xamxam/docs/refactoring.md

# Posterg: Refactoring Recommendations

Concrete improvements to the separation between templating, routing, and backend logic — staying in PHP, no framework required.

---

## 1. Extract a Micro-Router + Middleware Pipeline

### Problem

Every file repeats the same preamble. The 7 action handlers and 17 page controllers all independently:

```php
require_once __DIR__ . '/../../config/bootstrap.php';
require_once __DIR__ . '/../../src/AdminAuth.php';
AdminAuth::requireLogin();
if (empty($_SESSION['csrf_token'])) {
    $_SESSION['csrf_token'] = bin2hex(random_bytes(32));
}
require_once __DIR__ . '/../../src/Database.php';
```

This is ~6-8 identical lines per file × 24 files = ~170 lines of pure duplication. When the CSRF check pattern changes, every action handler must be updated in lockstep.

### Solution

Create `src/App.php` — a thin request dispatcher with middleware hooks:

```php
// src/App.php
class App {
    private static bool $booted = false;

    /** Boot once per request: load Database, ensure CSRF token exists. */
    public static function boot(): Database {
        if (!self::$booted) {
            require_once APP_ROOT . '/src/Database.php';
            self::$booted = true;
        }
        if (empty($_SESSION['csrf_token'])) {
            $_SESSION['csrf_token'] = bin2hex(random_bytes(32));
        }
        return Database::getInstance();
    }

    /** Gate for admin pages: auth + CSRF token. */
    public static function adminGuard(): Database {
        require_once APP_ROOT . '/src/AdminAuth.php';
        AdminAuth::requireLogin();
        return self::boot();
    }

    /** Validate CSRF on POST. Call at the top of every action handler. */
    public static function verifyCsrf(): void {
        if ($_SERVER['REQUEST_METHOD'] !== 'POST'
            || !isset($_POST['csrf_token'], $_SESSION['csrf_token'])
            || !hash_equals($_SESSION['csrf_token'], $_POST['csrf_token'])) {
            http_response_code(403);
            exit('CSRF token invalide.');
        }
    }

    /** Regenerate CSRF after a successful mutation. */
    public static function rotateCsrf(): void {
        $_SESSION['csrf_token'] = bin2hex(random_bytes(32));
    }

    /** Flash a message into the session and redirect. */
    public static function redirect(string $url, ?string $success = null, ?string $error = null): never {
        if ($success) $_SESSION['success'] = $success;
        if ($error)   $_SESSION['error']   = $error;
        header('Location: ' . $url);
        exit;
    }
}
```

Every admin page becomes:

```php
<?php
require_once __DIR__ . '/../../config/bootstrap.php';
$db = App::adminGuard();
// ... page-specific logic
```

Every action handler becomes:

```php
<?php
require_once __DIR__ . '/../../../config/bootstrap.php';
$db = App::adminGuard();
App::verifyCsrf();
// ... mutation logic
App::rotateCsrf();
App::redirect('/admin/', success: 'Done.');
```

**Impact**: Eliminates ~170 lines of duplication. Centralises the CSRF lifecycle (generate, verify, rotate) in one place. Any change to the auth or CSRF pattern is a single-file edit.

---

## 2. Separate Controllers from Templates

### Problem

Every page file (e.g. `public/index.php`, `public/search.php`, `public/admin/edit.php`) is a single file that mixes three concerns:

1. **Data fetching** (DB queries, input validation, pagination math)
2. **View variable preparation** (`$pageTitle`, `$ogTags`, `$extraCss`, `$bodyClass`)
3. **HTML rendering** (the entire template, inline)

`system.php` is the extreme case: 400+ lines of PHP logic (systemd checks, curl pings, disk stats, log parsing, nginx syntax highlighting) followed by 200+ lines of inline `<style>`, then 200+ lines of HTML, then 30+ lines of inline `<script>`.

`search.php` is another: the répertoire index view and the search results view are two entirely different pages sharing a single file because they share a URL.

### Solution

Introduce a `controllers/` directory. Each controller is a function that does the data work and returns an associative array. The page file becomes a thin bridge.

