# GSD-Lite Work Log

---

## 1. Current Understanding (Read First)

<current_mode>
Example: execution (following execution.md workflow)
Example: moodboard (extracting user vision)
Example: checkpoint (pausing for session handoff)
</current_mode>

<active_task>
Example: Task: MODEL-A - Design card-based post layout with engagement metrics
Example: Task: AUTH-IMPL - Implement JWT authentication with refresh tokens
</active_task>

<parked_tasks>
Example: Task: MODEL-B - Timeline view implementation (deferred until card layout complete)
Example: Task: PERF-OPT - Database query optimization (waiting on schema finalization)
</parked_tasks>

<vision>
Example: User wants Linear-like feel + Bloomberg density for power users
Example: Authentication must support refresh token rotation for security
Example: Interface should not patronize advanced users with excessive whitespace
</vision>

<decisions>
Example: Use card-based layout, not timeline view (cards support varying content length)
Example: Separate reset tokens from main JWT (better security isolation)
Example: Log all EXEC/DISCOVERY entries with code snippets (enables PR extraction)
</decisions>

<blockers>
Example: None currently. Proceeding with card layout implementation.
Example: Password reset token expiry unclear - waiting on user decision (1 hour vs 24 hours)
</blockers>

<next_action>
Example: Complete card component styling, then verify against Linear reference
Example: Implement token validation middleware (TASK-003)
</next_action>

---

## 2. Key Events Index (Project Foundation)

### Architecture Decisions
- EXAMPLE-005: Card Layout — Card-based over timeline for content flexibility
- EXAMPLE-022: Token Expiry — Separate reset token with 1-hour expiry

### Pattern Decisions
- EXAMPLE-012: Engagement Pattern — Reusable engagement metrics display pattern

### Data Flow Decisions
- EXAMPLE-030: Auth Performance — bcrypt cost factor 12 balances security/speed

---

## 3. Atomic Session Log (Chronological)

### [EXAMPLE-001] - [VISION] - User wants Linear-like feel + Bloomberg density for power users - Task: MODEL-A
**Timestamp:** 2026-01-22 14:00
**Details:**
- Context: Discussed UI patterns during moodboard session
- Reference: Clean layout (Linear) but with information density (Bloomberg terminal)
- Implication: Interface should not patronize advanced users with excessive whitespace

### [EXAMPLE-002] - [PLAN] - Broke card layout into 3 sub-tasks - Task: MODEL-A
**Timestamp:** 2026-01-22 14:10
**Details:**
- SUBTASK-001: Base card component with props interface
- SUBTASK-002: Engagement metrics display (likes, comments, shares)
- SUBTASK-003: Layout grid with responsive breakpoints
- Risk: Responsive behavior may need user verification on mobile

### [EXAMPLE-003] - [DECISION] - Use card-based layout, not timeline view - Task: MODEL-A
**Timestamp:** 2026-01-22 14:15
**Details:**
- Rationale: Cards support varying content length (post + engagement + metadata); timeline more rigid
- Alternative considered: Timeline view (simpler implementation, less flexible for content types)
- Impact: Unblocks component design; affects SUBTASK-001 (card props interface)

### [EXAMPLE-004] - [EXEC] - Created base card component with TypeScript interface - Task: MODEL-A
**Timestamp:** 2026-01-22 14:30
**Details:**
- Files modified: src/components/Card.tsx (created), src/types/post.ts (created)
- Code snippet:
```typescript
interface PostCardProps {
  post: {
    id: string;
    content: string;
    author: string;
    timestamp: Date;
    engagement: {
      likes: number;
      comments: number;
      shares: number;
    };
  };
}
```
- Status: SUBTASK-001 complete, proceeding to SUBTASK-002

### [EXAMPLE-005] - [DISCOVERY] - Found engagement pattern in Linear reference app - Task: MODEL-A
**Timestamp:** 2026-01-22 15:00
**Details:**
- Observation: Linear shows engagement inline, not in dropdown/modal
- Evidence from inspection:
```html
<div class="engagement-bar">
  <span class="metric">👍 12</span>
  <span class="metric">💬 5</span>
  <span class="metric">🔄 3</span>
</div>
```
- Impact: Informs SUBTASK-002 design (inline engagement, emoji + count)

### [EXAMPLE-006] - [EXEC] - Implemented engagement metrics component - Task: MODEL-A
**Timestamp:** 2026-01-22 15:30
**Details:**
- Files modified: src/components/EngagementBar.tsx (created)
- Code snippet:
```typescript
export function EngagementBar({ likes, comments, shares }: EngagementProps) {
  return (
    <div className="engagement-bar">
      <Metric icon="👍" count={likes} />
      <Metric icon="💬" count={comments} />
      <Metric icon="🔄" count={shares} />
    </div>
  );
}
```
- Status: SUBTASK-002 complete, proceeding to SUBTASK-003

### [EXAMPLE-007] - [BLOCKER] - Mobile breakpoint unclear - 768px or 640px? - Task: MODEL-A
**Timestamp:** 2026-01-22 16:00
**Details:**
- Issue: User hasn't specified mobile breakpoint preference
- Context: Linear uses 768px, Bloomberg uses custom breakpoints
- Waiting on: User decision on responsive strategy
- Impact: Blocks SUBTASK-003 (layout grid) until clarified

