# Extension Plan: Canva Interop (Import MVP Projects into Canva)

## CI-0. Interop requirements lock
- CI-0.1 Define “Canva-compatible export” modes
  - CI-0.1.1 Mode A (manual): user downloads `.pptx` / `.pdf` and uploads to Canva
  - CI-0.1.2 Mode B (direct): “Send to Canva” via Canva Connect Design Import API ([canva.dev](https://www.canva.dev/docs/connect/api-reference/design-imports/))
- CI-0.2 Set primary export target
  - CI-0.2.1 Primary: **PPTX**
  - CI-0.2.2 Secondary: **PDF**
- CI-0.3 Define supported MVP element set for “editable-in-Canva” guarantee
  - CI-0.3.1 Text (single box, no path text)
  - CI-0.3.2 Shapes (rect/roundrect/ellipse/line)
  - CI-0.3.3 Images (placed + cropped)
  - CI-0.3.4 Groups (flatten to children for export unless grouping supported)
  - CI-0.3.5 Background (solid color or image)
- CI-0.4 Define “flattening policy” (auto-rasterize unsupported features)
  - CI-0.4.1 Effects: blur, complex shadows, blend modes → rasterize element
  - CI-0.4.2 Gradients/pattern fills → rasterize element (unless verified editable)
  - CI-0.4.3 Masks/frames → rasterize masked result
- CI-0.5 Create a fixed “Canva Import Compatibility Test Pack” document
  - CI-0.5.1 1 page: text styling matrix
  - CI-0.5.2 1 page: shapes matrix
  - CI-0.5.3 1 page: images + crop matrix
  - CI-0.5.4 1 page: layering + transparency matrix
  - CI-0.5.5 1 page: mixed stress test (50+ objects)

## CI-1. “Export for Canva” UX + preflight
- CI-1.1 Add Export entry point
  - CI-1.1.1 Top bar: **Export → Export for Canva**
  - CI-1.1.2 Options: **PPTX (recommended)**, **PDF**
- CI-1.2 Add export settings panel
  - CI-1.2.1 Pages: current page / all pages
  - CI-1.2.2 Scale: 1x / 2x
  - CI-1.2.3 Text handling: “Keep text editable” (default on)
  - CI-1.2.4 Fallback: “Rasterize text” (toggle)
  - CI-1.2.5 Flattening: “Auto-flatten unsupported features” (default on)
  - CI-1.2.6 Font substitution policy: “Use Canva-safe fonts” (toggle)
- CI-1.3 Implement export preflight scanner (runs before file generation)
  - CI-1.3.1 Traverse document model and collect unsupported features, fonts, images, counts
  - CI-1.3.2 Preflight report: editable list, flattened list (ids), layout warnings
  - CI-1.3.3 Controls: Continue / Cancel / “Export with more flattening”
- CI-1.4 Export delivery options
  - CI-1.4.1 Download file
  - CI-1.4.2 (Optional, if CI-5 enabled) Send to Canva

## CI-2. PPTX export engine (primary)
- CI-2.1 Package `packages/export-pptx`
  - `exportPptx(doc, options) -> Uint8Array`
  - `preflightPptx(doc) -> Report`
  - `mapFonts(fonts) -> FontMap`
- CI-2.2 Geometry/units
  - Choose DPI (e.g., 96); helpers `pxToIn/pxToPt/pxToEmu`
  - Slide sizing: presets → layout; custom sizes supported
  - Rotation around center; bbox matches selection
- CI-2.3 Element mapping
  - Background: solid or image as base layer
  - Shapes: rect/roundrect/ellipse/line; stroke/fill; opacity else flatten
  - Text: textbox, map font/size/color/align/lineHeight; warn letterSpacing; rotation ok
  - Images: embed bytes; native crop if supported else bake; opacity else bake
  - Groups: flatten to children with composed transforms
  - Z-order: ascending z; background first
- CI-2.4 Font strategy
  - Canva-safe font list; fallback map; warn missing fonts; option to rasterize all text
- CI-2.5 QA
  - Unit tests: conversions, transforms, z-order
  - Golden exports from CI-0.5 pack (property assertions)
  - Manual Canva import checklist; target ≥95% editable (excluding intentional flatten)

## CI-3. PDF export engine (secondary)
- CI-3.1 Package `packages/export-pdf`
  - `exportPdf(doc, options) -> Uint8Array`
  - `preflightPdf(doc) -> Report`
- CI-3.2 Rendering strategies (flagged)
  - Vector-first: draw shapes/text/images directly
  - Browser-rendered: headless print of HTML/SVG/canvas
- CI-3.3 Multi-page sizing: per-page PDFs, exact dims, optional bleed/trim
- CI-3.4 Canva editability checklist: keep text vector, flatten risky constructs, warn
- CI-3.5 QA: run CI-0.5 pack; verify editability on Canva import

## CI-4. Compatibility mode + mapping rules
- CI-4.1 Document-level “Canva Compatibility Mode”
  - Disable/flag unsupported effects; enforce safe fonts/solid fills; auto-flatten
- CI-4.2 Element-level rules (must have tests)
  - Text: single-style runs; letter spacing/shadows flatten or warn
  - Shapes: solid fills; normalize unsupported strokes; gradients flatten
  - Images: native crop or bake; masks flatten
  - Transforms: rotation ok; skew flatten
  - Blending: per-element opacity if supported; blend modes flatten
- CI-4.3 Import fidelity score
  - Score from preflight (% editable, % flattened, font subs); gate releases on threshold

## CI-5. Direct “Send to Canva” (optional)
- CI-5.1 Canva app + OAuth (scope `design:content:write`)
- CI-5.2 Backend endpoints: `POST /canva/import/start`, `GET /canva/import/status`
- CI-5.3 Call Canva Design Import API (`POST /rest/v1/imports`, job polling)
- CI-5.4 Frontend flow: Export modal “Send to Canva”, progress states, “Open in Canva”, persist doc↔design id

## CI-6. Release checklist (interop)
- Docs: best-practices + supported vs flattened list
- Regression: CI-0.5 pack exports on every release; invariants checked
- Telemetry: export success/fail by format, preflight warnings, (if CI-5) import job latency/success