docs: add failure display design spec

Defines "failing source" as error_count >= configurable threshold
(default 5), adds per-platform health bars and a strict failing-source
list to the Dashboard, surfaces the threshold on the Settings page.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
This commit is contained in:
2026-04-17 22:56:23 -04:00
parent a11861197c
commit 38bade0320
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# Failure Display — Design Spec
**Date:** 2026-04-17
**Scope:** Define a single "failing source" state and surface it on the Dashboard as per-platform health bars plus a filtered failing-source list. Make the threshold configurable via Settings.
---
## Motivation
The user is seeing a large number of source failures and needs a way to spot which platforms are affected at a glance. Today, the Dashboard's "Sources Needing Attention" card shows any source with a failed download in the last 7 days — a transient, noisy definition. A single bad run puts a source on the list; a later success does nothing to clear it.
This spec introduces a stricter, self-clearing definition: a source is *failing* when it has N consecutive failures (default 5), and a single success resets the counter. That semantic already exists in the data model — `Source.error_count` increments on failure and is set to 0 on success — so this is a presentation change with one small settings addition, not a schema change.
---
## Design
### Backend
**File:** `backend/app/models/setting.py`
Add one entry to `DEFAULT_SETTINGS`:
```python
DEFAULT_SETTINGS = {
# ... existing keys unchanged ...
"dashboard.failure_threshold": 5,
}
```
No migration. The `settings` table is a key-value store and `get_setting_value(session, key, default)` already falls back through `DEFAULT_SETTINGS`. No new endpoint — the existing `GET /api/settings` returns it in the merged `settings` dict.
### Settings page — `frontend/src/views/Settings.vue`
Add a new section above the Notifications divider:
```vue
<v-divider class="my-6" />
<h3 class="text-h6 mb-4">Dashboard</h3>
<v-row>
<v-col cols="12" md="6">
<v-text-field
v-model.number="settings['dashboard.failure_threshold']"
label="Failing source threshold"
type="number"
min="1"
max="20"
hint="Consecutive download failures before a source is marked failing. One success resets the counter."
persistent-hint
/>
</v-col>
</v-row>
```
The existing save handler in `Settings.vue` already patches any key present in the `settings` object, so no handler changes are needed.
### Dashboard — `frontend/src/views/Dashboard.vue`
Replace the body of the existing "Sources Needing Attention" card. The card title, outer shell, and card actions remain unchanged. The inner `v-card-text` is rewritten.
#### New computeds
```js
// Read threshold from settings store, default 5 if unset
const settingsStore = useSettingsStore()
const failureThreshold = computed(() =>
settingsStore.settings?.['dashboard.failure_threshold'] ?? 5
)
// Fixed platform display order
const PLATFORM_ORDER = [
'patreon', 'subscribestar', 'hentaifoundry',
'discord', 'pixiv', 'deviantart',
]
// Per-platform health: { platform, total, failing } for platforms with ≥1 enabled source
const platformHealth = computed(() => {
const enabled = sourcesStore.sources.filter(s => s.enabled)
return PLATFORM_ORDER
.map(platform => {
const sources = enabled.filter(s => s.platform === platform)
if (sources.length === 0) return null // hide zero-enabled platforms
const failing = sources.filter(s => (s.error_count || 0) >= failureThreshold.value).length
return { platform, total: sources.length, failing }
})
.filter(Boolean)
})
// Sources currently in a failing state, most-recent-check first
const failingSources = computed(() => {
return sourcesStore.sources
.filter(s => s.enabled && (s.error_count || 0) >= failureThreshold.value)
.sort((a, b) => new Date(b.last_check || 0) - new Date(a.last_check || 0))
})
const totalFailingCount = computed(() => failingSources.value.length)
```
`useSettingsStore` already exists at `frontend/src/stores/settings.js` with `fetchSettings()` and a reactive `settings` ref. `Dashboard.vue` must call `settingsStore.fetchSettings()` in `loadDashboardData` (alongside the existing `fetchSources`/`fetchStats`/etc calls) so `settings` is populated before the threshold is read.
