[ghc] Add automation (#395)

Based on https://gitlab.haskell.org/ghc/ghc/-/wikis/GHC-status.

---------

Co-authored-by: Marc Wrobel <marc.wrobel@gmail.com>

src/ghc-wiki.py

@@ -0,0 +1,86 @@
+"""
+In addition to automation from git tags,
+use the GHC-status wiki page on GHC gitlab
+as a source for "Not recommended for use" end-of-support signals.
+
+TODO at some point maybe use https://gitlab.haskell.org/ghc/release/release-metadata/
+
+References:
+    https://github.com/endoflife-date/release-data/pull/395
+    https://github.com/endoflife-date/endoflife.date/pull/6287
+    https://gitlab.haskell.org/ghc/ghc/-/wikis/GHC-status
+"""
+
+import re
+from typing import Any, Generator, Iterator
+
+from common import dates, http, releasedata
+
+
+def parse_markdown_tables(lineiter: Iterator[str]) -> Generator[list[list[Any]], Any, None]:
+    """ Generator. Yields found tables until StopIteration """
+    while True:
+        try:
+            #-- fast-forward to table header
+            while True:
+                line = next(lineiter)
+                header = maybe_markdown_table_row(line)
+                if header:
+                    break
+            #-- underline
+            hr = maybe_markdown_table_row(next(lineiter))
+            assert len(hr) == len(header)
+            assert all(set(x) == {'-'} for x in hr)
+            #-- rows
+            rows = []
+            while True:
+                line = next(lineiter)
+                cells = maybe_markdown_table_row(line)
+                if not cells:
+                    break
+                assert len(cells) == len(header)
+                rows.append(cells)
+            yield [header] + rows
+        except StopIteration:
+            return # f**ing PEP 479
+
+def maybe_markdown_table_row(line: str) -> list[str] | None:
+    line = line.strip()
+    if not re.match(r'[|].*[|]', line):
+        return None
+    return [x.strip() for x in line.strip('|').split('|')]
+
+with releasedata.ProductData("ghc") as product:
+    resp = http.fetch_url("https://gitlab.haskell.org/api/v4/projects/1/wikis/GHC-Status")
+    resp.raise_for_status()
+    data = resp.json()
+    assert data['title'] == "GHC Status"
+    assert data['format'] == "markdown"
+    md = data['content'].splitlines()
+
+    #-- Parse tables out of the wiki text. At time of writing, the script expects exactly two:
+    #-- 1. "Most recent major" with 5 columns
+    #-- 2. "All released versions" with 5 columns
+    [series_table, patch_level] = parse_markdown_tables(iter(md))
+
+    for row in series_table[1:]:
+        [series, _download_link, _most_recent, next_planned, status] = row
+        series = series.split(' ') [0]
+        series = series.replace('\\.', '.')
+        if series == "Nightlies":
+            continue
+        status = status.lower()
+
+        #-- See discussion in https://github.com/endoflife-date/endoflife.date/pull/6287
+        r = product.get_release(series)
+        #-- The clearest semblance of an EOL signal we get
+        r.set_eol("not recommended for use" in status or ":red_circle:" in status)
+        #-- eoasColumn label is "Further releases planned"
+        r.set_eoas(any(keyword in next_planned for keyword in ("None",  "N/A")))
+
+    for row in patch_level[1:]:
+        [milestone, _download_link, date, _ticket, _manager] = row
+        version = milestone.lstrip('%')
+        version = version.split(' ') [0]
+        date = dates.parse_date(date)
+        product.declare_version(version, date)