From d475a5bde9bb0fb0b542c019aafc7e33ba647104 Mon Sep 17 00:00:00 2001
From: Hippo <badrihippo@gmail.com>
Date: Sat, 3 Apr 2021 21:29:01 +0530
Subject: [PATCH] ePub: download and insert article images before rendering

This includes the feature image as well as other inline images.
---
 package.json |   1 +
 seance.js    |  83 ++++++++++++++++++++++++++++++++++---
 yarn.lock    | 114 +++++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 193 insertions(+), 5 deletions(-)

diff --git a/package.json b/package.json
index cdddde8..bb5adbf 100644
--- a/package.json
+++ b/package.json
@@ -20,6 +20,7 @@
     "babel-preset-env": "^1.7.0",
     "body-parser": "^1.19.0",
     "bulma": "^0.8.2",
+    "cheerio": "^1.0.0-rc.5",
     "commander": "^3.0.2",
     "convict": "^5.2.0",
     "css-loader": "^3.5.3",
diff --git a/seance.js b/seance.js
index ef168ca..143a690 100644
--- a/seance.js
+++ b/seance.js
@@ -9,8 +9,10 @@ const readline = require('readline')
 const { markdown } = require('markdown')
 const GhostAdminAPI = require('@tryghost/admin-api')
 const { Canvas, Image } = require('canvas')
+const slugify = require('underscore.string/slugify')
 const Rembrandt = require('rembrandt')
 const nodepub = require('nodepub')
+const cheerio = require('cheerio')
 
 const config = require('./config')
 
@@ -742,6 +744,77 @@ class Seance {
       allPosts.push(post)
     }
 
+    // prepare for image downloads
+    let pics = []
+    let picFolder = path.join(options.outputFolder, 'seance-images')
+    if (!fs.existsSync(picFolder)) {
+      fs.mkdirSync(picFolder, { recursive: true })
+    }
+
+    // prepare array to collect processed posts
+    let processedPosts = []
+
+    for (let post of allPosts) {
+      // decide a post slug, for future files
+      let postSlug = slugify(post.title)
+
+      // get the cover pic
+      let featurePicTag
+      if (!!post.feature_image) {
+        let imgUrl = post.feature_image
+        if (/^\/\//i.test(imgUrl)) {
+          imgUrl = 'https:' + imgUrl
+        } else if (!/^https?:\/\//i.test(imgUrl)) {
+          imgUrl = 'https://' + imgUrl
+        }
+        let response = await (await r2.get(imgUrl).response).buffer()
+        let ext = post.feature_image.split('.').pop()
+        await await fs.promises.writeFile(path.join(picFolder, `${postSlug}.${ext}`), response, 'base64')
+        featurePicTag = `<img src="../images/${postSlug}.${ext}"/>`
+        pics.push(`${picFolder}/${postSlug}.${ext}`)
+      }
+
+      let c = cheerio.load(`${featurePicTag}<h1>${post.title}</h1>${post.html}`)
+
+      // hunt for other pics
+      // TODO: make asynchronous
+      let picCounter = 0
+      c('img').each(async function() {
+        // skip if it's a local image
+        if (c(this).attr('src').indexOf('../images') == 0) {
+          return
+        }
+
+        // first, process the url
+        let imgUrl = c(this).attr('src')
+        console.log('Downloading:', imgUrl)
+        if (/^\/\//i.test(imgUrl)) {
+          imgUrl = 'https:' + imgUrl
+        } else if (!/^https?:\/\//i.test(imgUrl)) {
+          imgUrl = 'https://' + imgUrl
+        }
+
+        // now decide an output name
+        let ext = c(this).attr('src').split('.').pop()
+        let imageFile = path.join(picFolder, `${postSlug}-insert-${picCounter}.${ext}`)
+
+        // note down our calculations
+        c(this).attr('src', `../images/${postSlug}-insert-${picCounter}.${ext}`)
+        pics.push(imageFile)
+        picCounter = picCounter + 1
+
+        // finally, download the images
+        let response = await (await r2.get(imgUrl).response).buffer()
+        await fs.promises.writeFile(imageFile, response, 'base64')
+        console.log('Downloaded to:', imageFile)
+      })
+
+      processedPosts.push({
+        title: post.title,
+        body: c.html(),
+      })
+    }
+
     // decide metadata
     let metadata = {
       id: 'seance-test', // FIXME
@@ -751,19 +824,19 @@ class Seance {
       contents: 'Table of Contents',
       genre: options.genre,
       cover: options.coverImage,
-      images: [],
+      images: pics,
     }
 
     // create the ePub
     let epub = nodepub.document(metadata)
 
