//One universal basic required here to get things going once loaded
let fromFile = false,theIsotherm=[], updating = false
window.onload = function () {
    //restoreDefaultValues(); //Un-comment this if you want to start with defaults
    document.getElementById('Load').addEventListener('click', clearOldName, false);
    document.getElementById('Load').addEventListener('change', handleFileSelect, false);

    Main();
};
//Any global variables go here


//Main is hard wired as THE place to start calculating when input changes
//It does no calculations itself, it merely sets them up, sends off variables, gets results and, if necessary, plots them.
function Main() {
    if (updating) return
    saveSettings();

    //Send all the inputs as a structured object
    //If you need to convert to, say, SI units, do it here!
    const inputs = {
        M: sliders.SlideM.value,
        C: sliders.SlideC.value,
        K: sliders.SlideK.value,
        RH: sliders.SlideRH.value,
    }

    //Get all the resonses as a structure
    const result = CalcIt(inputs)

    //Set all the text box outputs
    document.getElementById('PercW').value = result.PercW
    if (result.plots) {
        for (let i = 0; i < result.plots.length; i++) {
            plotIt(result.plots[i], result.canvas[i]);
        }
    }

}

//Here's the real app calculation
function CalcIt({ M,C,K,RH }) {
    //The structure automatically has the names provided from input
    //By convention the values are provided with the correct units within CalcIt
    if (updating) return
    if (fromFile){
        let x=[],y=[]
        for (let i=0; i=RH && ! GotRH){
             GotRH=true
             PercW=M1
         }
    }

    //Now we return everything - text boxes, plot and the name of the canvas, which is 'canvas' for a single plot
    let plotData=[WPts], showLines=[true], showPoints=[false]
    if (fromFile) {
        plotData=[WPts,theIsotherm]
        showLines = [true,false]
        showPoints = [false,true]
 
        fromFile=false
    }

    const prmap = {
        plotData: plotData, //An array of 1 or more datasets
        lineLabels: ["%Water","Data"], //An array of labels for each dataset
        showLines: showLines,
        showPoints: showPoints,
        borderWidth: [3, 10],
        hideLegend: true,
        xLabel: 'a_w& ', //Label for the x axis, with an & to separate the units
        yLabel: '%Water& ', //Label for the y axis, with an & to separate the units
        y2Label: null, //Label for the y2 axis, null if not needed
        yAxisL1R2: [], //Array to say which axis each dataset goes on. Blank=Left=1
        logX: false, //Is the x-axis in log form?
        xTicks: undefined, //We can define a tick function if we're being fancy
        logY: false, //Is the y-axis in log form?
        yTicks: undefined, //We can define a tick function if we're being fancy
        legendPosition: 'top', //Where we want the legend - top, bottom, left, right
        xMinMax: [,], //Set min and max, e.g. [-10,100], leave one or both blank for auto
        yMinMax: [,], //Set min and max, e.g. [-10,100], leave one or both blank for auto
        y2MinMax: [,], //Set min and max, e.g. [-10,100], leave one or both blank for auto
        xSigFigs: 'P3', //These are the sig figs for the Tooltip readout. A wide choice!
        ySigFigs: 'P3', //F for Fixed, P for Precision, E for exponential

    }
    return {
        PercW: PercW.toFixed(1),
        plots: [prmap],
        canvas: ['canvas'],
    };
}
function clearOldName() { //This is needed because otherwise you can't re-load the same file name!
    Loading = true
    document.getElementById('Load').value = ""
}
function handleFileSelect(evt) {
    var f = evt.target.files[0];
    if (f) {
        var r = new FileReader();
        r.onload = function (e) {
            var data = e.target.result;
            LoadData(data)
        }
        r.readAsText(f);
    } else {
        return;
    }
}

//Load data from a chosen file
function LoadData(S) {
    Papa.parse(S, {
        download: false,
        header: true,
        skipEmptyLines: true,
        complete: papaCompleteFn,
        error: papaErrorFn
    })
}
function papaErrorFn(error, file) {
    console.log("Error:", error, file)
}
function papaCompleteFn() {
    var theData = arguments[0]
    fromFile=false
    theIsotherm = [];
    if (theData.data.length < 3) return //Not a valid data file
    let maxX = 0
    for (i = 0; i < theData.data.length; i++) {
        theRow = theData.data[i]
        if (theRow.Item.toUpperCase() == "DATA") {
            // fitData.push({ x: parseFloat(theRow.a), y: parseFloat(theRow.n) })
            theIsotherm.push({ x: parseFloat(theRow.a), y: parseFloat(theRow.n) })
            maxX=Math.max(parseFloat(theRow.a),maxX)
        }
    }

    if (theIsotherm.length < 4) return //Invalid data
    //Accept 0-->1 as well as 0-->100
    if (maxX<1) {
        for (i=0;i 0) && funParm(P1) < funParm(P0)) { // if parm value going in the righ direction
                step[j] = 1.2 * step[j]; // then go a little faster
                P0 = cloneVector(P1);
            } else {
                step[j] = -(0.5 * step[j]); // otherwiese reverse and go slower
            }
        }
        //Stop trying too hard
        newfP = funParm(P0)
        if (i > 1000 && newfP < lastfP && Math.abs((newfP - lastfP) / lastfP) < eps) break
        lastfP = newfP
        lasti = i
    }
    //console.log(lasti)
    return P0
};