From fec475b5ef949d168a61db2ac59077ec566ccce3 Mon Sep 17 00:00:00 2001
From: Louis <spalax@gresille.org>
Date: Wed, 7 Oct 2015 15:46:11 +0200
Subject: [PATCH] Added a command line tool to convert between file formats

---
 patacrep/songs/chordpro/__init__.py | 16 ++++++----
 patacrep/songs/convert/__main__.py  | 48 +++++++++++++++++++++++++++++
 2 files changed, 58 insertions(+), 6 deletions(-)
 create mode 100644 patacrep/songs/convert/__main__.py

diff --git a/patacrep/songs/chordpro/__init__.py b/patacrep/songs/chordpro/__init__.py
index 6d4c0e39..e5579d97 100644
--- a/patacrep/songs/chordpro/__init__.py
+++ b/patacrep/songs/chordpro/__init__.py
@@ -1,8 +1,9 @@
 """Chordpro parser"""
 
 from jinja2 import Environment, FileSystemLoader, contextfunction
-import pkg_resources
+import jinja2
 import os
+import pkg_resources
 
 from patacrep import encoding, files
 from patacrep.songs import Song
@@ -63,11 +64,14 @@ class ChordproSong(Song):
         jinjaenv.filters['search_image'] = self.search_image
         jinjaenv.filters['search_partition'] = self.search_partition
 
-        return Renderer(
-            template=template,
-            encoding='utf8',
-            jinjaenv=jinjaenv,
-            ).template.render(context)
+        try:
+            return Renderer(
+                template=template,
+                encoding='utf8',
+                jinjaenv=jinjaenv,
+                ).template.render(context)
+        except jinja2.exceptions.TemplateNotFound:
+            raise NotImplementedError()
 
     @staticmethod
     @contextfunction
diff --git a/patacrep/songs/convert/__main__.py b/patacrep/songs/convert/__main__.py
new file mode 100644
index 00000000..5271637f
--- /dev/null
+++ b/patacrep/songs/convert/__main__.py
@@ -0,0 +1,48 @@
+"""Conversion between formats
+
+See the :meth:`__usage` method for more information.
+"""
+
+import logging
+import sys
+
+from patacrep.build import DEFAULT_CONFIG
+from patacrep import files
+
+LOGGER = logging.getLogger(__name__)
+
+def __usage():
+    return "python3 -m patacrep.songs.convert chordpro latex FILE"
+
+if __name__ == "__main__":
+    if len(sys.argv) != 4:
+        LOGGER.error("Invalid number of arguments.")
+        LOGGER.error("Usage: %s", __usage())
+        sys.exit(1)
+
+    source = sys.argv[1]
+    dest = sys.argv[2]
+    file = sys.argv[3]
+
+    song_parsers = files.load_plugins(
+        datadirs=DEFAULT_CONFIG.get('datadir', []),
+        root_modules=['songs'],
+        keyword='SONG_PARSERS',
+        )
+
+    if source not in song_parsers:
+        LOGGER.error(
+            "Unknown file format '%s'. Available ones are %s.",
+            source,
+            ", ".join(["'{}'".format(key) for key in song_parsers.keys()])
+            )
+        sys.exit(1)
+
+    song = song_parsers[source](".", file, DEFAULT_CONFIG)
+    try:
+        print(song.render(dest))
+    except NotImplementedError:
+        LOGGER.error("Cannot convert to format '%s'.", dest)
+        sys.exit(1)
+
+    sys.exit(0)