import { ParamCalculability } from "../param/param-definition";
import { Result } from "../util/result";
import { Structure, StructureFlowMode, StructureFlowRegime } from "./structure";
import { LoiDebit } from "./structure_props";
import { TriangularStructureParams } from "./structure_triangular_weir_params";
import { Villemonte } from "./villemonte";

export { TriangularStructureParams };

/**
 * Equation classique seuil triangulaire + Ennoiement Villemonte
 */
export class StructureTriangularWeir extends Structure {

    constructor(prms: TriangularStructureParams, dbg: boolean = false) {
        super(prms, dbg);
        this._loiDebit = LoiDebit.TriangularWeirFree;
    }

    /**
     * paramètres castés au bon type
     */
    get prms(): TriangularStructureParams {
        return this._prms as TriangularStructureParams;
    }

    /**
     * Calcul analytique Q = f(Cd, L, h1, h2, W) seuil dénoyé
     * @param sVarCalc Variable à calculer (doit être "Q")
     */
    public CalcQ(): Result {
        const data = this.getResultData();

        let Q = this.prms.Cd.v * this.getTanFromDegrees(this.prms.alpha2.v)
            * Math.pow(this.prms.h1.v, 2.5);

        if (data.ENUM_StructureFlowRegime !== StructureFlowRegime.FREE) {
            Q = Villemonte(this.prms.h1.v, this.prms.h2.v, 2.5) * Q;
        }

        return new Result(Q, this, data);
    }

    /**
     * Calcul de l'aire d'écoulement sur le seuil
     */
    public calcA(): number {
        return Math.pow(Math.max(this.prms.h1.v, this.prms.h2.v), 2) * this.getTanFromDegrees(this.prms.alpha2.v);
    }

    protected getFlowRegime() {
        if (this.prms.Z2.v <= this.prms.ZDV.v) {
            return StructureFlowRegime.FREE;
        } else {
            // La réduction de débit s'applique dès que Z2 > ZDV (Villemonte, 1946)
            if (this.prms.h2.v < 4 / 5 * this.prms.h1.v) {
                // Yc = 4 / 5 * H1 (Jameson, 1925)
                return StructureFlowRegime.PARTIAL;
            }
            return StructureFlowRegime.SUBMERGED;
        }
    }

    protected getFlowMode() {
        return StructureFlowMode.WEIR;
    }

    /**
     * Compute Tangent with angle in degrees
     * @param degrees Angle (degrees)
     */
    protected getTanFromDegrees(degrees: number) {
        return Math.tan(degrees * Math.PI / 180);
    }

    /**
     * paramétrage de la calculabilité des paramètres
     */
    protected setParametersCalculability() {
        super.setParametersCalculability();
        this.prms.alpha2.calculability = ParamCalculability.DICHO;
        this.prms.Cd.calculability = ParamCalculability.DICHO;
    }
}