const ASM3 = require('./asm3_class')
const math = require('mathjs')

class Reactor_CSTR {
    
    constructor(initial_state) {
        this.state = initial_state;
        this.asm = new ASM3();

        this.Vl = 10.0; // fluid volume reactor [m3]
        this.F = 1.0; // fluid debit [m3 d-1]
        this.C_in = Array(13).fill(0.0); // composition influent
        this.OTR = 100.0; // oxygen transfer rate [g O2 d-1]

        this.currentTime = Date.now(); // milliseconds since epoch [ms]
        this.timeStep = 1/(24*60) // time step [d]
    }

    // expect update with timestamp
    updateState(input) {
        throw new Error("Not implemented yet");

        let newTime = input.payload;

        const day2ms = 1000 * 60 * 60 * 24; 

        let n_iter = (newTime - this.currentTime) % (this.timeStep * day2ms);
    }

    tick_fe(time_step) { // tick reactor state using forward Euler method
        const r = this.asm.compute_dC(this.state);
        const dC_in = math.multiply(this.C_in, this.F/this.Vl);
        const dC_out = math.multiply(this.state, this.F/this.Vl);
        const T_O = Array(13).fill(0.0);
        T_O[0] = this.OTR;

        const dC_total = math.multiply(math.add(dC_in, dC_out, r, T_O), time_step);

        this.state = math.add(this.state, dC_total);
        return this.state;
    }
}

// testing stuff
// state: S_O, S_I, S_S, S_NH, S_N2, S_NO, S_HCO, X_I, X_S, X_H, X_STO, X_A, X_TS
let initial_state = [0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1, 0.1];
const Reactor = new Reactor_CSTR(initial_state);
Reactor.C_in = [0.0, 30., 100., 16., 0., 0., 5., 25., 75., 30., 0., 0., 125.];
N = 0;
while (N < 500) {
    console.log(Reactor.tick_fe(0.001));
    N += 1;
}