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-rw-r--r--blog_v2/src/blog/gemtext.py336
1 files changed, 336 insertions, 0 deletions
diff --git a/blog_v2/src/blog/gemtext.py b/blog_v2/src/blog/gemtext.py
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+++ b/blog_v2/src/blog/gemtext.py
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+import dataclasses
+import re
+import textwrap
+
+import htmlgenerator as h
+
+from blog import gemtext
+from blog import pretty
+
+
+def parse(s):
+ r"""
+ >>> parse('''# Header 1
+ ...
+ ... ## Header 2
+ ...
+ ... ### Header 3
+ ...
+ ... * List 1
+ ... * List 2
+ ...
+ ... > First line quote.
+ ... > Second line of quote.
+ ...
+ ... ```
+ ... Fenced
+ ... Lines
+ ... ```
+ ...
+ ... Paragraph.
+ ...
+ ... Another paragraph.
+ ... ''')
+ [Header(level=1, text='Header 1'),
+ Line(text=''),
+ Header(level=2, text='Header 2'),
+ Line(text=''),
+ Header(level=3, text='Header 3'),
+ Line(text=''),
+ List(items=[ListItem(text='List 1'),
+ ListItem(text='List 2')]),
+ Line(text=''),
+ BlockQuote(lines=[BlockQuoteLine(text='First line quote.'),
+ BlockQuoteLine(text='Second line of quote.')]),
+ Line(text=''),
+ Pre(content='Fenced\nLines\n'),
+ Line(text=''),
+ Line(text='Paragraph.'),
+ Line(text=''),
+ Line(text='Another paragraph.')]
+ """
+ lines = s.splitlines()
+
+ i = 0
+ gem = []
+
+ while i < len(lines):
+ line = parse_line(lines[i])
+
+ if isinstance(line, Link):
+ gem.append(line)
+ i = i + 1
+ continue
+
+ if isinstance(line, Header):
+ gem.append(line)
+ i = i + 1
+ continue
+
+ if isinstance(line, ListItem):
+ items = []
+ while i < len(lines) and isinstance(parse_line(lines[i]), ListItem):
+ items.append(parse_line(lines[i]))
+ i = i + 1
+ gem.append(List(items))
+ continue
+
+ if isinstance(line, BlockQuoteLine):
+ quotes = []
+ while i < len(lines) and isinstance(parse_line(lines[i]), BlockQuoteLine):
+ quotes.append(parse_line(lines[i]))
+ i = i + 1
+ gem.append(BlockQuote(quotes))
+ continue
+
+ if isinstance(line, PreFence):
+ content = ""
+ i = i + 1
+ while i < len(lines) and not isinstance(parse_line(lines[i]), PreFence):
+ content += lines[i]
+ content += "\n"
+ i = i + 1
+ gem.append(Pre(content))
+ i = i + 1
+ continue
+
+ gem.append(line)
+ i = i + 1
+
+ return gem
+
+
+def parse_line(l):
+ if Link.is_link(l):
+ return Link(l)
+ if Header.is_header(l):
+ return Header(l)
+ if ListItem.is_list_item(l):
+ return ListItem(l)
+ if BlockQuoteLine.is_block_quote_line(l):
+ return BlockQuoteLine(l)
+ if PreFence.is_pre_fence(l):
+ return PreFence()
+ return Line(l)
+
+
+@dataclasses.dataclass
+class Link:
+ """
+ >>> Link("=> http://example.com")
+ Link(url='http://example.com', text=None)
+
+ >>> Link("=> http://example.com Example text")
+ Link(url='http://example.com', text='Example text')
+ """
+
+ url: str
+ text: str | None
+
+ def __init__(self, line: str):
+ assert Link.is_link(line)
+ parts = line.split(None, 2)
+ self.url = parts[1]
+ self.text = parts[2] if len(parts) > 2 else None # noqa: PLR2004, > 2 "magic constant"
+
+ @staticmethod
+ def is_link(line: str):
+ return line.startswith("=>")
+
+
+@dataclasses.dataclass
+class Header:
+ """
+ >>> Header("# Level one")
+ Header(level=1, text='Level one')
+
+ >>> Header("## Level two")
+ Header(level=2, text='Level two')
+
+ >>> Header("### Level three")
+ Header(level=3, text='Level three')
+ """
+
+ level: int
+ text: str
+
+ def __init__(self, line: str):
+ assert Header.is_header(line)