**Directory structure:**

```
src/
  App.php               ← new: middleware/helpers
  controllers/
    HomeController.php
    SearchController.php
    TfeController.php
    admin/
      ThesisListController.php
      ThesisEditController.php
      ThesisAddController.php
      TagController.php
      PageController.php
      SystemController.php
      AccountController.php
  ...existing files...

templates/
  public/
    home.php
    search-results.php
    search-index.php
    tfe.php
    apropos.php
    licence.php
  admin/
    thesis-list.php
    thesis-edit.php
    thesis-add.php
    tags.php
    pages-list.php
    pages-edit.php
    system.php
    account.php
  ...existing shared templates (head.php, header.php, footer.php)...
```

**Example — `search.php` split:**

```php
// src/controllers/SearchController.php
class SearchController {
    public static function index(Database $db): array {
        // Collect params, run queries, compute pagination
        // ...all current logic from the top of search.php...
        return [
            'hasSearch'   => $hasSearch,
            'results'     => $results,
            'totalItems'  => $totalItems,
            'totalPages'  => $totalPages,
            'years'       => $years,
            'orientations'=> $orientations,
            'apPrograms'  => $apPrograms,
            'keywords'    => $keywords,
            'students'    => $students,
            'authorMap'   => $authorMap,
            'page'        => $page,
            'error'       => $validationError,
            // Template config
            'pageTitle'   => 'Répertoire – Posterg',
            'bodyClass'   => 'search-body',
            'extraCss'    => ['/assets/css/search.css'],
            'currentNav'  => 'repertoire',
        ];
    }
}
```

```php
// public/search.php (entire file)
<?php
require_once __DIR__ . '/../config/bootstrap.php';
require_once APP_ROOT . '/src/RateLimit.php';

// Rate limiting (stays here — it's a routing concern)
$rateLimit = new RateLimit(30, 60);
if (!$rateLimit->check()) { /* ...429 response... */ }
$rateLimit->sendHeaders();

$db = App::boot();
require_once APP_ROOT . '/src/controllers/SearchController.php';
$data = SearchController::index($db);
extract($data);  // populates $hasSearch, $results, $pageTitle, etc.

include APP_ROOT . '/templates/head.php';
include APP_ROOT . '/templates/header.php';
if ($hasSearch) {
    include APP_ROOT . '/templates/public/search-results.php';
} else {
    include APP_ROOT . '/templates/public/search-index.php';
}
include APP_ROOT . '/templates/footer.php';
```

```
// templates/public/search-results.php
// Pure HTML + minimal <?= ?> for output. No DB queries. No input processing.
```

**Impact**: Templates become auditable for XSS — they only do output. Controllers are testable — they return arrays, no output buffering needed. The `extract()` bridge keeps the familiar variable-name convention without changing every template.

---

## 3. Introduce a `render()` Helper to Replace the 5-Line Include Chain

### Problem

Every page ends with the same sequence:

```php
include APP_ROOT . '/templates/head.php';
include APP_ROOT . '/templates/header.php';
// ... main content ...
include APP_ROOT . '/templates/footer.php';        // or admin/footer.php
```

The admin variant also requires `$isAdmin = true; $bodyClass = 'admin-body';` to be set before the head include. Forgetting any variable or include breaks the page silently.

### Solution

Add a `render()` function to `App`:

```php
// In src/App.php
public static function render(string $template, array $vars = []): void {
    extract($vars);
    include APP_ROOT . '/templates/head.php';
    include APP_ROOT . '/templates/header.php';
    include APP_ROOT . '/templates/' . $template;
    // Choose footer based on admin flag
    if (!empty($isAdmin)) {
        include APP_ROOT . '/templates/admin/footer.php';
    } else {
        include APP_ROOT . '/templates/footer.php';
    }
}
```

Every page becomes:

```php
// public/licence.php
<?php
require_once __DIR__ . '/../config/bootstrap.php';
$db = App::boot();
require_once APP_ROOT . '/src/controllers/LicenceController.php';
App::render('public/licence.php', LicenceController::index($db));
```

Every admin page becomes:

```php
// public/admin/tags.php
<?php
require_once __DIR__ . '/../../config/bootstrap.php';
$db = App::adminGuard();
require_once APP_ROOT . '/src/controllers/admin/TagController.php';
App::render('admin/tags.php', TagController::index($db));
```

**Impact**: No more forgotten includes. The head→header→content→footer pipeline is enforced. Admin footer selection is automatic. Template variables are explicit (passed as array keys, not ambient scope).

---

## 4. Consolidate Action Handlers into Controller Methods

### Problem

The `public/admin/actions/` directory contains 7 POST-only files that each:

1. Require bootstrap + auth
2. Verify CSRF
3. Extract + validate `$_POST` data
4. Call `Database` methods
5. Rotate CSRF
6. Flash a message
7. Redirect

Steps 1-2 and 5-7 are identical in every file. The actual business logic (step 4) is usually 5-15 lines.

