Implement feed generation

4 files changed, 93 insertions, 39 deletions

diff --git a/README.md b/README.md
index e601bae..39b2fe1 100644
--- a/README.md
+++ b/README.md
@@ -1,9 +1,11 @@
 # rub
 
-Rub is a static generator.
+Rub is a static generator framework.
 
 ## Copying
 
+![AGPLv3](https://www.gnu.org/graphics/agplv3-155x51.png)
+
 This program is free software: you can redistribute it and/or modify
 it under the terms of the GNU Affero General Public License as published
 by the Free Software Foundation, either version 3 of the License, or
diff --git a/pyproject.toml b/pyproject.toml
index 50e3fab..452b087 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -7,7 +7,7 @@ name = "rub"
 version = "0.0.1"
 description = "A static generator"
 readme = "README.md"
-requires-python = ">=3.8"
+requires-python = ">=3.9"
 license = { file = "COPYING" }
 authors = [ { name = "Nguyễn Gia Phong", email = "mcsinyx@disroot.org" } ]
 keywords = [ "ssg", "feed", "xml" ]
diff --git a/src/rub/__init__.py b/src/rub/__init__.py
index 904f47a..3be303b 100644
--- a/src/rub/__init__.py
+++ b/src/rub/__init__.py
@@ -20,44 +20,49 @@ from functools import cached_property
 from os import walk
 from pathlib import Path
 from shutil import copytree, rmtree
+from typing import Iterator
 
-from rub import xml
+from doit import run as do
 
-__all__ = ['Rubber', 'xml']
+from rub.xml import Processor, gen_omnifeed
 
+__all__ = ['rub']
 
-def glob_files(root: Path, suffix=''):
+OMNIFEED = Path('feed.xml')
+
+
+def glob_files(root: Path, suffix='') -> list[Path]:
     """Return the list of all files in given directory, recursively."""
     return [Path(path).relative_to(root)/file
             for path, dirs, files in walk(root)
             for file in files if file.endswith(suffix)]
 
 
-def replace(source: Path, destination: Path):
+def replace(source: Path, destination: Path) -> None:
     """Replace destination with source directory."""
     rmtree(destination, ignore_errors=True)
     copytree(source, destination, dirs_exist_ok=True)
 
 
+def processing_task(proc: Processor, path: Path,
+                    src_dir: Path, dest_dir: Path, doc: str) -> dict:
+    source, dest = src_dir / path, proc.change_name(dest_dir/path)
+    return {'name': f'/{proc.change_name(path)}', 'doc': doc,
+            'file_dep': [proc.xslt, source],
+            'actions': [(proc.process, [source, dest])],
+            'targets': [dest], 'clean': True}
+
+
 class Rubber:
     """Static generator."""
 
-    def __init__(self, generate_article, base, src, cache, out):
-        self.generate_article = generate_article
+    def __init__(self, page_proc: Processor, feed_proc: Processor,
+                 base: Path, src: Path, cache: Path, out: Path) -> None:
+        self.page_proc, self.feed_proc = page_proc, feed_proc
         self.base, self.src = base, src
         self.cache, self.out = cache, out
 
-    @cached_property
-    def tasks(self):
-        def assox():
-            for k in dir(self):
-                if not k.startswith('task_'): continue
-                v = getattr(self, k)
-                if callable(v): yield k, v
-
-        return dict(assox())
-
-    def task_base(self):
+    def task_base(self) -> dict:
         paths = glob_files(self.base)
         return {'doc': 'copy base directory',
                 'file_dep': [self.base/path for path in paths],
@@ -65,12 +70,33 @@ class Rubber:
                 'targets': [self.out/path for path in paths],
                 'clean': True}
 
