Spry/examples/TodoComponent.vala

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

/**
 * TodoComponent Example
 * 
 * Demonstrates using the Spry.Component class with IoC composition.
 * Shows how to:
 *   - Build a complete CRUD interface with Components
 *   - Use inject<T>() for dependency injection
 *   - Use ComponentFactory to create component instances
 *   - Use spry-action and spry-target for declarative HTMX interactions
 *   - Use handle_action() for action handling
 * 
 * Usage: todo-component [port]
 */

/**
 * TodoItem - Simple task model for our todo list.
 */
class TodoItem : Object {
    public int id { get; set; }
    public string title { get; set; }
    public bool completed { get; set; }
    
    public TodoItem(int id, string title, bool completed = false) {
        this.id = id;
        this.title = title;
        this.completed = completed;
    }
}

/**
 * TodoStore - In-memory todo store registered as singleton.
 */
class TodoStore : Object {
    private Series<TodoItem> items = new Series<TodoItem>();
    private int next_id = 1;
    
    public TodoStore() {
        // Add some initial items
        add("Learn Spry.Component");
        add("Build dynamic HTML pages");
        add("Handle form submissions");
    }
    
    public void add(string title) {
        items.add(new TodoItem(next_id++, title));
    }
    
    public void toggle(int id) {
        items.to_immutable_buffer().iterate((item) => {
            if (item.id == id) {
                item.completed = !item.completed;
            }
        });
    }
    
    public void remove(int id) {
        var new_items = items.to_immutable_buffer()
            .where(item => item.id != id)
            .to_series();
        items = new_items;
    }
    
    public ImmutableBuffer<TodoItem> all() {
        return items.to_immutable_buffer();
    }
    
    public int count() {
        return (int)items.to_immutable_buffer().count();
    }
    
    public int completed_count() {
        return (int)items.to_immutable_buffer()
            .count(item => item.completed);
    }
}

/**
 * EmptyListComponent - Shown when no items exist.
 */
class EmptyListComponent : Component {
    public override string markup { get {
        return """
        <div class="empty">
            No tasks yet! Add one below.
        </div>
        """;
    }}
}

/**
 * TodoItemComponent - A single todo item with HTMX actions.
 */
class TodoItemComponent : Component {
    private TodoStore todo_store = inject<TodoStore>();
    private ComponentFactory factory = inject<ComponentFactory>();
    private HttpContext http_context = inject<HttpContext>();
    private HeaderComponent header = inject<HeaderComponent>();
    
    private int _item_id;
    public int item_id {
        set {
            _item_id = value;
        }
        get {
            return _item_id;
        }
    }
    
    public override string markup { get {
        return """
        <div class="todo-item" sid="item">
            <button type="button" class="btn-toggle" sid="toggle-btn" spry-action=":Toggle" spry-target="item" hx-swap="outerHTML"></button>
            <span class="title" sid="title"></span>
            <button type="button" class="btn-delete" sid="delete-btn" spry-action=":Delete" spry-target="item" hx-swap="delete">Delete</button>
        </div>
        """;
    }}
    
    // Called before serialization to prepare template with data from store
    public override async void prepare() throws Error {
        var item = todo_store.all().first_or_default(i => i.id == _item_id);
        if (item == null) return;
        
        this["title"].text_content = item.title;
        this["toggle-btn"].text_content = item.completed ? "Undo" : "Done";
        if (item.completed) {
            this["item"].add_class("completed");
        }
        
        // Set hx-vals on parent div - inherited by child buttons
        this["item"].set_attribute("hx-vals", @"{\"id\":$_item_id}");
    }
    
    public async override void handle_action(string action) throws Error {
        // Get the item id from query parameters (passed via hx-vals)
        var id_str = http_context.request.query_params.get_any_or_default("id");
        if (id_str == null) return;
        
        var id = int.parse(id_str);
        _item_id = id; // Set for prepare()
        
        switch (action) {
            case "Toggle":
                todo_store.toggle(id);
                // prepare() will be called automatically before serialization
                // Add header globals for OOB swap (header's prepare() fetches stats)
                add_globals_from(header);
                break;
            case "Delete":
                todo_store.remove(id);
                // With hx-swap="delete", we still need to return the header update
                add_globals_from(header);
                return;
        }
    }
}

