"use strict";
var __importDefault = (this && this.__importDefault) || function (mod) {
    return (mod && mod.__esModule) ? mod : { "default": mod };
};
Object.defineProperty(exports, "__esModule", { value: true });
const immutable_1 = __importDefault(require("immutable"));
/**
 Encode an article for next/prev
 @return {Object}
 */
function encodeArticle(pages, article) {
    const articlePath = article.getPath();
    return {
        path: articlePath,
        title: article.getTitle(),
        level: article.getLevel(),
        exists: articlePath && pages.has(articlePath),
        external: article.isExternal()
    };
}
/**
 this.navigation is a deprecated property from GitBook v2

 @return {Object}
 */
function encodeNavigation(output) {
    const book = output.getBook();
    const pages = output.getPages();
    const summary = book.getSummary();
    const articles = summary.getArticlesAsList();
    const navigation = articles
        .map((article, i) => {
        const ref = article.getRef();
        if (!ref) {
            return undefined;
        }
        const prev = articles.get(i - 1);
        const next = articles.get(i + 1);
        return [
            ref,
            {
                index: i,
                title: article.getTitle(),
                introduction: i === 0,
                prev: prev ? encodeArticle(pages, prev) : undefined,
                next: next ? encodeArticle(pages, next) : undefined,
                level: article.getLevel()
            }
        ];
    })
        .filter((e) => {
        return Boolean(e);
    });
    return immutable_1.default.Map(navigation).toJS();
}
exports.default = encodeNavigation;