import logging
import os
import time
from pathlib import Path
from typing import Optional

from openai import OpenAI

logger = logging.getLogger(__name__)

# Resolve secrets file: priority 1) env OPENCLAW_SECRETS,
# 2) workspace-document-analyzer/config/ (relative to skills dir),
# 3) .openclaw/config/
_SECRETS_FILE = None
for _candidate in (
    os.environ.get("OPENCLAW_SECRETS", ""),
    Path(__file__).resolve().parents[3] / "config" / "secrets.yaml",
    Path(__file__).resolve().parents[5] / ".openclaw" / "config" / "secrets.yaml",
):
    if _candidate and Path(_candidate).exists():
        _SECRETS_FILE = Path(_candidate)
        break
if _SECRETS_FILE is None:
    _SECRETS_FILE = Path("")  # empty fallback


def _load_secrets() -> dict:
    """Load API keys from secrets.yaml, with env-var overrides."""
    secrets = {}
    if _SECRETS_FILE.exists():
        try:
            import yaml
            with open(_SECRETS_FILE, "r", encoding="utf-8") as f:
                data = yaml.safe_load(f) or {}
            for provider in ("deepseek", "dashscope"):
                if provider in data and isinstance(data[provider], dict):
                    secrets[provider] = data[provider]
        except ImportError:
            logger.warning("pyyaml not installed, cannot read %s", _SECRETS_FILE)
        except Exception as e:
            logger.warning("Failed to load %s: %s", _SECRETS_FILE, e)

    # Env overrides
    dk_env = os.environ.get("DEEPSEEK_API_KEY", "")
    ds_env = os.environ.get("DASHSCOPE_API_KEY", "")
    if dk_env:
        secrets.setdefault("deepseek", {})["apiKey"] = dk_env
    if ds_env:
        secrets.setdefault("dashscope", {})["apiKey"] = ds_env
    return secrets


class LLMClient:
    """Multi-provider LLM client with retry and token tracking.

    Routes text models to DeepSeek, vision models to DashScope (Bailian).
    Reads API keys from openclaw config/secrets.yaml, with env-var overrides.

    Usage::

        llm = LLMClient()
        content = llm.chat("deepseek-v4-pro", [{"role": "user", "content": "Hello"}])
        print(llm.usage)
    """

    IMAGE_MODEL = "qwen3.6-flash"
    TEXT_MODEL = "deepseek-v4-flash"

    DASHSCOPE_BASE = "https://dashscope.aliyuncs.com/compatible-mode/v1"
    DEEPSEEK_BASE = "https://api.deepseek.com/v1"

    TIMEOUT = 120
    MAX_RETRIES = 3

    _VISION_KEYWORDS = ("vl", "vision", "qwen-vl", "qwen3-vl", "qwen3.6")

    def __init__(
        self,
        *,
        timeout: int | None = None,
    ):
        secrets = _load_secrets()

        ds_cfg = secrets.get("dashscope", {})
        dk_cfg = secrets.get("deepseek", {})

        dashscope_key = ds_cfg.get("apiKey", "")
        dashscope_url = ds_cfg.get("baseUrl", self.DASHSCOPE_BASE)
        deepseek_key = dk_cfg.get("apiKey", "")
        deepseek_url = dk_cfg.get("baseUrl", self.DEEPSEEK_BASE)

        self._ds_client = OpenAI(api_key=dashscope_key, base_url=dashscope_url) if dashscope_key else None
        self._dk_client = OpenAI(api_key=deepseek_key, base_url=deepseek_url) if deepseek_key else None

        self._timeout = timeout or self.TIMEOUT
        self._prompt_tokens = 0
        self._completion_tokens = 0

    @property
    def usage(self) -> dict:
        """Return accumulated token counts as ``{prompt, completion, total}``."""
        return {
            "prompt_tokens": self._prompt_tokens,
            "completion_tokens": self._completion_tokens,
            "total_tokens": self._prompt_tokens + self._completion_tokens,
        }

    @staticmethod
    def estimate_tokens(text: str) -> int:
        """Quick token estimate.  CJK ≈1.7/token, others ≈3.0/token."""
        cjk = sum(1 for c in text if '\u4e00' <= c <= '\u9fff' or '\u3000' <= c <= '\u303f')
        other = len(text) - cjk
        return max(1, int(cjk / 1.7 + other / 3.0))

    @staticmethod
    def estimate_image_tokens() -> int:
        """Fixed estimate for one vision-model image (~500 tokens)."""
        return 500

    @staticmethod
    def _is_vision_model(model: str) -> bool:
        return any(kw in model.lower() for kw in LLMClient._VISION_KEYWORDS)

    def _get_client(self, model: str) -> OpenAI:
        if self._is_vision_model(model):
            if self._ds_client is None:
                raise ValueError("DASHSCOPE_API_KEY not set but required for vision model")
            return self._ds_client
        else:
            if self._dk_client is None:
                raise ValueError("DEEPSEEK_API_KEY not set but required for text model")
            return self._dk_client

    def chat(
        self, model: str, messages: list[dict], *, timeout: int | None = None,
        response_format: dict | None = None,
    ) -> str:
        """Send a chat completion request and return the response content.

        Automatically retries on failure and accumulates token usage.
        Routes to DeepSeek for text, DashScope for vision.
        """
        label = f"chat({model})"
        client = self._get_client(model)

        def _call():
            t0 = time.time()
            kwargs = dict(model=model, messages=messages, timeout=timeout or self._timeout)
            if response_format is not None:
                kwargs["response_format"] = response_format
            kwargs["temperature"] = 0
            resp = client.chat.completions.create(**kwargs)
            content = resp.choices[0].message.content
            usg = resp.usage
            if usg:
                self._prompt_tokens += usg.prompt_tokens
                self._completion_tokens += usg.completion_tokens
            elapsed = time.time() - t0
            logger.info("%s: %d chars in %.1fs", label, len(content) if content else 0, elapsed)
            if not content:
                raise RuntimeError("Empty response from LLM")
            return content

        return self._retry(_call, label)

    def _retry(self, fn, label: str) -> str:
        """Call *fn()* with exponential-backoff retry."""
        last_error: Optional[Exception] = None
        for attempt in range(self.MAX_RETRIES):
            try:
                return fn()
            except Exception as e:
                last_error = e
                logger.warning(
                    "%s error (attempt %d/%d): %s",
                    label, attempt + 1, self.MAX_RETRIES, e,
                )
                if attempt < self.MAX_RETRIES - 1:
                    time.sleep(2 ** attempt)
        raise RuntimeError(f"{label}: all retries exhausted") from last_error