+ hashes, self.text = line.split(None, 1)
+ self.level = len(hashes)
+
+ @staticmethod
+ def is_header(line: str):
+ return re.match("#{1,3} .*", line)
+
+
+@dataclasses.dataclass
+class ListItem:
+ """
+ >>> ListItem("* foo")
+ ListItem(text='foo')
+ """
+
+ text: str
+
+ def __init__(self, line: str):
+ assert ListItem.is_list_item(line)
+ self.text = line[2:]
+
+ @staticmethod
+ def is_list_item(line: str):
+ return line.startswith("* ")
+
+
+@dataclasses.dataclass
+class BlockQuoteLine:
+ """
+ >>> BlockQuoteLine("> foo")
+ BlockQuoteLine(text='foo')
+
+ >>> BlockQuoteLine(">foo")
+ BlockQuoteLine(text='foo')
+ """
+
+ text: str
+
+ def __init__(self, line: str):
+ assert BlockQuoteLine.is_block_quote_line(line)
+ self.text = line[2:] if line.startswith("> ") else line[1:]
+
+ @staticmethod
+ def is_block_quote_line(line: str):
+ return line.startswith(">")
+
+
+class PreFence:
+ @staticmethod
+ def is_pre_fence(line: str):
+ return line == "```"
+
+
+@dataclasses.dataclass
+class Line:
+ text: str
+
+
+@dataclasses.dataclass
+class List:
+ items: list[ListItem]
+
+
+@dataclasses.dataclass
+class BlockQuote:
+ lines: list[BlockQuoteLine]
+
+
+@dataclasses.dataclass
+class Pre:
+ content: str
+
+
+def convert(gemtext, title=None):
+ content = parse(gemtext)
+ if not title:
+ title = content[0]
+ assert isinstance(title, Header), title
+ assert title.level == 1
+ title = title.text
+
+ return pretty.pretty_html(
+ h.render(
+ h.HTML(
+ h.HEAD(
+ h.TITLE(title),
+ h.STYLE(
+ textwrap.dedent("""
+ :root {
+ color-scheme: light dark;
+ }
+ body {
+ max-width: 40em;
+ margin-left: auto;
+ margin-right: auto;
+ padding-left: 2em;
+ padding-right: 2em;
+ }
+ p, blockquote, li {
+ /* from Mozilla reader mode */
+ line-height: 1.6em;
+ font-size: 20px;
+ }
+ """).lstrip()
+ ),
+ ),
+ h.BODY(
+ *gemini_to_html(content),
+ ),
+ doctype="html",
+ ),
+ {},
+ )
+ )
+
+
+def gemini_to_html(parsed): # noqa: C901, PLR0912, PLR0915
+ i = 0
+ result = []
+ while i < len(parsed):
+ gem_element = parsed[i]
+
+ if isinstance(gem_element, gemtext.Header):
+ header = [h.H1, h.H2, h.H3, h.H4, h.H5, h.H6][gem_element.level - 1]
+ result.append(header(gem_element.text))
+ i = i + 1
+ continue
+
+ if isinstance(gem_element, gemtext.List):
+ result.append(h.UL(*[h.LI(i.text) for i in gem_element.items]))
+ i = i + 1
+ continue
+
+ if isinstance(gem_element, gemtext.Link):
+ url = gem_element.url
+ if url.startswith("gemini://"):
+ url = url.replace("gemini://", "https://portal.mozz.us/gemini/")
+
+ result.append(h.P(h.A(gem_element.text or gem_element.url, href=url)))
+ i = i + 1
+ continue
+
+ if gem_element == gemtext.Line(""):
+ i = i + 1
+ continue
+
+ if isinstance(gem_element, gemtext.BlockQuote):
+ content = []
+ for line in gem_element.lines:
+ if line.text:
+ content.append(line.text)
+ content.append(h.BR())
+ result.append(h.BLOCKQUOTE(*content))
+ i = i + 1
+ continue
+
+ if isinstance(gem_element, gemtext.Line):
+ paragraph = [gem_element.text]
+ i = i + 1
+ while i < len(parsed):
+ gem_element = parsed[i]
+ if isinstance(gem_element, gemtext.Line) and gem_element.text != "":
+ paragraph.append(h.BR())
+ paragraph.append(gem_element.text)
+ i = i + 1
+ else:
+ break
+ result.append(h.P(*paragraph))
+ continue
+
+ if isinstance(gem_element, gemtext.Pre):
+ result.append(h.PRE(gem_element.content))
+ i = i + 1
+ continue
+
+ assert False, f"unknown element {gem_element}"
+
+ return result
generated by cgit v1.2.3 (git 2.46.0) at 2026-02-01 22:13:13 +0000