[scripts] Add generate-readme script

.github/workflows/update_readme.yml

@@ -0,0 +1,26 @@
+name: update_readme
+
+on:
+  push:
+    branches: ["main"]
+
+permissions:
+  contents: write
+
+jobs:
+  update_readme:
+    name: update readme
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - name: Generate readme
+        run: python3 scripts/generate-readme.py > README.md
+      - name: Commit and push
+        run: |
+          set -ex
+          git config user.name 'github-actions[bot]'
+          git config user.email 'github-actions[bot]@users.noreply.github.com'
+          git add .
+          if git commit -m 'Update README.md'; then
+            git push
+          fi

scripts/generate-readme.py

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+from datetime import date
+from pathlib import Path
+
+names = {"rs": "Rust", "hs": "Haskell", "py": "Python", "apl": "APL"}
+exts = {"rs": ["rs"], "hs": ["hs"], "py": ["py", "ipynb"], "apl": ["ipynb"]}
+logos = {
+    "rs": "https://rustacean.net/assets/rustacean-flat-noshadow.svg",
+    "hs": "https://upload.wikimedia.org/wikipedia/commons/1/1c/Haskell-Logo.svg",
+    "py": "https://upload.wikimedia.org/wikipedia/commons/c/c3/Python-logo-notext.svg",
+    "apl": "https://aplwiki.com/images/thumb/c/c6/APL_logo.png/600px-APL_logo.png",
+}
+
+
+def link(year, day, lang):
+    for ext in exts[lang]:
+        if not Path(f"{names[lang]}/{year}/{day:02}.{ext}").exists():
+            continue
+
+        return f' [<img height=12 src="{logos[lang]}">]({names[lang]}/{year}/{day:02}.{ext} "{names[lang]} solution for {year}/{day:02}")'
+
+    return ""
+
+
+print("# AdventOfCode")
+print(
+    f"[Advent of Code](https://adventofcode.com/) solutions in {', '.join([*names.values()][:-1])} and {[*names.values()][-1]}"
+)
+
+for year in range(2022, 2014, -1):
+    print()
+    print(f"## [{year}](https://adventofcode.com/{year})")
+    print("|Mo|Tu|We|Th|Fr|Sa|Su|")
+    print("|-|-|-|-|-|-|-|")
+
+    line = [""] * date(year, 12, 1).weekday()
+    for day in range(1, 26):
+        if len(line) == 7:
+            print("|" + "|".join(line) + "|")
+            line.clear()
+        line.append(f"[**{day}**](https://adventofcode.com/{year}/day/{day})")
+        for lang in names:
+            line[-1] += link(year, day, lang)
+
+    for day in range(26, 32):
+        if len(line) == 7:
+            print("|" + "|".join(line) + "|")
+            line.clear()
+        line.append(f"{day}")
+
+    if line:
+        print("|" + "|".join(line + [""] * (7 - len(line))) + "|")