from __future__ import annotations
import json
import os
import unicodedata
from io import BytesIO
from pathlib import Path
from typing import Optional
from urllib.error import HTTPError, URLError
from urllib.request import Request, urlopen

from dotenv import load_dotenv
from fastapi import FastAPI, File, Header, HTTPException, UploadFile, Form
from fastapi.middleware.cors import CORSMiddleware
from PIL import Image
from supabase import Client, create_client
from ultralytics import YOLO

# Pega a pasta atual onde o main.py está
BASE_DIR = Path(__file__).resolve().parent
MODEL_PATH = BASE_DIR / "best.pt"

# Tenta carregar localmente, mas no Hugging Face vai usar as Secrets
load_dotenv()

SUPABASE_URL = os.getenv("SUPABASE_URL") or os.getenv("VITE_SUPABASE_URL")
SUPABASE_KEY = (
    os.getenv("SUPABASE_ANON_KEY")
    or os.getenv("SUPABASE_PUBLISHABLE_KEY")
    or os.getenv("VITE_SUPABASE_PUBLISHABLE_KEY")
    or os.getenv("VITE_SUPABASE_ANON_KEY")
)

if not MODEL_PATH.exists():
    raise RuntimeError(f"Modelo YOLO nao encontrado em: {MODEL_PATH}")
if not SUPABASE_URL or not SUPABASE_KEY:
    raise RuntimeError("Configure SUPABASE_URL/SUPABASE_ANON_KEY ou as variaveis VITE_SUPABASE_*.")

model = YOLO(str(MODEL_PATH))
supabase: Client = create_client(SUPABASE_URL, SUPABASE_KEY)

app = FastAPI(title="Visiagro API", description="Deteccao de pragas com YOLOv8")

app.add_middleware(
    CORSMiddleware,
    allow_origins=["*"],
    allow_credentials=True,
    allow_methods=["*"],
    allow_headers=["*"],
)

def _normalize(value: Optional[str]) -> str:
    if not value:
        return ""
    without_accents = "".join(
        char for char in unicodedata.normalize("NFD", value) if unicodedata.category(char) != "Mn"
    )
    return without_accents.lower().replace("_", " ").replace("-", " ").strip()

def _get_user_id(user_response) -> str:
    user = getattr(user_response, "user", None)
    if user is None and hasattr(user_response, "dict"):
        user = user_response.dict().get("user")
    if isinstance(user, dict):
        user_id = user.get("id")
    else:
        user_id = getattr(user, "id", None)
    if not user_id:
        raise HTTPException(status_code=401, detail="Token invalido ou usuario nao encontrado.")
    return user_id

def _parse_bearer_token(authorization: Optional[str]) -> str:
    if not authorization or not authorization.lower().startswith("bearer "):
        raise HTTPException(status_code=401, detail="Envie o token do Supabase no header Authorization.")
    return authorization.split(" ", 1)[1].strip()

def _find_peste(label: Optional[str]):
    if not label:
        return None

    response = (
        supabase.table("pestes")
        .select(
            "id,nome_cientifico,nome_comum,descricao_simples,nivel_risco,"
            "periodo_mais_comum,acoes_recomendadas,danos_causados"
        )
        .execute()
    )
    label_normalized = _normalize(label)

    for peste in response.data or []:
        candidates = [
            peste.get("nome_comum"),
            peste.get("nome_cientifico"),
        ]
        if any(_normalize(candidate) == label_normalized for candidate in candidates):
            return peste

    for peste in response.data or []:
        candidates = [
            peste.get("nome_comum"),
            peste.get("nome_cientifico"),
        ]
        if any(label_normalized in _normalize(candidate) for candidate in candidates):
            return peste

    return None

def _insert_prediction(token: str, payload: dict):
    url = f"{SUPABASE_URL.rstrip('/')}/rest/v1/predictions"
    request = Request(
        url,
        data=json.dumps(payload).encode("utf-8"),
        headers={
            "apikey": SUPABASE_KEY,
            "Authorization": f"Bearer {token}",
            "Content-Type": "application/json",
            "Prefer": "return=representation",
        },
        method="POST",
    )

    try:
        with urlopen(request, timeout=20) as response:
            body = response.read().decode("utf-8")
            return json.loads(body) if body else []
    except HTTPError as error:
        detail = error.read().decode("utf-8")
        raise HTTPException(status_code=error.code, detail=f"Erro ao salvar prediction: {detail}") from error
    except URLError as error:
        raise HTTPException(status_code=502, detail=f"Falha ao conectar no Supabase: {error.reason}") from error

@app.get("/health")
def health_check():
    return {"status": "ok", "model": str(MODEL_PATH)}

@app.post("/analyze", summary="Analisa uma imagem e persiste o resultado")
async def analyze_image(
    file: UploadFile = File(...),
    authorization: Optional[str] = Header(default=None),
):
    token = _parse_bearer_token(authorization)
    try:
        user_response = supabase.auth.get_user(token)
        user_id = _get_user_id(user_response)
    except HTTPException:
        raise
    except Exception as error:
        raise HTTPException(status_code=401, detail=f"Falha ao validar usuario: {error}") from error

    contents = await file.read()
    try:
        image = Image.open(BytesIO(contents)).convert("RGB")
    except Exception as error:
        raise HTTPException(status_code=400, detail="Arquivo enviado nao e uma imagem valida.") from error

    results = model.predict(image, verbose=False)

    detections = []
    for result in results:
        for box in result.boxes:
            class_id = int(box.cls[0])
            label_name = model.names[class_id]
            confidence = float(box.conf[0]) if box.conf is not None else None
            detections.append(
                {
                    "class_id": class_id,
                    "label": label_name,
                    "confidence": confidence,
                }
            )

    top_detection = max(detections, key=lambda item: item["confidence"] or 0, default=None)
    unique_labels = list(dict.fromkeys(item["label"] for item in detections))
    label_final = ", ".join(unique_labels) if unique_labels else "Nenhuma deteccao"
    confidence = top_detection["confidence"] if top_detection else None
    peste = _find_peste(top_detection["label"] if top_detection else None)

    payload = {
        "filename": file.filename,
        "label": label_final,
        "user_id": user_id,
        "peste_id": peste["id"] if peste else None,
        "confianca": confidence,
    }

    inserted = _insert_prediction(token, payload)

    return {
        "status": "success",
        "filename": file.filename,
        "label": label_final,
        "confianca": confidence,
        "peste": peste,
        "detections": detections,
        "prediction": inserted[0] if inserted else None,
    }