import { repeat } from "./utils";

// See: https://stackoverflow.com/questions/9781218/how-to-change-node-jss-console-font-color
let disableColor = !(process.stdout.isTTY);

export function getProgressBar(action: string): (percent: number) => void {
    let lastProgress = -1;

    return function(percent: number): void {
        const progress = Math.trunc(percent * 100);

        if (disableColor) {
            if (lastProgress === -1) {
                console.log(action + "...");
            }
            lastProgress = progress;
            return;
        }

        process.stdin.setRawMode(false);
        process.stdin.pause();

        if (progress === lastProgress || lastProgress === 100) { return; }
        lastProgress = progress;

        (<any>(process.stdout)).clearLine();
        (<any>(process.stdout)).cursorTo(0);
        process.stdout.write(action + "... " + progress + "%");

        if (percent === 1) {
            process.stdout.write('\n');
        }

        return;
    }
}

const colorSequences: Record<string, string> = {
    blue: "\x1b[34m",
    cyan: "\x1b[36m",
    green: "\x1b[32m",
    magenta: "\x1b[35m",
    red:   "\x1b[31m",
    yellow: "\x1b[33m",
    bold: ""
};

function getColor(color?: string): string {
    if (!color || color === "normal") { return "\x1b[0m"; }
    return "\x1b[1m" + colorSequences[color];
}

export type ColorifyFunc = (text: string) => string;

function _colorify(format: string): ColorifyFunc {
    return function (text: string): string {
        if (disableColor) { return text; }
        return getColor(format) + text.replace(/[^ -~]+/g, "") + getColor();
    }
}

export const colorify: { [ format: string ]: ColorifyFunc } = Object.freeze({
    bold: _colorify("bold"),

    blue: _colorify("blue"),
    green: _colorify("green"),
    red: _colorify("red"),
});

export type PromptOptions = {
    choice?: Array<string>;
    defaultChoice?: string;
    mask?: string;
};

function _getPrompt(prompt: string, options: PromptOptions, callback: (ctrlC: boolean, message: string) => void) {
    process.stdout.write(prompt);

    let stdin = process.stdin;
    stdin.resume();
    stdin.setRawMode(true);
    stdin.resume();
    stdin.setEncoding('utf8');

    let message = '';

    let respond = (ctrlC: boolean, message: string) => {
        process.stdout.write('\n');
        stdin.setRawMode(false);
        stdin.pause();
        stdin.removeListener('data', handler);
        callback(ctrlC, message);
    }

    function handler(chr: string): void {
        chr = String(chr);

        switch (chr) {
            // Enter (ish)
            case "\n":
            case "\r":
            case "\u0004":
                if (options.choice) {
                    if (options.defaultChoice) {
                        respond(null, options.defaultChoice);
                    }
                } else {
                    respond(null, message);
                }
                break;

            // Backspace
            case "\u007f":
                if (message.length > 0 && options.choice == null) {
                    message = message.substring(0, message.length - 1);
                    (<any>(process.stdout)).clearLine();
                    (<any>(process.stdout)).cursorTo(0);
                    if (options.mask) {
                        process.stdout.write(prompt + repeat(options.mask, message.length));
                    } else {
                        process.stdout.write(prompt + message);
                    }
                }
                break;

            // Ctrl-C
            case "\u0003":
                process.stdout.write('\n[ CTRL-C ]');
                respond(true, null);
                break;

            // Any other character
            default:
                if (options.choice) {
                    if (options.choice.indexOf(chr) >= 0) {
                        process.stdout.write(chr);
                        respond(null, chr);
                    }
                } else {
                    // More passsword characters
                    if (options.mask) {
                        process.stdout.write('*');
                    } else {
                        process.stdout.write(chr);
                    }
                    message += chr;
                }
                break;
        }
    }
    stdin.on('data', handler);
}

export function getPrompt(prompt: string, options?: PromptOptions): Promise<string> {
    return new Promise((resolve, reject) => {
        _getPrompt(prompt, (options || { }), (ctrlC, password) => {
             if (ctrlC) {
                 return reject(new Error("cancelled"));
             }
             resolve(password);
        });
    });
}

export function getPassword(prompt: string): Promise<string> {
    return getPrompt(prompt, { mask: "*" });
}