Spry/examples/TemplateExample.vala

using Astralis;
using Invercargill;
using Invercargill.DataStructures;
using Inversion;
using Spry;

/**
 * TemplateExample.vala - Demonstrates PageComponent and PageTemplate usage
 * 
 * This example shows how to create template-based pages where:
 * - MainLayoutTemplate provides the base HTML structure with header and footer
 * - AdminSectionTemplate adds an admin navigation sidebar (nested template)
 * - PageComponents render their content into template outlets
 * 
 * Route structure:
 *   /              -> HomePage (uses MainLayoutTemplate)
 *   /about         -> AboutPage (uses MainLayoutTemplate)
 *   /admin         -> AdminDashboardPage (uses AdminSectionTemplate -> MainLayoutTemplate)
 *   /admin/users   -> AdminUsersPage (uses AdminSectionTemplate -> MainLayoutTemplate)
 */

// =============================================================================
// STYLESHEETS - CSS content served as FastResources
// =============================================================================

/**
 * Main CSS - Base styles for all pages
 */
private const string MAIN_CSS = """
/* Base Reset & Layout */
* { box-sizing: border-box; margin: 0; padding: 0; }
html, body {
    height: 100%;
}
body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    line-height: 1.6;
    background: #f5f7fa;
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

/* Header */
header {
    background: #2c3e50;
    color: white;
    padding: 1rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-shrink: 0;
}
header nav a {
    color: white;
    margin-right: 1.5rem;
    text-decoration: none;
    font-weight: 500;
    transition: opacity 0.2s;
}
header nav a:hover { opacity: 0.8; }
header nav a:last-child { margin-right: 0; }
header .visit-info {
    font-size: 0.85rem;
    opacity: 0.8;
}

/* Main Content - grows to fill space */
main.container {
    flex: 1;
    max-width: 1200px;
    width: 100%;
    margin: 0 auto;
    padding: 2rem 1rem;
}

/* Cards */
.card {
    background: white;
    border-radius: 12px;
    padding: 2rem;
    margin-bottom: 1.5rem;
    box-shadow: 0 2px 8px rgba(0,0,0,0.08);
}

/* Typography */
h1 { color: #2c3e50; margin-bottom: 1rem; }
h2 { color: #34495e; margin-bottom: 0.75rem; margin-top: 1.5rem; }
h3 { color: #34495e; margin-bottom: 0.5rem; margin-top: 1rem; }
p { color: #555; margin-bottom: 1rem; }
ul, ol { margin-left: 1.5rem; margin-bottom: 1rem; }
li { margin-bottom: 0.5rem; color: #555; }

/* Links */
a { color: #3498db; text-decoration: none; transition: color 0.2s; }
a:hover { color: #2980b9; text-decoration: underline; }

/* Code */
code {
    background: #f0f0f0;
    padding: 0.2rem 0.5rem;
    border-radius: 4px;
    font-size: 0.9em;
    color: #e74c3c;
}
pre {
    background: #263238;
    color: #aed581;
    padding: 1rem;
    border-radius: 8px;
    overflow-x: auto;
    font-size: 0.9rem;
    margin: 1rem 0;
}

/* Footer - at bottom */
footer {
    background: #2c3e50;
    color: rgba(255,255,255,0.7);
    padding: 1.5rem;
    text-align: center;
    flex-shrink: 0;
}

/* Buttons & Forms */
button {
    background: #3498db;
    color: white;
    border: none;
    padding: 0.75rem 1.5rem;
    border-radius: 6px;
    cursor: pointer;
    font-size: 1rem;
    font-weight: 500;
    transition: all 0.2s;
}
button:hover {
    background: #2980b9;
}
input[type="text"] {
    padding: 0.75rem;
    border: 2px solid #e0e0e0;
    border-radius: 6px;
    font-size: 1rem;
    transition: border-color 0.2s;
}
input[type="text"]:focus {
    outline: none;
    border-color: #3498db;
}
""";

/**
 * Admin CSS - Additional styles for admin section
 */
private const string ADMIN_CSS = """
/* Admin Section Layout */
.admin-section {
    display: flex;
    gap: 2rem;
}

/* Admin Sidebar */
.admin-sidebar {
    width: 220px;
    background: #34495e;
    padding: 1.5rem;
    border-radius: 12px;
    flex-shrink: 0;
}
.admin-sidebar h3 {
    color: white;
    margin-bottom: 1rem;
    font-size: 1.1rem;
    border-bottom: 1px solid rgba(255,255,255,0.2);
    padding-bottom: 0.75rem;
}
.admin-sidebar ul {
    list-style: none;
    margin: 0;
    padding: 0;
}
.admin-sidebar li { margin-bottom: 0.5rem; margin-left: 0; }
.admin-sidebar a {
    color: rgba(255,255,255,0.7);
    display: block;
    padding: 0.5rem 0.75rem;
    border-radius: 6px;
    transition: all 0.2s;
}
.admin-sidebar a:hover {
    color: white;
    background: rgba(255,255,255,0.1);
    text-decoration: none;
}

