/* 
    Constants
*/
const sin = Math.sin;
const TAU = 2*Math.PI;

ditty.bpm = 94;

// start position in song
START = 0;


// clamp11 and amp from https://dittytoy.net/ditty/989ebdaad7
let clamp11 = (x) => x < -1 ? -1 : x > 1 ? 1 : x;
const amp = filter.def(class {
    constructor(options) {
        this.amp  = options.amp || 0.5;
        // gain > 1 = overdrive
        this.gain = options.gain || 1.0;
    }

    process(inpt, options) {
        return [clamp11(this.gain*inpt[0]) * this.amp, clamp11(this.gain*inpt[1]) * this.amp];
    }
});



/* 
    Filters
*/

// from https://dittytoy.net/syntax#filters
const lowpass = filter.def(class {
    constructor(options) {
        this.hist0 = [0, 0];
        this.hist1 = [0, 0];
        this.t = 0;
    }
    process(input, options) {
        const alpha = clamp(options.cutoff, 0.01, 1);
        if (input) {
            for (let i = 0; i < 2; i++) {
                this.hist0[i] += alpha * (input[i] - this.hist0[i]);
                this.hist1[i] += alpha * (this.hist0[i] - this.hist1[i]);
            }
            return this.hist1;
        }
    }
});

const spread = filter.def(class {
    constructor(options) {
        this.size = 2 * options.delay || 256;
        this.hist = new Float32Array(this.size);
        this.write = options.delay;
        this.read = 0;
        this.width = options.width || 0.8;
    }
    process(input, options) {
        if (input) {
            // save current sample
            const x = input[0];
            this.hist[this.write++ % this.size] = x

            // add history to current 
            const spread = this.width; 
            const signal  = x + this.hist[this.read % this.size];
            const delayed = x + this.hist[(options.delay + this.read) % this.size];
            this.read++;

            const L = signal;
            const R = spread*delayed + (1.0-spread)*signal;
            const V = 0.5;
            return [V*L,V*R];
        }
    }
});

/*
    Synths
*/

const Strat = synth.def( class {
    constructor (options) {
        this.t = Math.random();
        this.i = 0;
        this.mul = options.mul;
        this.bend = options.bend || 0;
        this.coeff = options.coeff || [
            [1, 1],
        ];
        this.feedback = options.feedback || 0;
        this.last = 0;
    }
    add_fm(note, env, tick) {
        // carrier frequency
        let fc;
        if (this.bend) {
            const a = midi_to_hz(note);
            const b = midi_to_hz(note + this.bend)
            fc = lerp(a, b, this.i);
        } else {
            fc = midi_to_hz(note);
        }
        
        let x = 0;
        const fb = this.feedback * this.last;
        this.coeff.forEach(y => {
            let fm = fc * y[0] * this.mul;
            let mod = sin(TAU*this.t*fm + fb) * (Math.exp(tick * -16)*0.4+1);
            x += sin(TAU*this.t*fc*y[0] + mod) * y[1];
        });
        this.last = x;
        
        return (x / this.coeff.length) * env.value; 
    }
    process(note, env, tick, options) {
        // forward time
        this.t += ditty.dt;
        this.i += ditty.dt;

        const gain = 0.5; 
        let osc = this.add_fm(note, env, tick) * gain;
        osc *= env.value;
        
        return [osc, osc]; // left, right
    }
}); 


/* 
    Building blocks
*/
class Track {
    constructor(options) {
        this.patterns = options.patterns;
        this.pos = options.start || 0;
        this.base = options.base || 0;
        this.read = true;
        this.duration = 0.25;
        this.stop = false;
    }
    process(loopCount) {
        this.sleep = true;
        if (this.read) {
            if (this.stop) {
                sleep(1);
                return;
            }
            this.read = false;
            this.part = this.patterns[this.pos++];
            if (this.pos==this.patterns.length) this.stop = true;
            this.i = 0;
        }
    
        let x = this.part[this.i++];
        if (typeof x === 'number') {
            if (x > 24) {
                this.base = x;
                x = this.part[this.i++];
            } 
            if (x < 0) {
                this.duration = -x;
                x = this.part[this.i++];
            }
            if (typeof x === 'number') x += this.base;
        }
        if (this.i==this.part.length) {
            this.read = true;
        }

        this.play(x, loopCount);
        if (this.sleep) sleep(this.duration); // sleep in ticks
    }
}  

