epub/lib/epub.js

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
var xml2js = require('xml2js');
var xml2jsOptions = xml2js.defaults['0.1'];
var EventEmitter = require('events').EventEmitter;
// try {
//    // zipfile is an optional dependency:
//    var ZipFile = require("zipfile").ZipFile;
// } catch (err) {
//    // Mock zipfile using pure-JS adm-zip:
//    var AdmZip = require('adm-zip');
//    var ZipFile = function (filename) {
//       this.admZip = new AdmZip(filename);
//       this.names = this.admZip.getEntries().map(function (zipEntry) {
//          return zipEntry.entryName;
//       });
//       this.count = this.names.length;
//    };
//    ZipFile.prototype.readFile = function (name, cb) {
//       this.admZip.readFileAsync(this.admZip.getEntry(name), function (buffer, error) {
//          // `error` is bogus right now, so let's just drop it.
//          // see https://github.com/cthackers/adm-zip/pull/88
//          return cb(null, buffer);
//       });
//    };
// }
const fs = require("fs");
const JSZip = require("jszip");
//TODO: Cache parsed data
/**
 *  new EPub(fname[, imageroot][, linkroot])
 *  - fname (String): filename for the ebook
 *  - imageroot (String): URL prefix for images
 *  - linkroot (String): URL prefix for links
 *
 *  Creates an Event Emitter type object for parsing epub files
 *
 *      var epub = new EPub("book.epub");
 *      epub.on("end", function () {
 *           console.log(epub.spine);
 *      });
 *      epub.on("error", function (error) { ... });
 *      epub.parse();
 *
 *  Image and link URL format is:
 *
 *      imageroot + img_id + img_zip_path
 *
 *  So an image "logo.jpg" which resides in "OPT/" in the zip archive
 *  and is listed in the manifest with id "logo_img" will have the
 *  following url (providing that imageroot is "/images/"):
 *
 *      /images/logo_img/OPT/logo.jpg
 **/
class EPub {
    constructor(fname, imageroot, linkroot) {
        this.metadata = {};
        this.manifest = {};
        this.spine = { toc: undefined, contents: [] };
        this.flow = [];
        this.toc = [];
        this.filename = fname;
        this.imageroot = (imageroot || "/images/").trim();
        this.linkroot = (linkroot || "/links/").trim();
        if (this.imageroot.substr(-1) != "/") {
            this.imageroot += "/";
        }
        if (this.linkroot.substr(-1) != "/") {
            this.linkroot += "/";
        }
    }
    /**
     *  EPub#parse() -> undefined
     *
     *  Starts the parser, needs to be called by the script
     **/
    async parse() {
        this.containerFile = undefined;
        this.mimeFile = undefined;
        this.rootFile = undefined;
        this.metadata = {};
        this.manifest = {};
        this.spine = { toc: undefined, contents: [] };
        this.flow = [];
        this.toc = [];
        await this.open();
    }
    /**
     *  EPub#open() -> undefined
     *
     *  Opens the epub file with Zip unpacker, retrieves file listing
     *  and runs mime type check
     **/
    async open() {
        this.zip = await new Promise((resolve, reject) => {
            fs.readFile(this.filename, (err, data) => {
                if (err) {
                    reject(err);
                }
                else {
                    resolve(data);
                }
            });
        }).then((data) => {
            return JSZip.loadAsync(data);
        });
        if (Object.keys(this.zip.files).length < 1) {
            throw new Error("No files in archive");
        }
        await this.checkMimeType();
    }
    ;
    /**
     *  EPub#checkMimeType() -> undefined
     *
     *  Checks if there's a file called "mimetype" and that it's contents
     *  are "application/epub+zip". On success runs root file check.
     **/
    async checkMimeType() {
        var i, len;
        for (let file in this.zip.files) {
            if (file.toLowerCase() == "mimetype") {
                this.mimeFile = file;
                break;
            }
        }
        if (!this.mimeFile) {
            throw new Error("No mimetype file in archive");
        }
        let data = await this.zip.file(this.mimeFile).async("nodebuffer");
        let txt = data.toString("utf-8").toLowerCase().trim();
        if (txt != "application/epub+zip") {
            throw new Error("Unsupported mime type");
        }
        await this.getRootFiles();
    }
    ;
    /**
     *  EPub#getRootFiles() -> undefined
     *
     *  Looks for a "meta-inf/container.xml" file and searches for a
     *  rootfile element with mime type "application/oebps-package+xml".
