Allow to convert html->pdf via weasyprint

docker/docker-compose/docker-compose.yml

@@ -66,6 +66,7 @@ services:
       - DOCSPELL_JOEX_JDBC_URL=jdbc:postgresql://db:5432/dbname
       - DOCSPELL_JOEX_JDBC_USER=dbuser
       - DOCSPELL_JOEX_ADDONS_EXECUTOR__CONFIG_RUNNER=docker,trivial
+      - DOCSPELL_JOEX_CONVERT_HTML__CONVERTER=weasyprint
     ports:
       - "7878:7878"
     depends_on:

modules/convert/src/main/scala/docspell/convert/Conversion.scala

@@ -14,6 +14,7 @@ import fs2._
 
 import docspell.common._
 import docspell.convert.ConversionResult.Handler
+import docspell.convert.ConvertConfig.HtmlConverter
 import docspell.convert.extern._
 import docspell.convert.flexmark.Markdown
 import docspell.files.{ImageSize, TikaMimetype}
@@ -57,11 +58,21 @@ object Conversion {
 
           case MimeType.HtmlMatch(mt) =>
             val cs = mt.charsetOrUtf8
-            WkHtmlPdf
-              .toPDF(cfg.wkhtmlpdf, cfg.chunkSize, cs, sanitizeHtml, logger)(
-                in,
-                handler
-              )
+            cfg.htmlConverter match {
+              case HtmlConverter.Wkhtmltopdf =>
+                WkHtmlPdf
+                  .toPDF(cfg.wkhtmlpdf, cfg.chunkSize, cs, sanitizeHtml, logger)(
+                    in,
+                    handler
+                  )
+
+              case HtmlConverter.Weasyprint =>
+                Weasyprint
+                  .toPDF(cfg.weasyprint, cfg.chunkSize, cs, sanitizeHtml, logger)(
+                    in,
+                    handler
+                  )
+            }
 
           case MimeType.TextAllMatch(mt) =>
             val cs = mt.charsetOrUtf8

modules/convert/src/main/scala/docspell/convert/ConvertConfig.scala

@@ -6,10 +6,11 @@
 
 package docspell.convert
 
+import cats.data.NonEmptyList
+
 import docspell.common.Password
 import docspell.convert.ConvertConfig.DecryptPdf
-import docspell.convert.extern.OcrMyPdfConfig
-import docspell.convert.extern.{TesseractConfig, UnoconvConfig, WkHtmlPdfConfig}
+import docspell.convert.extern._
 import docspell.convert.flexmark.MarkdownConfig
 
 final case class ConvertConfig(
@@ -18,6 +19,8 @@ final case class ConvertConfig(
     maxImageSize: Int,
     markdown: MarkdownConfig,
     wkhtmlpdf: WkHtmlPdfConfig,
+    weasyprint: WeasyprintConfig,
+    htmlConverter: ConvertConfig.HtmlConverter,
     tesseract: TesseractConfig,
     unoconv: UnoconvConfig,
     ocrmypdf: OcrMyPdfConfig,
@@ -27,4 +30,25 @@ final case class ConvertConfig(
 object ConvertConfig {
 
   final case class DecryptPdf(enabled: Boolean, passwords: List[Password])
+
+  sealed trait HtmlConverter {
+    def name: String
+  }
+
+  object HtmlConverter {
+    case object Wkhtmltopdf extends HtmlConverter {
+      val name = "wkhtmlpdf"
+    }
+    case object Weasyprint extends HtmlConverter {
+      val name = "weasyprint"
+    }
+    val all: NonEmptyList[HtmlConverter] = NonEmptyList.of(Wkhtmltopdf, Weasyprint)
+
+    def fromString(str: String): Either[String, HtmlConverter] =
+      all
+        .find(_.name.equalsIgnoreCase(str))
+        .toRight(
+          s"Invalid html-converter value: $str. Use one of: ${all.toList.mkString(", ")}"
+        )
+  }
 }

