from __future__ import annotations

import os
from pathlib import Path
from typing import Any

import joblib
from fastapi import FastAPI, Header, HTTPException
from pydantic import BaseModel, Field

from aots_pipeline import DEFAULT_CONFIDENCE_THRESHOLD, predict_records

MODEL_PATH = Path(os.getenv("MODEL_PATH", "artifacts/aots_technology_model.joblib"))
SPACE_API_KEY = os.getenv("SPACE_API_KEY")


class AlertRequest(BaseModel):
    aots_number: str | None = Field(default=None, description="Ticket or AOTS number.")
    asset_id: str = Field(default="", description="Asset ID from the alert email.")
    problem_abstract: str = Field(
        default="",
        description="Problem abstract from the alert email.",
    )
    confidence_threshold: float | None = Field(
        default=None,
        ge=0.0,
        le=1.0,
        description="Optional override for manual review routing.",
    )
    top_k: int = Field(
        default=3,
        ge=1,
        le=5,
        description="How many ranked predictions to return.",
    )


class BatchRequest(BaseModel):
    alerts: list[AlertRequest]
    confidence_threshold: float | None = Field(default=None, ge=0.0, le=1.0)
    top_k: int = Field(default=3, ge=1, le=5)


app = FastAPI(
    title="AOTS Technology Predictor",
    version="1.0.0",
    description="Predicts the storage/network technology for an AOTS alert.",
)

_model_bundle: dict[str, Any] | None = None


def get_model_bundle() -> dict[str, Any]:
    global _model_bundle

    if _model_bundle is None:
        if not MODEL_PATH.exists():
            raise HTTPException(
                status_code=503,
                detail=(
                    f"Model bundle not found at '{MODEL_PATH}'. "
                    "Train the model with train_aots_model.py before calling /predict."
                ),
            )
        _model_bundle = joblib.load(MODEL_PATH)
    return _model_bundle


def validate_api_key(x_api_key: str | None) -> None:
    if not SPACE_API_KEY:
        return
    if x_api_key != SPACE_API_KEY:
        raise HTTPException(status_code=401, detail="Invalid or missing API key.")


@app.get("/health")
def health(x_api_key: str | None = Header(default=None)) -> dict[str, Any]:
    validate_api_key(x_api_key)
    model_ready = MODEL_PATH.exists()
    threshold = DEFAULT_CONFIDENCE_THRESHOLD
    if model_ready:
        bundle = get_model_bundle()
        threshold = bundle.get("confidence_threshold", DEFAULT_CONFIDENCE_THRESHOLD)

    return {
        "status": "ok" if model_ready else "degraded",
        "model_path": str(MODEL_PATH),
        "model_ready": model_ready,
        "confidence_threshold": threshold,
    }


@app.post("/predict")
def predict(
    request: AlertRequest,
    x_api_key: str | None = Header(default=None),
) -> dict[str, Any]:
    validate_api_key(x_api_key)
    bundle = get_model_bundle()
    result = predict_records(
        bundle=bundle,
        records=[request.model_dump(exclude_none=True)],
        confidence_threshold=request.confidence_threshold,
        top_k=request.top_k,
    )[0]
    return result


@app.post("/predict-batch")
def predict_batch(
    request: BatchRequest,
    x_api_key: str | None = Header(default=None),
) -> dict[str, Any]:
    validate_api_key(x_api_key)
    bundle = get_model_bundle()
    results = predict_records(
        bundle=bundle,
        records=[alert.model_dump(exclude_none=True) for alert in request.alerts],
        confidence_threshold=request.confidence_threshold,
        top_k=request.top_k,
    )
    return {"count": len(results), "results": results}


if __name__ == "__main__":
    import uvicorn

    uvicorn.run(
        "app:app",
        host="0.0.0.0",
        port=int(os.getenv("PORT", "7860")),
        reload=False,
    )