import os
import sys
import tempfile
from dotenv import load_dotenv

# Safe stdout/stderr wrapper to prevent OSError: [Errno 22] when stdout pipe is closed/unbuffered in background
class SafeStream:
    def __init__(self, original_stream):
        self.original_stream = original_stream

    def write(self, data):
        try:
            if self.original_stream:
                self.original_stream.write(data)
        except OSError as e:
            if e.errno != 22:
                raise

    def flush(self):
        try:
            if self.original_stream:
                self.original_stream.flush()
        except OSError:
            pass

    def __getattr__(self, attr):
        return getattr(self.original_stream, attr)

sys.stdout = SafeStream(sys.stdout)
sys.stderr = SafeStream(sys.stderr)

# Load .env variables (including HF_HOME and GROQ_API_KEY) before imports
load_dotenv()

from flask import Flask, request, jsonify
from flask_cors import CORS

# Import modular components
from config import Config
from models.groq_client import GroqClient
from models.clip_classifier import CLIPClassifier
from models.tesseract_ocr import TesseractOCR
from models.huggingface_models import HuggingFaceModels
from services.groq_vision_classifier import GroqVisionScriptClassifier
from services.script_detector import ScriptDetectionService
from utils.image_utils import validate_image
from utils.text_utils import clean_text
from processors.cuneiform_processor import CuneiformProcessor
from utils.gpu_diagnostics import log_gpu_info

# Initialize Flask app
app = Flask(__name__)

# CORS — restrict origins in production via ALLOWED_ORIGINS env var
# Example: ALLOWED_ORIGINS=https://your-frontend.vercel.app,https://custom-domain.com
allowed_origins = os.getenv(
    "ALLOWED_ORIGINS",
    "http://localhost:3000,http://localhost:5173,http://localhost:5000"
)
CORS(app, origins=allowed_origins.split(","))

# Global components
config = Config()
groq_client = None
clip_classifier = None
hf_models = None
script_detector = None
cuneiform_processor = None
references = {}


def load_references():
    """Load references from JSON file"""
    global references
    try:
        import json
        with open(config.REFERENCES_PATH, "r", encoding="utf-8") as f:
            data = json.load(f)
        
        references = {
            "egypt_symbol_notes": data.get("egypt_symbol_notes", {}),
            "greek_symbol_notes": data.get("greek_symbol_notes", {}),
            "greek_hint": data.get("greek_hint", "If no specific character note is found, treat as lexical marker considering diacriticals (breathing marks, accents, vowel quantity) which affect pronunciation, meaning, and grammatical function in ancient Greek texts."),
            "latin_symbol_notes": data.get("latin_symbol_notes", {}),
            "latin_hint": data.get("latin_hint", "If no specific character note is found, consider standard Latin letters or medieval scribal abbreviations."),
            # Cuneiform references
            "cuneiform_symbol_notes": data.get("cuneiform_symbol_notes", {}),
            "cuneiform_hint": data.get("cuneiform_hint", "Cuneiform signs represent syllables, words, or concepts in ancient Mesopotamian languages (Sumerian, Akkadian, etc.)")
        }

        print(f"[INFO] Loaded references from {config.REFERENCES_PATH}")
    except Exception as e:
        print(f"[WARN] Failed to load references: {e}")
        references = {
            "egypt_symbol_notes": {},
            "greek_symbol_notes": {},
            "greek_hint": "Possible Greek lexical marker.",
            "latin_symbol_notes": {},
            "latin_hint": "Latin scribal practice.",
            "cuneiform_symbol_notes": {},
            "cuneiform_hint": "Ancient cuneiform sign."
        }


def initialize_components():
    """Initialize lightweight component wrappers synchronously.
    
    No heavy model weights are loaded here — all ML models use lazy loading
    and will download/load on their first inference call. This ensures the
    app starts instantly on resource-constrained environments like HF Spaces.
    """
    global groq_client, clip_classifier, hf_models, script_detector, cuneiform_processor
    import time as _time
    _t0 = _time.time()
    
    print("[INIT] Initializing components (lazy loading — no model weights loaded yet)...", flush=True)
    
    # Log GPU Diagnostics
    log_gpu_info()
    
    # Load references (small JSON file, instant)
    load_references()
    
    # Groq client (API key check only, no model download)
    groq_client = GroqClient()
    groq_status = "ready" if groq_client.is_available() else "unavailable"
    print(f"[INIT] Groq client: {groq_status}", flush=True)
    
    # CLIP classifier (lazy — model loads on first classify call)
    clip_classifier = CLIPClassifier()
    
    # HF Translator (lazy — model loads on first translate call)
    hf_models = HuggingFaceModels()
    
    # Cuneiform processor (lazy — CLIP & translator load on first use)
    try:
        cuneiform_processor = CuneiformProcessor(
            groq_client=groq_client,
            references=references,
            clip_classifier=clip_classifier
        )
    except Exception as e:
        print(f"[ERROR] Failed to create cuneiform processor: {e}", flush=True)
        cuneiform_processor = None
    
