# Claude.md — JQC Developer Reference

> **Audience:** AI assistants and developers working on this codebase.  
> **Purpose:** Authoritative reference for architecture, conventions, gotchas, and decisions.  
> **Last reviewed:** April 2026 (Phase 11 complete)

---

## Table of Contents

1. [Project Overview](#1-project-overview)
2. [Tech Stack](#2-tech-stack)
3. [Repository Layout](#3-repository-layout)
4. [Environment & Configuration](#4-environment--configuration)
5. [Database Models](#5-database-models)
6. [Role & Permission Matrix](#6-role--permission-matrix)
7. [Blueprint Prefixes & Route Inventory](#7-blueprint-prefixes--route-inventory)
8. [Utility Modules](#8-utility-modules)
9. [Mobile API (Phase 7)](#9-mobile-api-phase-7)
10. [Notification System](#10-notification-system)
11. [SLA Engine](#11-sla-engine)
12. [Audit Trail](#12-audit-trail)
13. [PDF Export](#13-pdf-export)
14. [Scheduled Reports](#14-scheduled-reports)
15. [Alembic Migration Chain](#15-alembic-migration-chain)
16. [Frontend Conventions](#16-frontend-conventions)
17. [Infrastructure](#17-infrastructure)
18. [Known Constraints & Hard Rules](#18-known-constraints--hard-rules)
19. [Change Philosophy](#19-change-philosophy)

---

## 1. Project Overview

**JQC (Janitorial Quality Control)** is a production-grade, full-stack web application that manages:

- Janitorial service contracts organised as **Projects → Facilities → Areas**
- **Inspection** execution against configurable templates with dynamic form builder
- **Issue** tracking with SLA enforcement, follower subscriptions, and verification workflow
- **Customer portal** with scoped facility visibility and invitation-based onboarding
- **Notification** system (in-app + email) driven by an admin-controlled matrix
- **Reports** — on-demand PDF/CSV scorecards and scheduled email digests
- **Audit trail** — immutable log of every create/update/delete action
- **Mobile API** — JWT-authenticated REST layer (Phase 7) for a React Native / Expo mobile app

The application is actively deployed in production and maintained by a single developer/administrator.

---

## 2. Tech Stack

| Layer | Technology |
|---|---|
| Language | Python 3.11+ |
| Web framework | Flask (application factory pattern) |
| ORM | Flask-SQLAlchemy (SQLAlchemy 2.x) |
| Database | MySQL (via PyMySQL driver) |
| Auth (web) | Flask-Login + Flask-WTF CSRF |
| Auth (API) | JWT access tokens + opaque refresh tokens (PyJWT) |
| Migrations | Flask-Migrate / Alembic |
| Email | Flask-Mail (SMTP, background threading) |
| PDF generation | ReportLab |
| Forms | WTForms + Flask-WTF |
| Templating | Jinja2 |
| Frontend | Bootstrap 5, Chart.js, vanilla JS |
| Server | Gunicorn (sync workers) behind Nginx |
| OS | Ubuntu Linux |
| Mobile client | React Native + Expo (Expo Go for dev; cloud Mac for iOS builds) |
| Timezone | All datetimes stored as US/Eastern (naive, via `now_eastern()`) |

