[meta] Put back the unlevelled symlinks and timestamps.json code.

Author: tabatkins

bin/build-index.py

@@ -5,6 +5,200 @@
 
 
 
+"""Builds the CSSWG directory index.
+
+It also sets up redirects from shortnames to the current work spec, by building
+an index.html with a <meta refresh>.
+"""
+
+import json
+import os
+import os.path
+import re
+import sys
+import subprocess
+from collections import defaultdict
+
+import bikeshed
+from html.parser import HTMLParser
+
+def title_from_html(file):
+    class HTMLTitleParser(HTMLParser):
+        def __init__(self):
+            super().__init__()
+            self.in_title = False
+            self.title = ""
+            self.done = False
+
+        def handle_starttag(self, tag, attrs):
+            if tag == "title":
+                self.in_title = True
+
+        def handle_data(self, data):
+            if self.in_title:
+                self.title += data
+
+        def handle_endtag(self, tag):
+            if tag == "title" and self.in_title:
+                self.in_title = False
+                self.done = True
+                self.reset()
+
+    parser = HTMLTitleParser()
+    with open(file, encoding="UTF-8") as f:
+        for line in f:
+            parser.feed(line)
+            if parser.done:
+                break
+    if not parser.done:
+        parser.close()
+
+    return parser.title if parser.done else None
+
+
+def get_date_authored_timestamp_from_git(path):
+    source = os.path.realpath(path)
+    proc = subprocess.run(["git", "log", "-1", "--format=%at", source],
+                          capture_output = True, encoding = "utf_8")
+    return int(proc.stdout.splitlines()[-1])
+
+
+def get_bs_spec_metadata(folder_name, path):
+    spec = bikeshed.Spec(path)
+    spec.assembleDocument()
+
+    level = int(spec.md.level) if spec.md.level else 0
+
+    if spec.md.shortname == "css-animations-2":
+        shortname = "css-animations"
+    elif spec.md.shortname == "css-gcpm-4":
+        shortname = "css-gcpm"
+    elif spec.md.shortname == "css-transitions-2":
+        shortname = "css-transitions"
+    elif spec.md.shortname == "scroll-animations-1":
+        shortname = "scroll-animations"
+    else:
+        # Fix CSS snapshots (e.g. "css-2022")
+        snapshot_match = re.match(
+            "^css-(20[0-9]{2})$", spec.md.shortname)
+        if snapshot_match:
+            shortname = "css-snapshot"
+            level = int(snapshot_match.group(1))
+        else:
+            shortname = spec.md.shortname
+
+    return {
+        "timestamp": get_date_authored_timestamp_from_git(path),
+        "shortname": shortname,
+        "level": level,
+        "title": spec.md.title,
+        "workStatus": spec.md.workStatus
+    }
+
+
+def get_html_spec_metadata(folder_name, path):
+    match = re.match("^([a-z0-9-]+)-([0-9]+)$", folder_name)
+    if match and match.group(1) == "css":
+        shortname = "css-snapshot"
+        title = f"CSS Snapshot {match.group(2)}"
+    else:
+        shortname = match.group(1) if match else folder_name
+        title = title_from_html(path)
+
+    return {
+        "shortname": shortname,
+        "level": int(match.group(2)) if match else 0,
+        "title": title,
+        "workStatus": "completed"  # It's a good heuristic
+    }
+
+
+def create_symlink(shortname, spec_folder):
+    """Creates a <shortname> symlink pointing to the given <spec_folder>.
+    """
+
+    if spec_folder in timestamps:
+        timestamps[shortname] = timestamps[spec_folder]
+
+    try:
+        os.symlink(spec_folder, shortname)
+    except OSError:
+        pass
+
+
+CURRENT_WORK_EXCEPTIONS = {
+    "css-conditional": 5,
+    "css-easing": 2,
+    "css-grid": 2,
+    "css-snapshot": None,  # always choose the last spec
+    "css-values": 4,
+    "css-writing-modes": 4,
+    "web-animations": 2
+}
+
+# ------------------------------------------------------------------------------
+
+
+bikeshed.constants.setErrorLevel("nothing")
+
+specgroups = defaultdict(list)
+timestamps = defaultdict(list)
+
+for entry in os.scandir("."):
+    if entry.is_dir(follow_symlinks=False):
+        # Not actual specs, just examples.
+        if entry.name in ["css-module"]:
+            continue
+
+        bs_file = os.path.join(entry.path, "Overview.bs")
+        html_file = os.path.join(entry.path, "Overview.html")
+        if os.path.exists(bs_file):
+            metadata = get_bs_spec_metadata(entry.name, bs_file)
+            timestamps[entry.name] = metadata["timestamp"]
+        elif os.path.exists(html_file):
+            metadata = get_html_spec_metadata(entry.name, html_file)
+        else:
+            # Not a spec
+            continue
+
+        metadata["dir"] = entry.name
+        metadata["currentWork"] = False
+        specgroups[metadata["shortname"]].append(metadata)
+
+# Reorder the specs with common shortname based on their level (or year, for
+# CSS snapshots), and determine which spec is the current work.
+for shortname, specgroup in specgroups.items():
+    if len(specgroup) == 1:
+        if shortname != specgroup[0]["dir"]:
+            create_symlink(shortname, specgroup[0]["dir"])
+    else:
+        specgroup.sort(key=lambda spec: spec["level"])
+
+        # TODO: This algorithm for determining which spec is the current work
+        # is wrong in a number of cases. Try and come up with a better
+        # algorithm, rather than maintaining a list of exceptions.
+        for spec in specgroup:
+            if shortname in CURRENT_WORK_EXCEPTIONS:
+                if CURRENT_WORK_EXCEPTIONS[shortname] == spec["level"]:
+                    spec["currentWork"] = True
+                    currentWorkDir = spec["dir"]
+                    break
+            elif spec["workStatus"] != "completed":
+                spec["currentWork"] = True
+                currentWorkDir = spec["dir"]
+                break
+        else:
+            specgroup[-1]["currentWork"] = True
+            currentWorkDir = specgroup[-1]["dir"]
+
+        if shortname != currentWorkDir:
+            create_symlink(shortname, currentWorkDir)
+        if shortname == "css-snapshot":
+            create_symlink("css", currentWorkDir)
+
+with open('./timestamps.json', 'w') as f:
+    json.dump(timestamps, f, indent = 2, sort_keys=True)
+
 with open("./index.html", mode='w', encoding="UTF-8") as f:
     f.write("""
 <!doctype html>