var utilLib = require('/lib/enonic/util');
var ioLib = require('/lib/xp/io');

// Adjusted from https://werxltd.com/wp/2010/05/13/javascript-implementation-of-javas-string-hashcode-method/
exports.hash = (string) => {
    var hash = 0, i, chr;
    if (string.length === 0) return hash;
    for (i = 0; i < string.length; i++) {
        chr   = string.charCodeAt(i);
        hash  = ((hash << 5) - hash) + chr;
        hash |= 0; // Convert to 32bit integer
    }
    return (Math.abs(hash)).toString(36);
};

exports.getResourceAsString = (resource) =>
    utilLib.data.forceArray(
        ioLib.readLines(
            resource.getStream()
        )
    ).join("\n");


exports.getReact4xpEntry = (resource) => {
    //const then = new Date().getTime();
    const fileContent = exports.getResourceAsString(resource);
    const ETag = exports.hash(fileContent);
    //const now = new Date().getTime();
    //.info(`ETag '${ETag}' in ${now - then} ms.`);
    return {
        body: fileContent,
        headers: {
            'Content-Type': 'application/javascript;charset=utf-8',
            'Cache-Control': 'no-cache',
            ETag,
        }
    };
};


exports.getReact4xpHashedChunk = (resource) => {
    const fileContent = exports.getResourceAsString(resource);
    return {
        body: fileContent,
        headers: {
            'Content-Type': 'application/javascript;charset=utf-8',
            'Cache-Control': 'public, max-age=31536000'
        }
    };
};