---

## 3. Repository Layout

```
lt_janitorial_quality_control/
├── app/
│   ├── __init__.py              # Application factory — create_app()
│   ├── add_form_schema.py       # One-off migration helper (safe re-run)
│   ├── api/                     # Mobile REST API (Phase 7)
│   │   ├── __init__.py          # api_bp parent blueprint + register_api()
│   │   ├── auth.py              # /api/v1/auth/* and /api/v1/devices/*
│   │   ├── decorators.py        # @jwt_required
│   │   ├── errors.py            # JSON error helpers + error handler registration
│   │   └── jwt_utils.py         # generate_access_token()
│   ├── models/
│   │   ├── __init__.py          # Re-exports all models
│   │   ├── api_token.py         # RefreshToken, DeviceToken
│   │   ├── audit.py             # AuditLog
│   │   ├── facility.py          # Facility, Area
│   │   ├── inspection.py        # InspectionTemplate, ChecklistItem, Inspection, InspectionResult
│   │   ├── issue.py             # Issue, IssueComment, IssueFollower
│   │   ├── notification.py      # Notification, NotificationPreference + event constants
│   │   ├── notification_matrix.py  # NotificationMatrix + MATRIX_DEFAULTS, MATRIX_EVENTS
│   │   ├── project.py           # Project, CustomerAssignment
│   │   ├── scheduled_report.py  # ScheduledReport
│   │   └── user.py              # User (with password-setup workflow)
│   ├── routes/
│   │   ├── __init__.py
│   │   ├── audit.py             # /audit/*
│   │   ├── auth.py              # /auth/* (users, login, notification matrix)
│   │   ├── customers.py         # /customers/*
│   │   ├── dashboard.py         # /
│   │   ├── facilities.py        # /facilities/*
│   │   ├── inspections.py       # /inspections/*
│   │   ├── issues.py            # /issues/*
│   │   ├── notifications.py     # /notifications/*
│   │   ├── projects.py          # /projects/*
│   │   ├── reports.py           # /reports/*
│   │   ├── scheduled_reports.py # /scheduled-reports/*
│   │   └── templates.py         # /templates/*
│   ├── static/
│   │   ├── css/ipad_responsive.css
│   │   └── uploads/             # User-uploaded photos (gitignored)
│   ├── templates/               # Jinja2 templates (mirrors routes/ structure)
│   │   ├── base.html            # Master layout (navbar, sidebar, flash messages)
│   │   ├── _sla_badge.html      # Reusable SLA status badge partial
│   │   └── ...
│   └── utils/
│       ├── __init__.py
│       ├── audit.py             # log_action() + ACTION_* constants
│       ├── decorators.py        # @admin_required, @supervisor_required, @project_manager_required, @customer_required
│       ├── forms.py             # All WTForms form classes
│       ├── notifications.py     # notify(), notify_by_matrix(), send_pending_digests()
│       ├── pdf_export.py        # generate_inspection_pdf(), scorecard PDF
│       ├── scope.py             # get_customer_scope() — facility access for customers
│       ├── sla.py               # sla_status(), sla_deadline(), sla_hours_remaining(), send_sla_alerts()
│       └── time_utils.py        # now_eastern()
├── migrations/
│   └── versions/
│       ├── phase1_projects_roles.py
│       ├── phase6_features.py
│       ├── phase7_mobile_api.py
│       ├── phase8_notification_matrix.py
│       ├── phase9_user_full_name.py
│       ├── phase10_customer_password_setup.py
│       └── phase11_director_role.py   # HEAD
├── config.py                    # Config, DevelopmentConfig, ProductionConfig
├── gunicorn_config.py           # bind, workers, log paths
├── requirements.txt
├── run.py                       # Development entry point
└── wsgi.py                      # Gunicorn entry point
```

---

## 4. Environment & Configuration

### Required Environment Variables

| Variable | Notes |
|---|---|
| `SECRET_KEY` | Flask secret — no fallback; startup fails if absent |
| `DATABASE_URL` | Full SQLAlchemy URI, e.g. `mysql+pymysql://user:pass@localhost/jqc` |
| `MAIL_SERVER` | SMTP hostname |
| `MAIL_USERNAME` | SMTP login |
| `MAIL_PASSWORD` | SMTP password |
| `MAIL_PORT` | 465 (SSL) or 587 (STARTTLS) — auto-selects `MAIL_USE_SSL`/`MAIL_USE_TLS` |
| `APP_BASE_URL` | Full URL prefix for email links, e.g. `https://jqc.example.com` |
| `MAIL_DEFAULT_SENDER` | From address |
| `DIGEST_SECRET` | Token used by cron to authenticate `/notifications/send-digest` |

### Email SSL Auto-Detection

```python
# config.py — port 465 → implicit SSL; port 587 → STARTTLS
MAIL_USE_SSL  = _mail_port == 465
MAIL_USE_TLS  = not MAIL_USE_SSL
```

> **Critical:** Never set both flags to `True` — Flask-Mail breaks silently.