class ElectricGuitar extends Track {
    constructor(options) {
        super(options);
        this.mul = options.mul || 0.503;
        this.pan = options.pan || 0;
        this.transpose = options.transpose || 0;
        this.feedback = options.feedback || 0;
        this.coeff = [ 
        /* [1, 1],
            [2, 0.5],
            [2.5, 0.25],
            [5.25, 0.125] */
            [1, 0.5],
            [2.01, 0.25],
            [3.02, 0.125],
            [4.03, 0.06]
        ];
    }
    strum(note, a, d, r) {
        Strat.play(note + this.transpose, {
            attack: a || 0.01, duration: d || this.duration, release: r || 0.15, 
            pan: this.pan, amp: 1, mul: this.mul,
            coeff: this.coeff, feedback: this.feedback
        });
    }
    chord(notes) {
        let string = 0;
        for (let x of notes) {
            if (x > 0) {
                this.strum(this.base + string + x);
            } else if (x == 0) { 
                // palm mute strings
                this.strum(this.base + string, 0.01, 0.05, 0.05);
            }
            string += 5;
        }
    }
    arp(notes) {
        this.sleep = false;
        for (let x of notes) {
            const [string, tone, duration, gap] = x;
            this.strum(string + tone, null, duration);
            sleep(gap);
        }        
    }
    bend(notes, a, d, r) {
        this.sleep = false;
        for (let x of notes) {
            const [string, fret, dur, bend] = x;
            Strat.play(string + fret + this.transpose, {
                attack: 0.01, duration: dur, release: 0.15, 
                pan: this.pan, amp: 1, mul: this.mul, bend: bend,
                coeff: this.coeff, feedback: this.feedback
            });
            sleep(dur);
        }
    }
    play(note) {
        if (note === null) return; // pause
        if (Array.isArray(note)) {
            // deduce type
            const type = note[0];
            const notes = note.slice(1);
            switch (type) {
                case 0:
                    this.chord(notes);
                    break;
                case 1: 
                    this.arp(notes);
                    break;
                case 2:
                    this.bend(notes);
                    break;
            }
        } else if (note > 0) {
            this.strum(note);
        }
        // sleep is done in the Track class!
    }
}

/*
    TODO: Vocals
*/

/*    
// +++ Parts +++
// intro, 1-8
// pre-verse, 9-16
// verse, 17-24

It's bugging me
Grating me
And twisting me around
Yeah, I'm endlessly
Caving in
And turning inside out

// chorus, 25-32

'Cause I want it now
I want it now
Give me your heart and your soul
And I'm breaking out
I'm breaking out
Last chance to lose control

// pre-verse2, 33-36
// verse2, 37-44

And it's holding me
Morphing me
And forcing me to strive
To be endlessly
Cold within
And dreaming I'm alive


// chorus2, 45-52

'Cause I want it now
I want it now
Give me your heart and your soul
I'm not breaking down
I'm breaking out
Last chance to lose control
// pre-solo riff, 53-56
// solo 57-72
// chorus w/ solo 73-80
// outro 81-87
*/


/*
    Electric Bass
*/
const bp1a = [a2,-0.25,0,0,10,0, 10,12,0,10, 0,7,0,8, 8,7,5,7,];
const bp1b = [e2,0,0,10,0, 10,12,0, a2,10, e2,0,12,0, a2,10,10, e2,12, a2,10,12,];
const bp1c = [d3,0,0,10,0, 10,12,0,10, 0,10,9,0, 9,8,0,8,];
const bp1d = [7, a2,0,10,0, 10,12,0,10, 0,7,0,8, 8,7,5,7];
const bp1e = [7,0,0,0, 6,0,0,0, 5,0,0,0, 4,0,0,0];
const bp3a = [
    a2,-0.5,3,   
    g3,5, -0.25,3, 5,      
    a2,3, -0.5,3, -0.25,3, 
    g3,-0.5,5, -0.25,3, 5,      
    a2,-0.5,3
];
const bp3b = [
    e2,-0.5,3,   
    d3,5, -0.25,3, 5,      
    e2,3, -0.5,3, -0.25,3, 
    d3,-0.5,5, -0.25,3, 5,      
    e2,-0.5,3
];
const bp3c = [
    a2,-0.5,5,   
    g3,7, -0.25,5, 7,      
    a2,5, -0.5,5, -0.25,5, 
    g3,-0.5,7, -0.25,5, 7,      
    a2,-0.5,5
];
const bp3d = [
    e2,-0.5,5,   
    d3,7, -0.25,5, 7,      
    e2,5, -0.5,5, -0.25,5, 
    d3,-0.5,7, -0.25,5, 7,      
    e2,-0.5,5
];
const bp3e = [    
    e2,-0.25, 0,0,10,0, 10,12,0, a2,10, e2,0,12,0, a2,10,10, e2,12, a2,10,12,
];
const bp3f = [
    e2,-0.5,5,   
    d3,7, -0.25,5, 7,
    e2,5,5,5,5,5,5,5, // add pinch harmonics here
    d3,-0.75,7
];
const bp6a = [
    e2,-0.25,
    0,0,10,0, 10,12,0,10, 0,10,9,0, 9,8,0,8, 
];
const bp6b = [
    e2,-0.25,
    7,0,10,0, 10,12,0,10, 0,10,9,0, 9,8,0,8,
];
const bp6c = [
    e2,-0.25,
    7,0,10,0, 10,12,0,10, 0,10,9,0, 9,8,0,8,
];
const bp6d = [
    e2,-0.25,
    7,0,10,0, 10,12,0,15, 0,12,0,15, 15,12,15, 
    a2,12
];
const bp7 = [
    e2,-0.25,
    0,0,10,0, 10,12,0,10, 0,10,9,0, 9,8,0,8, 
    7,0,10,0, 10,12,0,10, 0,10,9,0, 9,8,0,8, 
    7,0,10,0, 10,12,0,10, 0,10,9,0, 9,8,0,8, 
    7,0,10,0, 10,12,0,10, 0,10,9,0, 9,8,0,8, 
    7,0,10,0, 10,12,0,10, 0,10,9,0, 9,8,0,8, 
    7,0,10,0, 10,12,0,10, 0,10,9,0, 9,8,0,8, 
    -2, 0
];

