import commandLineArgs from "command-line-args";
import commandLineUsage from "command-line-usage";
import fs from "graceful-fs";
import url from "url";
import { parse } from "sparkson";
import {
    Config,
    hasOwnProperty,
    isLayerConfig,
    isPlainObject,
    isString,
    Url,
    Version,
} from "./types";

export let config: Config = {} as Config;
export let version: Version = "unknown" as Version;

export function parseCommandLine(): void {
    const commandLineDefs = [
        {
            name: "help",
            alias: "h",
            type: Boolean,
            description: "Show this help",
        },
        {
            name: "config",
            alias: "c",
            type: String,
            description: "Location of config.json",
        },
        {
            name: "version",
            alias: "v",
            type: Boolean,
            description: "Show ffffng version",
        },
    ];

    let commandLineOptions;
    try {
        commandLineOptions = commandLineArgs(commandLineDefs);
    } catch (error) {
        if (hasOwnProperty(error, "message")) {
            console.error(error.message);
        } else {
            console.error(error);
        }
        console.error("Try '--help' for more information.");
        process.exit(1);
    }

    const packageJsonFile = __dirname + "/../package.json";
    if (fs.existsSync(packageJsonFile)) {
        version = JSON.parse(fs.readFileSync(packageJsonFile, "utf8")).version;
    }

    function usage() {
        console.log(
            commandLineUsage([
                {
                    header:
                        "ffffng - " +
                        version +
                        " - Freifunk node management form",
                    optionList: commandLineDefs,
                },
            ])
        );
    }

    if (commandLineOptions.help) {
        usage();
        process.exit(0);
    }

    if (commandLineOptions.version) {
        console.log("ffffng - " + version);
        process.exit(0);
    }

    if (!commandLineOptions.config) {
        usage();
        process.exit(1);
    }

    const configJSONFile = commandLineOptions.config;
    let configJSON = {};

    if (fs.existsSync(configJSONFile)) {
        configJSON = JSON.parse(fs.readFileSync(configJSONFile, "utf8"));
    } else {
        console.error("config.json not found: " + configJSONFile);
        process.exit(1);
    }

    config = parse(Config, configJSON);

    if (!isPlainObject(config.client.coordsSelector.layers)) {
        console.error(
            "Error in config.json: client.coordsSelector.layers is not an JSON object."
        );
        process.exit(1);
    }

    for (const [id, layerConfig] of Object.entries(
        config.client.coordsSelector.layers
    )) {
        if (!isLayerConfig(layerConfig)) {
            console.error(
                `Error in config.json: client.coordsSelector.layers[${id}] is not a valid layer config.`
            );
            process.exit(1);
        }
    }

    function stripTrailingSlash(url: Url): Url {
        return url.endsWith("/")
            ? (url.substring(0, url.length - 1) as Url)
            : url;
    }

    config.server.baseUrl = stripTrailingSlash(config.server.baseUrl);
    config.client.map.mapUrl = stripTrailingSlash(config.client.map.mapUrl);

    config.server.rootPath = url.parse(config.server.baseUrl).pathname || "/";
    config.client.rootPath = config.server.rootPath;
}