<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Esteganografía</title>
    <style>
        body {
            font-family: 'Roboto', Arial, sans-serif;
            text-align: center;
            margin: 0;
            padding: 0;
            background-color: #121212;
            color: #ffffff;
        }
        header {
            padding: 20px;
            background-color: #1f1f1f;
            box-shadow: 0 2px 5px rgba(0, 0, 0, 0.2);
        }
        h1 {
            margin: 0;
            font-size: 2rem;
        }
        main {
            padding: 20px;
        }
        input[type="file"],
        textarea,
        button {
            font-family: 'Roboto', Arial, sans-serif;
            margin: 10px 0;
            padding: 10px;
            border: none;
            border-radius: 5px;
        }
        input[type="file"] {
            background-color: #1f1f1f;
            color: #ffffff;
            cursor: pointer;
        }
        textarea {
            width: 90%;
            max-width: 500px;
            background-color: #1f1f1f;
            color: #ffffff;
            border: 1px solid #333333;
        }
        button {
            background-color: #FF9800;
            color: #ffffff;
            cursor: pointer;
            transition: background-color 0.3s;
        }
        button:hover {
            background-color: #df8b1e;
        }
        canvas {
            margin-top: 20px;
            border: 1px solid #333333;
        }
        #downloadButton {
            display: none;
        }
    </style>
</head>
<body>
    <header>
        <h1>Herramienta de Esteganografía</h1>
    </header>
    <main>
        <input type="file" id="imageInput" accept="image/*">
        <br>
        <textarea id="secretText" placeholder="Escribe tu mensaje secreto aquí..." rows="4"></textarea>
        <br>
        <button onclick="encodeText()">Ocultar Texto</button>
        <button onclick="decodeText()">Extraer Texto</button>
        <br>
        <canvas id="imageCanvas"></canvas>
        <br>
        <button id="downloadButton">Descargar Imagen</button>
    </main>
    <footer>
        © 2024 LeoShield. Todos los derechos reservados.
    </footer>
    <script>
        const canvas = document.getElementById('imageCanvas');
        const ctx = canvas.getContext('2d');

        let img = new Image();

        document.getElementById('imageInput').addEventListener('change', (event) => {
            const file = event.target.files[0];
            const reader = new FileReader();

            reader.onload = function(e) {
                img.src = e.target.result;
            };

            reader.readAsDataURL(file);
        });

        img.onload = function() {
            canvas.width = img.width;
            canvas.height = img.height;
            ctx.drawImage(img, 0, 0);
        };

        function encodeText() {
            const text = document.getElementById('secretText').value;
            if (!text) {
                alert('Por favor, escribe un mensaje para ocultar.');
                return;
            }

            const binaryText = Array.from(text).map(char => char.charCodeAt(0).toString(2).padStart(8, '0')).join('') + '1111111111111110';
            const imageData = ctx.getImageData(0, 0, canvas.width, canvas.height);
            const pixels = imageData.data;

            let binaryIndex = 0;
            for (let i = 0; i < pixels.length; i += 4) {
                if (binaryIndex < binaryText.length) {
                    pixels[i] = (pixels[i] & ~1) | parseInt(binaryText[binaryIndex]);
                    binaryIndex++;
                } else {
                    break;
                }
            }

            ctx.putImageData(imageData, 0, 0);
            document.getElementById('downloadButton').style.display = 'block';
        }

        function decodeText() {
            const imageData = ctx.getImageData(0, 0, canvas.width, canvas.height);
            const pixels = imageData.data;

            let binaryText = '';
            for (let i = 0; i < pixels.length; i += 4) {
                binaryText += (pixels[i] & 1).toString();
            }

            const bytes = binaryText.match(/.{1,8}/g);
            let extractedText = '';
            for (let byte of bytes) {
                if (byte === '11111110') break;
                extractedText += String.fromCharCode(parseInt(byte, 2));
            }

            alert(`Texto extraído: ${extractedText}`);
        }

        document.getElementById('downloadButton').addEventListener('click', () => {
            const link = document.createElement('a');
            link.download = 'imagen_esteganografica.png';
            link.href = canvas.toDataURL();
            link.click();
        });
    </script>
</body>
</html>