const bass = [
    // intro, 1-8
    bp1a, bp1b, bp1c, bp1d,
    bp1a, bp1b, bp1c, bp1d,
    // pre-verse, 9-16
    bp1a, bp1b, bp1c, bp1d,
    bp1a, bp1b, bp1c, bp1d,
    // verse, 17-24
    bp1a, bp1b, bp1c, bp1d,
    bp1a, bp1b, bp1c, bp1e,
    // chorus, 25-32
    bp3a, bp3b, bp3c, bp3d,
    bp3a, bp3b, bp3c, bp3e, 
    // pre-verse2, 33-36
    bp1a, bp1b, bp1c, bp1d,
    // verse2, 37-44
    bp1a, bp1b, bp1c, bp1d,
    bp1a, bp1b, bp1c, bp1e,
    // chorus2, 45-52
    bp3a, bp3b, bp3c, bp3d, 
    bp3a, bp3b, bp3c, bp3f, 
    // pre-solo riff, 53-56
    bp6a, bp6b, bp6c, bp6d,
    // solo 57-72
    bp1a, bp1b, bp1c, bp1d,
    bp1a, bp1b, bp1c, bp1d,
    bp3a, bp3b, bp3c, bp3d,
    bp3a, bp3b, bp3c, bp3d,
    // chorus w/ solo 73-80
    bp3a, bp3b, bp3c, bp3d,
    bp3a, bp3b, bp3c, bp3f,
    // outro 81-87
    bp7
];

loop( class extends Track {
    play(note) {
        const A = 0.01;
        const D = 0.01;
        const S = 0.3;
        const R = 0.1;
        if (1) Strat.play(note, {
            attack: A, decay: D, sustain: S, duration: this.duration, release: R, pan: 0, amp: 30,
            mul: 0.997, // 1.99763,
            coeff: [
                [1.0003, 0.5],
                [2.0002, 0.3],
                [4.0001,0.2],
            ],
            feedback: 2.8
        });
        if (1) Strat.play(note, {
            attack: A, decay: D, sustain: S,duration: this.duration, release: R, pan: 0, amp: 30,
            mul: 1.01, // 1.99763,
            coeff: [
                [0.5003, 0.6],
                [1.0002, 0.25],
                [2.0001,0.1]
            ],
            feedback: 2.5
        });
    }
}, { 
    amp: 30, name: 'Electric bass', patterns: bass, start: START,
})
.connect(amp.create({ gain: 40 }))
.connect(lowpass.create( { cutoff: 0.35 } ))
.connect(amp.create({ gain: 1.5 }))
;


/*
    Main guitar
*/
const gp1 = [
    -4,0
];