/* Admin Content Area */
.admin-content {
    flex: 1;
    min-width: 0;
}

/* Dashboard Stats */
.dashboard-stats {
    display: flex;
    gap: 1.5rem;
    flex-wrap: wrap;
}
.stat-card {
    background: #3498db;
    color: white;
    padding: 1.5rem;
    border-radius: 12px;
    min-width: 180px;
}
.stat-card h3 {
    color: rgba(255,255,255,0.9);
    font-size: 0.85rem;
    text-transform: uppercase;
    letter-spacing: 1px;
    margin: 0 0 0.5rem 0;
}
.stat-card .stat-value {
    font-size: 2.5rem;
    font-weight: bold;
}

/* User List */
.user-list {
    margin: 1.5rem 0;
}
.user-item {
    display: flex;
    align-items: center;
    gap: 1rem;
    padding: 1rem 1.25rem;
    background: #f8f9fa;
    margin-bottom: 0.75rem;
    border-radius: 8px;
    transition: background 0.2s;
}
.user-item:hover {
    background: #e9ecef;
}
.user-item .user-name {
    flex: 1;
    font-weight: 500;
    color: #2c3e50;
}
.user-item .user-status {
    color: #27ae60;
    font-size: 0.9rem;
    font-weight: 500;
}

/* Add Form */
.add-form {
    display: flex;
    gap: 0.75rem;
    margin-top: 1.5rem;
}
.add-form input[type="text"] {
    flex: 1;
    max-width: 300px;
}

/* Navigation Links */
.nav-link {
    display: inline-block;
    margin-top: 1.5rem;
    color: #3498db;
    font-weight: 500;
}
.nav-link:hover { color: #2980b9; }
""";

// =============================================================================
// STORES - Simple data stores for demonstration
// =============================================================================

class AppState : Object {
    public int visit_count { get; set; }
    public string last_visit { get; set; }
}

class UserStore : Object {
    private Series<string> users = new Series<string>();

    construct {
        users.add("Alice");
        users.add("Bob");
        users.add("Charlie");
    }

    public Enumerable<string> get_all() {
        return users;
    }

    public void add_user(string name) {
        users.add(name);
    }

    public int count() {
        return (int)users.length;
    }
}

// =============================================================================
// TEMPLATES - Provide reusable page layouts
// =============================================================================

/**
 * MainLayoutTemplate - The base template for all pages
 * 
 * Provides:
 * - HTML document structure
 * - Common <head> elements (scripts, styles)
 * - Site-wide header with navigation
 * - Site-wide footer
 * 
 * Uses <spry-template-outlet> where child content/templates will be inserted
 */
class MainLayoutTemplate : PageTemplate {
    
    private AppState app_state = inject<AppState>();
    
    public override string markup { get {
        return """
        <!DOCTYPE html>
        <html lang="en">
        <head>
            <meta charset="UTF-8">
            <meta name="viewport" content="width=device-width, initial-scale=1.0">
            <title>Spry Template Example</title>
            <link rel="stylesheet" href="/styles/main.css">
            <script src="https://cdn.jsdelivr.net/npm/htmx.org@2.0.8/dist/htmx.min.js"></script>
        </head>
        <body>
            <header>
                <nav>
                    <a href="/">Home</a>
                    <a href="/about">About</a>
                    <a href="/admin">Admin</a>
                </nav>
                <small class="visit-info" sid="visit-info"></small>
            </header>
            <main class="container">
                <spry-template-outlet />
            </main>
            <footer>
                <p>Built with Spry Framework - Template Example</p>
            </footer>
        </body>
        </html>
        """;
    }}
    
    public override async void prepare() throws Error {
        this["visit-info"].text_content = @"Visits: $(app_state.visit_count) | Last: $(app_state.last_visit)";
    }
}

/**
 * AdminSectionTemplate - A nested template for admin pages
 * 
 * This template is applied to routes starting with /admin
 * It adds an admin sidebar navigation around the page content
 * 
 * Templates are applied in order of rank (based on prefix length):
 * 1. MainLayoutTemplate (rank 0, prefix "") - outermost
 * 2. AdminSectionTemplate (rank 1, prefix "/admin") - nested inside main
 * 3. PageComponent - innermost content
 */
class AdminSectionTemplate : PageTemplate {
    
    public override string markup { get {
        return """
        <head>
            <link rel="stylesheet" href="/styles/admin.css">
        </head>
        <div class="admin-section">
            <aside class="admin-sidebar">
                <h3>Admin Menu</h3>
                <ul>
                    <li><a href="/admin">Dashboard</a></li>
                    <li><a href="/admin/users">Users</a></li>
                </ul>
            </aside>
            <div class="admin-content">
                <spry-template-outlet />
            </div>
        </div>
        """;
    }}
}