### File Uploads

- `UPLOAD_FOLDER` = `app/static/uploads/`
- `MAX_CONTENT_LENGTH` = 50 MB (Flask-side limit; Nginx must also be configured)
- Allowed extensions: `png`, `jpg`, `jpeg`, `gif`
- Subfolders: `inspection_photos/`, `issue_photos/`

### Session Cookies

- `SESSION_COOKIE_SECURE = True` in production (HTTP only for dev)
- `SESSION_COOKIE_HTTPONLY = True`
- `SESSION_COOKIE_SAMESITE = 'Lax'`
- Session lifetime: 24 hours

---

## 5. Database Models

### User

```
users
├── id, username (unique), full_name, email (unique)
├── password_hash, role (ENUM), created_at, active
├── password_set (Bool)          — False until customer completes setup flow
├── set_password_token (str/64)  — time-limited invitation token
└── set_password_token_expires   — Eastern datetime
```

**Role ENUM (current):** `admin`, `director`, `inspector`, `project_manager`, `customer`  
> `supervisor` was renamed to `director` in Phase 11. The ENUM no longer contains `supervisor`.

**Key methods:**
- `display_name` → `full_name.strip()` or falls back to `username`
- `generate_set_password_token(expires_hours=72)` → creates 64-hex token + expiry
- `verify_set_password_token(token)` → returns User or None

### Facility / Area

```
facilities: id, name, address, contact_person, contact_phone, active, project_id (FK→projects)
areas:      id, facility_id (FK), name, area_type
```

### Project / CustomerAssignment

```
projects: id, name, description, project_manager_id (FK→users), active, created_at
customer_assignments: id, user_id, project_id, facility_id (nullable)
    └── UniqueConstraint(user_id, project_id, facility_id)
```

`facility_id = NULL` means the customer has access to all active facilities in the project.

### InspectionTemplate / ChecklistItem / Inspection / InspectionResult

```
inspection_templates: id, name, description, frequency, created_by, created_at, form_schema (JSON)
checklist_items: id, template_id, category, item_description, scoring_type, weight, requires_photo, display_order
inspections: id, template_id, facility_id, area_id, inspector_id, inspection_date, overall_score,
             status (in_progress/completed/flagged), notes, form_data (JSON), completed_at,
             parent_inspection_id (self-FK), follow_up_required, follow_up_note
inspection_results: id, inspection_id, checklist_item_id, score, passed, comments, photo_path
```

**Scoring rule:** Items with `score = 0` mean "unanswered" and are excluded from score calculation entirely.

**Follow-up workflow:** `parent_inspection_id` links re-inspections back to the original.

### Issue / IssueComment / IssueFollower

```
issues: id, inspection_id (nullable), area_id, severity (low/medium/high/critical),
        description, photo_path, status (open/in_progress/resolved/pending_verification),
        assigned_to (FK→users), reported_at, resolved_at, result_notes, result_photos (JSON),
        verified_by, verified_at, verification_note, sla_notified (None/'at_risk'/'breached')
issue_comments: id, issue_id, user_id, status_at_time, body, created_at
issue_followers: id, issue_id, user_id, created_at   — UniqueConstraint(issue_id, user_id)
```

**Issue status flow:** `open` → `in_progress` → `pending_verification` → `resolved`

### Notification / NotificationPreference

```
notifications: id, user_id, title, body, link, is_read, created_at, issue_id (nullable), event_type
notification_preferences: id, user_id, event_type, email_enabled, digest_mode, digest_frequency
```

### NotificationMatrix

```
notification_matrix: id, event_type, role_key, enabled, custom_emails (JSON text)
    └── UniqueConstraint(event_type, role_key)
```

### AuditLog

```
audit_logs: id, user_id (FK nullable on delete SET NULL), username (snapshot), user_role (snapshot),
            action, entity_type, entity_id, entity_label, details, created_at (indexed), ip_address
```

