astralis/examples/PathRouting.vala

using Astralis;
using Invercargill;
using Invercargill.DataStructures;

/**
 * PathRouting Example
 * 
 * Demonstrates path component parsing and routing in Astralis.
 * Uses Invercargill Enumerable for path processing.
 */
void main() {
    var router = new Router();
    var server = new Server(8082, router);
    
    // Root path
    router.map_func("/", (context) => {
        return new BufferedHttpResult.from_string(
            """Welcome to the Path Routing Example!
            
Available endpoints:
  GET /                           - This message
  GET /hello                      - Simple greeting
  GET /hello/{name}               - Greeting with name
  GET /users                      - List all users
  GET /users/{id}                 - Get user by ID
  GET /users/{id}/posts           - Get posts for a user
  GET /api/v1/status              - API status
  GET /api/v1/items/{id}         - Get item by ID
  GET /files/{category}/{name}    - Get file by category and name
"""
        );
    });
    
    // Simple path
    router.map_func("/hello", (context) => {
        return new BufferedHttpResult.from_string("Hello, World!");
    });
    
    // Path with one component (simulated dynamic routing)
    router.map_func("/hello/", (context) => {
        var components = context.request.path_components.to_vector();
        
        if (components.count() < 2) {
            return new BufferedHttpResult.from_string(
                "Please provide a name: /hello/{name}",
                StatusCode.BAD_REQUEST
            );
        }
        
        var name = components[1];
        return new BufferedHttpResult.from_string(@"Hello, $name!");
    });
    
    // Users list endpoint
    router.map_func("/users", (context) => {
        // Simulated user data using Invercargill data structures
        var users = new Series<User>();
        users.add(new User(1, "Alice", "alice@example.com"));
        users.add(new User(2, "Bob", "bob@example.com"));
        users.add(new User(3, "Charlie", "charlie@example.com"));
        
        var json_parts = new Series<string>();
        json_parts.add(@"{ \"users\": [");
        
        bool first = true;
        users.to_immutable_buffer().iterate((user) => {
            if (!first) json_parts.add(", ");
            json_parts.add(user.to_json());
            first = false;
        });
        
        json_parts.add("] }");
        
        var json_string = json_parts.to_immutable_buffer()
            .aggregate<string>("", (acc, s) => acc + s);
        
        var headers = new Catalogue<string, string>();
        headers.add("Content-Type", "application/json");
        return new BufferedHttpResult.from_string(
            json_string,
            StatusCode.OK,
            headers
        );
    });
    
    // User by ID endpoint (simulated)
    router.map_func("/users/", (context) => {
        var components = context.request.path_components.to_vector();
        
        if (components.count() < 2) {
            var headers = new Catalogue<string, string>();
            headers.add("Content-Type", "application/json");
            return new BufferedHttpResult.from_string(
                @"{ \"error\": \"User ID required\" }",
                StatusCode.BAD_REQUEST,
                headers
            );
        }
        
        var id_str = components[1];
        var id = int.parse(id_str);
        
        // Simulated user lookup
        var users = new Series<User>();
        users.add(new User(1, "Alice", "alice@example.com"));
        users.add(new User(2, "Bob", "bob@example.com"));
        users.add(new User(3, "Charlie", "charlie@example.com"));
        
        var user = users.to_immutable_buffer()
            .first_or_default(u => u.id == id);
        
        if (user == null) {
            var headers = new Catalogue<string, string>();
            headers.add("Content-Type", "application/json");
            return new BufferedHttpResult.from_string(
                @"{ \"error\": \"User not found\" }",
                StatusCode.NOT_FOUND,
                headers
            );
        }
        
        var headers = new Catalogue<string, string>();
        headers.add("Content-Type", "application/json");
        return new BufferedHttpResult.from_string(
            user.to_json(),
            StatusCode.OK,
            headers
        );
    });
    
    // User posts endpoint (nested path)
    router.map_func("/users/", (context) => {
        var components = context.request.path_components.to_vector();
        
        // Check for /users/{id}/posts pattern
        if (components.count() >= 3 && components[2] == "posts") {
            var id_str = components[1];
            var id = int.parse(id_str);
            
