lib: Introduce the PlainExporter

This class exports things into plain text. It follows a close format to
that of the one for UOC, but without any formatting.

Signed-off-by: Miquel Sabaté Solà <mikisabate@gmail.com>

1 files changed, 42 insertions, 0 deletions

diff --git a/lib/plain_exporter.rb b/lib/plain_exporter.rb
new file mode 100644
index 0000000..514d243
--- /dev/null
+++ b/lib/plain_exporter.rb
@@ -0,0 +1,42 @@
+# frozen_string_literal: true
+
+# Plain text exporter.
+class PlainExporter < BaseExporter
+  def export
+    @things.map { |thing| "#{head(thing:)} #{body(thing:)}".strip }.join("\n")
+  end
+
+  protected
+
+  # Returns the same text as the plain exporter does not have formatting.
+  def emph(text:)
+    text
+  end
+
+  # Returns the same text as the plain exporter does not have formatting.
+  def upper_case(text:)
+    text
+  end
+
+  # Returns the same text with underscores stripped, as the plain exporter does
+  # not have formatting.
+  def parse_title(title:)
+    title.delete('_')
+  end
+
+  # Returns text with information on the publisher, notes, year, address, etc;
+  # if available.
+  def body(thing:)
+    str = ''
+
+    if thing.publisher.present?
+      str += thing.note.present? ? "#{thing.note}. #{thing.publisher}" : thing.publisher
+    end
+
+    if thing.address.present?
+      str + ", #{thing.address}: #{thing.year}."
+    else
+      "#{str}."
+    end
+  end
+end