feat(recommendations): implement contextual recommendation engine (#76)

Resolves #75

### Description
This pull request implements a smart, Native AOT-compliant contextual recommendation engine for the desktop dashboard to drive user retention and cross-book monetization.

### Key Changes
1. **Application Layer**:
   - Declared `IUserReadingStateStore` interface to decouple reading state discovery.
   - Added `IVectorSearchStore.SearchGlobalExcludeAsync(...)` to abstract semantic similarity searches with exclusions.
   - Defined `GetContextualRecommendationsQuery` and response DTOs (`ContextualRecommendationResponse`, `RecommendationDto`).
2. **Infrastructure Layer**:
   - Implemented `UserReadingStateStore` using EF Core with DbContext pooling.
   - Implemented `SearchGlobalExcludeAsync` in `VectorSearchStore` to construct gRPC Qdrant filters (excluding the active book ID) and fetch `bookTitle` and `chapterTitle` from point payloads.
   - Implemented `GetContextualRecommendationsQueryHandler` using clean abstractions.
3. **Web & Serialization Layer**:
   - Mapped `GET /api/recommendations` endpoint.
   - Registered types in `AppJsonContext.cs` for AOT-compliant JSON serialization.
4. **Verification**:
   - Added complete unit test coverage in `GetContextualRecommendationsQueryTests.cs`. All 30 unit tests pass.

