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node
typescript
hono
htmx
atproto
docs: add design doc for ATB-59 admin theme token editor
Covers file structure (extract to admin-themes.tsx), editor page layout,
HTMX preview endpoint, save/reset flows, error handling, and test plan.
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docs/plans/2026-03-03-atb59-theme-token-editor-design.md
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docs/plans/2026-03-03-atb59-theme-token-editor-design.md
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# ATB-59 Design: Admin Theme Token Editor with Live Preview
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**Linear:** ATB-59
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**Date:** 2026-03-03
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**Status:** Approved — ready for implementation
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**Depends on:** ATB-57 (Done), ATB-58 (Done)
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---
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## Overview
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Build the theme token editor page at `GET /admin/themes/:rkey` and a HTMX-driven preview endpoint that shows a live sample forum page as token values change. The editor lets admins customize all 46 design tokens through grouped form controls, save to the PDS via the AppView, and reset to any built-in preset.
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---
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## Architecture
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### File Structure Changes
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**New file:** `apps/web/src/routes/admin-themes.tsx`
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Extract all existing theme-admin handlers from `admin.tsx` into a dedicated module and add the new editor and preview handlers there.
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| Route | Handler Location | Description |
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|-------|-----------------|-------------|
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| `GET /admin/themes` | moved from admin.tsx | Theme list page |
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| `POST /admin/themes` | moved | Create theme |
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| `POST /admin/themes/:rkey/duplicate` | moved | Duplicate theme |
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| `POST /admin/themes/:rkey/delete` | moved | Delete theme |
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| `POST /admin/theme-policy` | moved | Update policy |
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| `GET /admin/themes/:rkey` | **new** | Token editor page |
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| `POST /admin/themes/:rkey/preview` | **new** | HTMX preview fragment |
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| `POST /admin/themes/:rkey/save` | **new** | Save tokens to AppView |
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| `POST /admin/themes/:rkey/reset-to-preset` | **new** | Redirect with preset query param |
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In `admin.tsx`, replace all theme handler blocks with:
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```typescript
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import { createAdminThemeRoutes } from "./admin-themes.js";
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const themeRoutes = createAdminThemeRoutes(appviewUrl);
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app.route("/", themeRoutes);
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```
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The `createAdminThemeRoutes(appviewUrl: string)` factory matches the existing pattern for route modules in this project.
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---
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## Editor Page — `GET /admin/themes/:rkey`
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### Data Loading
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1. Fetch `GET /api/admin/themes/:rkey` from the AppView (requires `manageThemes` session cookie)
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2. If `?preset=<name>` is present in the query string, merge preset tokens over the DB tokens for initial input values (enables the reset-to-preset flow)
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3. If `?success=1`, show a success banner
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4. If `?error=<msg>`, show an error banner
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### Layout
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Two-column layout on desktop, stacked on mobile:
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```
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┌─ Metadata ─────────────────────────────────────────────────┐
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│ Name: [_________________] Color Scheme: [light ▾] │
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│ Font URLs: [textarea — one per line] │
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└──────────────────────────────────────────────────────────────┘
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┌─ Token Editor (~60%) ──────┐ ┌─ Live Preview (~40%) ───────┐
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│ <fieldset> Colors │ │ <div id="preview-pane" │
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│ color-bg [■] [#f5f0e8] │ │ hx-swap-oob="true"> │
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│ color-text [■] [#1a1a1a]│ │ │
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│ ... (14 color tokens) │ │ <style>:root{--tokens}</style>
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│ </fieldset> │ │ [Sample: card, button, │
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│ │ │ heading, text, code, │
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│ <fieldset> Typography │ │ input, nav strip] │
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│ font-body [___________] │ │ │
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│ font-size-base [16] px │ │ Updates on every change │
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│ ... (13 tokens) │ │ via hx-trigger="change │
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│ </fieldset> │ │ delay:300ms" │
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│ │ └──────────────────────────────┘
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│ <fieldset> Spacing & Layout│
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│ space-xs [____] │
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│ radius [____] │
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│ ... (9 tokens) │
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│ </fieldset> │
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│ │
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│ <fieldset> Components │
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│ button-shadow [________] │ (plain text — CSS shorthand)
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│ card-shadow [________] │
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│ ... (10 tokens) │
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│ </fieldset> │
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│ │
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│ [Save] [Reset to Preset] │