    # Script detection service (creates processor instances, all lazy)
    script_detector = ScriptDetectionService(
        groq_client=groq_client,
        references=references,
        clip_classifier=clip_classifier,
        translator_pipe=hf_models.get_translator(),
        cuneiform_processor=cuneiform_processor
    )
    
    print(f"[INIT] All components ready in {_time.time()-_t0:.1f}s (models will load on first request)", flush=True)


@app.route('/analyze', methods=['POST'])
def analyze():
    """Main analysis endpoint with Groq Vision classification"""
    tmp_path = None
    
    try:

        # Validate request
        if 'image' not in request.files:
            return jsonify({"error": "No image uploaded"}), 400
        
        img_file = request.files['image']
        if img_file.filename == '':
            return jsonify({"error": "Empty filename"}), 400
        
        # Validate image file
        try:
            validate_image(img_file)
        except ValueError as e:
            return jsonify({"error": str(e)}), 400
        
        # Save temporary file
        with tempfile.NamedTemporaryFile(delete=False, suffix=".png") as tmp:
            tmp_path = tmp.name
            img_file.save(tmp_path)
        
        # Process image with Groq Vision classification
        result = script_detector.detect_and_process(tmp_path)
        
        if not result:
            return jsonify({"error": "Could not process image"}), 500
        
        # Get Vision classification info
        vision_classification = result.get('vision_classification', 'unknown')
        classification_method = result.get('classification_method', 'unknown')
        classification_confidence = result.get('classification_confidence', 0.0)
        script_type = result.get('script_type', 'egyptian')
        
        # Base response with Vision classification info
        base_response = {
            "script_type": script_type,
            "vision_classification": vision_classification,
            "classification_method": classification_method,
            "classification_confidence": classification_confidence,
            "confidence": result.get('confidence', 0.0),
            "historical_context": result.get('historical_context', {}),
            "creative_story": result.get('creative_story', ''),
            "model_used": "llama-3.2-90b-vision-preview"
        }
        
        # Handle cuneiform processing
        if script_type == 'cuneiform':
            if not cuneiform_processor or not cuneiform_processor.cuneiform_available:
                return jsonify({
                    **base_response,
                    "error": "Cuneiform processing unavailable",
                    "labels": [],
                    "gardiner_codes": [],
                    "translation": "Cuneiform translation model not available",
                    "translation_ok": False
                }), 200
            
            try:
                # Process cuneiform text
                processed_result = result.get('processed_result', {})
                cuneiform_text = processed_result.get('text', '')
                
                # Translate cuneiform to English
                translation = ""
                translation_ok = False
                
                if cuneiform_text and len(cuneiform_text.strip()) > 2:
                    print(f"[INFO] Translating cuneiform: {cuneiform_text[:50]}...")
                    translation = cuneiform_processor.translate_cuneiform(cuneiform_text)
                    translation_ok = bool(translation and not translation.startswith("Error"))
                else:
                    translation = "No readable cuneiform text extracted"
                
                # Build cuneiform response
                response_data = {
                    **base_response,
                    "labels": [],
                    "gardiner_codes": [],
                    "translation": translation,
                    "translation_ok": translation_ok,
                    "cuneiform_text": cuneiform_text,
                    "validation": {
                        "quality_score": processed_result.get('validation', {}).get('quality_score', 0.0),
                        "cuneiform_ratio": processed_result.get('validation', {}).get('cuneiform_ratio', 0.0),
                        "atf_ratio": processed_result.get('validation', {}).get('atf_ratio', 0.0),
                        "char_analysis": processed_result.get('char_analysis', {}),
                        "ocr_method": "praeclarum/cuneiform (T5-based translation)",
                        "supports_translation": True,
                        "input_format": processed_result.get('char_analysis', {}).get('text_format', 'Unknown')
                    }
                }
                
                return jsonify(response_data)
                
            except Exception as e:
                print(f"[ERROR] Cuneiform processing failed: {e}")
                return jsonify({
                    **base_response,
                    "error": f"Cuneiform processing error: {str(e)}",
                    "labels": [],
                    "gardiner_codes": [],
                    "translation": "Cuneiform processing failed",
                    "translation_ok": False
                }), 200
        
        elif script_type in ['greek', 'latin']:
            processed_result = result.get('processed_result', {})
            validation = processed_result.get('validation', {})
            
            response_data = {
                **base_response,
                "labels": [],
                "gardiner_codes": [],
                "translation": processed_result.get('text', ''),
                "translation_ok": True,
            }
            
            # Add enhanced validation info for Greek
            if script_type == 'greek':
                response_data["validation"] = {
                    "quality_score": validation.get('quality_score', 0.0),
                    "greek_ratio": validation.get('greek_ratio', 0.0),
                    "has_polytonic": validation.get('has_polytonic', False),
                    "char_analysis": processed_result.get('char_analysis', {}),
                    "ocr_method": "ancient_greek_ocr" if validation.get('quality_score', 0) > 0.7 else "standard_greek_ocr"
                }
            
            elif script_type == 'latin':
                response_data["validation"] = {
                    "quality_score": validation.get('quality_score', 0.0),
                    "latin_ratio": validation.get('latin_ratio', 0.0),
                    "trocr_used": validation.get('tridis_used', False) or any(m in validation.get('ocr_method', '') for m in ['tridis', 'trocr-base-printed']),
                    "char_analysis": processed_result.get('char_analysis', {}),
                    "ocr_method": validation.get('ocr_method', 'standard_latin_ocr'),
                    "writing_style": validation.get('writing_style', 'cursive')
                }