/**
 * TodoListComponent - Container for todo items.
 */
class TodoListComponent : Component {
    private TodoStore todo_store = inject<TodoStore>();
    private ComponentFactory factory = inject<ComponentFactory>();
    private HttpContext http_context = inject<HttpContext>();
    private HeaderComponent header = inject<HeaderComponent>();
    
    public void set_items(Enumerable<Renderable> items) {
        set_outlet_children("items", items);
    }
    
    public override string markup { get {
        return """
        <div class="card" id="todo-list" sid="todo-list">
            <h2>Todo List</h2>
            <spry-outlet sid="items"/>
        </div>
        """;
    }}
    
    public async override void handle_action(string action) throws Error {
        if (action == "Add") {
            var title = http_context.request.query_params.get_any_or_default("title");
            
            if (title != null && title.strip() != "") {
                todo_store.add(title.strip());
            }
        }
        
        // Rebuild the list - only need to set item_id, prepare() handles the rest
        var count = todo_store.count();
        if (count == 0) {
            set_outlet_children("items", Iterate.single<Renderable>(factory.create<EmptyListComponent>()));
        } else {
            var items = new Series<Renderable>();
            todo_store.all().iterate((item) => {
                var component = factory.create<TodoItemComponent>();
                component.item_id = item.id;
                items.add(component);
            });
            set_outlet_children("items", items);
        }
        
        // Add header globals for OOB swap (header's prepare() fetches stats)
        add_globals_from(header);
    }
}

/**
 * HeaderComponent - Page header with stats.
 * Uses prepare() to fetch data from store automatically.
 */
class HeaderComponent : Component {
    private TodoStore todo_store = inject<TodoStore>();
    
    public override string markup { get {
        return """
        <div class="card" id="header" spry-global="header">
            <h1>Todo Component Example</h1>
            <p>This page demonstrates <code>Spry.Component</code> with IoC composition.</p>
            <div class="stats">
                <div class="stat">
                    <div class="stat-value" sid="total"></div>
                    <div class="stat-label">Total Tasks</div>
                </div>
                <div class="stat">
                    <div class="stat-value" sid="completed"></div>
                    <div class="stat-label">Completed</div>
                </div>
            </div>
        </div>
        """;
    }}
    
    // Called before serialization to populate stats from store
    public override async void prepare() throws Error {
        this["total"].text_content = todo_store.count().to_string();
        this["completed"].text_content = todo_store.completed_count().to_string();
    }
}

/**
 * AddFormComponent - Form to add new todos with HTMX.
 */
class AddFormComponent : Component {
    private TodoStore todo_store = inject<TodoStore>();
    private ComponentFactory factory = inject<ComponentFactory>();
    private HttpContext http_context = inject<HttpContext>();
    
    public override string markup { get {
        return """
        <div class="card">
            <h2>Add New Task</h2>
            <form sid="form" spry-action="TodoListComponent:Add" hx-target="#todo-list" hx-swap="outerHTML" style="display: flex; gap: 10px;">
                <input type="text" name="title" placeholder="Enter a new task..." required="required" sid="title-input"/>
                <button type="submit" class="btn-primary">Add Task</button>
            </form>
        </div>
        """;
    }}
}

/**
 * FeaturesComponent - Shows Component features used.
 */
class FeaturesComponent : Component {
    public override string markup { get {
        return """
        <div class="card">
            <h2>Component Features Used</h2>
            <div class="feature">
                <strong>Defining Components:</strong>
                <code>class MyComponent : Component { public override string markup { get { return "..."; } } }</code>
            </div>
            <div class="feature">
                <strong>Using Outlets:</strong>
                <code>&lt;spry-outlet sid="content"/&gt;</code>
            </div>
            <div class="feature">
                <strong>Preparing Templates:</strong>
                <code>public override void prepare() { this["title"].text_content = "..."; }</code>
            </div>
            <div class="feature">
                <strong>Declarative HTMX Actions:</strong>
                <code>&lt;button spry-action=":Toggle" hx-vals='{"id":1}'&gt;Toggle&lt;/button&gt;</code>
            </div>
            <div class="feature">
                <strong>IoC Injection:</strong>
                <code>private ComponentFactory factory = inject<ComponentFactory>();</code>
            </div>
            <div class="feature">
                <strong>Creating Components:</strong>
                <code>var child = factory.create&lt;MyComponent&gt;();</code>
            </div>
        </div>
        """;
    }}
}

