shinkan-jinkendo/backend/openrouter_chat.py

"""
Minimal OpenRouter REST client (sync). Reads OPENROUTER_API_KEY / OPENROUTER_MODEL / OPENROUTER_BASE_URL from env.
"""
from __future__ import annotations

import json
import logging
import os
from typing import Any, Dict, List, Optional

import httpx

_logger = logging.getLogger("shinkan.openrouter")

_SKIP_ANTHROPIC_BLOCK_TYPES = frozenset(
    {
        "thinking",
        "redacted_thinking",
        "reasoning",
        "tool_use",
        "tool_calls",
    }
)


def _shinkan_ai_debug() -> bool:
    return os.getenv("SHINKAN_AI_DEBUG", "").strip().lower() in ("1", "true", "yes", "full")


def _coerce_nested_text(val: Any) -> str:
    if val is None:
        return ""
    if isinstance(val, str):
        return val.strip()
    if isinstance(val, bool) or isinstance(val, (int, float)):
        return str(val).strip()
    if isinstance(val, list):
        return "".join(_coerce_nested_text(x) for x in val).strip()
    if isinstance(val, dict):
        # OpenRouter/Anthropic: verschachtelte text/content-Hüllen
        for key in ("text", "content", "value"):
            if key in val:
                nested = _coerce_nested_text(val.get(key))
                if nested:
                    return nested
        return ""
    return str(val).strip()


def _flatten_message_content(content: Any) -> str:
    """
    Chat-Completion: `content` als String oder als Liste strukturierter Blöcke
    (Anthropic Claude über OpenRouter/Bedrock, teils verschachtelt).
    """
    if content is None:
        return ""
    if isinstance(content, str):
        return content.strip()
    if isinstance(content, list):
        parts: List[str] = []
        for block in content:
            if isinstance(block, str):
                bits = _coerce_nested_text(block)
                if bits:
                    parts.append(bits)
            elif isinstance(block, dict):
                t_raw = block.get("type")
                ts = str(t_raw or "").strip().lower()
                if ts and (ts in _SKIP_ANTHROPIC_BLOCK_TYPES or ts.endswith("_thinking")):
                    continue
                txt = None
                if ts in ("text", "output_text", ""):
                    txt = block.get("text")
                    if txt is None:
                        txt = block.get("content")
                else:
                    # unbekannten Typ weiter versuchen (Provider-Varianten), aber tool-use überspringen
                    low = ts
                    if "tool_use" in low or low.startswith("tool_"):
                        continue
                    txt = block.get("text") if block.get("text") is not None else block.get("content")
                bits = _coerce_nested_text(txt)
                if bits:
                    parts.append(bits)
        return "".join(parts).strip()
    if isinstance(content, dict):
        return _coerce_nested_text(content)
    return str(content).strip()


class OpenRouterError(Exception):
    """Upstream or transport failure."""


def openrouter_chat_completion(
    *,
    api_key: str,
    model: str,
    user_content: str,
    system_content: Optional[str] = None,
    timeout_sec: float = 120.0,
    temperature: float = 0.25,
    site_url: Optional[str] = None,
    app_title: Optional[str] = None,
) -> str:
    """
    Returns assistant message content (plain string). Caller validates empty responses.
    """
    base = (os.getenv("OPENROUTER_BASE_URL") or "").strip().rstrip("/") or "https://openrouter.ai/api/v1"
    url = f"{base}/chat/completions"

    headers: Dict[str, str] = {
        "Authorization": f"Bearer {api_key}",
        "Content-Type": "application/json",
    }
    referer = (site_url or os.getenv("APP_URL") or "").strip()
    if referer:
        headers["HTTP-Referer"] = referer
    title = (app_title or os.getenv("OPENROUTER_APP_TITLE") or "Shinkan Jinkendo").strip()
    if title:
        headers["X-Title"] = title

    messages: List[Dict[str, str]] = []
    if system_content and str(system_content).strip():
        messages.append({"role": "system", "content": str(system_content).strip()})
    messages.append({"role": "user", "content": user_content})

    payload: Dict[str, Any] = {
        "model": model,
        "messages": messages,
        "temperature": temperature,
    }

    try:
        with httpx.Client(timeout=timeout_sec) as client:
            resp = client.post(url, headers=headers, json=payload)
    except httpx.RequestError as e:
        raise OpenRouterError(str(e)) from e

    if resp.status_code >= 400:
        detail = ""
        try:
            j = resp.json()
            detail = (
                str(j.get("error", {}).get("message"))
                if isinstance(j.get("error"), dict)
                else str(j.get("message") or j)
            )
        except Exception:
            detail = (resp.text or "")[:600]
        raise OpenRouterError(f"HTTP {resp.status_code}: {detail}".strip())

    try:
        data = resp.json()
    except json.JSONDecodeError as e:
        raise OpenRouterError("Ungueltige JSON-Antwort von OpenRouter") from e

    choices = data.get("choices") if isinstance(data, dict) else None
    if not choices or not isinstance(choices, list):
        raise OpenRouterError("OpenRouter: keine choices in Antwort")

    msg0 = choices[0] if choices else {}
    inner = msg0.get("message") if isinstance(msg0, dict) else None

    blobs: List[Any] = []
    if isinstance(inner, dict):
        if inner.get("content") is not None:
            blobs.append(inner.get("content"))
        if inner.get("refusal") is not None:
            blobs.append(inner.get("refusal"))
    elif isinstance(inner, str):
        blobs.append(inner)
    if isinstance(msg0, dict) and msg0.get("content") is not None and msg0.get("content") not in blobs:
        blobs.append(msg0.get("content"))

    pieces = [_flatten_message_content(b).strip() for b in blobs if b is not None]
    joined = ("\n".join(p for p in pieces if p)).strip()

    if _shinkan_ai_debug():
        fr = str(msg0.get("finish_reason") or "") if isinstance(msg0, dict) else ""
        fu = data.get("usage") if isinstance(data.get("usage"), dict) else {}
        pu = str(fu.get("prompt_tokens") or "")
        pc = str(fu.get("completion_tokens") or "")
        pt = str(fu.get("total_tokens") or "")
        raw_cls = type(blobs[0]).__name__ if blobs else "none"
        cc = str(len(joined))
        _logger.warning(
            "[AI_DEBUG/openrouter] model=%s finish_reason=%s usage_prompt=%s usage_completion=%s usage_total=%s "
            "raw_content_cls=%s out_chars=%s",
            model,
            fr,
            pu,
            pc,
            pt,
            raw_cls,
            cc,
        )

    return joined


def normalize_openrouter_env() -> tuple[str, str]:
    key = (os.getenv("OPENROUTER_API_KEY") or "").strip()
    model = (os.getenv("OPENROUTER_MODEL") or "anthropic/claude-sonnet-4").strip()
    return key, model