const fs = require('fs/promises');
const path = require('path');

const copyright_disclaimer = `
/**
 * This file is part of the jps-like-websites lib
 * URL: https://git.labos.goip.de/chris/jpc-like-websites
 * @copyright by its creator 
 */ 

`;

/**
 * Kept for future reference, might be that we will return to the dependency resolvement approach.
 * @param {OAO} oao 
 * @returns {OAO}
 */
function resolveDependencyOrder(oao) {
    let roots = oao.keys.filter(k => oao.objects[k].dependencies.length === 0);

    let folderList = [...new Set(oao.keys.map(k => oao.objects[k].folder))];

    console.log("Folders", folderList);

    /**
     * 
     * @param {OAO} oao 
     * @param {Array<Array<string>>} dealt 
     */
    function recursiveResolvement(oao, dealtLvls, dealt) {
        const arrsEqualSize = (arr1, arr2) => arr1.length === arr2.length;
        const arrHasAll = (arr1, arr2) => arr2.every(k => arr1.includes(k))

        if (oao.keys.length === dealt.length) {
            return [...dealt, ...current];
        } else {
            console.log(`Received ${dealt.length} dealt of ${oao.keys.length}`);
        }

        let remaining = oao.keys
            .filter(k => !dealt.includes(k));

        if (remaining.length < 2) {
            return [...dealt, ...remaining];
        }

        let current = remaining
            .filter(k => oao.objects[k].dependencies.every(sk => dealt.includes(sk)));

        if (current.length === 0) {
            console.log("Couldn't resolve", remaining);
            return remaining;
        }

        dealtLvls.push(current);

        if (arrsEqualSize(remaining, current)) {
            return [...dealt, ...current];
        }

        return recursiveResolvement(oao, dealtLvls, [...dealt, ...current]);
    }

    let recursiveResolved = recursiveResolvement(oao, [roots], roots);

    recursiveResolved
        .forEach((k, i) => {
            oao.objects[k].orderNr = i;
        });

    oao.isOrdered = recursiveResolved.slice(-1).length <= 2;
    if (oao.isOrdered) {
        oao.keys = recursiveResolved;
    }
    return oao;
}


/**
 * 
 * @param {string} srcFile path to src file
 * @param {string} targetFile path of target file that will contain all scripts
 */
async function appendContent(srcFile, targetFile, contentModifications = [], lineModifications = []) {
    try {
        let content = await fs.readFile(srcFile, 'utf8');
        console.log(`Processing '${srcFile}'`);
        console.log(`           READ: successfully!`);
        console.log(`           Adding Copyright disclaimer!`);
        console.log(`           Attepting to append to default script variant`);

        /* Apply modifications */
        content = contentModifications
            .reduce((a, c) => c(a), content.split('\r\n'))
            .map(line => lineModifications.reduce((a, c) => c(a), line))
            .join('\r\n');

        await fs.appendFile(targetFile, content);

        console.log(`           Append/Write: successfully!`);
    } catch (error) {
        console.error(`Error reading/writing files: ${error.message}`);
    }
}



/**
 * 
 * @param {string} srcFile path to src file
 * @param {string} targetFile path of target file that will contain all scripts
 */
async function bundleWithSpecifiedMode(targetFile, fileList, modulize = true) {
    let contentModifications = [
        function (content) {
            return [
                ...copyright_disclaimer.split('\r\n'),
                ...content
            ];
        }
    ];

    let lineModifications = [
        function (line) {
            let starters = ["function", "const", "let", "class"];
            return (starters.some(s => line.startsWith(s)) ? "export " : "") + line;
        }
    ];


    fileList
        .reduce((prevPromise, filePath) => prevPromise
            .then(
                () => appendContent(filePath, targetFile, contentModifications)
            ), Promise.resolve()
        )

    if (modulize) {
        let targetModule = path.basename(targetFile).split('.', 1)[0] + '.mjs';
        fileList
            .reduce((prevPromise, filePath) => prevPromise
                .then(
                    () => appendContent(filePath, targetModule, contentModifications, lineModifications)
                ), Promise.resolve()
            )
    }

}



/**
 * @deprecated Currently this function takles the task of successfully bundling the jpc-framework.
 *              A custom bundler will replace this function/file.
 *              Some logic might be copied/used from here.
 * 
 * Takes the given order from the jpclw-bundle.json and bundles the scripts accordingly. 
 * 
 * @param {string|path} targetFile path to the targetfile (without file extension)
 * @param {boolean} modulize flag to decide to generate a mjs module as well 
 * @param {string|path} bundleFile path to the bundleFile if there is some 
 *                      - preparation for jpclw-bundler
 */
function bundle(targetFile = "./jpc-like-websites.js", modulize = true, bundleFile = './jpclw-bundle.json') {
    let fileOrder = require(bundleFile);

    console.log("(Re-) Creating target file: '" + targetFile + "'");
    /* EMPTY (create?) TARGET FILE */
    fs.writeFile(targetFile, "", err => { });

    if (modulize) {
        let targetModule = path.basename(targetFile).split('.', 1)[0] + 'mjs';
        fs.writeFile(targetModule, "", err => { });
    }

    let fileList = Object.keys(fileOrder.orderedGroups)
        .flatMap(groupName => fileOrder.orderedGroups[groupName])
        .map(fileName => {
            let f = fileOrder.objects[fileName];
            /* The Path build by name and folder */
            return `${f.folder}/${f.name}`;
        });


    bundleWithSpecifiedMode(targetFile, fileList, modulize);

}

let args = process.argv.slice(2);
bundle(args[0], args[1], args[2]);