`actions/publish.php` (95 lines) does exactly one thing: flip `is_published` on 1-N theses. The other 80 lines are auth, CSRF, validation boilerplate.

### Solution

Merge each action into its controller as a `handlePost()` or action-specific static method:

```php
// src/controllers/admin/ThesisListController.php
class ThesisListController {
    public static function index(Database $db): array {
        // ... current admin/index.php data logic ...
    }

    public static function publish(Database $db): never {
        App::verifyCsrf();
        $action = $_POST['action'] ?? '';
        $isBulk = !empty($_POST['bulk']);
        // ... 15 lines of actual logic ...
        App::rotateCsrf();
        App::redirect('/admin/', success: "$count TFE(s) publié(s).");
    }

    public static function toggleMaintenance(Database $db): never {
        App::verifyCsrf();
        // ... 6 lines ...
        App::rotateCsrf();
        App::redirect('/admin/', success: 'Maintenance toggled.');
    }
}
```

The page file handles dispatch:

```php
// public/admin/index.php
<?php
require_once __DIR__ . '/../../config/bootstrap.php';
$db = App::adminGuard();
require_once APP_ROOT . '/src/controllers/admin/ThesisListController.php';

if ($_SERVER['REQUEST_METHOD'] === 'POST') {
    $action = $_POST['_action'] ?? '';
    match($action) {
        'publish'     => ThesisListController::publish($db),
        'maintenance' => ThesisListController::toggleMaintenance($db),
        default       => App::redirect('/admin/', error: 'Action inconnue.'),
    };
}

App::render('admin/thesis-list.php', ThesisListController::index($db));
```

**Or** keep the existing `actions/*.php` files but reduce each to 3 lines:

```php
// public/admin/actions/publish.php (entire file)
<?php
require_once __DIR__ . '/../../../config/bootstrap.php';
$db = App::adminGuard();
App::verifyCsrf();
require_once APP_ROOT . '/src/controllers/admin/ThesisListController.php';
ThesisListController::publish($db);
```

**Impact**: The `actions/` directory goes from 7 files × 50-100 lines each ≈ 500 lines, to 7 files × 5 lines each ≈ 35 lines. The business logic moves into testable controller methods.

---

## 5. Extract Inline CSS and JS from `system.php`

### Problem

`system.php` contains:
- 180 lines of `<style>` embedded in the page
- 40 lines of `<script>` embedded in the page
- 12 PHP helper functions defined inline (`safeExec`, `systemdStatus`, `localHttpCheck`, `humanBytes`, `statusLabel`, `statusClass`, `readLogTail`, `logLineClass`, `nginxLineClass`)

This makes it the largest file in the project (500+ lines) and impossible to cache the CSS/JS independently.

### Solution

1. Move the `<style>` block → `public/assets/css/system.css`, reference it via `$extraCss`
2. Move the `<script>` block → `public/assets/js/system.js`, reference it via `$extraJs`
3. Move the 12 helper functions → `src/controllers/admin/SystemController.php`
4. Move the data-gathering logic (checks array, PHP info, disk stats, log reading) into `SystemController::index()`

The template becomes pure HTML with `<?= ?>` interpolation.

**Impact**: `system.php` goes from ~500 lines to ~5 lines (boot + controller + render). The CSS/JS becomes cacheable by the browser (nginx `expires 30d` rule already exists for `.css`/`.js`). The helpers become unit-testable.

---

## 6. Introduce Template Partials for Repeated UI Patterns

### Problem

Several HTML patterns are copy-pasted across templates:

**Flash messages** — Identical block in `admin/index.php`, `admin/edit.php`, `admin/tags.php`, `admin/pages.php`, `admin/account.php`:
```php
<?php if (isset($_SESSION['error'])): ?>
<div class="admin-alert admin-alert--error">⚠ <?= htmlspecialchars($_SESSION['error']); unset($_SESSION['error']); ?></div>
<?php endif; ?>
<?php if (isset($_SESSION['success'])): ?>
<div class="admin-alert admin-alert--success">✓ <?= htmlspecialchars($_SESSION['success']); unset($_SESSION['success']); ?></div>
<?php endif; ?>
```

**Pagination** — Near-identical block in `index.php` and `search.php` (30 lines each, slightly different URL building).

**Select dropdowns with "selected" logic** — Repeated in `admin/add.php` and `admin/edit.php` for orientation, AP, finality, license, access type.

