Image Calendar Date And Time Stamper

function processImage(
    originalImg, 
    stampDate = "current", 
    stampTime = "current", 
    position = "bottom-right", 
    textColor = "#ffaa00", 
    strokeColor = "#000000", 
    fontSizePercent = 3
) {
    const canvas = document.createElement('canvas');
    canvas.width = originalImg.width;
    canvas.height = originalImg.height;
    const ctx = canvas.getContext('2d');

    // Draw the original image onto the canvas
    ctx.drawImage(originalImg, 0, 0);

    // Get current date and time if requested
    const now = new Date();
    const yyyy = now.getFullYear();
    const mm = String(now.getMonth() + 1).padStart(2, '0');
    const dd = String(now.getDate()).padStart(2, '0');
    const hh = String(now.getHours()).padStart(2, '0');
    const min = String(now.getMinutes()).padStart(2, '0');
    const ss = String(now.getSeconds()).padStart(2, '0');

    const finalDate = stampDate === "current" ? `${yyyy}-${mm}-${dd}` : stampDate;
    const finalTime = stampTime === "current" ? `${hh}:${min}:${ss}` : stampTime;

    // Combine date and time, trimming any leading/trailing spaces if one is empty
    const stampText = `${finalDate} ${finalTime}`.trim();

    // Calculate font size relative to image height to ensure it scales correctly
    let fontSize = (canvas.height * parseFloat(fontSizePercent)) / 100;
    if (fontSize < 10) fontSize = 10; // Minimum size for readability
    
    // Set standard styling for a digital camera style timestamp
    ctx.font = `bold ${fontSize}px "Courier New", Courier, monospace`;
    ctx.textBaseline = "middle";

    const padding = fontSize;
    const textWidth = ctx.measureText(stampText).width;

    let x = 0;
    let y = 0;

    // Determine target location based on the position setting
    switch(position.toLowerCase()) {
        case 'bottom-right':
            x = canvas.width - textWidth - padding;
            y = canvas.height - padding;
            break;
        case 'bottom-left':
            x = padding;
            y = canvas.height - padding;
            break;
        case 'top-right':
            x = canvas.width - textWidth - padding;
            y = padding;
            break;
        case 'top-left':
            x = padding;
            y = padding;
            break;
        case 'center':
            x = (canvas.width - textWidth) / 2;
            y = canvas.height / 2;
            break;
        default:
            x = canvas.width - textWidth - padding;
            y = canvas.height - padding;
            break;
    }

    // Draw a dark stroke/outline first for text visibility on light/white backgrounds
    ctx.lineWidth = Math.max(2, fontSize * 0.1);
    ctx.strokeStyle = strokeColor;
    ctx.strokeText(stampText, x, y);

    // Fill the text over the outline
    ctx.fillStyle = textColor;
    ctx.fillText(stampText, x, y);

    return canvas;
}