// =============================================================================
// PAGE COMPONENTS - Render content into templates
// =============================================================================

/**
 * HomePage - The main landing page
 * 
 * Extends PageComponent (not Component) to automatically use template rendering
 * The handle_request method in PageComponent:
 * 1. Finds all matching templates (MainLayoutTemplate matches "")
 * 2. Renders each template in order
 * 3. Inserts each rendered content into the previous template's outlet
 */
class HomePage : PageComponent {
    
    private AppState app_state = inject<AppState>();
    
    public const string ROUTE = "/";
    
    public override string markup { get {
        return """
        <div class="card" sid="home">
            <h1>Welcome to Spry!</h1>
            <p>This example demonstrates template-based pages using <code>PageComponent</code> and <code>PageTemplate</code>.</p>
            
            <h2>Features</h2>
            <ul>
                <li><strong>MainLayoutTemplate</strong> - Provides base HTML, header, footer</li>
                <li><modulestrong>AdminSectionTemplate</strong> - Adds sidebar for /admin/* routes</li>
                <li><strong>PageComponent</strong> - Pages automatically inherit templates</li>
            </ul>
            
            <h2>Try These Pages</h2>
            <ul>
                <li><a href="/about">About Page</a> - Uses main layout only</li>
                <li><a href="/admin">Admin Dashboard</a> - Uses admin template + main layout</li>
                <li><a href="/admin/users">Admin Users</a> - Interactive user list</li>
            </ul>
            
            <p sid="visit-count"></p>
        </div>
        """;
    }}
    
    public override async void prepare() throws Error {
        app_state.visit_count++;
        app_state.last_visit = new DateTime.now_local().format("%H:%M:%S");
        this["visit-count"].text_content = @"You have visited $(app_state.visit_count) times.";
    }
}

/**
 * AboutPage - A simple about page
 */
class AboutPage : PageComponent {
    
    public const string ROUTE = "/about";
    
    public override string markup { get {
        return """
        <div class="card">
            <h1>About Spry Templates</h1>
            
            <h2>How Templates Work</h2>
            <p>Templates use <code><spry-template-outlet /></code> to define where child content will be inserted.</p>
            
            <h3>Template Resolution</h3>
            <p>When a <code>PageComponent</code> handles a request:</p>
            <ol>
                <li>It finds all registered <code>PageTemplate</code>s matching the route</li>
                <li>Templates are ordered by their prefix length (rank)</li>
                <li>Each template is rendered, with content nested into outlets</li>
            </ol>
            
            <h3>Route Matching</h3>
            <pre>
Prefix "" matches all routes
Prefix "/admin" matches /admin and /admin/*
Prefix "/admin/users" matches /admin/users only
            </pre>
            
            <a href="/" class="nav-link">Back to Home</a>
        </div>
        """;
    }}
}

/**
 * AdminDashboardPage - Admin dashboard with statistics
 */
class AdminDashboardPage : PageComponent {
    
    private UserStore user_store = inject<UserStore>();
    
    public const string ROUTE = "/admin";
    
    public override string markup { get {
        return """
        <div class="card">
            <h1>Admin Dashboard</h1>
            
            <div class="dashboard-stats">
                <div class="stat-card">
                    <h3>Total Users</h3>
                    <div class="stat-value" sid="user-count"></div>
                </div>
            </div>
            
            <a href="/" class="nav-link">Back to Home</a>
        </div>
        """;
    }}
    
    public override async void prepare() throws Error {
        this["user-count"].text_content = user_store.count().to_string();
    }
}

/**
 * AdminUsersPage - Admin page with interactive user list
 * 
 * Demonstrates HTMX interactions within a templated page.
 * The form targets the card with outerHTML swap so the entire card
 * is replaced with the updated content.
 */
class AdminUsersPage : PageComponent {
    
    private UserStore user_store = inject<UserStore>();
    private ComponentFactory factory = inject<ComponentFactory>();
    private HttpContext http_context = inject<HttpContext>();
    
    public const string ROUTE = "/admin/users";
    
    public override string markup { get {
        return """
        <div class="card" sid="users-card">
            <h1>User Management</h1>
            
            <div class="user-list">
                <spry-outlet sid="user-list"/>
            </div>
            