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│ [← Back to themes] │
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└─────────────────────────────┘
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```
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### Token Groups (all 46 tokens from preset JSON)
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**Colors (14):** `color-bg`, `color-surface`, `color-text`, `color-text-muted`, `color-primary`, `color-primary-hover`, `color-secondary`, `color-border`, `color-shadow`, `color-success`, `color-warning`, `color-danger`, `color-code-bg`, `color-code-text`
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- Input: `<input type="color">` + adjacent text input for hex value
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**Typography (13):** `font-body`, `font-heading`, `font-mono`, `font-size-base`, `font-size-sm`, `font-size-xs`, `font-size-lg`, `font-size-xl`, `font-size-2xl`, `font-weight-normal`, `font-weight-bold`, `line-height-body`, `line-height-heading`
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- Font families: text inputs; sizes: text inputs with `px` unit hint
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**Spacing & Layout (9):** `space-xs`, `space-sm`, `space-md`, `space-lg`, `space-xl`, `radius`, `border-width`, `shadow-offset`, `content-width`
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- Input: text inputs
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**Components (10):** `button-radius`, `button-shadow`, `card-radius`, `card-shadow`, `btn-press-hover`, `btn-press-active`, `input-radius`, `input-border`, `nav-height`
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- Input: plain text inputs (CSS shorthand values)
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### HTMX Wiring
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The token fieldsets (not the metadata inputs) carry:
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```html
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<form id="token-form"
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hx-post="/admin/themes/:rkey/preview"
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hx-trigger="change delay:300ms from:find input, change delay:300ms from:find select"
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hx-target="#preview-pane"
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hx-swap="innerHTML">
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```
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This debounces preview updates 300ms after any input change.
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### Reset to Preset Dialog
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```html
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<dialog id="reset-dialog">
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<form method="post" action="/admin/themes/:rkey/reset-to-preset">
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<label for="reset-preset">Reset tokens to:</label>
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<select name="preset" id="reset-preset">
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<option value="neobrutal-light">Neobrutal Light</option>
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<option value="neobrutal-dark">Neobrutal Dark</option>
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<option value="blank">Blank (empty tokens)</option>
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</select>
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<p>This will replace all token values. Your current changes will be lost.</p>
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<button type="submit">Reset</button>
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<button type="button" onclick="document.getElementById('reset-dialog').close()">Cancel</button>
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</form>
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</dialog>
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<button type="button" onclick="document.getElementById('reset-dialog').showModal()">
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Reset to Preset
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</button>
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```
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### CSS Override Field
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Hidden/disabled pending ATB-62 (CSS sanitization). Render a disabled textarea with a note explaining it will be available after sanitization is implemented.
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---
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## Preview Endpoint — `POST /admin/themes/:rkey/preview`
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**This is a pure web-server computation — no AppView call, no DB, no PDS write.**
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### Request
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Form data containing all token name/value pairs submitted by the HTMX form.
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### Processing
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1. Parse form fields into `tokens: Record<string, string>`
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2. Sanitize each value: reject values containing `<`, `;` outside strings, or that look like injected markup. For color tokens, validate hex format.
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3. Call `tokensToCss(tokens)` from `apps/web/src/lib/theme.ts`
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4. Build and return an HTML fragment
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### Response
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```html
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<style>
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:root {
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--color-bg: #f5f0e8;
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--color-text: #1a1a1a;
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/* ... all 46 tokens */
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}
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</style>
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<div class="preview-sample">
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<!-- Representative forum elements using the theme classes -->
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<nav class="preview-nav">atBB Forum Preview</nav>
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<div class="card">
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<h2>Sample Thread Title</h2>
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<p>Body text showing font, color, and spacing tokens at work.</p>
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<code>const example = "code block";</code>
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<input type="text" placeholder="Reply..." />
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<button class="btn-primary">Post Reply</button>
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</div>
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</div>
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```
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The sample HTML uses existing `.card`, `.btn-primary`, and other CSS classes from `theme.css` so the preview reflects the real design system.