            // Simulated posts for user
            var posts = new Series<Post>();
            posts.add(new Post(101, id, "First Post", "This is my first post"));
            posts.add(new Post(102, id, "Second Post", "This is my second post"));
            
            var json_parts = new Series<string>();
            json_parts.add(@"{ \"user_id\": $id, \"posts\": [");
            
            bool first = true;
            posts.to_immutable_buffer().iterate((post) => {
                if (!first) json_parts.add(", ");
                json_parts.add(post.to_json());
                first = false;
            });
            
            json_parts.add("] }");
            
            var json_string = json_parts.to_immutable_buffer()
                .aggregate<string>("", (acc, s) => acc + s);
            
            var headers = new Catalogue<string, string>();
            headers.add("Content-Type", "application/json");
            return new BufferedHttpResult.from_string(
                json_string,
                StatusCode.OK,
                headers
            );
        }
        
        // Fall back to user detail
        if (components.count() < 2) {
            var headers = new Catalogue<string, string>();
            headers.add("Content-Type", "application/json");
            return new BufferedHttpResult.from_string(
                @"{ \"error\": \"User ID required\" }",
                StatusCode.BAD_REQUEST,
                headers
            );
        }
        
        var id_str = components[1];
        var id = int.parse(id_str);
        
        var users = new Series<User>();
        users.add(new User(1, "Alice", "alice@example.com"));
        users.add(new User(2, "Bob", "bob@example.com"));
        users.add(new User(3, "Charlie", "charlie@example.com"));
        
        var user = users.to_immutable_buffer()
            .first_or_default(u => u.id == id);
        
        if (user == null) {
            var headers = new Catalogue<string, string>();
            headers.add("Content-Type", "application/json");
            return new BufferedHttpResult.from_string(
                @"{ \"error\": \"User not found\" }",
                StatusCode.NOT_FOUND,
                headers
            );
        }
        
        var headers = new Catalogue<string, string>();
        headers.add("Content-Type", "application/json");
        return new BufferedHttpResult.from_string(
            user.to_json(),
            StatusCode.OK,
            headers
        );
    });
    
    // API versioned endpoint
    router.map_func("/api/v1/status", (context) => {
        var status = new Dictionary<string, string>();
        status.set("status", "operational");
        status.set("version", "1.0.0");
        status.set("timestamp", new DateTime.now_local().format_iso8601());
        
        var json_parts = new Series<string>();
        json_parts.add("{ ");
        
        bool first = true;
        status.to_immutable_buffer().iterate((kv) => {
            if (!first) json_parts.add(", ");
            json_parts.add(@"\"$(kv.key)\": \"$(kv.value)\"");
            first = false;
        });
        
        json_parts.add(" }");
        
        var json_string = json_parts.to_immutable_buffer()
            .aggregate<string>("", (acc, s) => acc + s);
        
        var headers = new Catalogue<string, string>();
        headers.add("Content-Type", "application/json");
        return new BufferedHttpResult.from_string(
            json_string,
            StatusCode.OK,
            headers
        );
    });
    
    // API items endpoint
    router.map_func("/api/v1/items/", (context) => {
        var components = context.request.path_components.to_vector();
        
        if (components.count() < 4) {
            var headers = new Catalogue<string, string>();
            headers.add("Content-Type", "application/json");
            return new BufferedHttpResult.from_string(
                @"{ \"error\": \"Item ID required\" }",
                StatusCode.BAD_REQUEST,
                headers
            );
        }
        
        var id_str = components[3];
        var id = int.parse(id_str);
        
        var items = new Dictionary<int, Item>();
        items.set(1, new Item(1, "Widget", "A useful widget", 9.99));
        items.set(2, new Item(2, "Gadget", "A fancy gadget", 19.99));
        items.set(3, new Item(3, "Doohickey", "A mysterious doohickey", 29.99));
        
        Item? item = null;
        if (items.try_get(id, out item)) {
            var headers = new Catalogue<string, string>();
            headers.add("Content-Type", "application/json");
            return new BufferedHttpResult.from_string(
                item.to_json(),
                StatusCode.OK,
                headers
            );
        }
        
        var headers = new Catalogue<string, string>();
        headers.add("Content-Type", "application/json");
        return new BufferedHttpResult.from_string(
            @"{ \"error\": \"Item not found\" }",
            StatusCode.NOT_FOUND,
            headers
        );
    });
    
    // Files endpoint with category and name
    router.map_func("/files/", (context) => {
        var components = context.request.path_components.to_vector();
        
        if (components.count() < 3) {
            var headers = new Catalogue<string, string>();
            headers.add("Content-Type", "application/json");
            return new BufferedHttpResult.from_string(
                @"{ \"error\": \"Category and filename required\" }",
                StatusCode.BAD_REQUEST,
                headers
            );
        }
        
        var category = components[1];
        var name = components[2];
        
