astralis/examples/QueryParameters.vala

using Astralis;
using Invercargill;
using Invercargill.DataStructures;

/**
 * QueryParameters Example
 * 
 * Demonstrates how to handle query parameters in Astralis.
 * Uses Invercargill Dictionary for parameter storage and
 * Enumerable for processing parameters.
 */

// Greet handler - simple query parameter access
class GreetHandler : Object, RouteHandler {
    public async HttpResult handle_route(HttpContext http_context, RouteContext route_context) throws Error {
        var name = http_context.request.get_query_or_default("name", "World");
        var greeting = http_context.request.get_query_or_default("greeting", "Hello");
        
        return new BufferedHttpResult.from_string(
            @"$greeting, $name!"
        );
    }
}

// Search handler - multiple query parameters with validation
class SearchHandler : Object, RouteHandler {
    public async HttpResult handle_route(HttpContext http_context, RouteContext route_context) throws Error {
        var query = http_context.request.get_query("q");
        var limit = int.parse(http_context.request.get_query_or_default("limit", "10"));
        var offset = int.parse(http_context.request.get_query_or_default("offset", "0"));
        
        if (query == null || query == "") {
            var headers = new Catalogue<string, string>();
            headers.add("Content-Type", "application/json");
            return new BufferedHttpResult.from_string(
                @"{ \"error\": \"Query parameter 'q' is required\" }",
                StatusCode.BAD_REQUEST,
                headers
            );
        }
        
        // Build response using Enumerable operations
        var results = Wrap.array<string>({"Result 1", "Result 2", "Result 3", "Result 4", "Result 5"})
            .skip(offset)
            .take(limit);
        
        var json_parts = new Series<string>();
        json_parts.add(@"{ \"query\": \"$query\", \"results\": [");
        
        bool first = true;
        results.iterate((result) => {
            if (!first) json_parts.add(", ");
            json_parts.add(@"\"$result\"");
            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
        );
    }
}

// Debug handler - boolean flag query parameters
class DebugHandler : Object, RouteHandler {
    public async HttpResult handle_route(HttpContext http_context, RouteContext route_context) throws Error {
        var verbose = http_context.request.has_query("verbose");
        var level = http_context.request.get_query_or_default("level", "info");
        
        var parts = new Series<string>();
        parts.add("Debug Information:\n");
        parts.add(@"  Verbose mode: $(verbose ? "enabled" : "disabled")\n");
        parts.add(@"  Log level: $level\n");
        
        // Add query parameters listing using Enumerable
        parts.add("\nAll query parameters:\n");
        http_context.request.query_params.to_immutable_buffer()
            .iterate((grouping) => {
                grouping.iterate((value) => {
                    parts.add(@"  - $(grouping.key): $value\n");
                });
            });
        
        var result = parts.to_immutable_buffer()
            .aggregate<string>("", (acc, s) => acc + s);
        
        return new BufferedHttpResult.from_string(result);
    }
}

// Filter handler - query parameter with multiple values (comma-separated)
class FilterHandler : Object, RouteHandler {
    public async HttpResult handle_route(HttpContext http_context, RouteContext route_context) throws Error {
        var tags_param = http_context.request.get_query("tags");
        
        if (tags_param == null) {
            var headers = new Catalogue<string, string>();
            headers.add("Content-Type", "application/json");
            return new BufferedHttpResult.from_string(
                @"{ \"message\": \"No tags provided\" }",
                StatusCode.OK,
                headers
            );
        }
        
        // Parse comma-separated tags using Enumerable operations
        var tags = Wrap.array<string>(tags_param.split(","))
            .select<string>(tag => tag.strip())
            .where(tag => tag != "")
            .to_vector();
        
        var json_parts = new Series<string>();
        json_parts.add(@"{ \"tags\": [");
        
        bool first = true;
        tags.to_immutable_buffer().iterate((tag) => {
            if (!first) json_parts.add(", ");
            json_parts.add(@"\"$tag\"");
            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
        );
    }
}

// Range handler - numeric query parameters with range validation
class RangeHandler : Object, RouteHandler {
    public async HttpResult handle_route(HttpContext http_context, RouteContext route_context) throws Error {
        var min = int.parse(http_context.request.get_query_or_default("min", "0"));
        var max = int.parse(http_context.request.get_query_or_default("max", "100"));
        var step = int.parse(http_context.request.get_query_or_default("step", "1"));
        
        if (min >= max) {
            var headers = new Catalogue<string, string>();
            headers.add("Content-Type", "application/json");
            return new BufferedHttpResult.from_string(
                @"{ \"error\": \"min must be less than max\" }",
                StatusCode.BAD_REQUEST,
                headers
            );
        }
        
        // Generate range using Iterate.range and Enumerable operations
        var numbers = Iterate.range(min, max)
            .where(n => (n - min) % step == 0);
        
        var json_parts = new Series<string>();
        json_parts.add(@"{ \"min\": $min, \"max\": $max, \"step\": $step, \"numbers\": [");
        
        bool first = true;
        numbers.iterate((n) => {
            if (!first) json_parts.add(", ");
            json_parts.add(n.to_string());
            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
        );
    }
}

void main() {
    var router = new Router();
    var server = new Server(8081, router);
    
    // Register routes
    router.get("/greet", new GreetHandler());
    router.get("/search", new SearchHandler());
    router.get("/debug", new DebugHandler());
    router.get("/filter", new FilterHandler());
    router.get("/range", new RangeHandler());
    
    print("Query Parameters Example Server running on port 8081\n");
    print("Try these endpoints:\n");
    print("  - http://localhost:8081/greet?name=Alice\n");
    print("  - http://localhost:8081/search?q=test&limit=3\n");
    print("  - http://localhost:8081/debug?verbose&level=debug\n");
    print("  - http://localhost:8081/filter?tags=foo,bar,baz\n");
    print("  - http://localhost:8081/range?min=1&max=20&step=2\n");
    
    server.run();
}