import os
# Ensure all CPU-only models never touch CUDA
os.environ['CUDA_VISIBLE_DEVICES'] = ''

import io
import base64
import logging
import cv2
import numpy as np
from PIL import Image
from datetime import datetime
from transformers import pipeline
from ultralytics import YOLO
from tensorflow.keras.models import load_model
from langchain_community.document_loaders import PyPDFLoader
from langchain.text_splitter import RecursiveCharacterTextSplitter
from langchain_community.embeddings import HuggingFaceEmbeddings
from langchain_community.vectorstores import FAISS
from huggingface_hub import HfApi, HfFolder
import spaces
from .config import Config

# System prompt for MedGemma
default_system_prompt = (
    "You are a world-class medical AI assistant specializing in wound care "
    "with expertise in wound assessment and treatment. Provide concise, "
    "evidence-based medical assessments focusing on: (1) Precise wound "
    "classification based on tissue type and appearance, (2) Specific "
    "treatment recommendations with exact product names or interventions when "
    "appropriate, (3) Objective evaluation of healing progression or deterioration "
    "indicators, and (4) Clear follow-up timelines. Avoid general statements and "
    "prioritize actionable insights based on the visual analysis measurements and "
    "patient context."
)

@spaces.GPU(enable_queue=True, duration=120)
def generate_medgemma_report(
    patient_info: str,
    visual_results: dict,
    guideline_context: str,
    detection_image_path: str,
    segmentation_image_path: str,
    max_new_tokens: int = None
) -> str:
    """
    Runs on GPU. Lazy-loads the MedGemma pipeline and returns the markdown report.
    Accepts only primitive types and file-paths, so pickling works.
    """
    # Lazy-load pipeline
    if not hasattr(generate_medgemma_report, "_pipe"):
        try:
            cfg = Config()
            generate_medgemma_report._pipe = pipeline(
                'image-text-to-text',
                model='google/medgemma-4b-it',
                device='auto',
                torch_dtype='auto',
                offload_folder='offload',
                token=cfg.HF_TOKEN
            )
            logging.info("✅ MedGemma pipeline loaded on GPU")
        except Exception as e:
            logging.warning(f"MedGemma pipeline load failed: {e}")
            return None

    pipe = generate_medgemma_report._pipe

    # Assemble messages
    msgs = [
        {'role':'system','content':[{'type':'text','text':default_system_prompt}]},
        {'role':'user','content':[]}
    ]
    # Attach images
    for path in (detection_image_path, segmentation_image_path):
        if path and os.path.exists(path):
            msgs[1]['content'].append({'type':'image','image': Image.open(path)})
    # Attach text
    prompt = f"## Patient\n{patient_info}\n## Wound Type: {visual_results.get('wound_type','Unknown')}"
    msgs[1]['content'].append({'type':'text','text': prompt})

    out = pipe(
        text=msgs,
        max_new_tokens=max_new_tokens or Config().MAX_NEW_TOKENS,
        do_sample=False
    )
    return out[0]['generated_text'][-1].get('content','')


class AIProcessor:
    def __init__(self):
        self.models_cache = {}
        self.knowledge_base_cache = {}
        self.config = Config()
        self.px_per_cm = self.config.PIXELS_PER_CM
        self._initialize_models()
        self._load_knowledge_base()

    def _initialize_models(self):
        """Load all CPU-only models here."""
        # Set HuggingFace token
        if self.config.HF_TOKEN:
            HfFolder.save_token(self.config.HF_TOKEN)
            logging.info("✅ HuggingFace token set")

        # YOLO detection (CPU)
        try:
            self.models_cache['det'] = YOLO(self.config.YOLO_MODEL_PATH)
            logging.info("✅ YOLO model loaded (CPU only)")
        except Exception as e:
            logging.error(f"YOLO load failed: {e}")
            raise

        # Segmentation (CPU)
        try:
            self.models_cache['seg'] = load_model(self.config.SEG_MODEL_PATH, compile=False)
            logging.info("✅ Segmentation model loaded (CPU)")
        except Exception as e:
            logging.warning(f"Segmentation model not available: {e}")

        # Classification (CPU)
        try:
            self.models_cache['cls'] = pipeline(
                'image-classification',
                model='Hemg/Wound-classification',
                token=self.config.HF_TOKEN,
                device='cpu'
            )
            logging.info("✅ Classification pipeline loaded (CPU)")
        except Exception as e:
            logging.warning(f"Classification pipeline not available: {e}")

