/*
 * 	BSD 3-Clause License
 *
 * Copyright (c) 2019, NTT Ltd.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 *  Redistributions of source code must retain the above copyright notice, this
 *   list of conditions and the following disclaimer.
 *
 *  Redistributions in binary form must reproduce the above copyright notice,
 *   this list of conditions and the following disclaimer in the documentation
 *   and/or other materials provided with the distribution.
 *
 *  Neither the name of the copyright holder nor the names of its
 *   contributors may be used to endorse or promote products derived from
 *   this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

import yaml from "js-yaml";
import fs from "fs";
import Input from "./input";
import ipUtils from "../ipUtils";
import { AS, Path } from "../model";


export default class InputYml extends Input {

    constructor(config){
        super(config);
        this.prefixes = [];

            if (!config.monitoredPrefixesFiles || config.monitoredPrefixesFiles.length === 0) {
                throw new Error("The monitoredPrefixesFiles key is missing in the config file");
            }

            const uniquePrefixes = {};
            for (let prefixesFile of config.monitoredPrefixesFiles) {

                let monitoredPrefixesFile = {};
                let fileContent;

                if (fs.existsSync('./' + prefixesFile)) {
                    fileContent = fs.readFileSync('./' + prefixesFile, 'utf8');
                    try {
                        monitoredPrefixesFile = yaml.safeLoad(fileContent) || {};
                    } catch (error) {
                        throw new Error("The file " + prefixesFile + " is not valid yml: " + error.message.split(":")[0]);
                    }

                    if (Object.keys(monitoredPrefixesFile).length === 0) {
                        throw new Error("No prefixes to monitor in " + prefixesFile);
                    }

                    if (this.validate(monitoredPrefixesFile)) {

                        const monitoredPrefixes = Object
                            .keys(monitoredPrefixesFile)
                            .map(i => {
                                if (uniquePrefixes[i]) {
                                    throw new Error("Duplicate entry for " + i);
                                }
                                uniquePrefixes[i] = true;
                                monitoredPrefixesFile[i].asn = new AS(monitoredPrefixesFile[i].asn);

                                return Object.assign({
                                    prefix: i,
                                    group: 'default',
                                    ignore: false,
                                    excludeMonitors: [],
                                    includeMonitors: [],
                                }, monitoredPrefixesFile[i])
                            })
                            .filter(i => i !== null);

                        this.prefixes = this.prefixes.concat(monitoredPrefixes);
                    }

                } else {
                    fs.writeFileSync(prefixesFile, "");
                    throw new Error("The file " + prefixesFile + " cannot be loaded. An empty one has been created.");
                }
            }

            this.prefixes = this.prefixes.sort((a, b) => {
                return ipUtils.sortByPrefixLength(b.prefix, a.prefix);
            });

    };

    validate = (fileContent) => {
        const errors = Object
            .keys(fileContent)
            .map(prefix => {
                const item = fileContent[prefix];
                let asns;

                if (!prefix || !ipUtils.isValidPrefix(prefix)) {
                    return "Not a valid prefix: " + prefix;
                }

                if (["string", "number"].includes(typeof(item.asn))) {
                    asns = [item.asn];
                } else if (item.asn instanceof Array) {
                    asns = item.asn;
                } else {
                    return "Not a valid AS number for: " + prefix;
                }

                if (!new AS(asns).isValid()) {
                    return "Not a valid AS number for: " + prefix;
                }

                if (!["string", "number"].includes(typeof(item.description))) {
                    return "Not a valid description for: " + prefix;
                }

                if (typeof(item.ignoreMorespecifics) !== "boolean") {
                    return "Not a valid ignoreMorespecifics value for: " + prefix;
                }

                if (item.ignore !== undefined && typeof(item.ignore) !== "boolean") {
                    return "Not a valid ignore value for: " + prefix;
                }

                if (item.includeMonitors !== undefined && item.excludeMonitors !== undefined) {
                    return "You can define only one of includeMonitor or excludeMonitor for: " + prefix;

                }

                if (item.excludeMonitors !== undefined && !Array.isArray(item.excludeMonitors)) {
                    return "Not a valid excludeMonitor value for: " + prefix;
                }

                if (item.includeMonitors !== undefined && !Array.isArray(item.includeMonitors)) {
                    return "Not a valid includeMonitor value for: " + prefix;
                }

                if (item.path) {
                    if (!item.path.matchDescription){
                        return "No matchDescription set";
                    }
                    this._validateRegex(item.path.match);
                    this._validateRegex(item.path.notMatch);
                    if (item.path.maxLength && !(typeof(item.path.maxLength) == "number" && item.path.maxLength > 1)) {
                        return "Not valid maxLength";
                    }

                    if (item.path.minLength && !(typeof(item.path.minLength) == "number" && item.path.minLength > 1)) {
                        return "Not valid minLength";
                    }
                }

                return null;
            })
            .filter(i => i != null)
            .map(error => {
                throw new Error(error);
            });

        return errors.length === 0;
    };

    _validateRegex = (regex) => {
        if (regex) {
            try {
                new RegExp(regex);
            } catch (e) {
                return "Not valid Path regex" + regex;
            }
        }

    };

    getMonitoredMoreSpecifics = () => {
        return this.prefixes.filter(p => !p.ignoreMorespecifics);
    };

    getMonitoredPrefixes = () => {
        return this.prefixes;
    };

}