#### Template — replace `v-card-text` body
```vue
<v-card-text>
<!-- Section 1: Platform Health bars -->
<div class="mb-4">
<div class="text-caption text-medium-emphasis mb-2">Platform Health</div>
<div
v-for="row in platformHealth"
:key="row.platform"
class="d-flex align-center mb-2"
>
<v-icon :color="getPlatformColor(row.platform)" size="small" class="mr-2">
{{ getPlatformIcon(row.platform) }}
</v-icon>
<div class="text-body-2 platform-label">{{ row.platform }}</div>
<v-progress-linear
:model-value="row.failing > 0 ? (row.failing / row.total) * 100 : 100"
:color="row.failing > 0 ? 'error' : 'success'"
height="12"
rounded
class="mx-3 flex-grow-1"
/>
<div class="text-caption text-medium-emphasis count-label">
{{ row.failing }}/{{ row.total }}
</div>
</div>
</div>
<v-divider class="my-3" />
<!-- Section 2: Failing Sources list -->
<v-table v-if="failingSources.length" density="compact">
<thead>
<tr>
<th>Source</th>
<th>Consecutive failures</th>
<th>Last check</th>
<th>Actions</th>
</tr>
</thead>
<tbody>
<tr v-for="source in failingSources" :key="source.id">
<td>{{ getSourceLabel(source) }}</td>
<td>
<v-chip color="error" size="small">{{ source.error_count }}</v-chip>
</td>
<td>{{ formatDate(source.last_check) }}</td>
<td>
<v-btn size="small" variant="text" color="primary" @click="retrySource(source)">
Retry
</v-btn>
<v-btn size="small" variant="text" to="/subscriptions">View</v-btn>
</td>
</tr>
</tbody>
</v-table>
<div v-else class="text-caption text-medium-emphasis text-center py-3">
No sources in failing state
</div>
</v-card-text>
```
#### Header chip
The card title already has:
```vue
<v-chip class="ml-2" color="error" size="small" v-if="sourcesWithErrors.length">
{{ sourcesWithErrors.length }}
</v-chip>
```
Swap the binding to `totalFailingCount`:
```vue
<v-chip class="ml-2" color="error" size="small" v-if="totalFailingCount">
{{ totalFailingCount }}
</v-chip>
```
#### Removed code
- `sourcesWithErrors` computed (derived from recent activity) is no longer used. Delete it.
- The existing `v-else` empty state block ("All sources healthy" big icon) is removed — its role is now played by the always-visible bars plus the small inline "No sources in failing state" line.
#### Minor CSS (scoped block)
```css
.platform-label {
min-width: 110px;
text-transform: capitalize;
}
.count-label {
min-width: 50px;
text-align: right;
}
```
---
## Data flow
1. `Dashboard.vue` on mount fetches sources (already happens), recent activity (already happens), and settings (new — one call to `settingsStore.fetchSettings()`).
2. `platformHealth` and `failingSources` are purely derived from `sourcesStore.sources` + `failureThreshold`.
3. When a download completes or fails, the existing `download.completed` / `download.failed` websocket handlers already trigger `sourcesStore.fetchSources()` through `source.updated`. Re-render happens via Vue reactivity.
No polling changes; no new backend work beyond the one default value.
---
## Visual behavior
- **All platforms healthy:** each bar is 100% green.
- **One platform has failures:** that bar shows red fill proportional to `failing / total` against a neutral track; the others stay green.
- **Platform has zero enabled sources:** row omitted entirely.
- **Header chip:** visible only when `totalFailingCount > 0`, shows that count.
- **Failing sources list:** rendered when non-empty; otherwise inline "No sources in failing state" caption sits directly under the bars.
---
## Files changed
| File | Change |
|---|---|
| `backend/app/models/setting.py` | Add `"dashboard.failure_threshold": 5` to `DEFAULT_SETTINGS` |
| `frontend/src/views/Settings.vue` | Add Dashboard section with threshold `v-text-field` (120, default 5) |
| `frontend/src/views/Dashboard.vue` | Replace "Sources Needing Attention" card body; add `platformHealth`, `failingSources`, `totalFailingCount`, `failureThreshold` computeds; fetch settings on mount; remove `sourcesWithErrors` computed and the old empty state; small scoped CSS |
---
## Non-goals
- No changes to `Source.error_count` increment/reset behavior — the logic in `backend/app/tasks/downloads.py` already has the correct semantics.
- No alembic migration (the settings table is key-value; new keys arrive via `DEFAULT_SETTINGS`).
- No new API endpoints.
- No click-through navigation on platform rows — bars are pure display.
- No changes to `Subscriptions.vue` or `Downloads.vue`.
- No per-subscription health view (only per-platform).