            
            return jsonify(response_data)
        
        else:  # Egyptian
            processed = result['processed_result']
            return jsonify({
                **base_response,
                "labels": processed['labels'],
                "gardiner_codes": processed['codes'],
                "translation": processed['translation'],
                "translation_ok": processed['translation_ok']
            })
    
    except Exception as e:
        print(f"[ERROR] Analysis failed: {e}")
        import traceback
        traceback.print_exc()
        return jsonify({"error": "Processing failed"}), 500
    
    finally:
        # Cleanup temporary file
        if tmp_path:
            try:
                os.remove(tmp_path)
            except Exception:
                pass


@app.route('/chat', methods=['POST'])
def chat():
    """Chatbot endpoint for manuscript queries and general dialogue"""
    try:
        data = request.get_json() or {}
        message = data.get("message", "")
        history = data.get("history", [])
        context = data.get("context", "")
        
        if not message:
            return jsonify({"error": "Message is required"}), 400
            
        system_prompt = (
            "You are DecipherAI's helpful historical assistant. You are an expert paleographer and historian.\n"
            "Answer the user's questions about ancient scripts, translations, and history in a helpful, "
            "academic yet accessible manner. Cite historical sources when appropriate."
        )
        if context:
            system_prompt += f"\n\nHere is the context of the current manuscript translation:\n{context}"
            
        if not groq_client or not groq_client.is_available():
            reply = (
                f"Thank you for your question: '{message}'. I'm currently running in offline fallback mode "
                f"because the Groq API key is not set. Once configured, I will be able to answer all your "
                f"scholarly questions about the translated scripts, historical context, and paleography in real time!"
            )
        else:
            prompt = ""
            for turn in history[-5:]:
                role = turn.get("role", "user")
                content = turn.get("content", "")
                prompt += f"{role.upper()}: {content}\n"
            prompt += f"USER: {message}\nASSISTANT:"
            
            reply = groq_client.generate_response(
                system_prompt=system_prompt,
                user_prompt=prompt,
                max_tokens=500
            ) or "I'm sorry, I encountered an error generating a response."
            
        return jsonify({"reply": reply})
    except Exception as e:
        print(f"[ERROR] Chat failed: {e}")
        return jsonify({"error": "Failed to process chat message"}), 500


@app.route('/health', methods=['GET'])
def health_check():
    """Health check endpoint — app is always ready, models load lazily on demand"""
    models_loaded = {
        "groq": groq_client.is_available() if groq_client else False,
        "clip": clip_classifier.is_loaded if clip_classifier else False,
        "translator": hf_models is not None if hf_models else False,
        "cuneiform": cuneiform_processor is not None if cuneiform_processor else False,
        "script_detector": script_detector is not None
    }
    return jsonify({
        "status": "healthy",
        "architecture": "lazy_loading",
        "models_loaded": models_loaded
    })


@app.route('/info', methods=['GET'])
def info():
    """Information endpoint"""
    return jsonify({
        "app": "Ancient Script Recognition System",
        "version": "2.1.0",
        "supported_scripts": [
            "Egyptian Hieroglyphs", 
            "Ancient Greek", 
            "Latin", 
            "Ancient Cuneiform"
        ],
        "features": [
            "Multi-script detection",
            "OCR text extraction", 
            "Historical context generation",
            "Creative story generation",
            "Cuneiform translation (Sumerian/Akkadian → English)"
        ]
    })


# --- Component initialization ---
# Lightweight init runs synchronously at module level. No heavy model weights
# are loaded here — all ML models use lazy loading on first inference call.
def _auto_initialize():
    """Initialize components when running under a WSGI server (gunicorn, waitress, etc.)"""
    if os.getenv("WERKZEUG_RUN_MAIN") == "true":
        # Flask reloader child process — handled by __main__ block
        return
    print("[INIT] WSGI server detected — initializing components...", flush=True)
    initialize_components()


if __name__ == "__main__":
    print("[INIT] Starting Ancient Script Recognition System (lazy loading)...", flush=True)
    
    # Start Flask app
    port = int(os.getenv("PORT", 7860))
    debug = os.getenv("DEBUG", "False").lower() == "true"
    
    # Initialize lightweight components (only in child process if debug mode is on)
    if not debug or os.environ.get("WERKZEUG_RUN_MAIN") == "true":
        initialize_components()
    else:
        print("[INFO] Reloader active. Component initialization deferred to child process.")
        
    print(f"[INFO] Starting server on port {port}", flush=True)
    app.run(host="0.0.0.0", port=port, debug=debug)
else:
    # Running under gunicorn / WSGI
    _auto_initialize()