"""
Mad Turtle Inference Server
FastAPI service that loads ONNX ensemble models and exposes REST endpoints
for MT5 EA to get BUY/SELL/HOLD signals + confidence scores.
"""

import json
import logging
from datetime import datetime, timezone
from pathlib import Path
from typing import Optional

import numpy as np
import onnxruntime as ort
from fastapi import FastAPI, HTTPException
from pydantic import BaseModel, Field

logging.basicConfig(level=logging.INFO)
logger = logging.getLogger("mad_turtle_server")

ROOT = Path(__file__).resolve().parents[2]
MODELS_DIR = ROOT / "models"
META_PATH = MODELS_DIR / "metadata.json"

app = FastAPI(title="Mad Turtle Inference Server", version="2.0.0")

class HealthResponse(BaseModel):
    status: str
    models_loaded: int
    uptime_seconds: float

class SignalRequest(BaseModel):
    features: list[float] = Field(..., min_length=14, max_length=14)
    model: Optional[str] = "ensemble"

class SignalResponse(BaseModel):
    signal: str
    confidence: float
    buy_prob: float
    sell_prob: float
    hold_prob: float
    model_version: str

class OHLCVRequest(BaseModel):
    open: float
    high: float
    low: float
    close: float
    volume: float

class Engine:
    def __init__(self):
        self.sessions: dict[str, ort.InferenceSession] = {}
        self.metadata: dict = {}
        self.feature_names: list[str] = []
        self.started_at: Optional[str] = None

    def load(self):
        self.started_at = datetime.now(timezone.utc).isoformat()
        if not META_PATH.exists():
            raise FileNotFoundError(f"metadata.json not found at {META_PATH}. Run build_onnx_raw.py first.")
        with open(META_PATH) as f:
            self.metadata = json.load(f)
        self.feature_names = self.metadata["features"]

        for name, info in self.metadata.get("models", {}).items():
            path = ROOT / info["path"]
            if not path.exists():
                logger.warning("Model file missing: %s", path)
                continue
            sess = ort.InferenceSession(str(path), providers=["CPUExecutionProvider"])
            self.sessions[name] = sess
            logger.info("Loaded model '%s' from %s", name, path)

    def predict(self, features: list[float], model_name: str = "ensemble") -> dict:
        if model_name not in self.sessions:
            raise ValueError(f"Model '{model_name}' not loaded. Available: {list(self.sessions.keys())}")
        if len(features) != len(self.feature_names):
            raise ValueError(f"Expected {len(self.feature_names)} features, got {len(features)}")

        x = np.array([features], dtype=np.float32)
        sess = self.sessions[model_name]
        input_name = sess.get_inputs()[0].name
        outputs = sess.run(None, {input_name: x})[0]
        probs = outputs[0]
        classes = ["SELL", "HOLD", "BUY"]
        idx = int(np.argmax(probs))
        return {
            "signal": classes[idx],
            "confidence": float(probs[idx]),
            "buy_prob": float(probs[2]),
            "sell_prob": float(probs[0]),
            "hold_prob": float(probs[1]),
            "model_version": self.metadata.get("built_at", "unknown"),
        }

    def engineer_features(self, ohlcv: dict) -> list[float]:
        import pandas as pd
        df = pd.DataFrame([ohlcv])
        df["returns_1"] = np.log(df["close"] / df["open"])
        df["returns_3"] = np.log(df["close"] / df["close"])
        df["returns_6"] = np.log(df["close"] / df["close"])
        df["sma_10"] = df["close"]
        df["sma_20"] = df["close"]
        df["sma_50"] = df["close"]
        df["ema_12"] = df["close"]
        df["ema_26"] = df["close"]
        df["macd"] = 0.0
        df["macd_signal"] = 0.0
        delta = df["close"].diff().fillna(0)
        gain = delta.clip(lower=0).rolling(14).mean().fillna(0)
        loss = (-delta.clip(upper=0)).rolling(14).mean().fillna(0)
        rs = gain / (loss + 1e-9)
        df["rsi_14"] = (100.0 - (100.0 / (1.0 + rs))).fillna(50.0)
        df["atr_14"] = (df["high"] - df["low"]).fillna(0.0)
        df["atr_pct"] = (df["atr_14"] / (df["close"] + 1e-9)).fillna(0.0)
        df["vol_ratio"] = 1.0
        df["high_low_range"] = ((df["high"] - df["low"]) / (df["close"] + 1e-9)).fillna(0.0)
        df["dist_sma20"] = 0.0
        row = df.iloc[-1]
        return [float(row[c]) for c in self.feature_names]

engine = Engine()

@app.on_event("startup")
async def startup():
    engine.load()

@app.get("/health", response_model=HealthResponse)
async def health():
    now = datetime.now(timezone.utc)
    start = datetime.fromisoformat(engine.started_at) if engine.started_at else now
    return HealthResponse(
        status="ok" if engine.sessions else "degraded",
        models_loaded=len(engine.sessions),
        uptime_seconds=(now - start).total_seconds(),
    )

@app.post("/v1/signal", response_model=SignalResponse)
async def get_signal(req: SignalRequest):
    try:
        res = engine.predict(req.features, req.model or "ensemble")
        return SignalResponse(**res)
    except Exception as e:
        raise HTTPException(status_code=400, detail=str(e))

@app.post("/v1/signal/ohlcv", response_model=SignalResponse)
async def get_signal_ohlcv(req: OHLCVRequest):
    try:
        feats = engine.engineer_features(req.dict())
        res = engine.predict(feats)
        return SignalResponse(**res)
    except Exception as e:
        raise HTTPException(status_code=400, detail=str(e))

if __name__ == "__main__":
    import uvicorn
    uvicorn.run(app, host="0.0.0.0", port=8000, log_level="info")