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---
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## Save Flow — `POST /admin/themes/:rkey/save`
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1. Parse form: `name` (string), `colorScheme` (light|dark), `fontUrls` (string → split by newline), plus all 46 token key/value pairs
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2. Build `tokens: Record<string, string>` from the token fields
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3. `fetch(PUT /api/admin/themes/:rkey, { body: JSON.stringify({ name, colorScheme, tokens, fontUrls }) })`
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4. On success (2xx) → `redirect /admin/themes/:rkey?success=1`
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5. On AppView 4xx → extract error message → `redirect /admin/themes/:rkey?error=<msg>`
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6. On network error → `redirect /admin/themes/:rkey?error=Forum+temporarily+unavailable`
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---
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## Reset Flow — `POST /admin/themes/:rkey/reset-to-preset`
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1. Parse `preset` from body
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2. Validate: must be one of `neobrutal-light`, `neobrutal-dark`, `blank`; otherwise return 400
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3. On valid preset → `redirect /admin/themes/:rkey?preset=<name>`
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The `GET /admin/themes/:rkey` handler already handles `?preset=<name>` by loading preset tokens from the imported JSON files and using them as the initial input values instead of the DB values.
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---
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## Error Handling
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| Scenario | Behavior |
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|----------|----------|
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| Theme not found (AppView 404) | 404 page |
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| Network error loading theme | Error banner, no crash |
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| Unauthenticated | Redirect to /login |
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| No manageThemes permission | 403 page |
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| Preview parse error | Return preview pane with fallback style |
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| Save AppView failure | Redirect with `?error=<message>` |
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| Save network error | Redirect with generic error message |
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| Invalid preset name in reset | 400 response |
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---
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## Testing Plan
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All tests added to `apps/web/src/routes/__tests__/admin.test.tsx` (or a new `admin-themes.test.tsx` if extracted).
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**`GET /admin/themes/:rkey`**
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- Redirects unauthenticated users to /login
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- Returns 403 for users without manageThemes permission
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- Returns 404 for unknown rkey
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- Renders editor with correct initial token values from theme data
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- `?preset=neobrutal-light` populates inputs from preset instead of DB values
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- `?success=1` shows success banner
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- `?error=<msg>` shows error banner
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- CSS overrides field is rendered disabled
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**`POST /admin/themes/:rkey/preview`**
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- Returns HTML fragment containing a `<style>` block with submitted token values
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- Sanitizes malicious input (drops values containing `<` or `;`)
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- Returns a fallback preview on parse error (doesn't crash)
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**`POST /admin/themes/:rkey/save`**
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- Redirects to `?success=1` on AppView 2xx
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- Redirects with `?error=<msg>` on AppView 4xx
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- Redirects with generic error on network failure
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**`POST /admin/themes/:rkey/reset-to-preset`**
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- Redirects to `?preset=neobrutal-light` for valid preset name
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- Returns 400 for unknown preset name
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---
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## Bruno Collection Update
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Add to `bruno/AppView API/Admin Themes/`:
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- No new AppView endpoints are introduced in ATB-59 (preview is web-only; save reuses the existing `PUT /api/admin/themes/:rkey`). The existing `Update Theme.bru` file covers the save path.
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---
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## Implementation Notes
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- The `THEME_PRESETS` constant (already in `admin.tsx`) moves to `admin-themes.tsx`
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- `tokensToCss()` is imported from `apps/web/src/lib/theme.ts` — already exists, no changes needed
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- The Edit button in the theme list (`aria-disabled="true"`) becomes a real `<a href="/admin/themes/:rkey">` link
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- `admin.tsx` imports `createAdminThemeRoutes` and mounts it — all other theme-handler blocks are deleted