Spry/website/Endpoints/AuroraSseEndpoint.vala

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

/**
 * AuroraSseEndpoint - Singleton SSE endpoint for aurora updates
 * 
 * Broadcasts aurora canvas and stats updates to all connected clients
 * when aurora actions are triggered (BoostSolarWind, CalmAurora, etc.)
 * 
 * Uses the Astralis SseEndpoint pattern - NOT continuations, since
 * continuations are for per-connection streaming, not broadcasting.
 */
public class AuroraSseEndpoint : SseEndpoint {
    
    private AuroraState aurora_state;
    
    public AuroraSseEndpoint(AuroraState aurora_state) {
        this.aurora_state = aurora_state;
    }
    
    /// Retry interval: clients should wait 2 seconds before reconnecting
    public override uint retry_interval { get { return 2000; } }
    
    /// Called when a new client connects - send current state
    public override async void new_connection(HttpContext http_context, RouteContext route_context, SseStream stream) {
        print(@"Aurora SSE client connected (total: $(get_open_streams().length))\n");
        
        // Send current aurora state to new client
        try {
            yield send_aurora_update(stream);
        } catch (Error e) {
            print(@"Failed to send aurora update: $(e.message)\n");
        }
        
        stream.disconnected.connect(() => {
            print(@"Aurora SSE client disconnected\n");
        });
    }
    
    /// Boost solar wind and broadcast update
    public async void boost_solar_wind() {
        aurora_state.boost_solar_wind();
        yield broadcast_aurora_update();
    }
    
    /// Calm aurora and broadcast update
    public async void calm() {
        aurora_state.calm();
        yield broadcast_aurora_update();
    }
    
    /// Shift colors and broadcast update
    public async void shift_colors() {
        aurora_state.shift_colors();
        yield broadcast_aurora_update();
    }
    
    /// Add wave and broadcast update
    public async void add_wave() {
        aurora_state.add_wave();
        yield broadcast_aurora_update();
    }
    
    /// Broadcast aurora update to all connected clients
    private async void broadcast_aurora_update() {
        try {
            // Create canvas HTML
            string canvas_html = build_canvas_html();
            var canvas_event = new SseEvent.with_type("aurora-canvas", canvas_html);
            
            // Create stats HTML
            string stats_html = build_stats_html();
            var stats_event = new SseEvent.with_type("aurora-stats", stats_html);
            
            // Broadcast both events
            yield broadcast_event(canvas_event);
            yield broadcast_event(stats_event);
        } catch (Error e) {
            printerr(@"Failed to broadcast aurora update: $(e.message)\n");
        }
    }
    
    /// Send aurora update to a single stream (for new connections)
    private async void send_aurora_update(SseStream stream) throws Error {
        string canvas_html = build_canvas_html();
        yield stream.send_event(new SseEvent.with_type("aurora-canvas", canvas_html));
        
        string stats_html = build_stats_html();
        yield stream.send_event(new SseEvent.with_type("aurora-stats", stats_html));
    }
    
    /// Build the canvas HTML with all wave components
    private string build_canvas_html() {
        var builder = new StringBuilder();
        int wave_num = 0;
        foreach (var wave in aurora_state.get_waves()) {
            // Build the wave div with inline styles
            builder.append(@"<div class=\"aurora-wave\" style=\"--wave-y: $(wave.y_offset)%%; --wave-amplitude: $(wave.amplitude)px; --wave-freq: $(wave.frequency); --wave-color1: $(wave.color1); --wave-color2: $(wave.color2); --wave-opacity: $(wave.opacity); --wave-delay: $(wave.animation_delay)s; animation-delay: var(--wave-delay);\"></div>");
            wave_num++;
        }
        return builder.str;
    }
    
    /// Build the stats HTML
    private string build_stats_html() {
        return @"<div class=\"aurora-stat\"><div class=\"aurora-stat-value\">%.1f km/s</div><div class=\"aurora-stat-label\">Solar Wind</div></div><div class=\"aurora-stat\"><div class=\"aurora-stat-value\">$(aurora_state.wave_count)</div><div class=\"aurora-stat-label\">Waves</div></div><div class=\"aurora-stat\"><div class=\"aurora-stat-value\">%.0f%%</div><div class=\"aurora-stat-label\">Intensity</div></div><div class=\"aurora-stat\"><div class=\"aurora-stat-value\">$(aurora_state.color_mode)</div><div class=\"aurora-stat-label\">Color Mode</div></div>".printf(
            aurora_state.solar_wind_speed,
            aurora_state.intensity * 100
        );
    }
}