### RefreshToken / DeviceToken

```
api_refresh_tokens: id, user_id, token_hash (SHA-256, unique), device_id, device_name,
                    created_at, expires_at, revoked
api_device_tokens: id, user_id, device_id, apns_token, device_name, app_version, registered_at
    └── UniqueConstraint(user_id, device_id)
```

### ScheduledReport

```
scheduled_reports: id, name, report_type (summary/facility/issues), frequency (daily/weekly/monthly),
                   facility_id (nullable), recipients (JSON), include_pdf, include_csv,
                   active, created_by, created_at, last_sent_at, next_send_at
```

---

## 6. Role & Permission Matrix

| Route Area | admin | director | project_manager | inspector | customer |
|---|---|---|---|---|---|
| Dashboard | ✅ full | ✅ full | ✅ full | ✅ limited | ✅ scoped |
| Users (`/auth/users`) | ✅ | ✅ | ❌ | ❌ | ❌ |
| Notification Matrix | ✅ only | ❌ | ❌ | ❌ | ❌ |
| Customers (`/customers`) | ✅ | ✅ | ❌ | ❌ | ❌ |
| Facilities | ✅ | ✅ | ✅ | ✅ read | ✅ scoped |
| Projects | ✅ | ✅ | ✅ | ✅ read | ✅ scoped |
| Templates (create/edit) | ✅ | ✅ | ❌ | ❌ | ❌ |
| Inspections (execute) | ✅ | ✅ | ✅ | ✅ | ✅ read |
| Issues (create/assign) | ✅ | ✅ | ✅ | ✅ | ✅ read |
| Issue verification | ✅ | ✅ | ❌ | ❌ | ❌ |
| Reports (export) | ✅ | ✅ | ✅ | ✅ | ✅ scoped |
| Scheduled Reports | ✅ | ✅ | ✅ | ❌ | ❌ |
| Audit Trail | ✅ only | ❌ | ❌ | ❌ | ❌ |
| Mobile API | ✅ | ✅ | ✅ | ✅ | ❌ (TBD) |

### Decorator Map

```python
@admin_required          # role == 'admin' only
@supervisor_required     # role in ('admin', 'director')  — intentionally kept as-is (Phase 11)
@project_manager_required # role in ('admin', 'director', 'project_manager')
@customer_required       # role == 'customer' only
```

> **Important:** `@supervisor_required` is **not** renamed to `director_required` — that would require touching 30+ route decorators. The function name is a legacy artefact; the access list is correct.

### Customer Scoping

Customer visibility is derived from `CustomerAssignment` rows via `get_customer_scope(user)`:
- Returns `list[int]` of facility IDs, or `None` for non-customer roles
- `facility_id = NULL` assignment → access to all active facilities in that project
- All customer-facing queries must filter by `facility_id.in_(scope)` or `area.facility_id.in_(scope)`

---

## 7. Blueprint Prefixes & Route Inventory

| Blueprint | Prefix | Key Routes |
|---|---|---|
| `auth` | `/auth` | `/login`, `/logout`, `/profile`, `/users`, `/users/new`, `/users/<id>/edit`, `/users/<id>/delete`, `/users/<id>/toggle-active`, `/notification-matrix` |
| `dashboard` | `/` | `GET /` |
| `facilities` | `/facilities` | CRUD + `/facilities/<id>/areas` |
| `projects` | `/projects` | CRUD + assignment management |
| `customers` | `/customers` | list, create, edit, delete, manage assignments, invite, set-password |
| `inspections` | `/inspections` | list, start, execute, view, PDF export, flag issue |
| `templates` | `/templates` | list, create, edit, delete, form editor, preview |
| `issues` | `/issues` | list, view, create, update, assign, verify, comment, follow/unfollow, verification queue |
| `notifications` | `/notifications` | list, mark-read, preferences, send-digest (cron) |
| `audit` | `/audit` | list (admin-only), view |
| `reports` | `/reports` | index, facility report, scorecard, CSV/PDF export |
| `scheduled_reports` | `/scheduled-reports` | CRUD + manual trigger |
| `api` (parent) | `/api/v1` | — |
| `api_auth` | `/api/v1` | `/auth/login`, `/auth/refresh`, `/auth/logout`, `/auth/me`, `/devices/register` |