-    def task_articles(self):
-        """process articles into XHTML"""
-        for path in glob_files(self.src, '.xml'):
-            source = self.src / path
-            destination = self.out / path
-            yield {'name': path, 'doc': f'process {path} into XHTML',
-                   'file_dep': [source],
-                   'actions': [(self.generate_article, [source, destination])],
-                   'targets': [destination], 'clean': True}
+    @cached_property
+    def sources(self) -> list[Path]:
+        return glob_files(self.src, '.xml')
+
+    def task_pages(self) -> Iterator[dict]:
+        yield {'name': None, 'doc': 'process sources into web pages'}
+        for path in self.sources:
+            yield processing_task(self.page_proc, path, self.src, self.out,
+                                  f'process {path} into a web page')
+
+    def task_feeds(self) -> Iterator[dict]:
+        yield {'name': None, 'doc': 'generate web feeds'}
+        feed_src = self.cache / OMNIFEED
+        sources = [self.src/path for path in self.sources]
+        pages = [self.page_proc.change_name(self.out/path)
+                 for path in self.sources]
+        yield {'name': 'source', 'doc': 'generate generic global feed',
+               'file_dep': sources+pages,
+               'actions': [(gen_omnifeed,
+                            [sources, pages, self.out, feed_src])],
+               'targets': [feed_src], 'clean': True}
+        yield processing_task(self.feed_proc, OMNIFEED, self.cache, self.out,
+                              'generate global feed')
+
+
+def rub(page_proc: Processor, feed_proc: Processor,
+        base: Path, src: Path, cache: Path, out: Path) -> None:
+    """Generate static website."""
+    rubber = Rubber(page_proc, feed_proc, base, src, cache, out)
+    do({k: getattr(rubber, k) for k in dir(rubber)})
diff --git a/src/rub/xml.py b/src/rub/xml.py
index ed61a8b..4c3a2ae 100644
--- a/src/rub/xml.py
+++ b/src/rub/xml.py
@@ -17,12 +17,13 @@
 # along with rub.  If not, see <https://www.gnu.org/licenses/>.
 
 from copy import deepcopy
-from functools import partial
 from pathlib import Path
 
-from lxml.etree import QName, XML, XSLT, XSLTExtension
+from lxml.builder import E
+from lxml.html import document_fromstring as from_html
+from lxml.etree import QName, XML, XSLT, XSLTExtension, tostring as serialize
 
-__all__ = ['NS', 'generator', 'recurse']
+__all__ = ['NS', 'Processor', 'recurse']
 
 NS = 'https://rub.parody'
 
@@ -57,14 +58,39 @@ class Evaluator(XSLTExtension):
         handle(self, context, input_node, output_parent)
 
 
-def generator(xslt, **handlers):
-    """Return a function taking an XML file and apply given XSLT."""
-    stylesheet = xslt.read_bytes()
-    extensions = {(NS, 'eval'): Evaluator(**handlers)}
-    transform = XSLT(XML(stylesheet), extensions=extensions)
+class Serializer(XSLTExtension):
+    def execute(self, context, self_node, input_node, output_parent):
+        output_parent.text = serialize(deepcopy(input_node))
+
+
+class Processor:
+    """Callable XSLT processor."""
 
-    def make(src, dest):
+    def __init__(self, xslt: Path, change_name, **handlers) -> None:
+        self.xslt, self.change_name = xslt, change_name
+        stylesheet = xslt.read_bytes()
+        extensions = {(NS, 'eval'): Evaluator(**handlers),
+                      (NS, 'serialize'): Serializer()}
+        self.transform = XSLT(XML(stylesheet), extensions=extensions)
+
+    def process(self, src: Path, dest: Path) -> None:
         dest.parent.mkdir(mode=0o755, parents=True, exist_ok=True)
-        dest.write_text(str(transform(XML(src.read_bytes()))))
+        dest.write_text(str(self.transform(XML(src.read_bytes()))))
+
 
-    return make
+def gen_omnifeed(sources: list[Path], pages: list[Path],
+                 out_dir: Path, dest: Path) -> None:
+    """Generate generic global feed."""
+    entries = []
+    for src, page in zip(sources, pages):
+        src_root = XML(src.read_bytes())
+        desc = src_root.findtext('description', '', {None: NS})
+        if not desc: continue
+        title = src_root.findtext('title', '', {None: NS})
+        date = src_root.findtext('date', '', {None: NS})
+        page_root = from_html(page.read_bytes())
+        path = str(page.relative_to(out_dir))
+        entries.append(E.entry(E.title(title), E.description(desc),
+                               E.date(date), E.path(path), page_root))
+    dest.parent.mkdir(mode=0o755, parents=True, exist_ok=True)
+    dest.write_bytes(serialize(E.feed(*entries), pretty_print=True))