const gp2 = [
    e3,-0.125,
    6.0,6.042,6.083,6.125,6.167,6.208,6.25,6.292, 6.333,6.375,6.417,6.458,6.5,6.542,6.583,6.625, 6.667,6.708,6.75,6.792,6.833,6.875,6.917,6.958, 7.0,7.042,7.083,7.125,7.167,7.208,7.25,7.292
];
const gp3 = [
    e3,-0.125,
    7.333,7.375,7.417,7.458,7.5,7.542,7.583,7.625,7.667,7.708,7.75,7.792,7.833,7.875,7.917,7.958,8.0,8.042,8.083,8.125,8.167,8.208,8.25,8.292,8.333,8.375,8.417,8.458,8.5,8.542,8.583,8.625
];
const gp4 = [
    e3,-0.125,
    8.667,8.708,8.75,8.792,8.833,8.875,8.917,8.958,9.0,9.042,9.083,9.125,9.167,9.208,9.25,9.292,9.333,9.375,9.417,9.458,9.5,9.542,9.583,9.625,9.667,9.708,9.75,9.79
];
const gp5 = [
    e3,-0.125,
    10.0,10.042,10.083,10.125,10.167,10.208,10.25,10.292,
    10.333,10.375,10.417,10.458,10.5,10.542,10.583,10.625,
    10.667,10.708,10.75,10.792,10.833,10.875,10.917,10.958,
    11.0,11.042,11.083,11.125, 
    12,13,14,15,16,17,18,19,
];
/* jshint elision: true */
const gp6 = [
    a3,
    -0.5,[0,12,,14],-0.25,[0,12,,14],[0,12,,14],-0.5,[0,12,,14],[0,12,,14],[0,12,,14],
    // string, fret, duration, bend
    b4,-0.25,12,
    [2, [b4,12,0.25,0.5]],
    b4,-0.5,12,10,
];
const gp7 = [
    a3,
    -0.5,[0,11,,13],-0.25,[0,11,,13],[0,11,,13],-0.5,[0,11,,13],[0,11,,13],[0,11,,13],
    b4,-0.25,12,
    [2, [b4,12,0.25,0.5]],
    b4,-0.5,12,10,
];
const gp8 = [
    a3,
    -0.5,[0,8,,10],-0.25,[0,8,,10],[0,8,,10],-0.5,[0,8,,10],[0,8,,10],[0,8,,10],
    b4,-0.25,12,
    [2, [b4,12,0.25,0.5]],
    b4,-0.5,12,10,
];
const gp9 = [
    a3,
    -0.5,[0,7,,9],-0.25,[0,7,,9],[0,7,,9],-0.5,[0,7,,9],[0,7,,9],[0,7,,9],
    b4,12,-1,12,
];
const gp10 = [
    b3,-1,10,-3,null
];
const rake = [0,0,0,0];
const gp11 = [
    d3,-0.25,
    rake,rake,rake,rake,rake,rake,rake,rake,
    rake,rake,rake,rake,rake,rake,rake,rake,
];
const pause = [-4,null];
const cC = [0,3,5,5]; //,4];
const cG = [0,3,5,5]; //,4];
const cDm = [0,5,5,7]; //,7];
const cAm = [0,5,7,7]; //,5];
const gp12 = [
    a3,
    -0.5,cC,
    -0.25,cC,cC,cC,cC,cC,
    -2.25,cC
];
const gp13 = [
    e3,
    -0.5,cG,
    -0.25,cG,cG,cG,cG,cG,
    -2.25,cG
];
const gp14 = [
    e3,
    -0.5,cDm,
    -0.25,cDm,cDm,cDm,cDm,cDm,
    -2.25,cDm
];
const gp15 = [
    e3,
    -0.5,cAm,
    -0.25,cAm,cAm,cAm,cAm,cAm,
    -2.25,cAm
];
const gp16 = [
    e3,-0.25,
    0,0,10,7, 10,12,0,15, 0,12,0,15, 15,12,15,
    a3,12
];
const gp17 = [
    e3,-1, [0,5,7,7],
    a3,-0.25, 10,12,0,10, 0,7,0,8, 8,7,5,7
];
const gp18 = [
    e3,-0.25,
    0,0,10,0, 10,12,0,15, 0,12,0,15, 15,12,15,a3,12
];
const gp19 = [
    d4,-0.25,
    0,0,10,0, 10,12,0,10, 0,10,9,0, 9,8,0,8
];
const gp20 = [
    d3,-0.25,
    7,a3,0,10,0, 10,12,0,10, 0,7,0,8, 8,7,5,7
];
const gp21 = [
    a3,-0.25, 
    0,0,10,0, 10,12,0,10, 0,7,0,8, 8,7,5,7
];
const gp22 = [
    e3,
    -0.5,cAm,
    -0.25,cAm,cAm,cAm,cAm,cAm,
    // bak -2.25,cAm,
    -1.25,cAm,
    [2, [a3, 12, 1,  -6]],
];
const gp23a = [
    e3,-0.25, 
    0,0,10,0, 10,12,0,10, 0,10,9,0, 9,8,0,8,
];
const gp23b = [
    e3,-0.25, 
    7,0,10,0, 10,12,0,10, 0,10,9,0, 9,8,0,8,
];
const gp23c = [
    e3,-0.25, 
    7,0,10,0, 10,12,0,15, 0,12,0,15, 15,12,15,a3,12
];
const gp24 = [
    g4,-0.25,
    14,14,b4,17,17, g4,14,14,b4,18,18, g4,14,14,b4,18,18, 17,17,g4,14,b4,17
];
const gp25 = [
    g4,-0.25,
    13,13,b4,17,17, g4,13,13,b4,18,18, g4,13,13,b4,18,18, 17,17,g4,13,b4,17
];
const gp26 = [
    g4,-0.25,
    14,14,b4,18,18, g4,14,14,e5,17,17, g4,14,14,b4,18,18, g4,14,14,b4,17,17
];
const gp27 = [
    b4,-0.25,
    17,g4,14,14,14, b4,15,d4,15,15,15, b4,13,d4,14,14,14, b4,12,d4,12,12,12 
];
const gp28 = [ // bar 65
    [1, [b4,13,2.5,0.5],[g4,12,2.0,0.5],[d4,14,1.5,1]],
    b4,-1,
    // bak: 13,
    [2, [b4,12,1,0.5]],
    -0.5,12,10
];
const gp29 = [ // bar 66
    [1, [b4,12,2.5,0.5],[g4,12,2.0,0.5],[d4,12,1.5,1]],
    b4,-1,12,-0.5,12,-0.25,13,15
];
const gp30 = [ // bar 67
    [1, [b4,15,2.5,0.5],[g4,14,2.0,0.5],[d4,15,1.5,1]],
    b4,-1,
    // bak: 15,
    [2, [b4,13,1,1]],
    -0.5,13,12
];
const gp31 = [ // bar 68
    [1, [b4,13,2.5,0.5],[g4,14,2.0,0.5],[d4,14,1.5,1]],
    b4,-1,15,-0.5,13,12
];
const gp32 = [ // bar 69
    [1, [b4,13,2.5,0.5],[g4,12,2.0,0.5],[d4,14,1.5,1]],
    b4,-1.5,12,-0.5,10
];
const gp33 = [ // bar 70
    [1, [b4,12,2.5,0.5],[g4,12,2.0,0.5],[d4,12,1.5,1]],
    b4,-1,12,-0.5,13,
     // bend: string, fret, duration, bend
    [2, [b4, 12, 1,  1.5]],
];
const gp34 = [ // bar 71
    b4,-0.5,15,
    // bend: string, fret, duration, bend
    -0.25,rake,14,
    d4,-1, 14,
    b4,-0.5,15,13,12
];
const gp35 = [
    [1, [b4,13,2.5,0.5],[g4,14,2.0,0.5],[d4,14,1.5,1]],
    e3,-0.25,pause,rake,rake,rake,rake,rake,rake,rake
];
const gp36 = [
    e3,-0.25,
    0,0,10,0, 10,12,0,10, 0,10,9,0, 9,8,0,8, 
    7,0,10,0, 10,12,0,10, 0,10,9,0, 9,8,0,8, 
    7,0,10,0, 10,12,0,10, 0,10,9,0, 9,8,0,8, 
    7,0,10,0, 10,12,0,10, 0,10,9,0, 9,8,0,8, 
    7,0,10,0, 10,12,0,10, 0,10,9,0, 9,8,0,8, 
    7,0,10,0, 10,12,0,10, 0,10,9,0, 9,8,0,8, 
    -2, 0
];

