From b1d1b36fbb604b4c595ddbadbbe4d58283f6888d Mon Sep 17 00:00:00 2001
From: Daniel Bulant <danbulant@gmail.com>
Date: Sat, 22 May 2021 21:25:04 +0200
Subject: [PATCH] refactor epub generation

---
 src/pages/[manga]/index.svelte | 123 +++----------------------------
 src/util/generateEpub.js       | 130 +++++++++++++++++++++++++++++++++
 2 files changed, 140 insertions(+), 113 deletions(-)
 create mode 100644 src/util/generateEpub.js

diff --git a/src/pages/[manga]/index.svelte b/src/pages/[manga]/index.svelte
index 2bd4f08..50cbf17 100644
--- a/src/pages/[manga]/index.svelte
+++ b/src/pages/[manga]/index.svelte
@@ -1,6 +1,7 @@
 <script>
     import { url } from "@roxi/routify/runtime/helpers";
     import { Zip, ZipPassThrough } from "fflate";
+    import { prepareEpub } from "../../util/generateEpub";
     // import * as streamSaver from "streamsaver";
 
     import request from "../../util/request";
@@ -43,123 +44,19 @@
         }
 
         text = "Found " + URLs.length + " pages";
+
         const file = streamSaver.createWriteStream(`${manga.title.en} ${chapter.data.attributes.chapter}.epub`, {
             writableStrategy: undefined, // (optional)
             readableStrategy: undefined,  // (optional)
-        })
-        const writer = file.getWriter();
-        const zip = new Zip();
-        zip.ondata = (error, data, final) => {
-            if(error) {
-                console.error(error);
-                text = "Error: " + error.message;
-                state = "error";
-            }
-            if(data) {
-                writer.write(data);
-            }
-            if(final) {
-                writer.close();
-            }
-        };
-        
-        const mimetype = new ZipPassThrough("mimetype");
-        zip.add(mimetype);
-        mimetype.push(enc.encode("application/epub+zip"), true);
+        });
 