            <form class="add-form" sid="add-form" spry-action=":AddUser" spry-target="users-card" hx-swap="outerHTML">
                <input type="text" name="username" placeholder="Enter username" required>
                <button type="submit">Add User</button>
            </form>
            
            <a href="/admin" class="nav-link">Back to Dashboard</a>
        </div>
        """;
    }}
    
    public override async void prepare() throws Error {
        refresh_user_list();
    }
    
    private void refresh_user_list() throws Error {
        var users = user_store.get_all();
        var items = new Series<Renderable>();
        
        users.iterate((name) => {
            var item = factory.create<UserItemComponent>();
            item.username = name;
            items.add(item);
        });
        
        set_outlet_children("user-list", items);
    }
    
    public async override void handle_action(string action) throws Error {
        if (action == "AddUser") {
            var username = http_context.request.query_params.get_any_or_default("username");
            if (username != null && username.length > 0) {
                user_store.add_user(username);
            }
            refresh_user_list();
        }
    }
}

/**
 * UserItemComponent - Individual user item in the list
 */
class UserItemComponent : Component {
    
    public string username { set; get; }
    
    public override string markup { get {
        return """
        <div class="user-item" sid="user-item">
            <span class="user-name" sid="name"></span>
            <span class="user-status">Active</span>
        </div>
        """;
    }}
    
    public override async void prepare() throws Error {
        this["name"].text_content = username;
    }
}

// =============================================================================
// APPLICATION SETUP
// =============================================================================

void main(string[] args) {
    int port = args.length > 1 ? int.parse(args[1]) : 8080;
    
    print("═══════════════════════════════════════════════════════════════\n");
    print("            Spry Template Example (PageComponent + PageTemplate)\n");
    print("═══════════════════════════════════════════════════════════════\n");
    print("  Port: %d\n", port);
    print("═══════════════════════════════════════════════════════════════\n");
    print("  Endpoints:\n");
    print("    /              - Home page (MainLayoutTemplate)\n");
    print("    /about         - About page (MainLayoutTemplate)\n");
    print("    /admin         - Admin dashboard (AdminSectionTemplate)\n");
    print("    /admin/users   - User management (AdminSectionTemplate)\n");
    print("    /styles/main.css  - Main stylesheet (FastResource)\n");
    print("    /styles/admin.css - Admin stylesheet (FastResource)\n");
    print("═══════════════════════════════════════════════════════════════\n");
    print("\nPress Ctrl+C to stop the server\n\n");
    
    try {
        var application = new WebApplication(port);
        
        // Enable compression
        application.use_compression();
        
        // Add Spry module for component actions
        application.add_module<SpryModule>();
        
        // Register stores as singletons
        application.add_singleton<AppState>();
        application.add_singleton<UserStore>();
        
        // Register templates with route prefixes
        // MainLayoutTemplate applies to ALL routes (empty prefix)
        var spry_cfg = application.configure_with<SpryConfigurator>();
        spry_cfg.add_template<MainLayoutTemplate>("");

        // AdminSectionTemplate applies to /admin/* routes
        spry_cfg.add_template<AdminSectionTemplate>("/admin");
        
        // Register page components as endpoints
        application.add_transient<HomePage>();
        application.add_endpoint<HomePage>(new EndpointRoute(HomePage.ROUTE));
        
        application.add_transient<AboutPage>();
        application.add_endpoint<AboutPage>(new EndpointRoute(AboutPage.ROUTE));
        
        application.add_transient<AdminDashboardPage>();
        application.add_endpoint<AdminDashboardPage>(new EndpointRoute(AdminDashboardPage.ROUTE));
        
        application.add_transient<AdminUsersPage>();
        application.add_endpoint<AdminUsersPage>(new EndpointRoute(AdminUsersPage.ROUTE));
        
        // Register child components
        application.add_transient<UserItemComponent>();
        
        // Register CSS as FastResources
        application.add_startup_endpoint<FastResource>(new EndpointRoute("/styles/main.css"), () => {
            try {
                return new FastResource.from_string(MAIN_CSS)
                    .with_content_type("text/css; charset=utf-8")
                    .with_default_compressors();
            } catch (Error e) {
                error("Failed to create main CSS resource: %s", e.message);
            }
        });
        
        application.add_startup_endpoint<FastResource>(new EndpointRoute("/styles/admin.css"), () => {
            try {
                return new FastResource.from_string(ADMIN_CSS)
                    .with_content_type("text/css; charset=utf-8")
                    .with_default_compressors();
            } catch (Error e) {
                error("Failed to create admin CSS resource: %s", e.message);
            }
        });
        
        application.run();
        
    } catch (Error e) {
        printerr("Error: %s\n", e.message);
        Process.exit(1);
    }
}