### API Blueprint Registration

The mobile API uses a **parent + child** pattern:
```python
# app/api/__init__.py
api_bp = Blueprint('api', __name__, url_prefix='/api/v1')

def register_api(app):
    from app.api.auth import bp as auth_bp
    api_bp.register_blueprint(auth_bp)
    app.register_blueprint(api_bp)
```

CSRF is exempted **before** registration:
```python
csrf.exempt(api_bp)
register_api(app)
```

---

## 8. Utility Modules

### `app/utils/time_utils.py`

```python
from app.utils.time_utils import now_eastern
```

Returns a **naive datetime** representing the current US/Eastern wall-clock time (adjusts automatically for EDT/EST). All `db.Column(db.DateTime, default=now_eastern)` calls use this. Never use `datetime.utcnow()` — it caused incorrect SLA purge cutoffs.

### `app/utils/audit.py`

```python
from app.utils.audit import log_action, ACTION_CREATE, ACTION_UPDATE, ACTION_DELETE, ACTION_LOGIN, ACTION_LOGOUT, ACTION_EXPORT

log_action(
    action       = ACTION_CREATE,
    entity_type  = 'Facility',
    entity_id    = facility.id,
    entity_label = facility.name,
    details      = f'address={facility.address}',
)
```

- Must be called **after** `db.session.commit()` to capture the entity's ID
- Never raises — failures are logged but never bubble up to break the primary request
- Snapshots `username` and `user_role` so records survive user deletion

### `app/utils/decorators.py`

Four decorators: `admin_required`, `supervisor_required`, `project_manager_required`, `customer_required`.  
All redirect to `dashboard.index` with a flash message on unauthorized access.

### `app/utils/scope.py`

```python
from app.utils.scope import get_customer_scope

facility_ids = get_customer_scope(current_user)  # None for non-customers
if facility_ids is not None:
    q = q.filter(Inspection.facility_id.in_(facility_ids))
```

### `app/utils/forms.py`

All WTForms classes live here:
- `LoginForm`, `ProfileForm`, `UserForm` (excludes `customer` role — use `/customers`)
- `FacilityForm`, `AreaForm`
- `InspectionTemplateForm`, `ChecklistItemForm`, `StartInspectionForm`
- `IssueForm`, `IssueUpdateForm`
- `ProjectForm`, `ProjectAssignmentForm`
- `CustomerUserForm`, `CustomerAssignmentForm`, `CustomerInviteForm`, `SetPasswordForm`
- `ScheduledReportForm`

### `app/utils/notifications.py`

```python
from app.utils.notifications import notify, notify_by_matrix, notify_customers_for_facility

notify(
    recipient  = user_obj,
    title      = 'Issue Updated',
    body       = 'Status changed to resolved.',
    link       = '/issues/42',
    issue_id   = 42,
    event_type = EVENT_ISSUE_STATUS,
    send_email = True,
)

notify_by_matrix(
    event_type       = 'inspection_completed',
    title            = '...',
    body             = '...',
    link             = '...',
    issue_id         = None,
    exclude_user_ids = {assignee.id},  # deduplicate
)
```

Email is sent in a background thread so it never blocks the HTTP response.

### `app/utils/pdf_export.py`

- `generate_inspection_pdf(inspection)` — full ReportLab inspection report with 12-column CSS grid preserved in print
- Scorecard generation for facility/project reports
- **Critical:** The 12-column grid layout must not be collapsed to single-column in print/PDF views

### `app/utils/sla.py`

SLA thresholds: `critical=4h`, `high=24h`, `medium=72h`, `low=168h`  
At-risk threshold: 75% of window elapsed.

```python
from app.utils.sla import sla_status, sla_deadline, sla_hours_remaining, send_sla_alerts

status = sla_status(issue)   # 'ok' | 'at_risk' | 'breached' | None (resolved)
```

`send_sla_alerts()` is called by cron. It deduplicates using `issue.sla_notified` — once `breached` is recorded, no further alerts fire for that issue.

