1 files changed, 188 insertions, 0 deletions
diff --git a/_ext/gemtext_builder.py b/_ext/gemtext_builder.py
new file mode 100644
index 0000000..9c31788
--- /dev/null
+++ b/_ext/gemtext_builder.py
@@ -0,0 +1,188 @@
+from pathlib import Path
+from typing import Set
+
+from docutils import nodes, writers
+from docutils.io import StringOutput
+from sphinx.builders import Builder
+from sphinx.util import logging
+from sphinx.util.docutils import SphinxTranslator
+from sphinx.util.osutil import ensuredir, os_path
+
+logger = logging.getLogger(__name__)
+
+class GemtextWriter(writers.Writer):
+    def __init__(self, builder):
+        super().__init__()
+        self.builder = builder
+    
+    def translate(self):
+        visitor = self.builder.create_translator(self.document, self.builder)
+        self.document.walkabout(visitor)
+        self.output = '\n'.join(visitor.body) + '\n'
+
+class GemtextTranslator(SphinxTranslator):
+    def __init__(self, document: nodes.document, builder):
+        super().__init__(document, builder)
+        self.heading_level = 0
+        self.current_line = ''
+        self.body = []
+        self.literal = False
+    
+    def _finish_line(self):
+        if self.current_line != '':
+            self.body.append(self.current_line)
+            self.current_line = ''
+    
+    def visit_document(self, node: nodes.document):
+        self.heading_level = 1
+        self.current_line = ''
+        self.body = []
+        self.literal = False
+    
+    def depart_document(self, node: nodes.document):
+        self._finish_line()
+    
+    def visit_section(self, node: nodes.section):
+        self.heading_level += 1
+        if len(self.body) > 0 and self.body[-1] != '':
+            self.body.append('')
+    
+    def depart_section(self, node: nodes.section):
+        self.heading_level -= 1
+    
+    def visit_title(self, node: nodes.title):
+        pass
+
+    def depart_title(self, node: nodes.title):
+        self.current_line = '#' * (self.heading_level - 1) + ' ' + self.current_line
+        self._finish_line()
+        self.body.append('')
+
+    def visit_Text(self, node: nodes.Text):
+        text = node.astext()
+        if not self.literal:
+            text = text.replace('\n', ' ')
+        self.current_line += text
+    
+    def depart_Text(self, node: nodes.Text):
+        pass
+
+    def visit_paragraph(self, node: nodes.paragraph):
+        pass
+
+    def depart_paragraph(self, node: nodes.paragraph):
+        self._finish_line()
+
+    def visit_reference(self, node: nodes.reference):
+        pass
+
+    def depart_reference(self, node: nodes.reference):
+        if self.current_line.startswith('=>'):
+            self._finish_line()
+            self.body.append('=> {} {}'.format(node.attributes['refuri'], node.astext()))
+        else:
+            self.current_line = '=> {} {}'.format(node.attributes['refuri'], self.current_line)
+
+    def visit_image(self, node: nodes.image):
+        if self.current_line == '':
+            self.body.append('=> {} {}'.format(node.attributes['uri'], node.attributes['alt']))
+        else:
+            raise NotImplementedError('inline images')
+    
+    def depart_image(self, node: nodes.image):
+        pass
+
+    def visit_comment(self, node: nodes.comment):
+        raise nodes.SkipNode
+
+    def visit_strong(self, node: nodes.strong):
+        self.current_line += '**'
+    
+    depart_strong = visit_strong
+
+    def visit_emphasis(self, node: nodes.emphasis):
+        self.current_line += '_'
+    
+    depart_emphasis = visit_emphasis
+
+    def visit_target(self, node: nodes.target):
+        raise nodes.SkipNode
+
+    def visit_bullet_list(self, node: nodes.bullet_list):
+        pass
+
+    def depart_bullet_list(self, node: nodes.bullet_list):
+        pass
+
+    def visit_list_item(self, node: nodes.list_item):
+        self.current_line += '* '
+
+    def depart_list_item(self, node: nodes.list_item):
+        pass
+
+    def visit_compound(self, node: nodes.compound):
+        pass
+
+    def depart_compound(self, node: nodes.compound):
+        pass
+
+    def visit_inline(self, node: nodes.inline):
+        pass
+
+    def depart_inline(self, node: nodes.inline):
+        pass
+
+    def visit_title_reference(self, nodes: nodes.title_reference):
+        pass
+
+    def depart_title_reference(self, nodes: nodes.title_reference):
+        pass
+
+    def visit_literal(self, nodes: nodes.literal):
+        self.current_line += '`'
+
+    depart_literal = visit_literal
+
+    def visit_literal_block(self, nodes: nodes.literal_block):
+        self.body.append('')
+        self.body.append('```')
+        self.literal = True
+
+    def depart_literal_block(self, nodes: nodes.literal_block):
+        self._finish_line()
+        self.body.append('```')
+        self.body.append('')
+        self.literal = False
+
+class GemtextBuilder(Builder):
+    name = 'gmi'
+    format = 'gmi'
+
+    out_suffix = '.gmi'
+    default_translator_class = GemtextTranslator
+
+    def get_outdated_docs(self):
+        return self.env.found_docs # can't be fucked to implement this right
+    
+    def get_target_uri(self, docname: str, typ: str = None):
+        return docname
+    
+    def prepare_writing(self, docnames: Set[str]):
+        self.writer = GemtextWriter(self)
+
+    def write_doc(self, docname: str, doctree: nodes.document):
+        destination = StringOutput(encoding='utf-8')
+        self.writer.write(doctree, destination)
+        out_name = Path(self.outdir, os_path(docname) + '.gmi')
+        out_name.parent.mkdir(parents=True, exist_ok=True)
+        with open(out_name, 'w', encoding='utf-8') as out_file:
+            out_file.write(self.writer.output)
+
+def setup(app):
+    app.add_builder(GemtextBuilder)
+
+    return {
+        'version': '0.1',
+        'parallel_read_safe': True,
+        'parallel_write_safe': True,
+    }