"use strict";

const AsteroidThreatAlarmSound = (function(){

    return function(audio_ctx, output_node, volume_multiplier = 1.0, threat_level = 0.5){
        const now = audio_ctx.currentTime;
        const threat = Math.max(0.0, Math.min(1.0, threat_level));

        // Bus maestro de cabina
        const master_bus = audio_ctx.createGain();
        master_bus.gain.setValueAtTime(volume_multiplier * 0.5, now);

        // Filtro de megafonía/altavoz de instrumentación (elimina graves y agudos molestos)
        const horn_filter = audio_ctx.createBiquadFilter();
        horn_filter.type = "bandpass";
        horn_filter.frequency.setValueAtTime(1150, now);
        horn_filter.Q.setValueAtTime(1.8, now);

        master_bus.connect(horn_filter);
        horn_filter.connect(output_node);

        // Función que sintetiza un 'BEEP' limpio de aviónica
        const trigger_avionics_beep = (start_time, freq) => {
            const beep_duration = 0.065; // 65ms: corto, clínico y penetrante

            // Envolvente de amplitud trapezoidal (ataque 4ms, salida 8ms)
            const env = audio_ctx.createGain();
            env.gain.setValueAtTime(0.0001, start_time);
            env.gain.linearRampToValueAtTime(0.85, start_time + 0.004);
            env.gain.setValueAtTime(0.85, start_time + beep_duration - 0.008);
            env.gain.exponentialRampToValueAtTime(0.0001, start_time + beep_duration);

            // 1. Tono fundamental limpio
            const osc_main = audio_ctx.createOscillator();
            osc_main.type = "sine";
            osc_main.frequency.setValueAtTime(freq, start_time);

            // 2. Segundo armónico discreto (le da presencia de instrumento de cabina)
            const osc_harm = audio_ctx.createOscillator();
            const harm_gain = audio_ctx.createGain();
            osc_harm.type = "sine";
            osc_harm.frequency.setValueAtTime(freq * 2, start_time);
            harm_gain.gain.setValueAtTime(0.18, start_time);

            // 3. Toque de onda triangular sutil para cuerpo mecánico
            const osc_tri = audio_ctx.createOscillator();
            const tri_gain = audio_ctx.createGain();
            osc_tri.type = "triangle";
            osc_tri.frequency.setValueAtTime(freq, start_time);
            tri_gain.gain.setValueAtTime(0.12, start_time);

            osc_main.connect(env);
            osc_harm.connect(harm_gain);
            harm_gain.connect(env);
            osc_tri.connect(tri_gain);
            tri_gain.connect(env);

            env.connect(master_bus);

            osc_main.start(start_time);
            osc_harm.start(start_time);
            osc_tri.start(start_time);

            osc_main.stop(start_time + beep_duration);
            osc_harm.stop(start_time + beep_duration);
            osc_tri.stop(start_time + beep_duration);
        };

        // Frecuencia estándar de advertencia: 1020 Hz (tono aeronáutico estándar)
        // Si la piedra viene de camino a la cabina (> 0.6), sube ligeramente a 1280 Hz
        const base_freq = threat > 0.6 ? 1280 : 1020;

        // Primer beep
        trigger_avionics_beep(now, base_freq);

        // Si el peligro es inminente (la roca ya fue lanzada a cabina), emite un doble beep militar ("PIP-PIP")
        if(threat > 0.6){
            trigger_avionics_beep(now + 0.09, base_freq);
        }
    };

})();