webserver-scripts-fileManager.js

// read text string from file
function readFile(types='*.*', timeout=60) {

    return new Promise((res) => {
        const input = document.createElement('input')
        input.type = 'file'
        input.accept = types
        input.addEventListener('change', async (event) => {
            if (event.target.files.length === 0) res(undefined)
            const type = event.target.files[0].name.split('.').slice(-1)[0]
            if (!types.includes(type.toLowerCase()) && !types.includes(type)) res(undefined)
            const fileResponse = await fetch(window.URL.createObjectURL(event.target.files[0]))
            fileResponse.fileType = type
            res(fileResponse)
        })
        input.click()
        setTimeout(() => {
            res(undefined)
            delete input
        }, timeout*1000)
    })
}



// parse CSV from file in JSON (nested arrays)
function parseCSV(file, timeout=60) {

    const parse = (csvString) => {
        if (typeof csvString !== 'string') return undefined

        const lines = []
        let currentLine = []
        let currentField = ''
        let insideQuotes = false
        let currentChar = ''

        for (let i = 0; i < csvString.length; i++) {
            currentChar = csvString[i]

            if (insideQuotes) {
                if (currentChar === '"') {
                    if (csvString[i + 1] === '"') {
                        currentField += '"'
                        i++
                    } else insideQuotes = false
                } else currentField += currentChar
            } else {
                if (currentChar === '"') insideQuotes = true
                else if (currentChar === ',') {
                    currentLine.push(currentField)
                    currentField = ''
                } else if (currentChar === '\n' || (currentChar === '\r' && csvString[i + 1] === '\n')) {
                    if (currentChar === '\r') i++
                    currentLine.push(currentField)
                    lines.push(currentLine)
                    currentLine = []
                    currentField = ''
                } else currentField += currentChar
            }
        }

        if (currentField || csvString[csvString.length - 1] === ',') currentLine.push(currentField)
        if (currentLine.length > 0) lines.push(currentLine)

        const numColumns = lines[0]?.length || 0
        for (let line of lines) {
            if (line.length !== numColumns) return undefined
        }

        return lines
    }

    return new Promise(async (res) => {
        setTimeout(() => res(undefined), timeout*1000)
        file.text().then((text) => res(parse(text))).then(() => res(undefined))
    })
}



function parseXLSX(file, timeout=60) {

    const parse = (xlsxString => {
        if (typeof xlsxString !== 'string') return undefined


    })

    console.log(file)

    // return new Promise(async (res) => {
    //     setTimeout(() => res(undefined), timeout*1000)
    //     file.text().then((text) => res(parse(text))).then(() => res(undefined))
    // })
}
    // Function to handle file input
    // document.getElementById('input').addEventListener('change', function(e) {
    //     const file = e.target.files[0];
    //     const reader = new FileReader();

    //     // When file is read
    //     reader.onload = function(event) {
    //         const arrayBuffer = event.target.result;
    //         processExcelFile(arrayBuffer);
    //     };

    //     reader.readAsArrayBuffer(file);
    // });

    // Function to process the Excel file
    // async function processExcelFile(arrayBuffer) {
    //     // Unzip the xlsx file
    //     const zip = await JSZip.loadAsync(arrayBuffer);

    //     // Get the 'sheet1.xml' from the unzipped file
    //     const sheetFile = zip.file("xl/worksheets/sheet1.xml");
    //     if (sheetFile) {
    //         const sheetXml = await sheetFile.async("string");

    //         // Parse the XML content
    //         const parser = new DOMParser();
    //         const xmlDoc = parser.parseFromString(sheetXml, "text/xml");

    //         // Extract cell values from the XML
    //         const rows = xmlDoc.getElementsByTagName("row");

    //         for (let i = 0; i < rows.length; i++) {
    //             const cells = rows[i].getElementsByTagName("c");
    //             let rowData = [];
    //             for (let j = 0; j < cells.length; j++) {
    //                 const valueElement = cells[j].getElementsByTagName("v")[0];
    //                 const value = valueElement ? valueElement.textContent : "";
    //                 rowData.push(value);
    //             }
    //             console.log(rowData.join(", ")); // Log the row as comma-separated values
    //         }
    //     }
    // }





// serialize JSON (nested arrays) to CSV
function serializeCSV(csvData, timeout=60) {

    const serialize = () => {
        if (!Array.isArray(csvData) || csvData.length === 0) return undefined
        let csvString = ''
        for (const line of csvData) {
            if (!Array.isArray(line) || line.length === 0) continue
            let lineString = ''
            for (const element of line) lineString += `"${element.replaceAll('"', '""')}",`
            csvString += lineString.slice(0, -1) + '\r\n'
        }
        return csvString
    }

    return new Promise((res) => {
        setTimeout(() => res(undefined), timeout*1000)
        res(serialize())
    })
}



// write data (text/plain by default) to file
function writeFile(data, filename, type='text/plain', timeout=60) {
    return new Promise((res) => {
        if (data === undefined) {
            res(false)
            return
        }
        setTimeout(() => res(false), timeout*1000)
        const link = document.createElement('a')
        const file = new Blob([data], { type: type })
        link.href = URL.createObjectURL(file)
        link.download = filename
        link.click()
        URL.revokeObjectURL(link.href)
        res(true)
    })
}