     *  On success calls the rootfile parser
     **/
    async getRootFiles() {
        for (let file in this.zip.files) {
            if (file.toLowerCase() == "meta-inf/container.xml") {
                this.containerFile = file;
                break;
            }
        }
        if (!this.containerFile)
            throw new Error("No container file in archive");
        let data = await this.zip.files[this.containerFile].async("nodebuffer");
        var xml = data.toString("utf-8").toLowerCase().trim(), xmlparser = new xml2js.Parser(xml2jsOptions);
        let res = await new Promise((resolve, reject) => {
            xmlparser.on("end", (result) => {
                if (!result.rootfiles || !result.rootfiles.rootfile) {
                    reject(new Error("No rootfiles found"));
                    console.dir(result);
                    return;
                }
                var rootfile = result.rootfiles.rootfile, filename = undefined, i, len;
                if (Array.isArray(rootfile)) {
                    for (i = 0, len = rootfile.length; i < len; i++) {
                        if (rootfile[i]["@"]["media-type"] &&
                            rootfile[i]["@"]["media-type"] == "application/oebps-package+xml" &&
                            rootfile[i]["@"]["full-path"]) {
                            filename = rootfile[i]["@"]["full-path"].toLowerCase().trim();
                            break;
                        }
                    }
                }
                else if (rootfile["@"]) {
                    if (rootfile["@"]["media-type"] != "application/oebps-package+xml" || !rootfile["@"]["full-path"]) {
                        reject(new Error("Rootfile in unknown format"));
                        return;
                    }
                    filename = rootfile["@"]["full-path"].toLowerCase().trim();
                }
                if (!filename) {
                    reject(new Error("Empty rootfile"));
                    return;
                }
                for (let file in this.zip.files) {
                    if (file.toLowerCase() == filename) {
                        this.rootFile = file;
                        break;
                    }
                }
                if (!this.rootFile) {
                    reject(new Error("Rootfile not found from archive"));
                    return;
                }
                resolve();
            });
            xmlparser.on("error", (err) => {
                reject(new Error("Parsing container XML failed"));
                return;
            });
            xmlparser.parseString(xml);
        });
        await this.handleRootFile();
    }
    ;
    /**
     *  EPub#handleRootFile() -> undefined
     *
     *  Parses the rootfile XML and calls rootfile parser
     **/
    async handleRootFile() {
        let data = await this.zip.files[this.rootFile].async("nodebuffer");
        var xml = data.toString("utf-8");
        let rf = await new Promise((resolve, reject) => {
            let xmlparser = new xml2js.Parser(xml2jsOptions);
            xmlparser.on("end", (data) => {
                resolve(data);
            });
            xmlparser.on("error", err => {
                reject(err);
            });
            xmlparser.parseString(xml);
        });
        await this.parseRootFile(rf);
    }
    ;
    /**
     *  EPub#parseRootFile() -> undefined
     *
     *  Parses elements "metadata," "manifest," "spine" and TOC.
     *  Emits "end" if no TOC
     **/
    async parseRootFile(rootfile) {
        this.version = rootfile['@'].version || '2.0';
        var i, len, keys, keyparts, key;
        keys = Object.keys(rootfile);
        for (i = 0, len = keys.length; i < len; i++) {
            keyparts = keys[i].split(":");
            key = (keyparts.pop() || "").toLowerCase().trim();
            switch (key) {
                case "metadata":
                    this.parseMetadata(rootfile[keys[i]]);
                    break;
                case "manifest":
                    this.parseManifest(rootfile[keys[i]]);
                    break;
                case "spine":
                    this.parseSpine(rootfile[keys[i]]);
                    break;
                case "guide":
                    //this.parseGuide(rootfile[keys[i]]);
                    break;
            }
        }
        if (this.spine.toc) {
            await this.parseTOC();
        }
    }
    ;
    /**
     *  EPub#parseMetadata() -> undefined
     *
     *  Parses "metadata" block (book metadata, title, author etc.)
