// Phase 6.5 T6c — `.canva-handoff.md` artifact builder.
//
// Emits a self-contained markdown file with three sections:
//   1. Human-readable summary (artboard count, fidelity caveats)
//   2. Drag-drop instructions for the universal Canva web path
//   3. Fenced text-block prompt ready for the user's Canva MCP / agentic tool
//
// The prompt block is the load-bearing piece — anyone with a Canva MCP
// configured in Claude Code / Cursor / equivalent can paste it and let the
// MCP handle auth + import. Maude never touches credentials.

export interface HandoffSummary {
  /** Filename of the .pptx that ships next to this markdown (e.g. `home.pptx`). */
  pptxFilename: string;
  /** Absolute path to the .pptx after the user unzips. Resolved at render time. */
  absolutePath: string;
  /** Canvas slug — used as the Canva design title and as the prompt's anchor. */
  canvasSlug: string;
  /** Total artboard count (= PPTX slide count = expected Canva page count). */
  artboardCount: number;
  /** Optional list of artboard titles, in render order. */
  artboardTitles?: string[];
}

const CAVEATS = `
- **Fonts:** if your Canva Brand Kit doesn't include the source fonts, Canva substitutes its defaults. Text remains editable.
- **Gradients:** CSS gradients translate to native PPT gradients. Multi-stop fidelity is approximate.
- **Shadows, blend modes:** advanced effects rasterize on import.
- **Layouts:** flex / grid get flattened to absolute coordinates at export-time viewport (1440 × declared artboard height).
`.trim();

export function buildHandoffMarkdown(s: HandoffSummary): string {
  const plural = s.artboardCount === 1 ? 'artboard' : 'artboards';
  const titles = s.artboardTitles?.length
    ? s.artboardTitles.map((t, i) => `${i + 1}. ${t}`).join('\n')
    : `${s.artboardCount} ${plural}`;

  return `# Canva handoff — ${s.canvasSlug}

Editable handoff bundle exported from Maude. The companion file \`${s.pptxFilename}\` is a native PowerPoint document — Canva imports it as editable text, shapes, and images, **not** a flat raster.

## What's inside

- **${s.artboardCount}** artboard${s.artboardCount === 1 ? '' : 's'} → ${s.artboardCount} Canva page${s.artboardCount === 1 ? '' : 's'} on import.
${titles}

## Option A — drag-drop (works on any Canva tier)

1. Open https://www.canva.com in your browser.
2. Drag \`${s.pptxFilename}\` from this folder into the Canva home screen, or use **Create a design → Upload media → Import file**.
3. Canva opens the imported design. Text, shapes, and images are individually selectable and editable.

## Option B — automate via your Canva MCP

If you have a Canva MCP server configured in Claude Code / Cursor / Goose / any agentic tool, paste the prompt below into a fresh chat:

\`\`\`text
Use my Canva MCP to import the PowerPoint file at the path below into a new Canva design titled "${s.canvasSlug}". Preserve text editability, shape fills and strokes, image swappability, and the artboard-to-page mapping (one PPTX slide = one Canva page). After the import job completes, return the Canva design URL.

File path: ${s.absolutePath}
Slides expected: ${s.artboardCount}
\`\`\`

Maude doesn't see your Canva credentials — your MCP handles auth and the import call itself.

## Fidelity caveats

${CAVEATS}

---

Generated by [Maude](https://github.com/1aGh/maude).
`;
}