const main_guitar = [
    // intro, 1-8
    gp1,gp1,gp1,gp1,
    gp2,gp3,gp4,gp5,
    // pre-verse, 9-16
    gp6,gp7,gp8,gp9,
    gp6,gp7,gp8,gp9,
    // verse, 17-24
    gp10,pause,pause,pause,
    pause,pause,pause,gp11,
    // chorus, 25-32
    gp12,gp13,gp14,gp15,
    gp12,gp13,gp14,gp16,
    // pre-verse2, 33-36
    gp6,gp7,gp8,gp9,
    // verse2, 37-44
    gp17,gp18,gp19,gp20,
    gp21,gp18,gp19,gp11,
    // chorus2, 45-52
    gp12,gp13,gp14,gp15,
    gp12,gp13,gp14,gp22,
    // pre-solo riff, 53-56
    gp23a,gp23b,gp23b,gp23c,
    // solo 57-72
    gp24,gp25,gp26,gp24, // 57-60
    gp24,gp25,gp26,gp27, // 61-64
    
    gp28,gp29,gp30,gp31, // 65-68
    gp32,gp33,gp34,gp35, // 69-72
    // chorus w/ solo 73-80
    gp12,gp13,gp14,gp15,
    gp12,gp13,gp14,gp15,
    // outro 81-87
    gp36
];

loop(ElectricGuitar, { 
    name: 'Main guitar', patterns: main_guitar, start: START,
    amp: 1.2, pan: -0.5, mul: 0.495, feedback: 3
})
.connect(spread.create({ delay: 2000, width: 0.8 }))
.connect(amp.create({ gain: 47.456 })) // overdrive
//.connect(lowpass.create( { cutoff: 0.7 } ))
.connect(amp.create({ gain: 1.75 }))
;


/*
    2nd Guitar 
*/
const odp1 = [
    b4,-0.5,10,-0.25,[0,0,0],[0,0,0],-0.5,10,-0.25,[0,0,0],10,[0,0,0],[0,0,0],13,-0.75,12,-0.5,10
];
const odp2 = [
    b4,-0.5,9,-0.25,[0,0,0],[0,0,0],-0.5,9,-0.25,[0,0,0],9,[0,0,0],[0,0,0],13,-0.75,12,-0.5,10
];
const odp3 = [
    g4,-0.5,10,-0.25,[0,0,0],[0,0,0],-0.5,10,-0.25,[0,0,0],10,[0,0,0],[0,0,0],b4,13,-0.75,12,-0.5,10
];
const odp4 = [
    g4,-0.5,9,-0.25,[0,0,0],[0,0,0],-0.5,9,-0.25,[0,0,0],9,[0,0,0],[0,0,0],b4,12,-0.25,13,-0.5,12,-0.5,10
];
const odp5 = [
    -2,null,
    b4,-0.5,null,15,13,12
];
const odp6 = [
    e5,-0.5,12,b4,13,g4,-1.5,12,
    e5,-0.5,12,10,8
];
const odp7 = [
    e5,-0.5,10,b4,12,g4,-1.5,12,
    e5,-0.5,10,10,12
];
const odp8 = [
    e5,-0.5,13,b4,15,g4,-1.5,14,
    e5,-0.5,13,-0.5,15,-0.5,13
];
const odp9 = [
    e5,-0.5,12,b4,13,e5,-1.5,12,
    e5,-1,10,d4,-0.5,14
];
const odp10 = [
    e5,-0.5,10,b4,12,g4,-1.5,12,
    e5,-0.5,10,12,10
];
const odp11 = [
    -3,null,
     // bend: string, fret, duration, bend
    [2, [g3, 12, 1,  -4]],
];

const git2 = [
    // intro, 1-8
    gp1,gp1,gp1,gp1,
    gp2,gp3,gp4,gp5,
    // pre-verse, 9-16
    gp11,gp11,gp11,gp11,
    gp11,gp11,gp11,gp11,
    // verse, 17-24
    pause,pause,pause,pause,
    pause,pause,pause,pause,
    // chorus, 25-32
    pause,pause,pause,pause,
    pause,pause,pause,pause,
    // pre-verse2, 33-36
    odp1,odp2,odp3,odp4,
    // verse2, 37-44
    pause,pause,pause,pause,
    pause,pause,pause,pause,
    // chorus2, 45-52
    pause,pause,pause,pause,
    pause,pause,pause,pause, // odp11,
    // pre-solo riff, 53-56
    pause,pause,pause,pause,
    // solo 57-72
    pause,pause,pause,pause,
    pause,pause,pause,pause,
    pause,pause,pause,pause,
    pause,pause,pause,odp5,
    // chorus w/ solo 73-80
    odp6,odp7,odp8,odp9,
    odp6,odp10,odp8,odp9,
    // outro 81-87
    gp36
];

loop(class extends ElectricGuitar {
    strum(note, a, d, r) {
        super.strum(note - 0.02, a, d, r);
    }
}, { 
    name: '2nd Guitar', patterns: git2, start: START,
    amp: 1, pan: 0.5, mul: .497, feedback: 2.5
})
.connect(amp.create({ gain: 47.11 })) // overdrive
//.connect(lowpass.create( { cutoff: 0.5 } ))
.connect(amp.create({ gain: 0.85 }))
;