-    for (let post of allPosts) {
-      console.log(`Adding: ${post.title}`)
-      epub.addSection(post.title, `<h1>${post.title}</h1>${post.html}`)
+    // add the documents
+    for (let post of processedPosts) {
+      epub.addSection(post.title, post.body)
     }
 
     // generate it!
-    await epub.writeEPUB(options.outputFolder, options.title) // FIXME
+    await epub.writeEPUB(options.outputFolder, options.title)
   }
 
 }
diff --git a/yarn.lock b/yarn.lock
index 534d8ff..399c4e7 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -1143,6 +1143,11 @@ body-parser@1.19.0, body-parser@^1.19.0:
     raw-body "2.4.0"
     type-is "~1.6.17"
 
+boolbase@^1.0.0:
+  version "1.0.0"
+  resolved "https://registry.yarnpkg.com/boolbase/-/boolbase-1.0.0.tgz#68dff5fbe60c51eb37725ea9e3ed310dcc1e776e"
+  integrity sha1-aN/1++YMUes3cl6p4+0xDcwed24=
+
 brace-expansion@^1.1.7:
   version "1.1.11"
   resolved "https://registry.yarnpkg.com/brace-expansion/-/brace-expansion-1.1.11.tgz#3c7fcbf529d87226f3d2f52b966ff5271eb441dd"
@@ -1444,6 +1449,30 @@ chalk@^2.0.1, chalk@^2.4.1, chalk@^2.4.2:
     escape-string-regexp "^1.0.5"
     supports-color "^5.3.0"
 
+cheerio-select-tmp@^0.1.0:
+  version "0.1.1"
+  resolved "https://registry.yarnpkg.com/cheerio-select-tmp/-/cheerio-select-tmp-0.1.1.tgz#55bbef02a4771710195ad736d5e346763ca4e646"
+  integrity sha512-YYs5JvbpU19VYJyj+F7oYrIE2BOll1/hRU7rEy/5+v9BzkSo3bK81iAeeQEMI92vRIxz677m72UmJUiVwwgjfQ==
+  dependencies:
+    css-select "^3.1.2"
+    css-what "^4.0.0"
+    domelementtype "^2.1.0"
+    domhandler "^4.0.0"
+    domutils "^2.4.4"
+
+cheerio@^1.0.0-rc.5:
+  version "1.0.0-rc.5"
+  resolved "https://registry.yarnpkg.com/cheerio/-/cheerio-1.0.0-rc.5.tgz#88907e1828674e8f9fee375188b27dadd4f0fa2f"
+  integrity sha512-yoqps/VCaZgN4pfXtenwHROTp8NG6/Hlt4Jpz2FEP0ZJQ+ZUkVDd0hAPDNKhj3nakpfPt/CNs57yEtxD1bXQiw==
+  dependencies:
+    cheerio-select-tmp "^0.1.0"
+    dom-serializer "~1.2.0"
+    domhandler "^4.0.0"
+    entities "~2.1.0"
+    htmlparser2 "^6.0.0"
+    parse5 "^6.0.0"
+    parse5-htmlparser2-tree-adapter "^6.0.0"
+
 chokidar@^2.1.8:
   version "2.1.8"
   resolved "https://registry.yarnpkg.com/chokidar/-/chokidar-2.1.8.tgz#804b3a7b6a99358c3c5c61e71d8728f041cff917"
@@ -1916,6 +1945,17 @@ css-loader@^3.5.3:
     schema-utils "^2.6.6"
     semver "^6.3.0"
 
+css-select@^3.1.2:
+  version "3.1.2"
+  resolved "https://registry.yarnpkg.com/css-select/-/css-select-3.1.2.tgz#d52cbdc6fee379fba97fb0d3925abbd18af2d9d8"
+  integrity sha512-qmss1EihSuBNWNNhHjxzxSfJoFBM/lERB/Q4EnsJQQC62R2evJDW481091oAdOr9uh46/0n4nrg0It5cAnj1RA==
+  dependencies:
+    boolbase "^1.0.0"
+    css-what "^4.0.0"
+    domhandler "^4.0.0"
+    domutils "^2.4.3"
+    nth-check "^2.0.0"
+
 css-selector-tokenizer@^0.7.0:
   version "0.7.2"
   resolved "https://registry.yarnpkg.com/css-selector-tokenizer/-/css-selector-tokenizer-0.7.2.tgz#11e5e27c9a48d90284f22d45061c303d7a25ad87"
@@ -1930,6 +1970,11 @@ css-unit-converter@^1.1.1:
   resolved "https://registry.yarnpkg.com/css-unit-converter/-/css-unit-converter-1.1.1.tgz#d9b9281adcfd8ced935bdbaba83786897f64e996"
   integrity sha1-2bkoGtz9jO2TW9urqDeGiX9k6ZY=
 