**Jury fieldset + JS** — Duplicated between `admin/add.php` and `admin/edit.php` (50+ lines of identical HTML + 20 lines of identical JS).

### Solution

Create small partial templates:

```
templates/
  partials/
    flash-messages.php     ← reads $_SESSION['error'] / $_SESSION['success']
    pagination.php         ← receives $page, $totalPages, $baseUrl
    admin/
      select-field.php     ← receives $name, $label, $options, $selected
      checkbox-list.php    ← receives $name, $label, $options, $checked
      jury-fieldset.php    ← receives $jury (array), outputs fieldset + JS
```

**Example — `flash-messages.php`:**

```php
<?php
// templates/partials/flash-messages.php
$_flashError   = $_SESSION['error']   ?? $_SESSION['admin_error']   ?? $_SESSION['edit_error']   ?? null;
$_flashSuccess = $_SESSION['success'] ?? $_SESSION['admin_success'] ?? $_SESSION['edit_success'] ?? null;
unset($_SESSION['error'], $_SESSION['success'], $_SESSION['admin_error'],
      $_SESSION['admin_success'], $_SESSION['edit_error'], $_SESSION['edit_success']);
?>
<?php if ($_flashError): ?>
<div class="admin-alert admin-alert--error">⚠ <?= htmlspecialchars($_flashError) ?></div>
<?php endif; ?>
<?php if ($_flashSuccess): ?>
<div class="admin-alert admin-alert--success">✓ <?= htmlspecialchars($_flashSuccess) ?></div>
<?php endif; ?>
```

This also fixes a latent bug: the project uses 6 different session keys for flash messages (`error`, `success`, `admin_error`, `admin_success`, `edit_error`, `edit_success`, `form_error`). Centralising flash handling would unify these into two keys.

**Impact**: Eliminates ~200 lines of duplicated HTML. The jury fieldset (duplicated between add and edit) becomes a single 50-line partial. Form field partials make admin pages shorter and more consistent.

---

## 7. Unify Flash Message Keys

### Problem

The project uses 7 different session keys for flash messages across different pages:

| Key | Used by |
|-----|---------|
| `$_SESSION['error']` | `admin/index.php`, `visibility.php`, `account.php` |
| `$_SESSION['success']` | `admin/index.php`, `visibility.php`, `pages.php`, `account.php` |
| `$_SESSION['admin_error']` | `tags.php` |
| `$_SESSION['admin_success']` | `tags.php` |
| `$_SESSION['edit_error']` | `admin/edit.php` |
| `$_SESSION['edit_success']` | `admin/edit.php` |
| `$_SESSION['form_error']` | `admin/add.php` |
| `$_SESSION['form_data']` | `admin/add.php` (re-population) |

This means flash messages can silently persist across pages if a redirect sends the user somewhere that doesn't read the matching key.

### Solution

Standardise on two keys: `$_SESSION['_flash_error']` and `$_SESSION['_flash_success']`. Consume them in the shared `flash-messages.php` partial. Add `App::flash(string $type, string $message)` helper.

---

## 8. Move OG Tag Construction into Controller Logic

### Problem

Every public page constructs `$ogTags` inline before the template, with ~15 lines of boilerplate. `tfe.php` has 25 lines of OG logic including image resolution (banner → cover → none) and description truncation.

### Solution

Move OG tag logic into each controller's return array. Create a helper:

```php
// In src/App.php or a dedicated helpers file
public static function ogTags(array $overrides = []): array {
    return array_merge([
        'type'        => 'website',
        'site_name'   => 'Posterg – ERG',
        'title'       => 'Posterg',
        'description' => '',
        'url'         => '',
        'image'       => '',
    ], $overrides);
}
```

The TFE controller builds the OG image resolution as part of its data preparation. The template never touches it.

