pipeline": "other", "job": "x"}}},
 		},
 	}
-	svg := pipelineSVG(p)
+	svg := pipelineSVG(p, nil)
 	if !strings.Contains(svg, "<svg") { t.Error("expected <svg") }
 }
 
+func TestPipelineSVG_Tooltip(t *testing.T) {
+	p := &model.Pipeline{
+		Stages: []string{"build"},
+		Jobs: map[string]model.Job{
+			"build-job": {
+				Name:  "build-job",
+				Stage: "build",
+				When:  "on_success",
+				Image: "golang:1.21",
+				Needs: []any{"prep-job"},
+			},
+		},
+	}
+	svg := pipelineSVG(p, nil)
+	// Tooltip <title> and <desc> should appear inside the <g data-job> wrapper
+	if !strings.Contains(svg, `<title>build-job</title>`) {
+		t.Error("expected <title>build-job</title>")
+	}
+	if !strings.Contains(svg, `<desc>`) {
+		t.Error("expected <desc> element")
+	}
+	if !strings.Contains(svg, "image: golang:1.21") {
+		t.Error("expected image in desc")
+	}
+	if !strings.Contains(svg, "needs: prep-job") {
+		t.Error("expected needs in desc")
+	}
+	if !strings.Contains(svg, `data-job="build-job"`) {
+		t.Error("expected data-job attribute")
+	}
+}
+
+func TestPipelineSVG_SkippedJob(t *testing.T) {
+	// A job with rules that never match in the given context should be greyed out.
+	p := &model.Pipeline{
+		Stages: []string{"deploy"},
+		Jobs: map[string]model.Job{
+			"deploy-job": {
+				Name:   "deploy-job",
+				Stage:  "deploy",
+				Script: []any{"deploy.sh"},
+				Rules: []model.Rule{
+					{If: `$CI_COMMIT_TAG != ""`, When: "on_success"},
+				},
+			},
+		},
+	}
+	// Branch context: CI_COMMIT_TAG is empty → rule doesn't match → job skipped
+	ctx := cicontext.New("main", "", "push", nil)
+	svg := pipelineSVG(p, ctx)
+
+	// Skipped jobs use grey (#868686) instead of the regular blue
+	if !strings.Contains(svg, `fill="#868686"`) {
+		t.Error("expected grey fill for skipped job circle")
+	}
+	// Skipped state should appear in the tooltip desc
+	if !strings.Contains(svg, "state: skipped") {
+		t.Error("expected 'state: skipped' in tooltip desc")
+	}
+}
+
+func TestPipelineSVG_ContextNil(t *testing.T) {
+	// nil context → no skipped jobs, regular colors
+	p := &model.Pipeline{
+		Stages: []string{"build"},
+		Jobs: map[string]model.Job{
+			"j": {Name: "j", Stage: "build"},
+		},
+	}
+	svg := pipelineSVG(p, nil)
+	if !strings.Contains(svg, `fill="#1f75cb"`) {
+		t.Error("expected regular blue fill with nil context")
+	}
+}
+
 // ── RenderPipeline ────────────────────────────────────────────────────────────
 
 func TestRenderPipeline(t *testing.T) {
@@ -186,7 +298,7 @@ func TestRenderPipeline(t *testing.T) {
 		},
 	}
 	dir := t.TempDir()
-	path, err := RenderPipeline(p, dir)
+	path, err := RenderPipeline(p, dir, nil)
 	if err != nil {
 		t.Fatalf("RenderPipeline: %v", err)
 	}
@@ -202,7 +314,7 @@ func TestRenderPipeline_InvalidDir(t *testing.T) {
 	if err := os.WriteFile(filePath, []byte("x"), 0o644); err != nil {
 		t.Fatal(err)
 	}
-	_, err := RenderPipeline(&model.Pipeline{}, filePath+"/nested")
+	_, err := RenderPipeline(&model.Pipeline{}, filePath+"/nested", nil)
 	if err == nil {
 		t.Error("expected error writing to path under a file")
 	}
@@ -222,7 +334,7 @@ func TestRenderPipeline_WriteFileFails(t *testing.T) {
 		Stages: []string{"build"},
 		Jobs:   map[string]model.Job{"j": {Name: "j", Stage: "build"}},
 	}
-	_, err := RenderPipeline(p, dir)
+	_, err := RenderPipeline(p, dir, nil)
 	if err == nil {
 		t.Error("expected error when writing SVG to read-only directory")
 	}
@@ -241,7 +353,7 @@ func TestRenderPipeline_SVGFallback(t *testing.T) {
 		Jobs:   map[string]model.Job{"j": {Name: "j", Stage: "build"}},
 	}
 	dir := t.TempDir()
-	path, err := RenderPipeline(p, dir)
+	path, err := RenderPipeline(p, dir, nil)
 	if err != nil {
 		t.Fatalf("RenderPipeline: %v", err)
 	}
@@ -264,7 +376,7 @@ func TestConvertToPNG_NoConverter(t *testing.T) {
 
