"""Fetches a player's skin texture from Mojang, the same one the store viewer shows for that username.

    .venv/bin/python skin.py <username> [out.png]
"""
import base64
import json
import subprocess
import sys


def get(url):
    # curl uses the system's certificate store, which python.org's Python doesn't.
    return subprocess.run(["curl", "-sSf", url], capture_output=True, check=True).stdout


def fetch(username):
    """Returns (png bytes, slim arms)."""
    uuid = json.loads(get(f"https://api.mojang.com/users/profiles/minecraft/{username}"))["id"]
    profile = json.loads(get(f"https://sessionserver.mojang.com/session/minecraft/profile/{uuid}"))
    prop = next(p for p in profile["properties"] if p["name"] == "textures")
    skin = json.loads(base64.b64decode(prop["value"]))["textures"]["SKIN"]
    return get(skin["url"]), skin.get("metadata", {}).get("model") == "slim"


if __name__ == "__main__":
    png, slim = fetch(sys.argv[1])
    out = sys.argv[2] if len(sys.argv) > 2 else f"skins/{sys.argv[1]}.png"
    open(out, "wb").write(png)
    print(out, "slim" if slim else "wide")