---

## Summary: Proposed File Layout

```
src/
  App.php                          ← NEW: boot, adminGuard, verifyCsrf, render, redirect, flash
  Database.php                     ← unchanged
  AdminAuth.php                    ← unchanged
  RateLimit.php                    ← unchanged
  Parsedown.php                    ← unchanged
  config.php                       ← unchanged
  controllers/
    HomeController.php             ← extracted from public/index.php
    SearchController.php           ← extracted from public/search.php
    TfeController.php              ← extracted from public/tfe.php
    AproposController.php          ← extracted from public/apropos.php
    LicenceController.php          ← extracted from public/licence.php
    admin/
      ThesisListController.php     ← extracted from admin/index.php + actions/publish.php + actions/maintenance.php
      ThesisEditController.php     ← extracted from admin/edit.php + actions/edit.php
      ThesisAddController.php      ← extracted from admin/add.php + actions/formulaire.php
      TagController.php            ← extracted from admin/tags.php + actions/tag.php
      PageController.php           ← extracted from admin/pages.php + pages-edit.php + actions/page.php
      SystemController.php         ← extracted from admin/system.php (400 lines of logic)
      AccountController.php        ← extracted from admin/account.php + actions/account.php
      ImportController.php         ← extracted from admin/import.php

templates/
  head.php                         ← unchanged
  header.php                       ← unchanged
  footer.php                       ← unchanged
  search-bar.php                   ← unchanged
  admin/
    footer.php                     ← unchanged
  partials/
    flash-messages.php             ← NEW
    pagination.php                 ← NEW
    admin/
      jury-fieldset.php            ← NEW (deduplicated from add.php + edit.php)
      select-field.php             ← NEW
      checkbox-list.php            ← NEW
  public/
    home.php                       ← extracted HTML from index.php
    search-results.php             ← extracted HTML from search.php (results view)
    search-index.php               ← extracted HTML from search.php (répertoire view)
    tfe.php                        ← extracted HTML from tfe.php
    apropos.php                    ← extracted HTML from apropos.php
    licence.php                    ← extracted HTML from licence.php
  admin/
    thesis-list.php                ← extracted HTML from admin/index.php
    thesis-edit.php                ← extracted HTML from admin/edit.php
    thesis-add.php                 ← extracted HTML from admin/add.php
    tags.php                       ← extracted HTML from admin/tags.php
    pages-list.php                 ← extracted HTML from admin/pages.php
    pages-edit.php                 ← extracted HTML from admin/pages-edit.php
    system.php                     ← extracted HTML from admin/system.php
    account.php                    ← extracted HTML from admin/account.php

public/
  index.php                        ← 5-8 lines: boot, controller, render
  search.php                       ← 8-10 lines: boot, rate limit, controller, render
  tfe.php                          ← 5-8 lines
  apropos.php                      ← 5-8 lines
  licence.php                      ← 5-8 lines
  media.php                        ← unchanged (already clean)
  maintenance.php                  ← unchanged
  live-reload.php                  ← unchanged
  admin/
    index.php                      ← 8-10 lines: boot, dispatch POST or render
    edit.php                       ← 8-10 lines
    add.php                        ← 8-10 lines
    tags.php                       ← 6-8 lines
    pages.php                      ← 5-8 lines
    pages-edit.php                 ← 5-8 lines
    system.php                     ← 5-8 lines
    account.php                    ← 8-10 lines
    import.php                     ← 5-8 lines
    login.php                      ← unchanged
    logout.php                     ← unchanged
    actions/                       ← can be REMOVED (merged into controllers)
      OR reduced to 3-5 line stubs
```

## Estimated Impact

| Metric | Before | After |
|--------|--------|-------|
| Lines in `public/` page files | ~4,200 | ~200 |
| Lines in `actions/` handlers | ~500 | 0 (merged) |
| Duplicated boilerplate | ~300 lines | ~0 |
| Duplicated HTML (jury, flash, pagination) | ~200 lines | ~0 |
| `system.php` | 530 lines | ~8 lines (page) + ~180 (controller) + ~100 (CSS) + ~30 (JS) |
| Testable controller methods | 0 | ~15 |
| Flash session key variants | 7 | 2 |

Total net reduction: ~800–1,000 lines eliminated through deduplication, with cleaner separation making the remaining code auditable and testable.

## Execution Order

This can be done incrementally, one page at a time, with zero disruption:

1. **Create `src/App.php`** with `boot()`, `adminGuard()`, `verifyCsrf()`, `rotateCsrf()`, `redirect()`, `render()`, `flash()`
2. **Create `templates/partials/flash-messages.php`** and adopt it in one admin page
3. **Extract `SystemController`** — the biggest single-file win (500 → 8 lines)
4. **Extract `SearchController`** — the most complex public page
5. **Extract `ThesisEditController`** — merges `edit.php` + `actions/edit.php`, deduplicates jury fieldset
6. **Do remaining controllers one by one**, smallest first
7. **Unify flash keys** project-wide as the last step