/*
    Bass Drum
*/
const Bassdrum = synth.def(class {
    constructor(options) {
        this.t = 0; Math.random();
        this.noise = 0.05;
    }
    fm(fc, fm, iom, t) {
        return sin(fc*TAU*t + iom*sin(fm*TAU*t));
    }
    process(note, env, tick, options) {
        const f = 120;
        this.t += ditty.dt;
        
        const t = this.t;
        let sig = 0;

        // noise click
        sig += Math.random(1) * this.noise * Math.exp(-300*t);

        // body
        const df = -f *5.5* t;
        const fb = f + df;
        sig += this.fm(fb, fb, 1, t) * (1-this.noise) * Math.exp(-40*t);
 
        return [sig,sig];
    }
});

const bdp1  = "................";
const bdp2  = "x...............";
const bdp3  = "x...x...x...x...";
const bdp4  = "x.x..x..x.x..x..";
const bdp5  = "x.x..x..x.x.....";
const bdp6  = ".xx..x.xx..x.x..";
const bdp7  = "x...x...x...x.x.";
const bdp8  = ".xx.xx.xx.xx.x..";
const bdp9  = "x...x...x....x..";
const bdp10 = ".x.x.......x....";
const bdp11 = "x.x..x...xx.xx..";
const bdp12 = "x...x.......x.x.";
const bdp13 = "x.x.x.x.x.x.x.x.";
const bdp14 = "x..x..x.x..x..x.";
const bdp15 = "x";

const bd = [
    // intro, 1-8
    bdp1,bdp1,bdp1,bdp1,
    bdp2,bdp2,bdp2,bdp2,
    // pre-verse, 9-16
    bdp3,bdp3,bdp3,bdp3,
    bdp3,bdp3,bdp3,bdp3,
    // verse, 17-24
    bdp4,bdp4,bdp4,bdp5,
    bdp4,bdp4,bdp4,bdp6,
    // chorus, 25-32
    bdp7,bdp7,bdp7,bdp7,
    bdp7,bdp7,bdp7,bdp8,
    // pre-verse2, 33-36
    bdp3,bdp3,bdp3,bdp9,
    // verse2, 37-44
    bdp4,bdp4,bdp4,bdp5,
    bdp4,bdp4,bdp4,bdp6,
    // chorus2, 45-52
    bdp7,bdp7,bdp7,bdp7,
    bdp7,bdp7,bdp7,bdp10,
    // pre-solo riff, 53-56
    bdp3,bdp3,bdp4,bdp11,
    // solo 57-64
    bdp3,bdp3,bdp3,bdp3,
    bdp3,bdp3,bdp3,bdp8,
    // solo 65-68,
    bdp7,bdp7,bdp7,bdp7,
    bdp7,bdp7,bdp7,bdp12,
    // chorus w/ solo 73-80
    bdp7,bdp7,bdp7,bdp7,
    bdp7,bdp7,bdp7,bdp10,
    // outro 81-87
    bdp3,bdp3,bdp4,bdp4,
    bdp13,bdp14,bdp15
];

loop( class extends Track {
    play(note) {
        if (note == 'x') {            
            Bassdrum.play(1, {amp: Math.random()*0.1+0.9});
        }     
    }
},
{ 
    amp: 1.0, name: 'Bass drum', patterns: bd, start: START
})
.connect(amp.create({ amp: 2.5 }))
;


/*
    Snare Drum
*/

const Snare = synth.def(class {
    constructor(options) {
        this.t1 = 0; // + Math.random();
        this.t2 = 0; // - Math.random();
    }
    fm(fc, fm, iom, t) {
        return sin(fc*TAU*t + iom*sin(fm*TAU*t));
    }
    snare(f, t) {
        let sig = 0;
        // click
        sig += this.fm(f*10, 0, 0, this.t1*t) * 0.4 * Math.exp(-100*this.t1);

        // body
        const df = -f*2.5 * this.t2;
        const fb = f+df;
        sig += this.fm(fb, fb*3, 2.5, this.t2*t) * 0.8 * Math.exp(-60*this.t2);

        // noise
        sig += Math.random(1) * 0.3 * Math.exp(-15*this.t1);
        return sig;
    }
    process(note, env, tick, options) {
        const f = midi_to_hz(note);
        this.t1 += ditty.dt;
        this.t2 += ditty.dt;

        let l,r = 0;
        l = this.snare(f, 1.01);
        r = this.snare(f, 0.99);

        return [l,r];
    }
});

