import {
    evaluateDirectoryPath,
    getAllParentDirectories,
    getSubdirectories,
} from "./DirectoryHelpers";

import {
    Aliases,
    GlobalAliases
} from "../Alias";
import { DarkWebItems } from "../DarkWeb/DarkWebItems";
import { Message } from "../Message/Message";
import { IPlayer } from "../PersonObjects/IPlayer"
import { AllServers } from "../Server/AllServers";

// An array of all Terminal commands
const commands = [
    "alias",
    "analyze",
    "cat",
    "cd",
    "check",
    "clear",
    "cls",
    "connect",
    "download",
    "expr",
    "free",
    "hack",
    "help",
    "home",
    "hostname",
    "ifconfig",
    "kill",
    "killall",
    "ls",
    "lscpu",
    "mem",
    "mv",
    "nano",
    "ps",
    "rm",
    "run",
    "scan",
    "scan-analyze",
    "scp",
    "sudov",
    "tail",
    "theme",
    "top"
];

export function determineAllPossibilitiesForTabCompletion(p: IPlayer, input: string, index: number, currPath: string=""): string[] {
    let allPos: string[] = [];
    allPos = allPos.concat(Object.keys(GlobalAliases));
    const currServ = p.getCurrentServer();
    const homeComputer = p.getHomeComputer();

    let parentDirPath: string = "";
    let evaledParentDirPath: string | null = null;

    // Helper functions
    function addAllCodingContracts() {
        for (const cct of currServ.contracts) {
            allPos.push(cct.fn);
        }
    }

    function addAllLitFiles() {
        for (const file of currServ.messages) {
            if (!(file instanceof Message)) {
                allPos.push(file);
            }
        }
    }

    function addAllMessages() {
        for (const file of currServ.messages) {
            if (file instanceof Message) {
                allPos.push(file.filename);
            }
        }
    }

    function addAllPrograms() {
        for (const program of homeComputer.programs) {
            allPos.push(program);
        }
    }

    function addAllScripts() {
        for (const script of currServ.scripts) {
            const res = processFilepath(script.filename);
            if (res) {
                allPos.push(res);
            }
        }
    }

    function addAllTextFiles() {
        for (const txt of currServ.textFiles) {
            const res = processFilepath(txt.fn);
            if (res) {
                allPos.push(res);
            }
        }
    }

    function addAllDirectories() {
        // Directories are based on the currently evaluated path
        const subdirs = getSubdirectories(currServ, evaledParentDirPath == null ? "/" : evaledParentDirPath);

        for (let i = 0; i < subdirs.length; ++i) {
            const assembledDirPath = (evaledParentDirPath == null ? subdirs[i] : evaledParentDirPath + subdirs[i]);
            const res = processFilepath(assembledDirPath);
            if (res != null) {
                subdirs[i] = res;
            }
        }

        allPos = allPos.concat(subdirs);
    }

    // Convert from the real absolute path back to the original path used in the input
    function convertParentPath(filepath: string): string {
        if (parentDirPath == null || evaledParentDirPath == null) {
            console.warn(`convertParentPath() called when paths are null`);
            return filepath;
        }

        if (!filepath.startsWith(evaledParentDirPath)) {
            console.warn(`convertParentPath() called for invalid path. (filepath=${filepath}) (evaledParentDirPath=${evaledParentDirPath})`);
            return filepath;
        }

        return parentDirPath + filepath.slice(evaledParentDirPath.length);
    }

    // Given an a full, absolute filepath, converts it to the proper value
    // for autocompletion purposes
    function processFilepath(filepath: string): string | null {
        if (evaledParentDirPath) {
            if (filepath.startsWith(evaledParentDirPath)) {
                return convertParentPath(filepath);
            }
        } else if (parentDirPath !== "") {
            // If the parent directory is the root directory, but we're not searching
            // it from the root directory, we have to add the original path
             let t_parentDirPath = parentDirPath;
             if (!t_parentDirPath.endsWith("/")) { t_parentDirPath += "/"; }
             return parentDirPath + filepath;
        } else {
            return filepath;
        }

