From dc99ae38d99e2cc5683a540adcb3d7f28cc2c919 Mon Sep 17 00:00:00 2001
From: Erik Axel Nielsen <erikaxel@lucalabs.com>
Date: Thu, 6 Sep 2018 20:52:43 +0200
Subject: [PATCH] Support for using headless chrome instead of wkhtmltopdf.

---
 lib/wicked_pdf.rb     | 21 ++++++++----
 lib/wicked_pdf/pdf.js | 78 +++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 92 insertions(+), 7 deletions(-)
 create mode 100644 lib/wicked_pdf/pdf.js

diff --git a/lib/wicked_pdf.rb b/lib/wicked_pdf.rb
index e1ead7d2..f0d9b7af 100644
--- a/lib/wicked_pdf.rb
+++ b/lib/wicked_pdf.rb
@@ -37,11 +37,12 @@ class WickedPdf
   attr_accessor :binary_version
 
   def initialize(wkhtmltopdf_binary_path = nil)
-    @exe_path = wkhtmltopdf_binary_path || find_wkhtmltopdf_binary_path
-    raise "Location of #{EXE_NAME} unknown" if @exe_path.empty?
-    raise "Bad #{EXE_NAME}'s path: #{@exe_path}" unless File.exist?(@exe_path)
-    raise "#{EXE_NAME} is not executable" unless File.executable?(@exe_path)
-
+    unless WickedPdf.config[:use_puppeteer]
+      @exe_path = wkhtmltopdf_binary_path || find_wkhtmltopdf_binary_path
+      raise "Location of #{EXE_NAME} unknown" if @exe_path.empty?
+      raise "Bad #{EXE_NAME}'s path: #{@exe_path}" unless File.exist?(@exe_path)
+      raise "#{EXE_NAME} is not executable" unless File.executable?(@exe_path)
+    end
     retrieve_binary_version
   end
 
@@ -67,8 +68,14 @@ def pdf_from_url(url, options = {})
     # merge in global config options
     options.merge!(WickedPdf.config) { |_key, option, _config| option }
     generated_pdf_file = WickedPdfTempfile.new('wicked_pdf_generated_file.pdf', options[:temp_path])
-    command = [@exe_path]
-    command << '-q' unless on_windows? # suppress errors on stdout
+    if WickedPdf.config[:use_puppeteer]
+      spec = Gem::Specification.find_by_name('wicked_pdf')
+      node_modules_path = "#{Rails.root.to_s}/node_modules"
+      command = ['node', File.join(spec.gem_dir, 'lib', 'wicked_pdf', 'pdf.js'), node_modules_path]
+    else
+      command = [@exe_path]
+      command << '-q' unless on_windows? # suppress errors on stdout
+    end
     command += parse_options(options)
     command << url
     command << generated_pdf_file.path.to_s
diff --git a/lib/wicked_pdf/pdf.js b/lib/wicked_pdf/pdf.js
new file mode 100644
index 00000000..49cf8ea9
--- /dev/null
+++ b/lib/wicked_pdf/pdf.js
@@ -0,0 +1,78 @@
+"use strict";
+const puppeteer = require(`${process.argv[2]}/puppeteer`);
+const createPdf = async options => {
+  let browser;
+  try {
+    browser = await puppeteer.launch({
+      args: ["--no-sandbox", "--disable-setuid-sandbox"]
+    });
+    const page = await browser.newPage();
+    await page.goto(options.input, { waitUntil: "networkidle2" });
+    delete options.input;
+    await page.pdf(options);
+  } catch (err) {
+    console.log(err.message);
+  } finally {
+    if (browser) {
+      browser.close();
+    }
+    process.exit();
+  }
+};
+const parseCmd = () => {
+  let options = {
+    margin: {
+      top: "10mm",
+      bottom: "10mm",
+      left: "10mm",
+      right: "10mm"
+    },
+    landscape: false,
+    format: "A4", // Format takes precedence over width and height if set
+    height: "297", // A4
+    width: "210", // A4
+    path: process.argv[process.argv.length - 1],
+    input: process.argv[process.argv.length - 2],
+    scale: 1.0,
+    displayHeaderFooter: false,
+    printBackground: true
+  };
+  for (let i = 3; i < process.argv.length - 2; i += 2) {
+    const value = process.argv[i + 1];
+    switch (process.argv[i]) {
+      case "--page-size":
+        options.format = value;
+        break;
+      case "--orientation":
+        options.landscape = value === "Landscape";
+        break;
+      case "--zoom":
+        options.scale = parseFloat(value);
+        break;
+      case "--width":
+        delete options.format;
+        options.width = value;
+        break;
+      case "--height":
+        delete options.format;
+        options.height = value;
+        break;
+      case "--margin-top":
+        options.margin.top = value;
+        break;
+      case "--margin-bottom":
+        options.margin.bottom = value;
+        break;
+      case "--margin-left":
+        options.margin.left = value;
+        break;
+      case "--margin-right":
+        options.margin.right = value;
+        break;
+      default:
+        console.log("Unknown argument: " + value);
+    }
+  }
+  return options;
+};
+createPdf(parseCmd());