     **/
    parseMetadata(metadata) {
        var i, j, len, keys, keyparts, key;
        keys = Object.keys(metadata);
        for (i = 0, len = keys.length; i < len; i++) {
            keyparts = keys[i].split(":");
            key = (keyparts.pop() || "").toLowerCase().trim();
            switch (key) {
                case "publisher":
                    if (Array.isArray(metadata[keys[i]])) {
                        this.metadata.publisher = String(metadata[keys[i]][0] && metadata[keys[i]][0]["#"] || metadata[keys[i]][0] || "").trim();
                    }
                    else {
                        this.metadata.publisher = String(metadata[keys[i]]["#"] || metadata[keys[i]] || "").trim();
                    }
                    break;
                case "language":
                    if (Array.isArray(metadata[keys[i]])) {
                        this.metadata.language = String(metadata[keys[i]][0] && metadata[keys[i]][0]["#"] || metadata[keys[i]][0] || "").toLowerCase().trim();
                    }
                    else {
                        this.metadata.language = String(metadata[keys[i]]["#"] || metadata[keys[i]] || "").toLowerCase().trim();
                    }
                    break;
                case "title":
                    if (Array.isArray(metadata[keys[i]])) {
                        this.metadata.title = String(metadata[keys[i]][0] && metadata[keys[i]][0]["#"] || metadata[keys[i]][0] || "").trim();
                    }
                    else {
                        this.metadata.title = String(metadata[keys[i]]["#"] || metadata[keys[i]] || "").trim();
                    }
                    break;
                case "subject":
                    if (Array.isArray(metadata[keys[i]])) {
                        this.metadata.subject = String(metadata[keys[i]][0] && metadata[keys[i]][0]["#"] || metadata[keys[i]][0] || "").trim();
                    }
                    else {
                        this.metadata.subject = String(metadata[keys[i]]["#"] || metadata[keys[i]] || "").trim();
                    }
                    break;
                case "description":
                    if (Array.isArray(metadata[keys[i]])) {
                        this.metadata.description = String(metadata[keys[i]][0] && metadata[keys[i]][0]["#"] || metadata[keys[i]][0] || "").trim();
                    }
                    else {
                        this.metadata.description = String(metadata[keys[i]]["#"] || metadata[keys[i]] || "").trim();
                    }
                    break;
                case "creator":
                    if (Array.isArray(metadata[keys[i]])) {
                        this.metadata.creator = String(metadata[keys[i]][0] && metadata[keys[i]][0]["#"] || metadata[keys[i]][0] || "").trim();
                        this.metadata.creatorFileAs = String(metadata[keys[i]][0] && metadata[keys[i]][0]['@'] && metadata[keys[i]][0]['@']["opf:file-as"] || this.metadata.creator).trim();
                    }
                    else {
                        this.metadata.creator = String(metadata[keys[i]]["#"] || metadata[keys[i]] || "").trim();
                        this.metadata.creatorFileAs = String(metadata[keys[i]]['@'] && metadata[keys[i]]['@']["opf:file-as"] || this.metadata.creator).trim();
                    }
                    break;
                case "date":
                    if (Array.isArray(metadata[keys[i]])) {
                        this.metadata.date = String(metadata[keys[i]][0] && metadata[keys[i]][0]["#"] || metadata[keys[i]][0] || "").trim();
                    }
                    else {
                        this.metadata.date = String(metadata[keys[i]]["#"] || metadata[keys[i]] || "").trim();
                    }
                    break;
                case "identifier":
                    if (metadata[keys[i]]["@"] && metadata[keys[i]]["@"]["opf:scheme"] == "ISBN") {
                        this.metadata.ISBN = String(metadata[keys[i]]["#"] || "").trim();
                    }
                    else if (metadata[keys[i]]["@"] && metadata[keys[i]]["@"].id && metadata[keys[i]]["@"].id.match(/uuid/i)) {
                        this.metadata.UUID = String(metadata[keys[i]]["#"] || "").replace('urn:uuid:', '').toUpperCase().trim();
                    }
                    else if (Array.isArray(metadata[keys[i]])) {
                        for (j = 0; j < metadata[keys[i]].length; j++) {
                            if (metadata[keys[i]][j]["@"]) {
                                if (metadata[keys[i]][j]["@"]["opf:scheme"] == "ISBN") {
                                    this.metadata.ISBN = String(metadata[keys[i]][j]["#"] || "").trim();
                                }
                                else if (metadata[keys[i]][j]["@"].id && metadata[keys[i]][j]["@"].id.match(/uuid/i)) {
                                    this.metadata.UUID = String(metadata[keys[i]][j]["#"] || "").replace('urn:uuid:', '').toUpperCase().trim();
                                }
                            }
                        }
                    }
                    break;
            }
        }
        var metas = metadata['meta'] || {};
        Object.keys(metas).forEach((key) => {
            var meta = metas[key];
            if (meta['@'] && meta['@'].name) {
                var name = meta['@'].name;
                this.metadata[name] = meta['@'].content;
            }
            if (meta['#'] && meta['@'].property) {
                this.metadata[meta['@'].property] = meta['#'];
            }
            if (meta.name && meta.name == "cover") {
                this.metadata[meta.name] = meta.content;
            }
        }, this);
    }
    ;
    /**
     *  EPub#parseManifest() -> undefined
     *
     *  Parses "manifest" block (all items included, html files, images, styles)