        # Embedding model (CPU)
        try:
            self.models_cache['embedding_model'] = HuggingFaceEmbeddings(
                model_name='sentence-transformers/all-MiniLM-L6-v2',
                model_kwargs={'device':'cpu'}
            )
            logging.info("✅ Embedding model loaded (CPU)")
        except Exception as e:
            logging.warning(f"Embedding model not available: {e}")

    def _load_knowledge_base(self):
        """Load PDF guidelines into a FAISS vector store."""
        docs = []
        for pdf in self.config.GUIDELINE_PDFS:
            if os.path.exists(pdf):
                loader = PyPDFLoader(pdf)
                docs.extend(loader.load())
                logging.info(f"Loaded PDF: {pdf}")

        if docs and 'embedding_model' in self.models_cache:
            splitter = RecursiveCharacterTextSplitter(chunk_size=1000, chunk_overlap=100)
            chunks = splitter.split_documents(docs)
            vs = FAISS.from_documents(chunks, self.models_cache['embedding_model'])
            self.knowledge_base_cache['vectorstore'] = vs
            logging.info(f"✅ Knowledge base loaded ({len(chunks)} chunks)")
        else:
            self.knowledge_base_cache['vectorstore'] = None
            logging.warning("Knowledge base unavailable")

    def perform_visual_analysis(self, image_pil: Image.Image) -> dict:
        """Detect & segment on CPU; return metrics + file paths."""
        if 'det' not in self.models_cache:
            raise RuntimeError("YOLO model ('det') not loaded")

        img_cv = cv2.cvtColor(np.array(image_pil), cv2.COLOR_RGB2BGR)
        res = self.models_cache['det'].predict(img_cv, verbose=False)[0]
        if not res.boxes:
            raise ValueError("No wound detected")

        x1, y1, x2, y2 = res.boxes.xyxy[0].cpu().numpy().astype(int)
        region = img_cv[y1:y2, x1:x2]

        # Save detection overlay
        det_vis = img_cv.copy()
        cv2.rectangle(det_vis, (x1, y1), (x2, y2), (0,255,0), 2)
        os.makedirs(f"{self.config.UPLOADS_DIR}/analysis", exist_ok=True)
        ts = datetime.now().strftime('%Y%m%d_%H%M%S')
        det_path = f"{self.config.UPLOADS_DIR}/analysis/detection_{ts}.png"
        cv2.imwrite(det_path, det_vis)

        # Segmentation metrics
        length = breadth = area = 0
        seg_path = None
        if 'seg' in self.models_cache:
            h, w = self.models_cache['seg'].input_shape[1:3]
            inp = cv2.resize(region, (w,h)) / 255.0
            mask = (self.models_cache['seg'].predict(inp[None])[0,:,:,0] > 0.5).astype(np.uint8)
            mask_rs = cv2.resize(mask, (region.shape[1], region.shape[0]), interpolation=cv2.INTER_NEAREST)
            ov = region.copy(); ov[mask_rs==1] = [0,0,255]
            seg_vis = cv2.addWeighted(region,0.7,ov,0.3,0)
            seg_path = f"{self.config.UPLOADS_DIR}/analysis/segmentation_{ts}.png"
            cv2.imwrite(seg_path, seg_vis)
            cnts, _ = cv2.findContours(mask_rs, cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_SIMPLE)
            if cnts:
                cnt = max(cnts, key=cv2.contourArea)
                _,_,w0,h0 = cv2.boundingRect(cnt)
                length = round(h0/self.px_per_cm,2)
                breadth= round(w0/self.px_per_cm,2)
                area   = round(cv2.contourArea(cnt)/(self.px_per_cm**2),2)

        # Classification
        wound_type = 'Unknown'
        if 'cls' in self.models_cache:
            try:
                preds = self.models_cache['cls'](
                    Image.fromarray(cv2.cvtColor(region, cv2.COLOR_BGR2RGB))
                )
                wound_type = max(preds, key=lambda x: x['score'])['label']
            except Exception:
                pass

        return {
            'wound_type': wound_type,
            'length_cm': length,
            'breadth_cm': breadth,
            'surface_area_cm2': area,
            'detection_confidence': float(res.boxes.conf[0].cpu().item()),
            'detection_image_path': det_path,
            'segmentation_image_path': seg_path
        }

    def query_guidelines(self, query: str) -> str:
        vs = self.knowledge_base_cache.get('vectorstore')
        if not vs:
            return "Clinical guidelines unavailable"
        docs = vs.as_retriever(search_kwargs={'k':10}).invoke(query)
        return '\n\n'.join(
            f"Source: {d.metadata.get('source','?')}, Page: {d.metadata.get('page','?')}\n{d.page_content}"
            for d in docs
        )