// snare-drum patterns
const sp1  = "................";
const sp2  = "....x.......x...";
const sp2a = "....x.......x..x";
const sp3  = "....x.......xxxx";
const sp4  = "x.....x.....x...";
const sp5  = "....x....x..x...";
const sp6  = "....x....x....x.";
const sp7  = "x..x..x..x..x.x.";
const sp8  = "....x.....xxx.x.";
const sp9  = "x...xxxxxx.x....";
const sp10 = "....x...x.....x.";
const sp11 = "x..x..x..x....x.";
const sp12 = ".xx.xx.x.xx.....";

const snare = [
    // intro, 1-8
    sp1,sp1,sp1,sp1,
    sp2,sp2,sp2,sp3,
    // pre-verse, 9-16
    sp2,sp2,sp2,sp3,
    sp2,sp2,sp2,sp3,
    // verse, 17-24
    sp2,sp2,sp2,sp3,
    sp2,sp2,sp2,sp4,
    // chorus, 25-32
    sp5,sp5,sp5,sp6,
    sp5,sp5,sp5,sp7,
    // pre-verse2, 33-36
    sp2,sp2,sp2,sp8,
    // verse2, 37-44
    sp2,sp2,sp2,sp3,
    sp2,sp2,sp2,sp4,
    // chorus2, 45-52
    sp5,sp5,sp5,sp6,
    sp5,sp5,sp5,sp9,
    // pre-solo riff, 53-56
    sp2,sp2,sp2,sp10,
    // solo 57-72
    sp2,sp2,sp2,sp3,
    sp2,sp2,sp2,sp11,
    sp5,sp5,sp5,sp6,
    sp5,sp5,sp5,sp9,
    // chorus w/ solo 73-80
    sp5,sp5,sp5,sp6,
    sp5,sp5,sp5,sp9,
    // outro 81-86
    sp2,sp2,sp2,sp2a,sp2,
    sp12
];

loop( class extends Track {
    play(note) {
        if (note == 'x') {
            Snare.play(23, { 
                pan: -0.15
            }); 
        }         
    }
},
{ 
    amp: 2.8, pan: 0, name: 'Snare drum', patterns: snare, start: START
})
.connect(lowpass.create({ cutoff: 0.6 }))
;


/*
    Ride cymbal
*/
const Ride = synth.def( class {
    constructor (options) {
        this.t = Math.random();
        this.iom = 65.51;
        this.mul = 3.8;
    }
    add_fm(note) {
        // carrier frequency
        const fc = midi_to_hz(note);
        // modulator frequency
        const fm = fc * this.mul;
        let mod = sin(TAU*this.t*fm);
        return sin(TAU*this.t*fc + this.iom*mod);
    }
    add_noise() {
        return sin(TAU*Math.random());
    }
    process(note, env, tick, options) {
        // forward time
        this.t += ditty.dt;

        let osc = this.add_fm(note) * 0.2;
        osc += this.add_noise() * 0.2;
        
        osc = (osc * 0.5) * env.value;
        //debug.probe("ride", 50*osc, 10, 2);

        return [osc, osc]; // left, right
    }
}); 

// "Make the ride crash while playing it on downbeats"
const rp1 = "................";
const rp2 = "..x.x.x.x.x.x.x.";
const rp3 = "x.x.x.x.x.x.x.x.";
const rp4 = "x.x.x.x.x.x.....";
const rp5 = "..x.............";

const ride = [
    // intro, 1-8
    rp1,rp1,rp1,rp1,
    rp1,rp1,rp1,rp1,
    // pre-verse, 9-16
    rp2,rp3,rp3,rp4,
    rp2,rp3,rp3,rp4,
    // verse, 17-24
    rp1,rp1,rp1,rp1,
    rp1,rp1,rp1,rp1,
    // chorus, 25-32
    rp2,rp3,rp3,rp4,
    rp2,rp3,rp3,rp1,
    // pre-verse2, 33-36
    rp3,rp3,rp3,rp4,
    // verse2, 37-44
    rp1,rp1,rp1,rp1,
    rp1,rp1,rp1,rp1,
    // chorus2, 45-52
    rp2,rp3,rp3,rp4,
    rp2,rp3,rp3,rp1,
    // pre-solo riff, 53-56
    rp1,rp1,rp1,rp1,
    // solo 57-72
    rp2,rp3,rp3,rp4,
    rp2,rp3,rp3,rp1,
    rp2,rp3,rp3,rp4,
    rp2,rp3,rp3,rp5,
    // chorus w/ solo 73-80
    rp2,rp3,rp3,rp4,
    rp2,rp3,rp3,rp1,
    // outro 81-87
    rp1,rp1,rp1,rp1,rp1,rp1,rp1
];

loop( class extends Track {
    play(note) {
        if (note == 'x') {            
            Ride.play(79, { 
                amp: Math.random()*0.1+0.9,
                attack: 0, decay: 2, sustain: 0, release: 0, curve: -5
            }); 
        }
    }
},
{ 
    amp: 1.6, pan: 0.6, name: 'Ride cymbal', patterns: ride, start: START,
})
.connect(lowpass.create({ cutoff: 0.6 }))
.connect(amp.create({amp: 1.5}))
;


/*
    Percussion helpers
*/

function add_fm(t, fc, options) {
    // modulator frequency
    const fm = fc * options.mul;
    const mod = sin(TAU*t*fm);
    const osc = sin(TAU*t*fc + options.iom*mod);
    return osc;
}

function add_noise(t, fc, options) {
    const osc = sin(TAU * Math.random());
    return osc;
}


