from fastapi import APIRouter, File, UploadFile
import numpy as np
import cv2
import faiss
import pickle
import os
import torch
import insightface
from insightface.utils import face_align
import sys

# ✅ Dockerfile에서 클론한 AdaFace 경로 추가
sys.path.append('/app/AdaFace')
import net

router = APIRouter()

# --- 설정 및 경로 ---
faiss_index_name = "face_faiss_index_v2.index"
faiss_label_name = "face_faiss_labels_v2.pkl"
load_path = os.path.abspath("embedding/person")  # 실제 FAISS 파일 위치로 변경 필요
threshold = 45.0  # Unknown 판별 임계값

# ✅ Hugging Face 무료 CPU 강제 설정
device = torch.device('cpu')

# --- 1. InsightFace (탐지기) 로드 ---
detector = insightface.app.FaceAnalysis(name='buffalo_l', providers=['CPUExecutionProvider'], allowed_modules=['detection'])
detector.prepare(ctx_id=0, det_size=(640, 640))

# --- 2. AdaFace (인식기) 로드 ---
model_path = "/app/adaface_ir101_webface12m.ckpt"
adaface_model = net.build_model('ir_101')
statedict = torch.load(model_path, map_location=device)["state_dict"]
model_statedict = {key[6:]: val for key, val in statedict.items() if key.startswith("model.")}
adaface_model.load_state_dict(model_statedict)
adaface_model.to(device)
adaface_model.eval()

# --- 3. FAISS 로드 ---
index = faiss.read_index(os.path.join(load_path, faiss_index_name))
with open(os.path.join(load_path, faiss_label_name), "rb") as f:
    labels = pickle.load(f)

# ✅ AdaFace 임베딩 추출 함수
def extract_adaface_embedding(img_bgr, face_kps):
    aligned_face = face_align.norm_crop(img_bgr, landmark=face_kps, image_size=112)
    img_norm = (aligned_face / 255.0 - 0.5) / 0.5
    img_tensor = torch.tensor(img_norm.transpose(2, 0, 1)).float().unsqueeze(0).to(device)
    with torch.no_grad():
        embedding, _ = adaface_model(img_tensor)
    return embedding.cpu().numpy()[0]

@router.post("/predict")
async def predict(file: UploadFile = File(...)):
    contents = await file.read()
    nparr = np.frombuffer(contents, np.uint8)
    img = cv2.imdecode(nparr, cv2.IMREAD_COLOR)

    if img is None:
        return {"success": False, "message": "❌ 이미지를 읽을 수 없습니다."}

    faces = detector.get(img)
    if not faces:
        return {"success": False, "message": "❌ 얼굴을 찾을 수 없습니다."}

    results = []
    for face in faces:
        # AdaFace 임베딩 추출 및 정규화
        emb = extract_adaface_embedding(img, face.kps)
        emb = np.array([emb], dtype='float32')
        emb /= np.linalg.norm(emb, axis=1, keepdims=True)

        # FAISS 검색
        distances, indices = index.search(emb, k=1)
        best_match_idx = indices[0][0]
        similarity_score = distances[0][0]
        
        # 일치율 계산 및 Threshold 적용
        score_percent = max(0, similarity_score) * 100
        if score_percent >= threshold:
            predicted_name = labels[best_match_idx]
        else:
            predicted_name = "Unknown"

        box = face.bbox.astype(int).tolist()

        results.append({
            "label": predicted_name,
            "score": float(score_percent),
            "bbox": box # 프론트엔드에서 박스를 그릴 수 있도록 좌표 반환
        })

    return {"success": True, "results": results, "message": f"✅ 총 {len(faces)}명의 얼굴을 처리했습니다."}