Is possible to write a script that can AUTO CROP image to best fit aspect ratio ?

Does this provide meaningful results? 

// determine closest ratio from a limited set;
// 2023, use at your own risk;
if (app.documents.length > 0) {
    app.togglePalettes();
    var originalRulerUnits = app.preferences.rulerUnits;
    app.preferences.rulerUnits = Units.PIXELS;
    var myDocument = activeDocument;
    var theW = myDocument.width;
    var theH = myDocument.height;
    var theProportion = theW/theH;
    var theProportions = [[2,3], [5,7], [3,4], [4,5], [1,1], [5,4], [4,3], [7,5], [3,2], [2,1], [3,1]];
    var theResult = theProportions.sort(sortArrayByDifference)[0];
    var thisProp = theResult[0]/theResult[1];
    if (theProportion < thisProp) {
        var targetW = theW;
        var targetH = theW*theResult[1]/theResult[0];
    }
    else {
        var targetW = theH*theResult[0]/theResult[1];
        var targetH = theH;
    };
    alert ("at the aspect ratio "+theResult.join("/")+" the image would be\n"+targetW+" x "+targetH);
    app.preferences.rulerUnits = originalRulerUnits;
    app.togglePalettes();
};
////// sort by difference to a number //////
function sortArrayByDifference(a,b) {
    if (Math.abs((a[0]/a[1])-theProportion)<Math.abs((b[0]/b[1])-theProportion)) return -1;
    if (Math.abs((a[0]/a[1])-theProportion)>Math.abs((b[0]/b[1])-theProportion)) return 1;
    return 0;
    };

There are different algorithms to determine aspect ratios, the following code uses 3 different ones:

/*
Photoshop Document Dimensions - MP Value - Aspect Ratio.jsx
v1.0, Stephen Marsh 13th February 2022
*/

#target photoshop

var savedRuler = app.preferences.rulerUnits;
app.preferences.rulerUnits = Units.PIXELS;

var w = app.activeDocument.width.value;
var h = app.activeDocument.height.value;
var r = gcd(w, h);
var mp = w * h / 1000000;
var pix = w * h;
var ppiRes = app.activeDocument.resolution;
var ppcmRes = ppiRes / 2.54;
var ratio = w / h;
var docName = app.activeDocument.name;
var wMetric = w / 72 * 2.54;
var hMetric = h / 72 * 2.54;
var wInches = w / 72;
var hInches = h / 72;
var doc = app.activeDocument;
var w = doc.width.value;
var h = doc.height.value;

alert(
    'Document Info' + '\n' +
    'Document Name: ' + docName + '\n' +
    'Dimensions: ' + w + ' x ' + h + ' pixels' + '\n' +
    'Dimensions: ' + Math.round(wMetric * 100) / 100 + ' x ' + Math.round(hMetric * 100) / 100 + ' cm / ' + Math.round(wInches * 1000) / 1000 + ' x ' + Math.round(hInches * 1000) / 1000 + ' inches' + '\n' +
    'Resolution: ' + Math.round(ppiRes * 10) / 10 + ' ppi / ' + Math.round(ppcmRes * 1000) / 1000 + ' ppcm' + '\n' +
    'Megapixel Value: ' + Math.round(mp * 10) / 10 + ' MP' + ' (' + pix + ' pixels)' + '\n' +
    'Aspect Ratio:' + '\n' + ratio.toFixed(2) + ':1' + ' / ' + ratio.toFixed(2) * 2 + ':2 / ' + ratio.toFixed(2) * 4 + ':4' + ' (Basic)' + '\n' +
    w / r + ':' + h / r + ' (GCD)' + '\n' +
    aspect_ratio(w / h, 50).toString().replace(',', ':') + ' (Farey)'
);

app.preferences.rulerUnits = savedRuler;


function gcd(a, b) {
    /* https://stackoverflow.com/questions/1186414/whats-the-algorithm-to-calculate-aspect-ratio-i-need-an-output-like-43-169 */
    return (b == 0) ? a : gcd(b, a % b);
}

function aspect_ratio(val, lim) {

    var lower = [0, 1];
    var upper = [1, 0];

    while (true) {
        var mediant = [lower[0] + upper[0], lower[1] + upper[1]];

        if (val * mediant[1] > mediant[0]) {
            if (lim < mediant[1]) {
                return upper;
            }
            lower = mediant;
        } else if (val * mediant[1] == mediant[0]) {
            if (lim >= mediant[1]) {
                return mediant;
            }
            if (lower[1] < upper[1]) {
                return lower;
            }
            return upper;
        } else {
            if (lim < mediant[1]) {
                return lower;
            }
            upper = mediant;
        }
    }
}

Adobe Bridge has a filter for aspect ratio, which you can use to open all files in a folder with the same ratio... But you would have to determine the threshold and fuzziness as to what matches what.

Have you studied, understood, and tried the File > Automate > Fit Image... script and is it not what you want...?

If it only works for some photos, you could indeed write a script that uses a different Fit Image... depending on sizes or ratios the script detects — or just do them in separate batches.

PS: Fit Image will use the Image Interpolation set in Preferences.

I don’t think I fully understand the process. 

Could you post screenshots for an example (what do you start with, what is the intended final result, …)?