        return null;
    }

    function isCommand(cmd: string) {
        let t_cmd = cmd;
        if (!t_cmd.endsWith(" ")) {
            t_cmd += " ";
        }

        return input.startsWith(t_cmd);
    }

    /**
     * If the command starts with './' and the index == -1, then the user
     * has input ./partialexecutablename so autocomplete the script or program.
     * Put './' in front of each script/executable
     */
    if (isCommand("./") && index == -1) {
        //All programs and scripts
        for (var i = 0; i < currServ.scripts.length; ++i) {
            allPos.push("./" + currServ.scripts[i].filename);
        }

        //Programs are on home computer
        for(var i = 0; i < homeComputer.programs.length; ++i) {
            allPos.push("./" + homeComputer.programs[i]);
        }
        return allPos;
    }

    // Autocomplete the command
    if (index === -1) {
        return commands.concat(Object.keys(Aliases)).concat(Object.keys(GlobalAliases));
    }

    // Since we're autocompleting an argument and not a command, the argument might
    // be a file/directory path. We have to account for that when autocompleting
    const commandArray = input.split(" ");
    if (commandArray.length === 0) {
        console.warn(`Tab autocompletion logic reached invalid branch`);
        return allPos;
    }
    const arg = commandArray[commandArray.length - 1];
    parentDirPath = getAllParentDirectories(arg);
    evaledParentDirPath = evaluateDirectoryPath(parentDirPath, currPath);
    if (evaledParentDirPath === "/") {
        evaledParentDirPath = null;
    } else if (evaledParentDirPath == null) {
        return allPos; // Invalid path
    } else {
        evaledParentDirPath += "/";
    }

    if (isCommand("buy")) {
        let options = [];
        for (const i in DarkWebItems) {
            const item = DarkWebItems[i]
            options.push(item.program);
        }

        return options.concat(Object.keys(GlobalAliases));
    }

    if (isCommand("scp") && index === 1) {
        for (const iphostname in AllServers) {
            allPos.push(AllServers[iphostname].ip);
            allPos.push(AllServers[iphostname].hostname);
        }

        return allPos;
    }

    if (isCommand("scp") && index === 0) {
        addAllScripts();
        addAllLitFiles();
        addAllTextFiles();
        addAllDirectories();

        return allPos;
    }

    if (isCommand("connect")) {
        // All network connections
        for (var i = 0; i < currServ.serversOnNetwork.length; ++i) {
            var serv = AllServers[currServ.serversOnNetwork[i]];
            if (serv == null) { continue; }
            allPos.push(serv.ip);
            allPos.push(serv.hostname);
        }

        return allPos;
    }

    if (isCommand("kill") || isCommand("tail") || isCommand("mem") || isCommand("check")) {
        addAllScripts();
        addAllDirectories();

        return allPos;
    }

    if (isCommand("nano")) {
        addAllScripts();
        addAllTextFiles();
        allPos.push(".fconf");
        addAllDirectories();

        return allPos;
    }

    if (isCommand("rm")) {
        addAllScripts();
        addAllPrograms();
        addAllLitFiles();
        addAllTextFiles();
        addAllCodingContracts();
        addAllDirectories();

        return allPos;
    }

    if (isCommand("run")) {
        addAllScripts();
        addAllPrograms();
        addAllCodingContracts();
        addAllDirectories();

        return allPos;
    }

    if (isCommand("cat")) {
        addAllMessages();
        addAllLitFiles();
        addAllTextFiles();
        addAllDirectories();

        return allPos;
    }

    if (isCommand("download") || isCommand("mv")) {
        addAllScripts();
        addAllTextFiles();
        addAllDirectories();

        return allPos;
    }

    if (isCommand("cd")) {
        addAllDirectories();

        return allPos;
    }

    if (isCommand("ls") && index === 0) {
        addAllDirectories();
    }

    return allPos;
}