     **/
    parseManifest(manifest) {
        var i, len, path = this.rootFile.split("/"), element, path_str;
        path.pop();
        path_str = path.join("/");
        if (manifest.item) {
            for (i = 0, len = manifest.item.length; i < len; i++) {
                if (manifest.item[i]['@']) {
                    element = manifest.item[i]['@'];
                    if (element.href && element.href.substr(0, path_str.length) != path_str) {
                        element.href = path.concat([element.href]).join("/");
                    }
                    this.manifest[manifest.item[i]['@'].id] = element;
                }
            }
        }
    }
    ;
    /**
     *  EPub#parseSpine() -> undefined
     *
     *  Parses "spine" block (all html elements that are shown to the reader)
     **/
    parseSpine(spine) {
        var i, len, path = this.rootFile.split("/"), element;
        path.pop();
        if (spine['@'] && spine['@'].toc) {
            this.spine.toc = this.manifest[spine['@'].toc] || false;
        }
        if (spine.itemref) {
            if (!Array.isArray(spine.itemref)) {
                spine.itemref = [spine.itemref];
            }
            for (i = 0, len = spine.itemref.length; i < len; i++) {
                if (spine.itemref[i]['@']) {
                    if (element = this.manifest[spine.itemref[i]['@'].idref]) {
                        this.spine.contents.push(element);
                    }
                }
            }
        }
        this.flow = this.spine.contents;
    }
    ;
    /**
     *  EPub#parseTOC() -> undefined
     *
     *  Parses ncx file for table of contents (title, html file)
     **/
    async parseTOC() {
        var i, len, path = this.spine.toc.href.split("/"), id_list = {}, keys;
        path.pop();
        keys = Object.keys(this.manifest);
        for (i = 0, len = keys.length; i < len; i++) {
            id_list[this.manifest[keys[i]].href] = keys[i];
        }
        let data = await this.zip.files[this.spine.toc.href].async("nodebuffer");
        var xml = data.toString("utf-8");
        await new Promise((resolve, reject) => {
            let xmlparser = new xml2js.Parser(xml2jsOptions);
            xmlparser.on("end", result => {
                if (result.navMap && result.navMap.navPoint) {
                    this.toc = this.walkNavMap(result.navMap.navPoint, path, id_list);
                }
                resolve();
            });
            xmlparser.on("error", (err) => {
                reject(err);
            });
            xmlparser.parseString(xml);
        });
    }
    ;
    /**
     *  EPub#walkNavMap(branch, path, id_list,[, level]) -> Array
     *  - branch (Array | Object): NCX NavPoint object
     *  - path (Array): Base path
     *  - id_list (Object): map of file paths and id values
     *  - level (Number): deepness
     *
     *  Walks the NavMap object through all levels and finds elements
     *  for TOC
     **/
    walkNavMap(branch, path, id_list, level) {
        level = level || 0;
        // don't go too far
        if (level > 7) {
            return [];
        }
        var output = [];
        if (!Array.isArray(branch)) {
            branch = [branch];
        }
        for (var i = 0; i < branch.length; i++) {
            if (branch[i].navLabel) {
                var title = '';
                if (branch[i].navLabel && typeof branch[i].navLabel.text == 'string') {
                    title = branch[i].navLabel && branch[i].navLabel.text || branch[i].navLabel === branch[i].navLabel ?
                        (branch[i].navLabel && branch[i].navLabel.text || branch[i].navLabel || "").trim() : '';
                }
                var order = Number(branch[i]["@"] && branch[i]["@"].playOrder || 0);
                if (isNaN(order)) {
                    order = 0;
                }
                var href = '';
                if (branch[i].content && branch[i].content["@"] && typeof branch[i].content["@"].src == 'string') {
                    href = branch[i].content["@"].src.trim();
                }
                var element = {
                    level: level,
                    order: order,
                    title: title,
                    href: undefined,
                    id: undefined
                };
                if (href) {
                    href = path.concat([href]).join("/");
                    element.href = href;
                    if (id_list[element.href]) {
                        // link existing object
                        element = this.manifest[id_list[element.href]];
                        element.title = title;
                        element.order = order;
                        element.level = level;
                    }
                    else {
                        // use new one
                        element.href = href;
                        element.id = (branch[i]["@"] && branch[i]["@"].id || "").trim();
                    }
                    output.push(element);
                }
            }
            if (branch[i].navPoint) {
                output = output.concat(this.walkNavMap(branch[i].navPoint, path, id_list, level + 1));
            }
        }
        return output;
    }
    ;
    /**
     *  EPub#getChapter(id, callback) -> undefined
     *  - id (String): Manifest id value for a chapter
     *  - callback (Function): callback function
     *
     *  Finds a chapter text for an id. Replaces image and link URL's, removes
     *  <head> etc. elements. Return only chapters with mime type application/xhtml+xml
     **/
    async getChapter(id) {
        let str = await this.getChapterRaw(id);
        var i, len, path = this.rootFile.split("/"), keys = Object.keys(this.manifest);
        path.pop();
        // remove linebreaks (no multi line matches in JS regex!)