modules/convert/src/main/scala/docspell/convert/extern/Weasyprint.scala

@@ -0,0 +1,55 @@
+/*
+ * Copyright 2020 Eike K. & Contributors
+ *
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+package docspell.convert.extern
+
+import java.nio.charset.Charset
+
+import cats.effect._
+import cats.implicits._
+import fs2.io.file.Path
+import fs2.{Chunk, Stream}
+
+import docspell.common._
+import docspell.convert.ConversionResult.Handler
+import docspell.convert.{ConversionResult, SanitizeHtml}
+import docspell.logging.Logger
+
+object Weasyprint {
+
+  def toPDF[F[_]: Async, A](
+      cfg: WeasyprintConfig,
+      chunkSize: Int,
+      charset: Charset,
+      sanitizeHtml: SanitizeHtml,
+      logger: Logger[F]
+  )(in: Stream[F, Byte], handler: Handler[F, A]): F[A] = {
+    val reader: (Path, SystemCommand.Result) => F[ConversionResult[F]] =
+      ExternConv.readResult[F](chunkSize, logger)
+
+    val cmdCfg = cfg.command.replace(Map("{{encoding}}" -> charset.name()))
+
+    // html sanitize should (among other) remove links to invalid
+    // protocols like cid: which is not supported by further
+    // processing.
+    //
+    // Since jsoup will load everything anyways, a stream-based
+    // conversion to java's inputstream doesn't make much sense.
+    val inSane = Stream.evalUnChunk(
+      Binary
+        .loadAllBytes(in)
+        .map(bv => sanitizeHtml(bv, charset.some))
+        .map(bv => Chunk.byteVector(bv))
+    )
+
+    ExternConv
+      .toPDF[F, A]("weasyprint", cmdCfg, cfg.workingDir, true, logger, reader)(
+        inSane,
+        handler
+      )
+  }
+
+}

modules/convert/src/main/scala/docspell/convert/extern/WeasyprintConfig.scala

@@ -0,0 +1,13 @@
+/*
+ * Copyright 2020 Eike K. & Contributors
+ *
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+package docspell.convert.extern
+
+import fs2.io.file.Path
+
+import docspell.common.SystemCommand
+
+case class WeasyprintConfig(command: SystemCommand.Config, workingDir: Path)

modules/convert/src/test/scala/docspell/convert/ConversionTest.scala

@@ -17,8 +17,8 @@ import fs2.Stream
 import docspell.common._
 import docspell.common.util.File
 import docspell.convert.ConversionResult.Handler
-import docspell.convert.extern.OcrMyPdfConfig
-import docspell.convert.extern.{TesseractConfig, UnoconvConfig, WkHtmlPdfConfig}
+import docspell.convert.ConvertConfig.HtmlConverter
+import docspell.convert.extern._
 import docspell.convert.flexmark.MarkdownConfig
 import docspell.files.ExampleFiles
 import docspell.logging.TestLoggingConfig
@@ -43,6 +43,15 @@ class ConversionTest extends FunSuite with FileChecks with TestLoggingConfig {
       ),
       target
     ),
+    WeasyprintConfig(
+      SystemCommand.Config(
+        "weasyprint",
+        Seq("--encoding", "UTF-8", "-", "{{outfile}}"),
+        Duration.seconds(20)
+      ),
+      target
+    ),
+    HtmlConverter.Wkhtmltopdf,
     TesseractConfig(
       SystemCommand.Config(
         "tesseract",

modules/joex/src/main/resources/reference.conf

@@ -551,6 +551,10 @@ Docpell Update Check
       """
     }
 
+    # Which HTML->PDF converter command to use. One of: wkhtmlpdf,
+    # weasyprint.
+    html-converter = "wkhtmlpdf"
+
     # To convert HTML files into PDF files, the external tool
     # wkhtmltopdf is used.
     wkhtmlpdf {
@@ -568,7 +572,22 @@ Docpell Update Check
         ]
         timeout = "2 minutes"
       }
-      working-dir = ${java.io.tmpdir}"/docspell-convert"
+      working-dir = ${java.io.tmpdir}"/docspell-wkhtmltopdf"
+    }
+
+    # An alternative to wkhtmltopdf is weasyprint.
+    weasyprint {
+      command = {
+        program = "weasyprint"
+        args = [
+          "--optimize-size", "all",
+          "--encoding", "{{encoding}}",
+          "-",
+          "{{outfile}}"
+        ]
+        timeout = "2 minutes"
+      }
+      working-dir = ${java.io.tmpdir}"/docspell-weasyprint"
     }
 
     # To convert image files to PDF files, tesseract is used. This

modules/joex/src/main/scala/docspell/joex/ConfigFile.scala

@@ -10,6 +10,7 @@ import cats.effect.Async
 
 import docspell.config.Implicits._
 import docspell.config.{ConfigFactory, FtsType, Validation}
+import docspell.convert.ConvertConfig.HtmlConverter
 import docspell.scheduler.CountingScheme
 import docspell.store.Db
 
@@ -38,6 +39,9 @@ object ConfigFile {
 
     implicit val mailAddressReader: ConfigReader[MailAddress] =
       ConfigReader[String].emap(reason(MailAddress.parse))
+
+    implicit val htmlConverterReader: ConfigReader[HtmlConverter] =
+      ConfigReader[String].emap(reason(HtmlConverter.fromString))
   }
 
   def validate: Validation[Config] =