rewrite the project as a static site generator

this removes Flask, reworks a number of library methods accordingly, and
adds generators and build commands to process the instance directory
(largely unchanged, except config.py is now config.json) and spit out
files suitable to be served by a web server such as Nginx.

there are probably some rough edges here, but overall this works.

also note, as this is no longer server software on a network, the
license has changed from AGPLv3 to GPLv3, and the "or any later version"
allowance has been removed

Signed-off-by: Brian S. Stephan <bss@incorporeal.org>

tests/functional_markdown_tests.py

@@ -1,67 +1,65 @@
 """Test graphviz functionality.
 
 SPDX-FileCopyrightText: © 2021 Brian S. Stephan <bss@incorporeal.org>
-SPDX-License-Identifier: AGPL-3.0-or-later
+SPDX-License-Identifier: GPL-3.0-only
 """
 import os
+import tempfile
 
-from incorporealcms import create_app
+import pytest
+
+from incorporealcms import init_instance
+from incorporealcms.ssg import StaticSiteGenerator
 
 HERE = os.path.dirname(os.path.abspath(__file__))
 
-
-def app_with_pydot():
-    """Create the test app, including the pydot extension."""
-    return create_app(instance_path=os.path.join(HERE, 'instance'),
-                      test_config={'MARKDOWN_EXTENSIONS': ['incorporealcms.mdx.pydot']})
-
-
-def test_functional_initialization():
-    """Test initialization with the graphviz config."""
-    app = app_with_pydot()
-    assert app is not None
+init_instance(instance_path=os.path.join(HERE, 'instance'),
+              extra_config={'MARKDOWN_EXTENSIONS': ['incorporealcms.mdx.pydot', 'incorporealcms.mdx.figures',
+                                                    'attr_list']})
 
 
 def test_graphviz_is_rendered():
     """Initialize the app with the graphviz extension and ensure it does something."""
-    app = app_with_pydot()
-    client = app.test_client()
+    with tempfile.TemporaryDirectory() as tmpdir:
+        src_dir = os.path.join(HERE, 'instance')
+        ssg = StaticSiteGenerator(src_dir, tmpdir)
+        os.chdir(os.path.join(src_dir, 'pages'))
 
-    response = client.get('/test-graphviz')
-    assert response.status_code == 200
-    assert b'~~~pydot' not in response.data
-    assert b'data:image/png;base64' in response.data
-
-
-def test_two_graphviz_are_rendered():
-    """Test two images are rendered."""
-    app = app_with_pydot()
-    client = app.test_client()
-
-    response = client.get('/test-two-graphviz')
-    assert response.status_code == 200
-    assert b'~~~pydot' not in response.data
-    assert b'data:image/png;base64' in response.data
+        ssg.build_file_in_destination(os.path.join(HERE, 'instance', 'pages'), '', 'test-graphviz.md', tmpdir, True)
+        with open(os.path.join(tmpdir, 'test-graphviz.html'), 'r') as graphviz_output:
+            data = graphviz_output.read()
+            assert 'data:image/png;base64' in data
+    os.chdir(HERE)
 
 
 def test_invalid_graphviz_is_not_rendered():
     """Check that invalid graphviz doesn't blow things up."""
-    app = app_with_pydot()
-    client = app.test_client()
+    with tempfile.TemporaryDirectory() as tmpdir:
+        src_dir = os.path.join(HERE, 'instance')
+        ssg = StaticSiteGenerator(src_dir, tmpdir)
+        os.chdir(os.path.join(src_dir, 'broken'))
 
-    response = client.get('/test-invalid-graphviz')
-    assert response.status_code == 500
-    assert b'INTERNAL SERVER ERROR' in response.data
+        with pytest.raises(ValueError):
+            ssg.build_file_in_destination(os.path.join(HERE, 'instance', 'broken'), '', 'test-invalid-graphviz.md',
+                                          tmpdir, True)
+    os.chdir(HERE)
 
 
-def test_figures_are_rendered(client):
+def test_figures_are_rendered():
     """Test that a page with my figure syntax renders as expected."""
-    response = client.get('/figures')
-    assert response.status_code == 200
-    assert (b'<figure class="right"><img alt="fancy captioned logo" src="bss-square-no-bg.png" />'
-            b'<figcaption>this is my cool logo!</figcaption></figure>') in response.data
-    assert (b'<figure><img alt="vanilla captioned logo" src="bss-square-no-bg.png" />'
-            b'<figcaption>this is my cool logo without an attr!</figcaption>\n</figure>') in response.data
-    assert (b'<figure class="left"><img alt="fancy logo" src="bss-square-no-bg.png" />'
-            b'<span></span></figure>') in response.data
-    assert b'<figure><img alt="just a logo" src="bss-square-no-bg.png" /></figure>' in response.data
+    with tempfile.TemporaryDirectory() as tmpdir:
+        src_dir = os.path.join(HERE, 'instance')
+        ssg = StaticSiteGenerator(src_dir, tmpdir)
+        os.chdir(os.path.join(src_dir, 'pages'))
+
+        ssg.build_file_in_destination(os.path.join(HERE, 'instance', 'pages'), '', 'figures.md', tmpdir, True)
+        with open(os.path.join(tmpdir, 'figures.html'), 'r') as graphviz_output:
+            data = graphviz_output.read()
+            assert ('<figure class="right"><img alt="fancy captioned logo" src="bss-square-no-bg.png" />'
+                    '<figcaption>this is my cool logo!</figcaption></figure>') in data
+            assert ('<figure><img alt="vanilla captioned logo" src="bss-square-no-bg.png" />'
+                    '<figcaption>this is my cool logo without an attr!</figcaption>\n</figure>') in data
+            assert ('<figure class="left"><img alt="fancy logo" src="bss-square-no-bg.png" />'
+                    '<span></span></figure>') in data
+            assert '<figure><img alt="just a logo" src="bss-square-no-bg.png" /></figure>' in data
+    os.chdir(HERE)