 func TestConvertToPNG_FakeConverter(t *testing.T) {
 	// Install a fake rsvg-convert that just creates the output file and exits 0.
-	// This exercises the "return true" branch (line 72) and os.Remove in RenderPipeline.
+	// This exercises the "return true" branch and os.Remove in RenderPipeline.
 	binDir := t.TempDir()
 	script := "#!/bin/sh\n# rsvg-convert --output <out> <in>\ncp \"$3\" \"$2\"\n"
 	fakeBin := binDir + "/rsvg-convert"
@@ -303,7 +415,7 @@ func TestRenderPipeline_PNGConversion(t *testing.T) {
 		Jobs:   map[string]model.Job{"j": {Name: "j", Stage: "build"}},
 	}
 	dir := t.TempDir()
-	path, err := RenderPipeline(p, dir)
+	path, err := RenderPipeline(p, dir, nil)
 	if err != nil {
 		t.Fatalf("RenderPipeline: %v", err)
 	}
@@ -315,7 +427,7 @@ func TestRenderPipeline_PNGConversion(t *testing.T) {
 // ── pipelineSVG coverage gaps ─────────────────────────────────────────────────
 
 func TestPipelineSVG_LShapedElbow(t *testing.T) {
-	// Classic mode with unequal stage sizes → different column heights → L-shaped elbow
+	// Classic mode with unequal stage sizes → vertical bus bar required
 	p := &model.Pipeline{
 		Stages: []string{"build", "test"},
 		Jobs: map[string]model.Job{
@@ -324,9 +436,10 @@ func TestPipelineSVG_LShapedElbow(t *testing.T) {
 			"j3": {Name: "j3", Stage: "test"},
 		},
 	}
-	svg := pipelineSVG(p)
-	if !strings.Contains(svg, "<polyline") {
-		t.Error("expected <polyline> for L-shaped elbow connector")
+	svg := pipelineSVG(p, nil)
+	// The bus bar is a <line>; arrowheads are <polygon>
+	if !strings.Contains(svg, "<polygon") {
+		t.Error("expected <polygon> arrowhead in bus-bar connector")
 	}
 }
 
@@ -339,9 +452,82 @@ func TestPipelineSVG_DAGNeedNotInPositionMap(t *testing.T) {
 			".hidden-template": {Name: ".hidden-template", Stage: "build"},
 		},
 	}
-	svg := pipelineSVG(p)
+	svg := pipelineSVG(p, nil)
 	// Should render without panic; .hidden-template is not visible so no connector drawn.
 	if !strings.Contains(svg, "<svg") {
 		t.Error("expected valid SVG output")
 	}
 }
+
+// ── RenderHTML ────────────────────────────────────────────────────────────────
+
+func TestRenderHTML(t *testing.T) {
+	p := &model.Pipeline{
+		Stages: []string{"build"},
+		Jobs: map[string]model.Job{
+			"build-job": {Name: "build-job", Stage: "build"},
+		},
+	}
+	dir := t.TempDir()
+	path, err := RenderHTML(p, dir, nil)
+	if err != nil {
+		t.Fatalf("RenderHTML: %v", err)
+	}
+	if !strings.HasSuffix(path, ".html") {
+		t.Errorf("expected .html output, got %q", path)
+	}
+	data, err := os.ReadFile(path)
+	if err != nil {
+		t.Fatalf("reading output: %v", err)
+	}
+	html := string(data)
+	if !strings.Contains(html, "<!DOCTYPE html>") { t.Error("expected DOCTYPE") }
+	if !strings.Contains(html, "<svg") { t.Error("expected embedded <svg") }
+	if !strings.Contains(html, "build-job") { t.Error("expected job name in HTML") }
+	if !strings.Contains(html, "applyTransform") { t.Error("expected JS pan/zoom function") }
+	if !strings.Contains(html, "sidebar") { t.Error("expected sidebar element") }
+}
+
+func TestRenderHTML_InvalidDir(t *testing.T) {
+	dir := t.TempDir()
+	filePath := dir + "/notadir"
+	if err := os.WriteFile(filePath, []byte("x"), 0o644); err != nil {
+		t.Fatal(err)
+	}
+	_, err := RenderHTML(&model.Pipeline{}, filePath+"/nested", nil)
+	if err == nil {
+		t.Error("expected error writing to path under a file")
+	}
+}
+
+func TestRenderHTML_WriteFileFails(t *testing.T) {
+	if os.Getuid() == 0 {
+		t.Skip("skipping as root — file permissions don't apply")
+	}
+	dir := t.TempDir()
+	if err := os.Chmod(dir, 0o555); err != nil {
+		t.Fatal(err)
+	}
+	t.Cleanup(func() { os.Chmod(dir, 0o755) })
+
+	p := &model.Pipeline{
+		Stages: []string{"build"},
+		Jobs:   map[string]model.Job{"j": {Name: "j", Stage: "build"}},
+	}
+	_, err := RenderHTML(p, dir, nil)
+	if err == nil {
+		t.Error("expected error when writing HTML to read-only directory")
+	}
+}
+
+// ── htmlPage ──────────────────────────────────────────────────────────────────
+
+func TestHtmlPage(t *testing.T) {
+	svgContent := `<svg xmlns="http://www.w3.org/2000/svg" width="100" height="50"><rect/></svg>`
+	html := htmlPage(svgContent)
+	if !strings.Contains(html, "<!DOCTYPE html>") { t.Error("expected DOCTYPE") }
+	if !strings.Contains(html, svgContent) { t.Error("expected SVG embedded in HTML") }
+	if !strings.Contains(html, "id=\"viewport\"") { t.Error("expected viewport element") }
+	if !strings.Contains(html, "id=\"sidebar\"") { t.Error("expected sidebar element") }
+	if !strings.Contains(html, "applyTransform") { t.Error("expected JS transform function") }
+}