    def generate_final_report(
        self,
        patient_info: str,
        visual_results: dict,
        guideline_context: str,
        image_pil: Image.Image,
        max_new_tokens: int = None
    ) -> str:
        """
        Signature unchanged. Gathers arguments, calls GPU function, and falls back if needed.
        """
        det = visual_results.get('detection_image_path', '')
        seg = visual_results.get('segmentation_image_path', '')
        report = generate_medgemma_report(
            patient_info,
            visual_results,
            guideline_context,
            det,
            seg,
            max_new_tokens
        )
        if report:
            return report
        return self._generate_fallback_report(patient_info, visual_results, guideline_context)

    def _generate_fallback_report(
        self,
        patient_info: str,
        visual_results: dict,
        guideline_context: str
    ) -> str:
        dp = visual_results.get('detection_image_path','N/A')
        sp = visual_results.get('segmentation_image_path','N/A')
        return (
            f"# Report\n{patient_info}\n"
            f"Type: {visual_results.get('wound_type','Unknown')}\n"
            f"Detection Image: {dp}\n"
            f"Segmentation Image: {sp}\n"
            f"Guidelines: {guideline_context[:200]}..."
        )

    def save_and_commit_image(self, image_pil: Image.Image) -> str:
        os.makedirs(self.config.UPLOADS_DIR, exist_ok=True)
        fn = f"{datetime.now():%Y%m%d_%H%M%S}.png"
        path = os.path.join(self.config.UPLOADS_DIR, fn)
        image_pil.convert('RGB').save(path)
        if self.config.HF_TOKEN and getattr(self.config, 'DATASET_ID', None):
            try:
                HfApi().upload_file(
                    path_or_fileobj=path,
                    path_in_repo=f"images/{fn}",
                    repo_id=self.config.DATASET_ID,
                    repo_type='dataset'
                )
            except Exception as e:
                logging.warning(f"HF upload failed: {e}")
        return path

    def full_analysis_pipeline(
        self,
        image_pil: Image.Image,
        questionnaire_data: dict
    ) -> dict:
        try:
            saved = self.save_and_commit_image(image_pil)
            vis = self.perform_visual_analysis(image_pil)
            info = ", ".join(f"{k}:{v}" for k,v in questionnaire_data.items() if v)
            gc = self.query_guidelines(info)
            report = self.generate_final_report(info, vis, gc, image_pil)
            return {
                'success': True,
                'visual_analysis': vis,
                'report': report,
                'saved_image_path': saved
            }
        except Exception as e:
            logging.error(f"Pipeline error: {e}")
            return {'success': False, 'error': str(e)}

    def analyze_wound(self, image, questionnaire_data: dict) -> dict:
        if isinstance(image, str):
            image = Image.open(image)
        return self.full_analysis_pipeline(image, questionnaire_data)

    def _assess_risk_legacy(self, questionnaire_data):
        """Legacy risk assessment for backward compatibility"""
        risk_factors = []
        risk_score = 0
        
        try:
            # Age factor
            age = questionnaire_data.get('patient_age', 0)
            if age > 65:
                risk_factors.append("Advanced age (>65)")
                risk_score += 2
            elif age > 50:
                risk_factors.append("Older adult (50-65)")
                risk_score += 1
            
            # Duration factor
            duration = questionnaire_data.get('wound_duration', '').lower()
            if any(term in duration for term in ['month', 'months', 'year']):
                risk_factors.append("Chronic wound (>4 weeks)")
                risk_score += 3
            
            # Pain level
            pain_level = questionnaire_data.get('pain_level', 0)
            if pain_level >= 7:
                risk_factors.append("High pain level")
                risk_score += 2
            
            # Medical history risk factors
            medical_history = questionnaire_data.get('medical_history', '').lower()
            if 'diabetes' in medical_history:
                risk_factors.append("Diabetes mellitus")
                risk_score += 3
            if 'circulation' in medical_history or 'vascular' in medical_history:
                risk_factors.append("Vascular/circulation issues")
                risk_score += 2
            if 'immune' in medical_history:
                risk_factors.append("Immune system compromise")
                risk_score += 2
            
            # Determine risk level
            if risk_score >= 7:
                risk_level = "High"
            elif risk_score >= 4:
                risk_level = "Moderate"
            else:
                risk_level = "Low"
            
            return {
                'risk_score': risk_score,
                'risk_level': risk_level,
                'risk_factors': risk_factors
            }
            
        except Exception as e:
            logging.error(f"Risk assessment error: {e}")
            return {'risk_score': 0, 'risk_level': 'Unknown', 'risk_factors': []}