'use strict';

const { BaseReactorEngine, math, S_O_INDEX, NUM_SPECIES } = require('./baseEngine.js');

class Reactor_CSTR extends BaseReactorEngine {
  constructor(config) {
    super(config);
    this.state = config.initialState;
  }

  // Forward Euler step over `time_step` days.
  tick(time_step) {
    const inflow  = math.multiply(math.divide([this.Fs], this.volume), this.Cs_in)[0];
    const outflow = math.multiply(-1 * math.sum(this.Fs) / this.volume, this.state);
    const reaction = this.asm.compute_dC(this.state, this.temperature);
    const transfer = Array(NUM_SPECIES).fill(0.0);
    transfer[S_O_INDEX] = isNaN(this.kla)
      ? this.OTR
      : this._calcOTR(this.state[S_O_INDEX], this.temperature);

    const dC_total = math.multiply(math.add(inflow, outflow, reaction, transfer), time_step);
    this.state = this._capDissolvedOxygen(this._arrayClip2Zero(math.add(this.state, dC_total)));
    return this.state;
  }
}

module.exports = Reactor_CSTR;