const gulp = require('gulp');
const fs = require('fs');

gulp.task('default', function () {

    const standardsDefDir = "data/standards";

    // Build all the standards listings into a single features.js file.
    const combinedStandards = fs.readdirSync(standardsDefDir)
        .reduce(function (prev, next) {

            if (next.indexOf(".json") === -1) {
                return prev;
            }

            const fileContents = fs.readFileSync(standardsDefDir + "/" + next, {encoding: "utf8"});
            const standardContents = JSON.parse(fileContents);
            prev[standardContents.info.name] = standardContents;
            return prev;
        }, {});

    let renderedStandardsModule = "/** This file is automatically generated by gulp. **/\n";
    renderedStandardsModule += `window.WEB_API_MANAGER.standards = ${JSON.stringify(combinedStandards)};`;

    fs.writeFileSync("content_scripts/dist/standards.js", renderedStandardsModule);

    const proxyBlockSrc = fs.readFileSync("content_scripts/src/proxyblock.js", "utf8");
    const instrumentSrc = fs.readFileSync("content_scripts/src/instrument.js", "utf8");
    
    const stripCommentsFromSource = function (source) {
        const fileLines = source.split("\n");
        const linesWithoutComments = fileLines.filter(function (aLine) {
            const lineStartsWithComment = (
                aLine.indexOf("// ") === 0 ||
                aLine.indexOf("/*") === 0 ||
                aLine.indexOf(" * ") === 0
            );
            return !lineStartsWithComment;
        });
        return linesWithoutComments.join("\n");
    };
    
    const proxyBlockSrcWOComments = stripCommentsFromSource(proxyBlockSrc);
    const instrumentSrcWOComments = stripCommentsFromSource(instrumentSrc);
    const instrumentSrcWithProxyInjected = instrumentSrcWOComments.replace(
        "###-INJECTED-PROXY-BLOCKING-CODE-###",
        proxyBlockSrcWOComments
    );

    fs.writeFileSync("content_scripts/dist/instrument.js", instrumentSrcWithProxyInjected);

    // Last, several content script files are just copied over, unmodified,
    // as script files to be injected.
    const srcFilesToCopy = ["defaults.js", "init.js"];
    srcFilesToCopy.forEach(function (aSrcPath) {
        fs.copyFileSync("content_scripts/src/" + aSrcPath, "content_scripts/dist/" + aSrcPath);
    });
});