        // Simulated file lookup
        var files = new Dictionary<string, Dictionary<string, File>>();
        var docs = new Dictionary<string, File>();
        docs.set("readme.txt", new File("readme.txt", "docs", "This is the readme file"));
        docs.set("guide.pdf", new File("guide.pdf", "docs", "User guide"));
        
        var images = new Dictionary<string, File>();
        images.set("logo.png", new File("logo.png", "images", "Company logo"));
        images.set("banner.jpg", new File("banner.jpg", "images", "Website banner"));
        
        files.set("docs", docs);
        files.set("images", images);
        
        Dictionary<string, File>? category_files = null;
        if (files.try_get(category, out category_files)) {
            File? file = null;
            if (category_files.try_get(name, out file)) {
                var headers = new Catalogue<string, string>();
                headers.add("Content-Type", "application/json");
                return new BufferedHttpResult.from_string(
                    file.to_json(),
                    StatusCode.OK,
                    headers
                );
            }
        }
        
        var headers = new Catalogue<string, string>();
        headers.add("Content-Type", "application/json");
        return new BufferedHttpResult.from_string(
            @"{ \"error\": \"File not found in category '$category'\" }",
            StatusCode.NOT_FOUND,
            headers
        );
    });
    
    // Path information endpoint - shows all path components
    router.map_func("/pathinfo", (context) => {
        var parts = new Series<string>();
        parts.add("Path Information:\n");
        parts.add(@"  Raw path: $(context.request.raw_path)\n");
        parts.add(@"  Path components: $(context.request.path_components.count())\n");
        parts.add("\n  Components:\n");
        
        context.request.path_components
            .with_positions()
            .iterate((pair) => {
                parts.add(@"    [$((int)pair.position)]: $(pair.item)\n");
            });
        
        parts.add(@"\n  Query string: $(context.request.query_string)\n");
        
        var result = parts.to_immutable_buffer()
            .aggregate<string>("", (acc, s) => acc + s);
        
        return new BufferedHttpResult.from_string(result);
    });
    
    print("Path Routing Example Server running on port 8082\n");
    print("Try these endpoints:\n");
    print("  - http://localhost:8082/\n");
    print("  - http://localhost:8082/hello\n");
    print("  - http://localhost:8082/hello/Alice\n");
    print("  - http://localhost:8082/users\n");
    print("  - http://localhost:8082/users/1\n");
    print("  - http://localhost:8082/users/1/posts\n");
    print("  - http://localhost:8082/api/v1/status\n");
    print("  - http://localhost:8082/api/v1/items/2\n");
    print("  - http://localhost:8082/files/docs/readme.txt\n");
    print("  - http://localhost:8082/pathinfo?test=1\n");
    
    server.run();
}

// Helper classes for the example
class User {
    public int id { get; private set; }
    public string name { get; private set; }
    public string email { get; private set; }
    
    public User(int id, string name, string email) {
        this.id = id;
        this.name = name;
        this.email = email;
    }
    
    public string to_json() {
        return @"{ \"id\": $id, \"name\": \"$name\", \"email\": \"$email\" }";
    }
}

class Post {
    public int id { get; private set; }
    public int user_id { get; private set; }
    public string title { get; private set; }
    public string content { get; private set; }
    
    public Post(int id, int user_id, string title, string content) {
        this.id = id;
        this.user_id = user_id;
        this.title = title;
        this.content = content;
    }
    
    public string to_json() {
        return @"{ \"id\": $id, \"user_id\": $user_id, \"title\": \"$title\", \"content\": \"$content\" }";
    }
}

class Item {
    public int id { get; private set; }
    public string name { get; private set; }
    public string description { get; private set; }
    public double price { get; private set; }
    
    public Item(int id, string name, string description, double price) {
        this.id = id;
        this.name = name;
        this.description = description;
        this.price = price;
    }
    
    public string to_json() {
        return @"{ \"id\": $id, \"name\": \"$name\", \"description\": \"$description\", \"price\": $price }";
    }
}

class File {
    public string name { get; private set; }
    public string category { get; private set; }
    public string description { get; private set; }
    
    public File(string name, string category, string description) {
        this.name = name;
        this.category = category;
        this.description = description;
    }
    
    public string to_json() {
        return @"{ \"name\": \"$name\", \"category\": \"$category\", \"description\": \"$description\" }";
    }
}