1 files changed, 156 insertions, 0 deletions
diff --git a/pkgs/games/minecraft-servers/update.py b/pkgs/games/minecraft-servers/update.py
new file mode 100755
index 0000000000000..0e7f10a8c9323
--- /dev/null
+++ b/pkgs/games/minecraft-servers/update.py
@@ -0,0 +1,156 @@
+#!/usr/bin/env nix-shell
+#!nix-shell -i python3 -p python3Packages.requests python3Packages.dataclasses-json
+
+import json
+from dataclasses import dataclass, field
+from datetime import datetime
+from pathlib import Path
+from typing import Any, Dict, List, Optional
+
+import requests
+from dataclasses_json import DataClassJsonMixin, LetterCase, config
+from marshmallow import fields
+
+
+@dataclass
+class Download(DataClassJsonMixin):
+    sha1: str
+    size: int
+    url: str
+
+
+@dataclass
+class Version(DataClassJsonMixin):
+    id: str
+    type: str
+    url: str
+    time: datetime = field(
+        metadata=config(
+            encoder=datetime.isoformat,
+            decoder=datetime.fromisoformat,
+            mm_field=fields.DateTime(format="iso"),
+        )
+    )
+    release_time: datetime = field(
+        metadata=config(
+            encoder=datetime.isoformat,
+            decoder=datetime.fromisoformat,
+            mm_field=fields.DateTime(format="iso"),
+            letter_case=LetterCase.CAMEL,
+        )
+    )
+
+    def get_manifest(self) -> Any:
+        """Return the version's manifest."""
+        response = requests.get(self.url)
+        response.raise_for_status()
+        return response.json()
+
+    def get_downloads(self) -> Dict[str, Download]:
+        """
+        Return all downloadable files from the version's manifest, in Download
+        objects.
+        """
+        return {
+            download_name: Download.from_dict(download_info)
+            for download_name, download_info in self.get_manifest()["downloads"].items()
+        }
+
+    def get_java_version(self) -> Any:
+        """
+        Return the java version specified in a version's manifest, if it is
+        present. Versions <= 1.6 do not specify this.
+        """
+        return self.get_manifest().get("javaVersion", {}).get("majorVersion", None)
+
+    def get_server(self) -> Optional[Download]:
+        """
+        If the version has a server download available, return the Download
+        object for the server download. If the version does not have a server
+        download avilable, return None.
+        """
+        downloads = self.get_downloads()
+        if "server" in downloads:
+            return downloads["server"]
+        return None
+
+
+def get_versions() -> List[Version]:
+    """Return a list of Version objects for all available versions."""
+    response = requests.get(
+        "https://launchermeta.mojang.com/mc/game/version_manifest.json"
+    )
+    response.raise_for_status()
+    data = response.json()
+    return [Version.from_dict(version) for version in data["versions"]]
+
+
+def get_major_release(version_id: str) -> str:
+    """
+    Return the major release for a version. The major release for 1.17 and
+    1.17.1 is 1.17.
+    """
+    if not len(version_id.split(".")) >= 2:
+        raise ValueError(f"version not in expected format: '{version_id}'")
+    return ".".join(version_id.split(".")[:2])
+
+
+def group_major_releases(releases: List[Version]) -> Dict[str, List[Version]]:
+    """
+    Return a dictionary containing each version grouped by each major release.
+    The key "1.17" contains a list with two Version objects, one for "1.17"
+    and another for "1.17.1".
+    """
+    groups: Dict[str, List[Version]] = {}
+    for release in releases:
+        major_release = get_major_release(release.id)
+        if major_release not in groups:
+            groups[major_release] = []
+        groups[major_release].append(release)
+    return groups
+
+
+def get_latest_major_releases(releases: List[Version]) -> Dict[str, Version]:
+    """
+    Return a dictionary containing the latest version for each major release.
+    The latest major release for 1.16 is 1.16.5, so the key "1.16" contains a
+    Version object for 1.16.5.
+    """
+    return {
+        major_release: sorted(releases, key=lambda x: x.id, reverse=True)[0]
+        for major_release, releases in group_major_releases(releases).items()
+    }
+
+
+def generate() -> Dict[str, Dict[str, str]]:
+    """
+    Return a dictionary containing the latest url, sha1 and version for each major
+    release.
+    """
+    versions = get_versions()
+    releases = list(
+        filter(lambda version: version.type == "release", versions)
+    )  # remove snapshots and betas
+    latest_major_releases = get_latest_major_releases(releases)
+
+    servers = {
+        version: Download.schema().dump(download_info)  # Download -> dict
+        for version, download_info in {
+            version: value.get_server()
+            for version, value in latest_major_releases.items()
+        }.items()
+        if download_info is not None  # versions < 1.2 do not have a server
+    }
+    for server in servers.values():
+        del server["size"]  # don't need it
+
+    for version, server in servers.items():
+        server["version"] = latest_major_releases[version].id
+        server["javaVersion"] = latest_major_releases[version].get_java_version()
+    return servers
+
+
+if __name__ == "__main__":
+    with open(Path(__file__).parent / "versions.json", "w") as file:
+        json.dump(generate(), file, indent=2)
+        file.write("\n")