---

## 9. Mobile API (Phase 7)

### Authentication Flow

1. `POST /api/v1/auth/login` → returns `access_token` (JWT, 60 min) + `refresh_token` (opaque hex, 30 days)
2. App stores both in iOS Keychain
3. Every authenticated request sends `Authorization: Bearer <access_token>`
4. When access token expires → `POST /api/v1/auth/refresh` → token rotation (old revoked, new issued)
5. `POST /api/v1/auth/logout` → revokes refresh token

### JWT Details

- Library: PyJWT
- Access token lifetime: 60 minutes (configurable in `jwt_utils.py`)
- Payload: `sub` (user ID), `exp`, `iat`, `role`
- `@jwt_required` decorator extracts and validates the token; sets `g.api_user`

### Refresh Token Storage

- Raw token is **never stored** — only its SHA-256 hex digest (`token_hash`)
- `RefreshToken.verify(raw_token)` hashes and looks up; returns None if expired/revoked
- Token rotation: old row's `revoked = True`, new row inserted

### CSRF Exemption Pattern

```python
# app/__init__.py — order matters
csrf = CSRFProtect()          # module-level instance
csrf.init_app(app)            # in create_app()
csrf.exempt(api_bp)           # BEFORE register_api(app)
register_api(app)
```

> **Never** use per-route decorators (`@csrf.exempt`) — Flask-WTF 1.0+ removed that API.

### Phase 2 Extensions (planned)

Commented stubs in `app/api/__init__.py`:
- `api_facilities`, `api_inspections`, `api_issues`, `api_notifications`, `api_photos`

---

## 10. Notification System

### Event Types (constants in `app/models/notification.py`)

```
EVENT_INSPECTION_DONE          = 'inspection_completed'
EVENT_ISSUE_ASSIGNED           = 'issue_assigned'
EVENT_ISSUE_REASSIGNED         = 'issue_reassigned'
EVENT_ISSUE_UNASSIGNED         = 'issue_unassigned'
EVENT_ISSUE_STATUS             = 'issue_status'
EVENT_ISSUE_COMMENT            = 'issue_comment'
EVENT_ISSUE_FOLLOW             = 'issue_follow_update'
EVENT_ISSUE_FLAGGED            = 'issue_flagged'
EVENT_ISSUE_CREATED            = 'issue_created'
EVENT_CUSTOMER_ISSUE_UPDATED   = 'issue_updated_customer'
EVENT_VERIFICATION_REQUESTED   = 'verification_requested'
EVENT_SLA_ALERT                = 'sla_alert'
EVENT_CUSTOMER_INSPECTION_DONE = 'customer_inspection_completed'
```

### Notification Matrix

The `notification_matrix` table controls which roles receive each event type. Admin UI at `/auth/notification-matrix` (admin-only).

- `role_key` values: `admin`, `director`, `inspector`, `project_manager`, `customer`, `custom`
- `custom` role_key stores a JSON list of arbitrary email addresses
- Matrix rows are auto-created from `MATRIX_DEFAULTS` on first access (`get_matrix_row()`)

### Implicit Notifications (always sent, not matrix-controlled)

- Issue **assignee** — always notified on assignment/status changes
- Issue **followers** — always notified on any update
- SLA **assignee + followers** — always notified on SLA events

### Notification Preferences

Users can configure per-event preferences at `/notifications/preferences`:
- `email_enabled` — receive email at all
- `digest_mode` — batch into digest rather than immediate send
- `digest_frequency` — daily/weekly/monthly

### Digest Cron

`POST /notifications/send-digest?frequency=daily&secret=<DIGEST_SECRET>` — triggered by server cron, authenticates via `DIGEST_SECRET`.

### Email Delivery

Emails are dispatched in a background thread:
```python
t = threading.Thread(target=_send_email_thread, args=(...))
t.daemon = True
t.start()
```

Never blocks the HTTP response. Failures are logged but not raised.