/*
    Open Hi-Hat
*/

const OpenHiHat = synth.def(class {
    constructor(options) {
        this.t = Math.random();
        this.env_fm = adsr.create( { 
            attack: 0.0, decay: 0.05, sustain: 0, release: 0, curve: -3
        });
        this.env_n =  adsr.create( { 
            attack: 0.01, decay: 0.15, sustain: 0, release: 0, curve: -5
        });
    }
    process(note, env, tick, options) {
        this.t += ditty.dt;
        const f = midi_to_hz(note);

        let osc = add_fm(this.t, f, options) * this.env_fm.value * 0.4;
        osc += add_noise(this.t, f, options) * this.env_n.value * 0.1;
        osc *= 0.7;
        //debug.probe( "OpenHiHat", osc, 0.5 );
        return [osc, osc]; // left, right
    }
});

const ohp1 = "................";
const ohp2 = "..x...x...x...x.";
const ohp3 = "..x...x...x.....";
const ohp4 = "........x.......";

const openhihat = [
    // intro, 1-8
    ohp1,ohp1,ohp1,ohp1,ohp1,ohp1,ohp1,ohp1,
    // pre-verse, 9-16
    ohp2,ohp2,ohp2,ohp2,ohp2,ohp2,ohp2,ohp3,
    // verse, 17-24
    ohp2,ohp2,ohp2,ohp2,ohp2,ohp2,ohp2,ohp1,
    // chorus, 25-32
    ohp4,ohp4,ohp4,ohp4,ohp4,ohp4,ohp4,ohp1,
    // pre-verse2, 33-36
    ohp2,ohp2,ohp2,ohp3,
    // verse2, 37-44
    ohp2,ohp2,ohp2,ohp2,ohp2,ohp2,ohp2,ohp1,
    // chorus2, 45-52
    ohp4,ohp4,ohp4,ohp4,ohp4,ohp4,ohp4,ohp1,
    // pre-solo riff, 53-56
    ohp1,ohp1,ohp1,ohp1,
    // solo 57-72
    ohp2,ohp2,ohp2,ohp3,ohp2,ohp2,ohp2,ohp1,
    ohp4,ohp4,ohp4,ohp4,ohp4,ohp4,ohp4,ohp1,
    // chorus w/ solo 73-80
    ohp4,ohp4,ohp4,ohp4,ohp4,ohp4,ohp4,ohp1,
    // outro 81-87
    ohp1,ohp1,ohp1,ohp1,ohp1,ohp1,ohp1,
];

loop( class extends Track {
    play(note) {
        if (note == 'x') {  
            OpenHiHat.play(58.5, { 
                iom: 2.4, mul: 31.5,
            });
        }
    }
},
{ 
    amp: 1.2, pan: -0.3, name: 'Open Hi-Hat', patterns: openhihat, start: START,
})
;


/*
    Closed Hi-Hat
*/

const ClosedHiHat = synth.def(class {
    constructor(options) {
        this.t = Math.random();
        this.env_fm = adsr.create( { 
            attack: 0.01, decay: 0.3, sustain: 0, release: 0, curve: -9
        });
        this.env_n =  adsr.create( { 
            attack: 0.01, decay: 0.2, sustain: 0, release: 0, curve: -7
        });
    }
    process(note, env, tick, options) {
        this.t += ditty.dt;
        const f = midi_to_hz(note);

        let osc = add_fm(this.t, f, options) * this.env_fm.value * 0.4;
        osc += add_noise(this.t, f, options) * this.env_n.value * 0.15;
        osc *= 0.5;
        return [osc, osc]; // left, right
    }
});

const chp1  = "................";
const chp2  = "..x.x.x.x.x.x.x.";
const chp2a = "x.x.x.x.x.x.x.x.";
const chp3  = "x.x.x.x.........";
const chp4  = ".x..............";
const chp5  = "x...............";

const closedhh = [
    // intro, 1-8
    chp1,chp1,chp1,chp1,chp1,chp1,chp1,chp1,
    // pre-verse, 9-16
    chp1,chp1,chp1,chp1,chp1,chp1,chp1,chp1,
    // verse, 17-24
    chp1,chp1,chp1,chp1,chp1,chp1,chp1,chp1,
    // chorus, 25-32
    chp1,chp1,chp1,chp1,chp1,chp1,chp1,chp1,
    // pre-verse2, 33-36
    chp1,chp1,chp1,chp1,
    // verse2, 37-44
    chp1,chp1,chp1,chp1,chp1,chp1,chp1,chp1,
    // chorus2, 45-52
    chp1,chp1,chp1,chp1,chp1,chp1,chp1,chp1,
    // pre-solo riff, 53-56
    chp2,chp2a,chp2a,chp3,
    // solo 57-72
    chp1,chp1,chp1,chp1,chp1,chp1,chp1,chp1,
    chp1,chp1,chp1,chp1,chp1,chp1,chp1,chp1,
    // chorus w/ solo 73-80
    chp1,chp1,chp1,chp1,chp1,chp1,chp1,chp4,
    // outro 81-87
    chp2,chp2a,chp2a,chp2a,chp2a,chp5
    
];

loop( class extends Track {
    play(note) {
        if (note == 'x') {         
            ClosedHiHat.play(95, { 
                iom: 2.4, mul: 31.5,
            });
        }
    }
},
{ 
    amp: 1.5, pan: -0.7, name: 'Closed Hi-Hat', patterns: closedhh, start: START,
})
;