/**
 * FooterComponent - Page footer.
 */
class FooterComponent : Component {
    public override string markup { get {
        return """
        <div class="card" style="text-align: center; color: #666;">
            <p>Built with <code>Spry.Component</code> |
                <a href="/api/todos">View JSON API</a>
            </p>
        </div>
        """;
    }}
}

/**
 * PageLayoutComponent - The main page structure.
 */
class PageLayoutComponent : Component {
    
    public void set_header(Renderable component) {
        set_outlet_child("header", component);
    }
    
    public void set_todo_list(Renderable component) {
        set_outlet_child("todo-list", component);
    }
    
    public void set_add_form(Renderable component) {
        set_outlet_child("add-form", component);
    }
    
    public void set_features(Renderable component) {
        set_outlet_child("features", component);
    }
    
    public void set_footer(Renderable component) {
        set_outlet_child("footer", component);
    }
    
    public override string markup { get {
        return """
        <!DOCTYPE html>
        <html>
        <head>
            <meta charset="UTF-8"/>
            <meta name="viewport" content="width=device-width, initial-scale=1.0"/>
            <title>Todo Component Example</title>
            <script src="https://cdn.jsdelivr.net/npm/htmx.org@2.0.8/dist/htmx.min.js"></script>
            <style>
                body { font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif; max-width: 800px; margin: 0 auto; padding: 20px; background: #f5f5f5; }
                .card { background: white; border-radius: 8px; padding: 20px; margin: 10px 0; box-shadow: 0 2px 4px rgba(0,0,0,0.1); }
                h1 { color: #333; margin-top: 0; }
                h2 { color: #555; border-bottom: 2px solid #4CAF50; padding-bottom: 10px; }
                .todo-item { display: flex; align-items: center; padding: 10px; margin: 5px 0; background: #fafafa; border-radius: 4px; border-left: 4px solid #4CAF50; }
                .todo-item.completed { border-left-color: #ccc; opacity: 0.7; }
                .todo-item.completed .title { text-decoration: line-through; color: #888; }
                .todo-item .title { flex: 1; margin: 0 10px; }
                .stats { display: flex; gap: 20px; margin: 10px 0; }
                .stat { background: #e8f5e9; padding: 10px 20px; border-radius: 4px; }
                .stat-value { font-size: 24px; font-weight: bold; color: #4CAF50; }
                .stat-label { font-size: 12px; color: #666; }
                input[type="text"] { padding: 10px; border: 1px solid #ddd; border-radius: 4px; flex: 1; }
                button { padding: 10px 20px; border: none; border-radius: 4px; cursor: pointer; }
                .btn-primary { background: #4CAF50; color: white; }
                .btn-primary:hover { background: #45a049; }
                .btn-toggle { background: #2196F3; color: white; padding: 5px 10px; font-size: 12px; }
                .btn-delete { background: #f44336; color: white; padding: 5px 10px; font-size: 12px; }
                code { background: #e8e8e8; padding: 2px 6px; border-radius: 4px; font-size: 14px; }
                pre { background: #263238; color: #aed581; padding: 15px; border-radius: 4px; overflow-x: auto; }
                .feature { margin: 15px 0; }
                .feature code { display: block; background: #f5f5f5; padding: 10px; margin: 5px 0; }
                a { color: #2196F3; text-decoration: none; }
                a:hover { text-decoration: underline; }
                .empty { color: #999; font-style: italic; padding: 20px; text-align: center; }
            </style>
        </head>
        <body>
            <spry-outlet sid="header"/>
            <spry-outlet sid="todo-list"/>
            <spry-outlet sid="add-form"/>
            <spry-outlet sid="features"/>
            <spry-outlet sid="footer"/>
        </body>
        </html>
        """;
    }}
}