        str = str.replace(/\r?\n/g, "\u0000");
        // keep only <body> contents
        str.replace(/<body[^>]*?>(.*)<\/body[^>]*?>/i, function (o, d) {
            str = d.trim();
            return "";
        });
        // remove <script> blocks if any
        str = str.replace(/<script[^>]*?>(.*?)<\/script[^>]*?>/ig, function (o, s) {
            return "";
        });
        // remove <style> blocks if any
        str = str.replace(/<style[^>]*?>(.*?)<\/style[^>]*?>/ig, function (o, s) {
            return "";
        });
        // remove onEvent handlers
        str = str.replace(/(\s)(on\w+)(\s*=\s*["']?[^"'\s>]*?["'\s>])/g, function (o, a, b, c) {
            return a + "skip-" + b + c;
        });
        // replace images
        str = str.replace(/(\ssrc\s*=\s*["']?)([^"'\s>]*?)(["'\s>])/g, (o, a, b, c) => {
            var img = path.concat([b]).join("/").trim(), element;
            for (i = 0, len = keys.length; i < len; i++) {
                if (this.manifest[keys[i]].href == img) {
                    element = this.manifest[keys[i]];
                    break;
                }
            }
            // include only images from manifest
            if (element) {
                return a + this.imageroot + element.id + "/" + img + c;
            }
            else {
                return "";
            }
        });
        // replace links
        str = str.replace(/(\shref\s*=\s*["']?)([^"'\s>]*?)(["'\s>])/g, (o, a, b, c) => {
            var linkparts = b && b.split("#"), link = path.concat([(linkparts.shift() || "")]).join("/").trim(), element;
            for (i = 0, len = keys.length; i < len; i++) {
                if (this.manifest[keys[i]].href.split("#")[0] == link) {
                    element = this.manifest[keys[i]];
                    break;
                }
            }
            if (linkparts.length) {
                link += "#" + linkparts.join("#");
            }
            // include only images from manifest
            if (element) {
                return a + this.linkroot + element.id + "/" + link + c;
            }
            else {
                return a + b + c;
            }
        });
        // bring back linebreaks
        str = str.replace(/\u0000/g, "\n").trim();
        return str;
    }
    ;
    /**
     *  EPub#getChapterRaw(id, callback) -> undefined
     *  - id (String): Manifest id value for a chapter
     *  - callback (Function): callback function
     *
     *  Returns the raw chapter text for an id.
     **/
    async getChapterRaw(id) {
        if (this.manifest[id]) {
            if (!(this.manifest[id]['media-type'] == "application/xhtml+xml" || this.manifest[id]['media-type'] == "image/svg+xml")) {
                throw new Error("Invalid mime type for chapter");
            }
            return this.zip.files[this.manifest[id].href].async("nodebuffer").then(b => b.toString("utf8"));
        }
        else {
            throw new Error("File not found");
        }
    }
    ;
    /**
     *  EPub#getImage(id, callback) -> undefined
     *  - id (String): Manifest id value for an image
     *  - callback (Function): callback function
     *
     *  Finds an image for an id. Returns the image as Buffer. Callback gets
     *  an error object, image buffer and image content-type.
     *  Return only images with mime type image
     **/
    async getImage(id) {
        if (this.manifest[id]) {
            if ((this.manifest[id]['media-type'] || "").toLowerCase().trim().substr(0, 6) != "image/") {
                throw new Error("Invalid mime type for image");
            }
            return this.getFile(id);
        }
        else {
            throw new Error("File not found");
        }
    }
    ;
    /**
     *  EPub#getFile(id, callback) -> undefined
     *  - id (String): Manifest id value for a file
     *  - callback (Function): callback function
     *
     *  Finds a file for an id. Returns the file as Buffer. Callback gets
     *  an error object, file contents buffer and file content-type.
     **/
    async getFile(id) {
        if (this.manifest[id]) {
            return await this.zip.files[this.manifest[id].href].async("nodebuffer");
        }
        else {
            throw new Error("File not found");
        }
    }
    ;
}
exports.EPub = EPub;
//# sourceMappingURL=epub.js.map