/**
 * This file is part of Satie music engraver <https://github.com/jnetterf/satie>.
 * Copyright (C) Joshua Netterfield <joshua.ca> 2015 - present.
 * 
 * Satie is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as
 * published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 * 
 * Satie is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Affero General Public License for more details.
 * 
 * You should have received a copy of the GNU Affero General Public License
 * along with Satie.  If not, see <http://www.gnu.org/licenses/>.
 */

import {readFile} from "fs";
import * as yargs from "yargs";

import Application from "./engine_application";
import SongImpl from "./engine_songImpl";

function readStdin(onEnd: (s: string) => void) {
    let content = "";
    process.stdin.resume();
    process.stdin.on("data", function(buf: Buffer) {
        content += buf.toString();
    });
    process.stdin.on("end", function() {
        onEnd(content);
    });
}

function read(file: string, onEnd: (s: string) => void, onErr: (err: any) => void) {
    if (file === "<stdin>") {
        readStdin(onEnd);
    } else {
        readFile(file, "utf8", function (err, data) {
            if (err) {
                onErr(err);
            }
            onEnd(data);
        });
    }
}

function cannotRead(err: any) {
    console.error("Fatal. Cannot read '%s'.", err.path);
    process.exit(1);
}

(function main() {
    let args = yargs
        .wrap(100)
        .usage("Usage: $0 <command> [options]")

        .example("$0 init -x file.xml", "print initialized MusicXML")
        .example("$0 init", "initialize from stdin")

        .example("$0 diff -x old.xml -x new.xml", "print a patch from old to new")
        .example("$0 diff -x old.xml", "print a patch from old to stdin")

        .example("$0 patch -x old.xml -p p.json", "print p.json applied to old.xml")
        .example("$0 patch -p p.json", "print p.json applied to stdin")

        .example("$0 render -x in.xml", "prints multiple svgs concatenated")
        .example("$0 render -x in.xml --as out", "writes out001.svg, out002.svg, ...")

        .demand(1)
        .alias("x", "xml")
        .describe("x", "Specify a MusicXML input")
        .default("xml", ["<stdin>"])

        .alias("p", "patch")
        .describe("p", "Specify a patch generated with 'satie diff'")

        .help("h")
        .alias("h", "help")
        .check(function(argv) {
            if (argv["_"].length > 1) {
                throw "Unexpected string '" + argv["_"][1] + "'.";
            }
            switch (argv["_"][0]) {
                case "init":
                case "render":
                    if (argv["xml"].length > 1) {
                        throw "Too many files specified.";
                    }
                    break;
                case "diff":
                    throw argv["_"][0] + " is not implemented, yet.";
                case "patch":
                    throw argv["_"][0] + " is not implemented, yet.";
                default:
                    throw new Error(`Invalid operation ${argv["_"][0]}`);
            }
            return true;
        })
        .strict();

    // Some of the type definitions are lacking.
    let argv = args
        .command("init", "adds revision tracking and layout information to a MusicXML file")
        .command("diff", "generate a patch between two initialized MusicXML files")
        .command("patch", "applies patch from 'satie diff' to an initialized MusicXML file")
        .command("render", "converts a MusicXML file to one or more SVGs page-by-page")
        .array("xml")
        .epilog("(C) Copyright Josh Netterfield 2015")

        .argv;

    /* tslint:disable */
    new Application({
        satieRoot: "https://nettek.ca/satie/vendor/",
        preloadedFonts: []
    });
    /* tslint:enable */

    let log = console.log.bind(console);

    switch (argv._[0]) {
        case "init":
            read(argv.xml[0],
                musicXML => {
                    let song = new SongImpl({
                        baseSrc: musicXML,

                        onError: cannotRead,
                        onLoaded: () => {
                            try {
                                const musicXML = song.toMusicXML();
                                log(musicXML);
                            } catch(err) {
                                cannotRead(err);
                            }
                        },
                    });
                }, cannotRead);
            break;
        case "diff":
            throw "not implemented";
        case "patch":
            throw "not implemented";
        case "render":
            read(argv.xml[0],
                musicXML => {
                    let song = new SongImpl({
                        baseSrc: musicXML,

                        onError: cannotRead,
                        onLoaded: () => {
                            try {
                                const svg = song.toSVG();
                                log(svg);
                            } catch (err) {
                                cannotRead(err);
                            }
                        },
                    });
                }, cannotRead);
            break;
        default:
            throw new Error(`Invalid operation ${argv._[0]}`);
    }
}());