-        const container = new ZipPassThrough("META-INF/container.xml");
-        zip.add(container);
-        container.push(enc.encode(`<?xml version="1.0" encoding="UTF-8" ?>
-<container version="1.0" xmlns="urn:oasis:names:tc:opendocument:xmlns:container">
-  <rootfiles>
-    <rootfile full-path="OEBPS/content.opf" media-type="application/oebps-package+xml"/>
-  </rootfiles>
-</container>`), true);
-
-        const opf = new ZipPassThrough("OEBPS/content.opf");
-        zip.add(opf);
-        opf.push(enc.encode(`<?xml version="1.0"?>
-<package version="3.0" xmlns="http://www.idpf.org/2007/opf" unique-identifier="bookid">
-
-  <metadata xmlns:opf="http://www.idpf.org/2007/opf"  xmlns:dc="http://purl.org/dc/elements/1.1/"
-            xmlns:dcterms="http://purl.org/dc/terms/">
-    <dc:title>${manga.title.en} ${chapter.data.attributes.chapter}</dc:title>
-    <dc:language>en</dc:language>
-    <dc:creator>Unknown</dc:creator>
-    <dc:identifier id="bookid">https://manga.danbulant.eu/${mangaId}/${chapter.data.id}</dc:identifier>
-    <dc:type>Image</dc:type>
-
-    <meta property="dcterms:modified">${chapter.data.attributes.updatedAt.toString().split("+")[0]}Z</meta>
-    <meta property="rendition:layout">pre-paginated</meta>
-    <meta property="rendition:orientation">portrait</meta>
-    <meta property="rendition:spread">landscape</meta>
-  </metadata>
-
-  <manifest>
-    <item id="fallback" href="fallback.xhtml" media-type="application/xhtml+xml" />
-    ${hashes.map((t, i) => `    <item id="i${i}" href="${t}" fallback="fallback" media-type="image/${t.substr(t.lastIndexOf(".") + 1) === "jpg" ? "jpeg" : "png"}"/>`).join("\n")}
-    ${hashes.map((t, i) => `    <item id="p${i}" href="${i}.xhtml"  media-type="application/xhtml+xml" />`).join("\n")}
-
-    <item id="ncxtoc" href="toc.ncx" media-type="application/x-dtbncx+xml"/>
-  </manifest>
-
-  <spine toc="ncxtoc">
-    ${hashes.map((t, i) => `    <itemref idref="p${i}" linear="yes" />`).join("\n")}
-    <itemref idref="fallback" linear="no" />
-  </spine>
-
-</package>`), true);
-
-        const ncx = new ZipPassThrough("OEBPS/toc.ncx");
-        zip.add(ncx);
-        ncx.push(enc.encode(`<?xml version="1.0" encoding="utf-8"?>
-<!DOCTYPE ncx PUBLIC "-//NISO//DTD ncx 2005-1//EN" "http://www.daisy.org/z3986/2005/ncx-2005-1.dtd">
-<ncx xmlns:ncx="http://www.daisy.org/z3986/2005/ncx/" version="2005-1">
-  <head>
-    <meta name="dtb:depth" content="1"/>
-    <meta name="dtb:totalPageCount" content="0"/>
-    <meta name="dtb:maxPageNumber" content="0"/>
-  </head>
-  <docTitle>
-    <text>${manga.title.en} ${chapter.data.attributes.chapter}</text>
-  </docTitle>
-  <docAuthor>
-    <text>Unknown</text>
-  </docAuthor>
-
-  <navMap>
-    ${hashes.map((t, i) => `
-        <navPoint id="p${i}" playOrder="${i + 1}">
-            <navLabel>
-                <text>${manga.title.en} ${chapter.data.attributes.chapter} ${i}</text>
-            </navLabel>
-            <content src="${i}.xhtml"/>
-        </navPoint>
-    `).join("\n")}
-    </navMap>
-</ncx>`), true);
-
-        const fallback = new ZipPassThrough("OEBPS/fallback.xhtml");
-        zip.add(fallback);
-        fallback.push(enc.encode(`<?xml version="1.0" encoding="UTF-8"?>
-<html xmlns="http://www.w3.org/1999/xhtml" xmlns:epub="http://www.idpf.org/2007/ops">
-  <head>
-    <title>${manga.title.en} ${chapter.data.attributes.chapter}</title>
-  </head>
-  <body>
-    <h2>This book cannot be opened on this device or using this program</h2>
-    <p>We're sorry</p>
-
-    <nav epub:type="toc">
-        <h1>Chapter list</h1>
-        <ol>
-            <li>
-                <a href="p0.xhtml">Chapter ${chapter.data.attributes.chapter}</a>
-            </li>
-        </ol>
-    </nav>
-  </body>
-</html>`), true);
+        const zip = await prepareEpub({
+            title: `https://manga.danbulant.eu/${mangaId}/${chapter.data.id}`,
+            file,
+            chapter: chapter.data.attributes.chapter,
+            links: hashes,
+            updatedAt: chapter.data.attributes.updatedAt
+        });
 
