const fileSystem = require("../filesystem.json");

function getCurrentDir(sessionState) {
    return sessionState.directory;
}

function customTextResponse(req, res, txt) {
    respondToCommand(req, res, txt, req.session.state.directory, "");
}

function ls(req, res) {
    const command = "ls";
    const contents = fileSystem[req.session.state.directory];

    if (contents && typeof contents === 'object') {
        let keys = Object.keys(contents);
        respondToCommand(req, res, keys.join("  "), req.session.state.directory, command);
    } else {
        respondToCommand(req, res, "No Files Found In Current Directory", req.session.state.directory, command);
    }
}

function whoami(req, res) {
    const command = "whoami";
    respondToCommand(req, res, req.session.state.username, req.session.state.directory, command);
}

function cd(req, res, raw_command) {
    const command = "cd";
    let argument = raw_command.split(" ")[1];
    const contents = fileSystem[req.session.state.directory];

    if (contents && typeof contents === "object") {
        let keys = Object.keys(contents);
        for (let i = 0; i < keys.length; i++) {
            let key = keys[i];

            if (key === argument && fileSystem[req.session.state.directory][key] === "dir") {
                req.session.state.directory += argument;
                if (!req.session.state.directory.endsWith("/")) req.session.state.directory += "/";
                respondToCommand(req, res, "", req.session.state.directory, command);
                return;
            }
            else if (key === argument && fileSystem[req.session.state.directory][key] === "noperms") {
                respondToCommand(req, res, "You don't have permission to open this directory", req.session.state.directory, command);
                return;
            } else if (key === argument) {
                respondToCommand(req, res, "You cannot open a file as a directory", req.session.state.directory, command);
                return;
            }
        }

        if (argument === "/") {
            req.session.state.directory = "/";
            respondToCommand(req, res, "", req.session.state.directory, command);
            return;
        }

        if (argument === "~" || argument === "~/"){
            req.session.state.directory = `/home/${req.session.state.username}/`;
            respondToCommand(req, res, "", req.session.state.directory, command);
            return;
        }

        if (argument === ".." || argument === "../") {
            const lastSlashIndex = req.session.state.directory.lastIndexOf('/');
            const pathWithoutTrailingSlash = lastSlashIndex === req.session.state.directory.length - 1 ? req.session.state.directory.substring(0, req.session.state.directory.length - 1) : req.session.state.directory;
            const secondLastSlashIndex = pathWithoutTrailingSlash.lastIndexOf('/');
            req.session.state.directory = pathWithoutTrailingSlash.substring(0, secondLastSlashIndex + 1);

            respondToCommand(req, res, "", req.session.state.directory, command);
            return;
        }

        respondToCommand(req, res, "Unable to open directory", req.session.state.directory, command);
    } else {
        respondToCommand(req, res, "Internal Server Error, try again later.", req.session.state.directory, command);
    }
}

function pwd(req, res) {
    const command = "pwd";
    respondToCommand(req, res, req.session.state.directory, req.session.state.directory, command);
}

function cat(req, res, raw_command) {
    const command = "cat";
    let argument = raw_command.split(" ")[1];
    const contents = fileSystem[req.session.state.directory];

    if (contents && typeof contents === "object") {
        let keys = Object.keys(contents);
        for (let i = 0; i < keys.length; i++) {
            let key = keys[i];

            if (key === argument && fileSystem[req.session.state.directory][key] !== "dir") {
                respondToCommand(req, res, fileSystem[req.session.state.directory][key], req.session.state.directory, command);
                return;
            } else if (key === argument) {
                respondToCommand(req, res, "You cannot open a directory as a file", req.session.state.directory, command);
                return;
            }
        }
        respondToCommand(req, res, "Unable to open file", req.session.state.directory, command);
    } else {
        respondToCommand(req, res, "Internal Server Error, try again later.", req.session.state.directory, command);
    }
}

function help(req, res) {
    const command = "help";
    const text = `
    Welcome to the fancy help menu!!<br>
    Here is a list of the available commands:<br><br>

    "help" - shows you this menu<br>
    "info" - shows you some information about the system<br>
    "clear" - clears the screen from previous ran commands<br>
    "ls" - shows you the files and directories in your current directory<br>
    "cd" - move into a folder you specify, you can use the name of the folder, or you can also use things like ../ to move back one folder<br>
    "whoami" - shows you as what user you are logged in as<br>
    "pwd" - shows you the current directory you are currently working in<br>
    "cat" - shows you the content of files, for example, cat file.txt shows you the content of file.txt if it is in the current directory<br>
    `;
    respondToCommand(req, res, text, req.session.state.directory, command);
}


function info(req, res){
    respondToCommand(
        req, res, 
        `<div style='display:flex; justify-content:flex-start; gap:5px;'>
            <img src='icon-ascii.png' alt='ascii image' style='height: 600px;'/>
            <div style='display:flex; flex-direction: column; gap:15px; justify-content: center;'>
                <p>OS: HerpDerpOS</p>
                <p>USER: ${req.session.state.username}</p>
                <p>CPU: 12th Gen Intel i7-1260P (12) @ 2.496GHz</p>
                <p>GPU: NVIDIA Geforce RTX 4060 TI</p>
                <p>Memory: ${Math.floor(Math.random()*(2048-102)+102)}MiB/2048MiB</p>
            </div>
        </div>`,
        req.session.state.directory,
        "info"
    )
}

function respondToCommand(req, res, text, directory, command) {
    res.json({
        "username": req.session.state.username,
        "directory": directory,
        "response": text,
        "command": command
    });
}

module.exports = {
    getCurrentDir,
    customTextResponse,
    
    ls,
    whoami,
    cd,
    pwd,
    cat,
    help,
    info,
};