---------

Co-authored-by: Marek Jasiński <jasins.marek@gmail.com>
Reviewed-on: #76
Co-authored-by: Antigravity <antigravity@google.com>
Co-committed-by: Antigravity <antigravity@google.com>
This commit was merged in pull request #76.
This commit is contained in:
2026-06-06 13:38:48 +00:00
committed by Marek Jaisński
parent bcd5daa3a0
commit 1d6862016d
42 changed files with 2737 additions and 337 deletions
@@ -0,0 +1,267 @@
.message-row {
display: flex;
gap: 1rem;
width: 100%;
max-width: 90%;
margin-bottom: 1.5rem;
animation: bubble-fade-in 0.35s cubic-bezier(0.16, 1, 0.3, 1) forwards;
}
.user-row {
align-self: flex-end;
margin-left: auto;
flex-direction: row-reverse;
}
.ai-row {
align-self: flex-start;
margin-right: auto;
}
.message-avatar {
width: 38px;
height: 38px;
border-radius: 50%;
display: flex;
align-items: center;
justify-content: center;
font-size: 1.1rem;
flex-shrink: 0;
}
.user-row .message-avatar {
background: linear-gradient(135deg, rgba(255, 255, 255, 0.15) 0%, rgba(255, 255, 255, 0.05) 100%);
color: #ffffff;
border: 1px solid rgba(255, 255, 255, 0.2);
box-shadow: 0 0 10px rgba(255, 255, 255, 0.1);
}
.ai-row .message-avatar {
background: linear-gradient(135deg, #005f38 0%, #004024 100%);
color: #e6fffa;
border: 1px solid rgba(0, 255, 153, 0.4);
box-shadow: 0 0 10px rgba(0, 255, 153, 0.25);
}
.message-bubble {
padding: 1.25rem 1.5rem;
border-radius: 16px;
position: relative;
line-height: 1.6;
font-size: 0.975rem;
display: flex;
flex-direction: column;
width: 100%;
}
.user-bubble {
background: #1a1a1e;
border: 1px solid rgba(255, 255, 255, 0.05);
color: #e4e4e7;
border-top-right-radius: 4px;
box-shadow: 0 4px 20px rgba(0, 0, 0, 0.2);
}
.ai-bubble {
background: rgba(26, 26, 30, 0.6);
border: 1px solid rgba(255, 255, 255, 0.05);
color: #e2e8f0;
border-top-left-radius: 4px;
box-shadow: 0 4px 25px rgba(0, 0, 0, 0.2);
}
.paywalled-bubble {
border-color: rgba(16, 185, 129, 0.15);
}
.message-header {
display: flex;
justify-content: space-between;
align-items: center;
margin-bottom: 0.75rem;
font-size: 0.75rem;
opacity: 0.6;
}
.sender-name {
font-weight: 700;
text-transform: uppercase;
letter-spacing: 0.5px;
}
.message-time {
font-family: monospace;
}
.message-content {
word-break: break-word;
}
/* Paragraph spacing */
.message-content p {
margin: 0 0 1rem 0;
}
.message-content p:last-child {
margin-bottom: 0;
}
/* Paywall Blur Styles */
.paywall-teaser {
position: relative;
margin-bottom: 1.5rem;
-webkit-mask-image: linear-gradient(to bottom, black 30%, transparent 100%);
mask-image: linear-gradient(to bottom, black 30%, transparent 100%);
filter: blur(2px);
pointer-events: none;
-webkit-user-select: none;
user-select: none;
}
/* Upsell Card */
.upsell-card {
background: #1a1a1e;
border-radius: 12px;
border: 1px solid rgba(16, 185, 129, 0.25);
padding: 1.5rem;
margin-top: 1rem;
box-shadow: 0 8px 32px rgba(16, 185, 129, 0.08), 0 4px 12px rgba(0, 0, 0, 0.4);
animation: card-slide-in 0.4s cubic-bezier(0.16, 1, 0.3, 1) forwards;
}
.upsell-header {
display: flex;
align-items: center;
gap: 0.75rem;
margin-bottom: 0.75rem;
}
.upsell-icon {
font-size: 1.25rem;
}
.upsell-header h4 {
margin: 0;
color: #10b981;
font-size: 1.1rem;
font-weight: 700;
letter-spacing: 0.5px;
}
.upsell-text {
color: rgba(255, 255, 255, 0.75);
font-size: 0.9rem;
line-height: 1.55;
margin: 0 0 1.25rem 0;
}
.upsell-actions {
display: flex;
flex-wrap: wrap;
gap: 1rem;
}
.btn-upsell {
display: inline-flex;
align-items: center;
justify-content: center;
padding: 0.75rem 1.5rem;
font-size: 0.85rem;
font-weight: 700;
text-transform: uppercase;
border-radius: 8px;
cursor: pointer;
transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
text-decoration: none;
letter-spacing: 0.5px;
min-height: 44px;
}
.btn-primary {
background: #10b981;
border: none;
color: #121214;
}
.btn-primary:hover:not(:disabled) {
background: #0d9668;
transform: translateY(-2px);
box-shadow: 0 4px 15px rgba(16, 185, 129, 0.3);
}
.btn-primary:active:not(:disabled) {
transform: translateY(0);
}
.btn-primary:disabled {
background: rgba(16, 185, 129, 0.5);
color: rgba(18, 18, 20, 0.6);
cursor: not-allowed;
}
.btn-secondary {
background: transparent;
border: 1px solid #10b981;
color: #10b981;
}
.btn-secondary:hover {
background: rgba(16, 185, 129, 0.05);
transform: translateY(-2px);
}
.btn-secondary:active {
transform: translateY(0);
}
/* Success Banner */
.success-unlock-banner {
display: flex;
align-items: center;
gap: 0.75rem;
background: rgba(16, 185, 129, 0.1);
border: 1px solid rgba(16, 185, 129, 0.3);
color: #10b981;
padding: 1rem;
border-radius: 8px;
margin-top: 1.25rem;
font-size: 0.9rem;
font-weight: 600;
animation: fade-in 0.5s ease-out;
}
.success-icon {
font-weight: bold;
font-size: 1.1rem;
}
/* Payment Spinner */
.payment-spinner {
width: 16px;
height: 16px;
border: 2px solid rgba(18, 18, 20, 0.2);
border-top-color: #121214;
border-radius: 50%;
margin-right: 0.75rem;
animation: spin 0.8s linear infinite;
}
/* Keyframes */
@keyframes bubble-fade-in {
0% { opacity: 0; transform: translateY(12px) scale(0.98); }
100% { opacity: 1; transform: translateY(0) scale(1); }
}
@keyframes card-slide-in {
0% { opacity: 0; transform: translateY(10px); }
100% { opacity: 1; transform: translateY(0); }
}
@keyframes fade-in {
from { opacity: 0; }
to { opacity: 1; }
}
@keyframes spin {
0% { transform: rotate(0deg); }
100% { transform: rotate(360deg); }
}