         for(var i = 0; i < URLs.length; i++) {
             text = `Saving page ${i + 1} of ${URLs.length}`;
diff --git a/src/util/generateEpub.js b/src/util/generateEpub.js
new file mode 100644
index 0000000..fac79ad
--- /dev/null
+++ b/src/util/generateEpub.js
@@ -0,0 +1,130 @@
+import { Zip, ZipPassThrough } from "fflate";
+
+const enc = new TextEncoder();
+
+/**
+ * @param {object} opts
+ * @param {string[]} opts.links 
+ * @param {WritableStream} opts.file
+ * @param {number} opts.chapter
+ * @param {string|Date} opts.updatedAt
+ */
+export async function prepareEpub(opts) {
+    const writer = opts.file.getWriter();
+    const zip = new Zip();
+    zip.ondata = (error, data, final) => {
+        if(error) {
+            console.error(error);
+            text = "Error: " + error.message;
+            state = "error";
+        }
+        if(data) {
+            writer.write(data);
+        }
+        if(final) {
+            writer.close();
+        }
+    };
+
+    const hashes = opts.links;
+    
+    const mimetype = new ZipPassThrough("mimetype");
+    zip.add(mimetype);
+    mimetype.push(enc.encode("application/epub+zip"), true);
+
+    const container = new ZipPassThrough("META-INF/container.xml");
+    zip.add(container);
+    container.push(enc.encode(`<?xml version="1.0" encoding="UTF-8" ?>
+    <container version="1.0" xmlns="urn:oasis:names:tc:opendocument:xmlns:container">
+    <rootfiles>
+    <rootfile full-path="OEBPS/content.opf" media-type="application/oebps-package+xml"/>
+    </rootfiles>
+    </container>`), true);
+
+    const opf = new ZipPassThrough("OEBPS/content.opf");
+    zip.add(opf);
+    opf.push(enc.encode(`<?xml version="1.0"?>
+    <package version="3.0" xmlns="http://www.idpf.org/2007/opf" unique-identifier="bookid">
+
+    <metadata xmlns:opf="http://www.idpf.org/2007/opf"  xmlns:dc="http://purl.org/dc/elements/1.1/"
+            xmlns:dcterms="http://purl.org/dc/terms/">
+    <dc:title>${opts.title}</dc:title>
+    <dc:language>en</dc:language>
+    <dc:creator>Unknown</dc:creator>
+    <dc:identifier id="bookid"></dc:identifier>
+    <dc:type>Image</dc:type>
+
+    <meta property="dcterms:modified">${opts.updatedAt.toString().split("+")[0]}Z</meta>
+    <meta property="rendition:layout">pre-paginated</meta>
+    <meta property="rendition:orientation">portrait</meta>
+    <meta property="rendition:spread">landscape</meta>
+    </metadata>
+
+    <manifest>
+    <item id="fallback" href="fallback.xhtml" media-type="application/xhtml+xml" />
+    ${hashes.map((t, i) => `    <item id="i${i}" href="${t}" fallback="fallback" media-type="image/${t.substr(t.lastIndexOf(".") + 1) === "jpg" ? "jpeg" : "png"}"/>`).join("\n")}
+    ${hashes.map((t, i) => `    <item id="p${i}" href="${i}.xhtml"  media-type="application/xhtml+xml" />`).join("\n")}
+
+    <item id="ncxtoc" href="toc.ncx" media-type="application/x-dtbncx+xml"/>
+    </manifest>
+
+    <spine toc="ncxtoc">
+    ${hashes.map((t, i) => `    <itemref idref="p${i}" linear="yes" />`).join("\n")}
+    <itemref idref="fallback" linear="no" />
+    </spine>
+
+    </package>`), true);
+
+    const ncx = new ZipPassThrough("OEBPS/toc.ncx");
+    zip.add(ncx);
+    ncx.push(enc.encode(`<?xml version="1.0" encoding="utf-8"?>
+    <!DOCTYPE ncx PUBLIC "-//NISO//DTD ncx 2005-1//EN" "http://www.daisy.org/z3986/2005/ncx-2005-1.dtd">
+    <ncx xmlns:ncx="http://www.daisy.org/z3986/2005/ncx/" version="2005-1">
+    <head>
+    <meta name="dtb:depth" content="1"/>
+    <meta name="dtb:totalPageCount" content="0"/>
+    <meta name="dtb:maxPageNumber" content="0"/>
+    </head>
+    <docTitle>
+    <text>${opts.title}</text>
+    </docTitle>
+    <docAuthor>
+    <text>Unknown</text>
+    </docAuthor>
+
+    <navMap>
+    ${hashes.map((t, i) => `
+        <navPoint id="p${i}" playOrder="${i + 1}">
+            <navLabel>
+                <text>${opts.title} ${i}</text>
+            </navLabel>
+            <content src="${i}.xhtml"/>
+        </navPoint>
+    `).join("\n")}
+    </navMap>
+    </ncx>`), true);
+
+    const fallback = new ZipPassThrough("OEBPS/fallback.xhtml");
+    zip.add(fallback);
+    fallback.push(enc.encode(`<?xml version="1.0" encoding="UTF-8"?>
+    <html xmlns="http://www.w3.org/1999/xhtml" xmlns:epub="http://www.idpf.org/2007/ops">
+    <head>
+    <title>${opts.title}</title>
+    </head>
+    <body>
+    <h2>This book cannot be opened on this device or using this program</h2>
+    <p>We're sorry</p>
+
+    <nav epub:type="toc">
+        <h1>Chapter list</h1>
+        <ol>
+            <li>
+                <a href="p0.xhtml">Chapter ${opts.chapter}</a>
+            </li>
+        </ol>
+    </nav>
+    </body>
+    </html>`), true);
+
+    return zip;
+}
\ No newline at end of file