+css-what@^4.0.0:
+  version "4.0.0"
+  resolved "https://registry.yarnpkg.com/css-what/-/css-what-4.0.0.tgz#35e73761cab2eeb3d3661126b23d7aa0e8432233"
+  integrity sha512-teijzG7kwYfNVsUh2H/YN62xW3KK9YhXEgSlbxMlcyjPNvdKJqFx5lrwlJgoFP1ZHlB89iGDlo/JyshKeRhv5A==
+
 cssesc@^3.0.0:
   version "3.0.0"
   resolved "https://registry.yarnpkg.com/cssesc/-/cssesc-3.0.0.tgz#37741919903b868565e1c09ea747445cd18983ee"
@@ -2146,11 +2191,41 @@ diffie-hellman@^5.0.0:
     miller-rabin "^4.0.0"
     randombytes "^2.0.0"
 
+dom-serializer@^1.0.1, dom-serializer@~1.2.0:
+  version "1.2.0"
+  resolved "https://registry.yarnpkg.com/dom-serializer/-/dom-serializer-1.2.0.tgz#3433d9136aeb3c627981daa385fc7f32d27c48f1"
+  integrity sha512-n6kZFH/KlCrqs/1GHMOd5i2fd/beQHuehKdWvNNffbGHTr/almdhuVvTVFb3V7fglz+nC50fFusu3lY33h12pA==
+  dependencies:
+    domelementtype "^2.0.1"
+    domhandler "^4.0.0"
+    entities "^2.0.0"
+
 domain-browser@^1.1.1:
   version "1.2.0"
   resolved "https://registry.yarnpkg.com/domain-browser/-/domain-browser-1.2.0.tgz#3d31f50191a6749dd1375a7f522e823d42e54eda"
   integrity sha512-jnjyiM6eRyZl2H+W8Q/zLMA481hzi0eszAaBUzIVnmYVDBbnLxVNnfu1HgEBvCbL+71FrxMl3E6lpKH7Ge3OXA==
 
+domelementtype@^2.0.1, domelementtype@^2.1.0, domelementtype@^2.2.0:
+  version "2.2.0"
+  resolved "https://registry.yarnpkg.com/domelementtype/-/domelementtype-2.2.0.tgz#9a0b6c2782ed6a1c7323d42267183df9bd8b1d57"
+  integrity sha512-DtBMo82pv1dFtUmHyr48beiuq792Sxohr+8Hm9zoxklYPfa6n0Z3Byjj2IV7bmr2IyqClnqEQhfgHJJ5QF0R5A==
+
+domhandler@^4.0.0, domhandler@^4.1.0:
+  version "4.1.0"
+  resolved "https://registry.yarnpkg.com/domhandler/-/domhandler-4.1.0.tgz#c1d8d494d5ec6db22de99e46a149c2a4d23ddd43"
+  integrity sha512-/6/kmsGlMY4Tup/nGVutdrK9yQi4YjWVcVeoQmixpzjOUK1U7pQkvAPHBJeUxOgxF0J8f8lwCJSlCfD0V4CMGQ==
+  dependencies:
+    domelementtype "^2.2.0"
+
+domutils@^2.4.3, domutils@^2.4.4:
+  version "2.5.1"
+  resolved "https://registry.yarnpkg.com/domutils/-/domutils-2.5.1.tgz#9b8e84b5d9f788499ae77506ea832e9b4f9aa1c0"
+  integrity sha512-hO1XwHMGAthA/1KL7c83oip/6UWo3FlUNIuWiWKltoiQ5oCOiqths8KknvY2jpOohUoUgnwa/+Rm7UpwpSbY/Q==
+  dependencies:
+    dom-serializer "^1.0.1"
+    domelementtype "^2.2.0"
+    domhandler "^4.1.0"
+
 dotenv@^8.2.0:
   version "8.2.0"
   resolved "https://registry.yarnpkg.com/dotenv/-/dotenv-8.2.0.tgz#97e619259ada750eea3e4ea3e26bceea5424b16a"
@@ -2240,6 +2315,16 @@ entities@^1.1.1:
   resolved "https://registry.yarnpkg.com/entities/-/entities-1.1.2.tgz#bdfa735299664dfafd34529ed4f8522a275fea56"
   integrity sha512-f2LZMYl1Fzu7YSBKg+RoROelpOaNrcGmE9AZubeDfrCEia483oW4MI4VyFd5VNHIgQ/7qm1I0wUHK1eJnn2y2w==
 
