!(function() {
	/*
		(c) Dyrk.org 2024 - 2025
		  ZipDetailsExplorer 1.0
		  Dave-Hill [{o.o}] Dyrk.org
	*/
    let html = document.getElementsByTagName('html')[0],
        genEl = (parrent, type, value) => {
            let el = document.createElement(type);
            if (value) el.textContent = value;
            if (parent) parrent.appendChild(el);
            return el;
        },
        fileHeaderStruct = function() {
            return {
                "Signature": 4, // (0x04034b50)
                "Version Needed to Extract": 2,
                "General Purpose Bit Flag": 2,
                "Compression Method": 2,
                "Last Mod File Time": 2,
                "Last Mod File Date": 2,
                "CRC-32": 4,
                "Compressed Size": 4,
                "Uncompressed Size": 4,
                "File Name Length": 2,
                "Extra Field Length": 2,
                "File Name": null,
                "Extra Field": null,
                "RawFileData": null
            };
        },
        CentralDirectoryFileHeader = function() {
            return {
                "Signature": 4, //  (0x02014b50),
                "Version Made by": 2,
                "Version Needed to Extract": 2,
                "General Purpose Bit Flag": 2,
                "Compression Method": 2,
                "Last Mod File Time": 2,
                "Last Mod File Date": 2,
                "CRC-32": 4,
                "Compressed Size": 4,
                "Uncompressed Size": 4,
                "File Name Length": 2,
                "Extra Field Length": 2,
                "File Comment Length": 2,
                "Disk Number Start": 2,
                "Internal File Attributes": 2,
                "External File Attributes": 4,
                "Relative Offset of Local Header": 4,
                "File Name": null,
                "Extra Field": null,
                "File Comment": null,
                "RawFileData": null
            };
        },
        EndCentralDirectoryRecord = function() {
            return {
                "Signature": 4, //(0x06054b50)
                "Number of this Disk": 2,
                "Disk where Central Directory starts": 2,
                "Number of Central Directory Records on this Disk": 2,
                "Total Number of Central Directory Records": 2,
                "Size of Central Directory": 4,
                "Offset of Start of Central Directory": 4,
                "ZIP File Comment Length": 2,
                "ZIP File Comment": null,
                "RawFileData": null
            };
        },
        file = document.createElement('input');
    html.textContent = '';
    file.type = 'file';
    file.addEventListener('change', (evt) => {
        reader = new FileReader();
        reader.addEventListener('load', (content) => {
            let bin2Hex = (str, prefix) => (prefix ? '0x' : '').concat(str.split('').map(l => '0'.concat(l.charCodeAt(0).toString(16)).substr(-2)).reverse().join('').toUpperCase()),
                binContent = content.target.result,
                hexContent = bin2Hex(binContent),
                zipStruct = {
                    'LocalFileHeader': {
                        'signature': '04034B50',
                        'model': fileHeaderStruct()
                    },
                    'CentralDirectoryFileHeader': {
                        'signature': '02014B50',
                        'model': CentralDirectoryFileHeader()
                    },
                    'EndCentralDirectoryRecord': {
                        'signature': '06054B50',
                        'model': EndCentralDirectoryRecord()
                    }
                },
                position, sum, part;

            table = genEl(html, 'table');
            table.border = 1;
            table.width = '100%';
            hexContent.match(/.+?(04034B50|02014B50|06054B50)/g).map(function(fileContent) {
                if (fileContent.length == 0) return;
                //console.log(fileContent);
                position = 0;
                part = Object.keys(zipStruct).filter(kpart => zipStruct[kpart].signature == fileContent.substr(-8))[0];
                tmpBinContent = fileContent.match(/[0-9A-Z]{2}/g).reverse().map(e => String.fromCharCode(parseInt(e, 16))).join('');
                newFile = Object.assign({}, zipStruct[part].model);
                Object.keys(newFile).map(k => {
                    bin = tmpBinContent.substr(position, k == 'RawFileData' ? tmpBinContent.length : newFile[k]);
                    isDynamicField = ["File Name", "Extra Field", "File Comment", "ZIP File Comment"].indexOf(k) != -1;
                    if (isDynamicField) bin = tmpBinContent.substr(position, newFile[k.concat(" Length")].val);
                    newFile[k] = {
                            bin: bin,
                            hex: bin2Hex(bin, true),
                            dec: bin.split('').map(d => d.charCodeAt(0)),
                            position: position,
                            offset: newFile[k],
                            val: null
                        },
                        position += !isDynamicField ? newFile[k].offset : newFile[k.concat(" Length")].val;
                    if (k.indexOf('Length') != -1) {
                        sum = 0;
                        newFile[k].dec.forEach(x => sum += x);
                        newFile[k].val = sum;
                    };
                });
                console.log(part, newFile);
                let tr = genEl(table, 'tr');
                let td = genEl(tr, 'td', part);
                td.setAttribute('colspan', 7);
                td.style = 'background:#000;color:#FFF';
                Object.keys(newFile).map(k => {
                    let tr = genEl(table, 'tr');
                    [k].concat(Object.values(newFile[k])).map((v, pos) => {
                        let td = genEl(tr, 'td', v);
                        td.style = 'word-break: break-all;width:15%';
                    });
                });
            });
        });
        reader.readAsBinaryString(evt.target.files[0]);
    });
    file.click();
}());