---

## 11. SLA Engine

| Severity | Window | At-Risk Trigger |
|---|---|---|
| critical | 4 hours | 3 hours |
| high | 24 hours | 18 hours |
| medium | 72 hours | 54 hours |
| low | 168 hours (7 days) | 126 hours |

- Cron calls `send_sla_alerts()` from within Flask app context
- `Issue.sla_notified` prevents duplicate notifications — tracked per-issue at level (`at_risk` / `breached`)
- `breached` supersedes `at_risk` — user receives two notifications total (once at-risk, once breached)
- SLA does not apply once `issue.status == 'resolved'`

---

## 12. Audit Trail

Covered entities: `User`, `Facility`, `Area`, `Template`, `ChecklistItem`, `Inspection`, `Issue`, `IssueComment`, `Project`, `CustomerAssignment`, `ScheduledReport`, `NotificationMatrix`

Actions: `CREATE`, `UPDATE`, `DELETE`, `LOGIN`, `LOGOUT`, `EXPORT`

- Admin-only access: `/audit/` and `/audit/<id>`
- Director role: **excluded** from viewing the Audit Trail
- IP captured from `X-Forwarded-For` (Nginx) or `request.remote_addr`
- `username` and `user_role` are snapshotted at write time — survives user deletion (`ondelete='SET NULL'`)

---

## 13. PDF Export

Uses **ReportLab** directly (not weasyprint or wkhtmltopdf). Located in `app/utils/pdf_export.py`.

- Inspection PDF: full checklist results, scores, photos, notes, follow-up status
- Scorecard PDF: facility/project performance summary with charts
- **12-column grid must be preserved** — do not collapse to single-column in PDF views

Reports also support CSV export (Python `csv` module, streamed as `Response`).

---

## 14. Scheduled Reports

`ScheduledReport` records drive recurring email reports:
- Types: `summary` (KPI digest), `facility` (single facility scorecard), `issues` (open issues list)
- Frequencies: `daily`, `weekly`, `monthly`
- Attachments: optional PDF and/or CSV via `include_pdf` / `include_csv`
- `next_send_at` and `last_sent_at` track execution state
- Cron trigger: `POST /scheduled-reports/run?secret=<DIGEST_SECRET>`

---

## 15. Alembic Migration Chain

```
phase1_projects_roles
    └── phase6_features
            └── phase7_mobile_api
                    └── phase8_notification_matrix
                            └── phase9_user_full_name
                                    └── phase10_customer_password_setup
                                                └── phase11_director_role   ← HEAD
```

### MySQL ENUM Change Protocol (3 Steps)

**Always** follow this sequence when modifying an ENUM column — skipping steps causes data loss or migration failures:

```sql
-- Step 1: Expand ENUM to include BOTH old and new values
ALTER TABLE users MODIFY COLUMN role ENUM('admin','supervisor','director',...) NOT NULL;

-- Step 2: Migrate existing data
UPDATE users SET role = 'director' WHERE role = 'supervisor';

-- Step 3: Contract ENUM to remove old value
ALTER TABLE users MODIFY COLUMN role ENUM('admin','director',...) NOT NULL;
```

### Adding New Migrations

```bash
flask db migrate -m "description"
flask db upgrade
```

All migration scripts include existence checks for safe re-runs.

### Deprecated SQLAlchemy Patterns

```python
# WRONG — deprecated in SQLAlchemy 2.x
User.query.get(user_id)

# CORRECT
db.session.get(User, user_id)
```

Also: `filter()` must precede `limit()`. Avoid N+1 query patterns — use eager loading or bulk queries.

---

## 16. Frontend Conventions

### Base Template (`base.html`)

- Bootstrap 5 (CDN)
- Chart.js (CDN, for dashboard charts)
- Navbar includes unread notification badge (injected via `@app.context_processor`)
- `pending_verification_count` badge for admin/director roles
- Jinja2 globals available in all templates: `csrf_token`, `enumerate`, `sla_status`, `sla_deadline`, `sla_hours_remaining`, `SLA_HOURS`

### Forms

- All web forms use Flask-WTF CSRF protection automatically
- Manual forms (without a WTForms object) must include `<input type="hidden" name="csrf_token" value="{{ csrf_token() }}">`
- **Never nest `<form>` tags** — browsers silently discard inner forms. Toggle/action forms must be siblings, not children, of edit forms.