### [EXAMPLE-008] - [DECISION] - Use 768px breakpoint, standard tablet/mobile split - Task: MODEL-A
**Timestamp:** 2026-01-22 16:15
**Details:**
- Rationale: 768px is industry standard, matches Linear reference
- User preference: "Keep it simple, use standard breakpoints"
- Impact: Unblocks SUBTASK-003

### [EXAMPLE-009] - [EXEC] - Implemented responsive grid with 768px breakpoint - Task: MODEL-A
**Timestamp:** 2026-01-22 16:45
**Details:**
- Files modified: src/components/CardGrid.tsx (created), src/styles/grid.css (created)
- Code snippet:
```css
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 1rem;
}

@media (max-width: 768px) {
  .card-grid {
    grid-template-columns: 1fr;
  }
}
```
- Status: SUBTASK-003 complete, Task: MODEL-A ready for verification

### [EXAMPLE-010] - [VISION] - Authentication must support refresh token rotation - Task: AUTH-IMPL
**Timestamp:** 2026-01-23 10:00
**Details:**
- Security requirement from user: "Don't want long-lived tokens floating around"
- Reference: OAuth 2.0 refresh token rotation best practice
- Success criteria: Access token 15min, refresh token rotates on use

### [EXAMPLE-011] - [PLAN] - JWT auth broken into 3 tasks - Task: AUTH-IMPL
**Timestamp:** 2026-01-23 10:20
**Details:**
- TASK-001: Library setup (jose v0.5.0) + token generation
- TASK-002: Login endpoint with bcrypt password hashing
- TASK-003: Token validation middleware + refresh rotation
- Risk: Token expiry strategy may need user decision

### [EXAMPLE-012] - [EXEC] - Installed jose library and created token generation - Task: AUTH-IMPL
**Timestamp:** 2026-01-23 10:30
**Details:**
- Files modified: src/auth/token.ts (created), package.json (jose added)
- Code snippet:
```typescript
export async function generateAccessToken(userId: string): Promise<string> {
  const secret = new TextEncoder().encode(process.env.JWT_SECRET);
  return await new SignJWT({ userId })
    .setProtectedHeader({ alg: 'HS256' })
    .setExpirationTime('15m')
    .sign(secret);
}
```
- Status: TASK-001 complete

### [EXAMPLE-013] - [DISCOVERY] - bcrypt cost factor 12 optimal for performance - Task: AUTH-IMPL
**Timestamp:** 2026-01-23 11:00
**Details:**
- Benchmark: Cost 10 = 50ms, Cost 12 = 150ms, Cost 14 = 600ms
- Code used for testing:
```typescript
import bcrypt from 'bcrypt';
for (const cost of [10, 12, 14]) {
  const start = Date.now();
  await bcrypt.hash('password', cost);
  console.log(`Cost ${cost}: ${Date.now() - start}ms`);
}
```
- Decision: Use cost 12 (150ms acceptable for login latency)

### [EXAMPLE-014] - [EXEC] - Created login endpoint with bcrypt hashing - Task: AUTH-IMPL
**Timestamp:** 2026-01-23 11:30
**Details:**
- Files modified: src/api/auth/login.ts (created)
- Code snippet:
```typescript
export async function loginHandler(req: Request, res: Response) {
  const { email, password } = req.body;
  const user = await db.findUserByEmail(email);
  const valid = await bcrypt.compare(password, user.passwordHash);
  if (!valid) throw new AuthError('Invalid credentials');
  const accessToken = await generateAccessToken(user.id);
  res.json({ accessToken });
}
```
- Status: TASK-002 complete, proceeding to TASK-003

### [EXAMPLE-015] - [BLOCKER] - Password reset flow unclear - same JWT or separate token? - Task: AUTH-IMPL
**Timestamp:** 2026-01-23 12:00
**Details:**
- Issue: Security model for password reset not specified
- Question: Reuse main JWT or generate separate reset token?
- Waiting on: User decision on security approach
- Impact: Blocks finalization of auth module architecture

### [EXAMPLE-016] - [DECISION] - Use separate reset token, not main JWT - Task: AUTH-IMPL
**Timestamp:** 2026-01-23 12:15
**Details:**
- Rationale: Separate token provides better security isolation
- User preference: "Don't reuse auth token for password reset - keep them separate"
- Expiry: 1 hour for reset token (short-lived for security)
- Impact: Need to add generateResetToken() to auth module

### [EXAMPLE-017] - [EXEC] - Added password reset token generation - Task: AUTH-IMPL
**Timestamp:** 2026-01-23 12:45
**Details:**
- Files modified: src/auth/token.ts (updated), src/api/auth/reset.ts (created)
- Code snippet:
```typescript
export async function generateResetToken(userId: string): Promise<string> {
  const secret = new TextEncoder().encode(process.env.JWT_SECRET);
  return await new SignJWT({ userId, type: 'reset' })
    .setProtectedHeader({ alg: 'HS256' })
    .setExpirationTime('1h')
    .sign(secret);
}
```
- Status: Password reset complete, Task: AUTH-IMPL ready for verification

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