+entities@^2.0.0:
+  version "2.2.0"
+  resolved "https://registry.yarnpkg.com/entities/-/entities-2.2.0.tgz#098dc90ebb83d8dffa089d55256b351d34c4da55"
+  integrity sha512-p92if5Nz619I0w+akJrLZH0MX0Pb5DX39XOwQTtXSdQQOaYH03S1uIQp4mhOZtAXrxq4ViO67YTiLBo2638o9A==
+
+entities@~2.1.0:
+  version "2.1.0"
+  resolved "https://registry.yarnpkg.com/entities/-/entities-2.1.0.tgz#992d3129cf7df6870b96c57858c249a120f8b8b5"
+  integrity sha512-hCx1oky9PFrJ611mf0ifBLBRW8lUUVRlFolb5gWRfIELabBlbp9xZvrqZLZAs+NxFnbfQoeGd8wDkygjg7U85w==
+
 errno@^0.1.3, errno@~0.1.7:
   version "0.1.7"
   resolved "https://registry.yarnpkg.com/errno/-/errno-0.1.7.tgz#4684d71779ad39af177e3f007996f7c67c852618"
@@ -2899,6 +2984,16 @@ html-comment-regex@^1.1.0:
   resolved "https://registry.yarnpkg.com/html-comment-regex/-/html-comment-regex-1.1.2.tgz#97d4688aeb5c81886a364faa0cad1dda14d433a7"
   integrity sha512-P+M65QY2JQ5Y0G9KKdlDpo0zK+/OHptU5AaBwUfAIDJZk1MYf32Frm84EcOytfJE0t5JvkAnKlmjsXDnWzCJmQ==
 
+htmlparser2@^6.0.0:
+  version "6.0.1"
+  resolved "https://registry.yarnpkg.com/htmlparser2/-/htmlparser2-6.0.1.tgz#422521231ef6d42e56bd411da8ba40aa36e91446"
+  integrity sha512-GDKPd+vk4jvSuvCbyuzx/unmXkk090Azec7LovXP8as1Hn8q9p3hbjmDGbUqqhknw0ajwit6LiiWqfiTUPMK7w==
+  dependencies:
+    domelementtype "^2.0.1"
+    domhandler "^4.0.0"
+    domutils "^2.4.4"
+    entities "^2.0.0"
+
 http-errors@1.7.2:
   version "1.7.2"
   resolved "https://registry.yarnpkg.com/http-errors/-/http-errors-1.7.2.tgz#4f5029cf13239f31036e5b2e55292bcfbcc85c8f"
@@ -4222,6 +4317,13 @@ npm-packlist@^1.1.6:
     gauge "~2.7.3"
     set-blocking "~2.0.0"
 
+nth-check@^2.0.0:
+  version "2.0.0"
+  resolved "https://registry.yarnpkg.com/nth-check/-/nth-check-2.0.0.tgz#1bb4f6dac70072fc313e8c9cd1417b5074c0a125"
+  integrity sha512-i4sc/Kj8htBrAiH1viZ0TgU8Y5XqCaV/FziYK6TBczxmeKm3AEFWqqF3195yKudrarqy7Zu80Ra5dobFjn9X/Q==
+  dependencies:
+    boolbase "^1.0.0"
+
 null-loader@^0.1.1:
   version "0.1.1"
   resolved "https://registry.yarnpkg.com/null-loader/-/null-loader-0.1.1.tgz#17be9abfcd3ff0e1512f6fc4afcb1f5039378fae"
@@ -4409,6 +4511,18 @@ parse-json@^4.0.0:
     error-ex "^1.3.1"
     json-parse-better-errors "^1.0.1"
 
+parse5-htmlparser2-tree-adapter@^6.0.0:
+  version "6.0.1"
+  resolved "https://registry.yarnpkg.com/parse5-htmlparser2-tree-adapter/-/parse5-htmlparser2-tree-adapter-6.0.1.tgz#2cdf9ad823321140370d4dbf5d3e92c7c8ddc6e6"
+  integrity sha512-qPuWvbLgvDGilKc5BoicRovlT4MtYT6JfJyBOMDsKoiT+GiuP5qyrPCnR9HcPECIJJmZh5jRndyNThnhhb/vlA==
+  dependencies:
+    parse5 "^6.0.1"
+
+parse5@^6.0.0, parse5@^6.0.1:
+  version "6.0.1"
+  resolved "https://registry.yarnpkg.com/parse5/-/parse5-6.0.1.tgz#e1a1c085c569b3dc08321184f19a39cc27f7c30b"
+  integrity sha512-Ofn/CTFzRGTTxwpNEs9PP93gXShHcTq255nzRYSKe8AkVpZY7e1fpmTfOyoIvjP5HG7Z2ZM7VS9PPhQGW2pOpw==
+
 parseurl@~1.3.3:
   version "1.3.3"
   resolved "https://registry.yarnpkg.com/parseurl/-/parseurl-1.3.3.tgz#9da19e7bee8d12dff0513ed5b76957793bc2e8d4"