### File Uploads in Templates

Photos are served from `app/static/uploads/` via `url_for('static', filename=path)`.

### Real-Time Updates

**SSE is banned.** Server-Sent Events exhausted the Gunicorn sync worker pool in production. All "live" updates use polling (JS `setInterval` + `fetch`).

---

## 17. Infrastructure

### Gunicorn (`gunicorn_config.py`)

```python
bind = "127.0.0.1:8000"
workers = multiprocessing.cpu_count() * 2 + 1
worker_class = "sync"   # SSE would require 'gevent' or 'eventlet' — banned
timeout = 30
```

Log paths: `/home/jqc/logs/gunicorn-error.log`, `/home/jqc/logs/gunicorn-access.log`

### Application Logging

Configured in `create_app()`:
- `RotatingFileHandler` → `logs/jqc.log` (5 × 5 MB)
- `StreamHandler` → stdout (captured by journalctl)
- Format: `[YYYY-MM-DD HH:MM:SS] LEVEL in module: message`
- Applied to both `app.logger` and the root logger

### Nginx

- Reverse proxies to `127.0.0.1:8000`
- Must set `client_max_body_size 50M` to match `MAX_CONTENT_LENGTH`
- Passes `X-Forwarded-For` for IP capture in audit logs

### Deployment Sequence (typical change)

```bash
git pull
pip install -r requirements.txt          # if dependencies changed
flask db upgrade                          # if migrations added
sudo systemctl restart jqc               # or equivalent gunicorn restart
```

---

## 18. Known Constraints & Hard Rules

| # | Rule | Rationale |
|---|---|---|
| 1 | **No SSE** | Exhausted Gunicorn sync worker pool in production |
| 2 | **`now_eastern()` always** | `datetime.utcnow()` caused incorrect SLA purge cutoffs |
| 3 | **3-step MySQL ENUM changes** | Skipping steps causes data loss |
| 4 | **Port 465 → SSL, port 587 → STARTTLS** | Both flags True breaks Flask-Mail |
| 5 | **`CSRFProtect` as extension instance, not per-route** | Flask-WTF 1.0+ removed `@csrf_exempt` |
| 6 | **`supervisor_required` decorator name preserved** | Changing it would touch 30+ route decorators |
| 7 | **Score 0 = unanswered, exclude from calculation** | Not the same as a score of zero |
| 8 | **12-column grid in PDF** | Must not collapse in print/PDF views |
| 9 | **No nested `<form>` tags** | Browsers silently discard inner forms |
| 10 | **`log_action()` after `db.session.commit()`** | Entity ID must be committed before audit capture |
| 11 | **`db.session.get(Model, id)` not `Model.query.get(id)`** | SQLAlchemy 2.x deprecation |
| 12 | **`filter()` before `limit()`** | SQLAlchemy ordering requirement |
| 13 | **Bulk queries in customer list** | Per-customer query loop caused N+1 in `/customers` |
| 14 | **Email sent in background thread** | Never block HTTP response |
| 15 | **Open-redirect guard on login** | `_safe_next()` validates relative URLs only |

---

## 19. Change Philosophy

1. **Surgical, additive patches** — smallest possible change to achieve the goal
2. **Preserve all routes, function names, and variable names** unless explicitly asked to rename
3. **Never remove existing functionality** unless explicitly directed
4. **Log all create/update/delete actions** via `log_action()`
5. **Test migrations with existence checks** so they are safe to re-run
6. **Full file contents for 1–3 file changes**; zip package with placement map for larger changesets
7. **Explicit deploy instructions** always included (migration steps separated from code changes)
8. **Root cause analysis** on errors — never apply temporary workarounds