watch_sceen_ai/wsai/backends/claude.py

"""Cloud brain + vision via the Anthropic (Claude) API.

Both share one auth resolver. Vision sends the frame as a base64 image; the
brain is a plain chat call that receives the latest screen description as
context.

Auth (two ways, tried in this order):
  1. ANTHROPIC_API_KEY  -> standard API-key auth.
  2. A Claude Code OAuth token (this deployment's Max login) read from the
     credentials file at $CLAUDE_CREDENTIALS_PATH. OAuth tokens require the
     first system block to be exactly the Claude Code identity string and are
     sent as a Bearer token (auth_token=), not x-api-key. The token is
     re-read before each request so a refresh rotated into the file by the
     host is picked up without a restart.

Requires: pip install anthropic
"""

from __future__ import annotations

import base64
import json
import os
import time

from ..interfaces import Frame, Reply, ScreenObservation

# Claude Code OAuth tokens only answer when the first system block is exactly
# this identity string; the real persona/instructions go in later blocks.
_CLAUDE_CODE_ID = "You are Claude Code, Anthropic's official CLI for Claude."


def _load_oauth_token() -> str | None:
    path = os.environ.get("CLAUDE_CREDENTIALS_PATH")
    if not path or not os.path.exists(path):
        return None
    try:
        with open(path) as f:
            return json.load(f)["claudeAiOauth"]["accessToken"]
    except (OSError, KeyError, ValueError):
        return None


class _Auth:
    """Resolves a Claude client, preferring an explicit/env API key and falling
    back to the deployment's OAuth token. The OAuth client is rebuilt whenever
    the token in the credentials file changes (host-side refresh)."""

    def __init__(self, api_key: str | None = None) -> None:
        import anthropic  # lazy so mock mode needs no dependency

        self._anthropic = anthropic
        self._explicit_key = api_key
        self._client = None
        self._token: str | None = None
        self._oauth = False

    def client(self):
        key = self._explicit_key or os.environ.get("ANTHROPIC_API_KEY")
        if key:
            if self._client is None:
                self._client = self._anthropic.AsyncAnthropic(api_key=key)
            self._oauth = False
            return self._client
        tok = _load_oauth_token()
        if not tok:
            raise RuntimeError(
                "No Claude auth: set ANTHROPIC_API_KEY or provide a Claude "
                "OAuth login via CLAUDE_CREDENTIALS_PATH."
            )
        if tok != self._token:
            self._token = tok
            self._client = self._anthropic.AsyncAnthropic(auth_token=tok)
        self._oauth = True
        return self._client

    def system(self, *blocks: str) -> list[dict]:
        """Build the system prompt, prepending the Claude Code identity block
        when authing via OAuth (required) — harmless to include either way."""
        texts = [_CLAUDE_CODE_ID, *blocks] if self._oauth else list(blocks)
        return [{"type": "text", "text": t} for t in texts if t]


class ClaudeVision:
    def __init__(self, *, model: str = "claude-sonnet-4-5", api_key: str | None = None) -> None:
        self.model = model
        self._auth = _Auth(api_key)

    async def describe(self, frame: Frame, hint: str | None = None) -> ScreenObservation:
        prompt = hint or (
            "이건 디스코드 화면공유 캡처야. 지금 화면에서 무슨 일이 벌어지는지 "
            "2~3문장으로 한국어로 간결하게 설명해줘. 코드/에러/게임/문서 등 맥락을 짚어줘."
        )
        b64 = base64.b64encode(frame.data).decode()
        client = self._auth.client()
        resp = await client.messages.create(
            model=self.model,
            max_tokens=300,
            system=self._auth.system(),
            messages=[
                {
                    "role": "user",
                    "content": [
                        {
                            "type": "image",
                            "source": {"type": "base64", "media_type": frame.mime, "data": b64},
                        },
                        {"type": "text", "text": prompt},
                    ],
                }
            ],
        )
        text = "".join(b.text for b in resp.content if b.type == "text")
        return ScreenObservation(text=text.strip(), ts=frame.ts)


class ClaudeBrain:
    PERSONA = (
        "너는 사용자의 디스코드 화면공유를 실시간으로 함께 보는 AI 파트너야. "
        "화면 설명을 참고해 자연스러운 반말/존댓말은 사용자에 맞추고, 짧고 대화하듯 답해. "
        "화면을 못 봤으면 솔직히 말해."
    )

    def __init__(self, *, model: str = "claude-sonnet-4-5", api_key: str | None = None) -> None:
        self.model = model
        self._auth = _Auth(api_key)

    async def respond(self, user_text, screen, history) -> Reply:
        msgs = []
        for user, ai in history:
            msgs.append({"role": "user", "content": user})
            msgs.append({"role": "assistant", "content": ai})
        screen_note = f"[지금 화면] {screen.text}\n\n" if screen else "[지금 화면] (아직 못 읽음)\n\n"
        msgs.append({"role": "user", "content": screen_note + user_text})
        client = self._auth.client()
        resp = await client.messages.create(
            model=self.model,
            max_tokens=400,
            system=self._auth.system(self.PERSONA),
            messages=msgs,
        )
        text = "".join(b.text for b in resp.content if b.type == "text")
        return Reply(text=text.strip(), ts=time.monotonic())