// Home page endpoint - builds the component tree
class HomePageEndpoint : Object, Endpoint {
    private TodoStore todo_store = inject<TodoStore>();
    private ComponentFactory factory = inject<ComponentFactory>();
    
    public async HttpResult handle_request(HttpContext context, RouteContext route) throws Error {
        // Create page layout
        var page = factory.create<PageLayoutComponent>();
        
        // Create header - prepare() fetches stats from store automatically
        page.set_header(factory.create<HeaderComponent>());
        
        // Create todo list - only need to set item_id, prepare() handles the rest
        var todo_list = factory.create<TodoListComponent>();
        
        var count = todo_store.count();
        if (count == 0) {
            todo_list.set_items(Iterate.single<Renderable>(factory.create<EmptyListComponent>()));
        } else {
            var items = new Series<Renderable>();
            todo_store.all().iterate((item) => {
                var component = factory.create<TodoItemComponent>();
                component.item_id = item.id;
                items.add(component);
            });
            todo_list.set_items(items);
        }
        page.set_todo_list(todo_list);
        
        // Add form
        page.set_add_form(factory.create<AddFormComponent>());
        
        // Features
        page.set_features(factory.create<FeaturesComponent>());
        
        // Footer
        page.set_footer(factory.create<FooterComponent>());
        
        // to_result() handles all outlet replacement automatically
        return yield page.to_result();
    }
}

// API endpoint that returns JSON representation of todos
class TodoJsonEndpoint : Object, Endpoint {
    private TodoStore todo_store = inject<TodoStore>();
    
    public async HttpResult handle_request(HttpContext context, RouteContext route) throws Error {
        var json_parts = new Series<string>();
        json_parts.add("{\"todos\": [");
        
        bool first = true;
        todo_store.all().iterate((item) => {
            if (!first) json_parts.add(",");
            var completed_str = item.completed ? "true" : "false";
            var escaped_title = item.title.replace("\"", "\\\"");
            json_parts.add(@"{\"id\":$(item.id),\"title\":\"$escaped_title\",\"completed\":$completed_str}");
            first = false;
        });
        
        json_parts.add("]}");
        
        var json = json_parts.to_immutable_buffer()
            .aggregate<string>("", (acc, s) => acc + s);
        
        return new HttpStringResult(json)
            .set_header("Content-Type", "application/json");
    }
}

void main(string[] args) {
    int port = args.length > 1 ? int.parse(args[1]) : 8080;
    
    print("═══════════════════════════════════════════════════════════════\n");
    print("             Spry TodoComponent Example (IoC)\n");
    print("═══════════════════════════════════════════════════════════════\n");
    print("  Port: %d\n", port);
    print("═══════════════════════════════════════════════════════════════\n");
    print("  Endpoints:\n");
    print("    /           - Todo list (Component-based)\n");
    print("    /api/todos  - JSON API for todos\n");
    print("═══════════════════════════════════════════════════════════════\n");
    print("  HTMX Actions (via SpryModule):\n");
    print("    Add, Toggle, Delete - Dynamic updates\n");
    print("═══════════════════════════════════════════════════════════════\n");
    print("\nPress Ctrl+C to stop the server\n\n");
    
    try {
        var application = new WebApplication(port);
        
        // Register compression components (optional, for better performance)
        application.use_compression();
        
        // Add Spry module for automatic HTMX endpoint registration
        application.add_module<SpryModule>();
        
        // Register the todo store as singleton
        application.add_singleton<TodoStore>();
        
        // Register components as transient (created via factory)
        application.add_transient<EmptyListComponent>();
        application.add_transient<TodoItemComponent>();
        application.add_transient<TodoListComponent>();
        application.add_transient<HeaderComponent>();
        application.add_transient<AddFormComponent>();
        application.add_transient<FeaturesComponent>();
        application.add_transient<FooterComponent>();
        application.add_transient<PageLayoutComponent>();
        
        // Register endpoints
        application.add_endpoint<HomePageEndpoint>(new EndpointRoute("/"));
        application.add_endpoint<TodoJsonEndpoint>(new EndpointRoute("/api/todos"));
        
        application.run();
        
    } catch (Error e) {
        printerr("Error: %s\n", e.message);
        Process.exit(1);
    }
}