import os
from flask import Blueprint, request, render_template, jsonify, current_app

# Import services
from .services.tokenizer_service import tokenizer_service
from .services.file_service import file_service
from .utils.validators import validators, ValidationError

# Create Blueprint
main_bp = Blueprint('main', __name__)


@main_bp.route('/tokenizer-info', methods=['GET'])
def tokenizer_info():
    """Endpoint to get tokenizer information without processing text."""
    model_id = request.args.get('model_id', '')
    is_custom = request.args.get('is_custom', 'false').lower() == 'true'
    
    if not model_id:
        return jsonify({"error": "No model ID provided"}), 400
    
    try:
        # Validate custom model path if it's a custom model
        if is_custom:
            try:
                validators.validate_model_path(model_id)
            except ValidationError as e:
                return jsonify({"error": str(e)}), 400
            
        # For predefined models, use the model name from the dictionary
        if not is_custom and tokenizer_service.is_predefined_model(model_id):
            model_id_or_name = model_id
        else:
            # For custom models, use the model ID directly
            model_id_or_name = model_id
            
        # Load the tokenizer and get info
        tokenizer, info, error = tokenizer_service.load_tokenizer(model_id_or_name)
        
        if error:
            return jsonify({"error": error}), 400
            
        return jsonify(info)
    except Exception as e:
        return jsonify({"error": f"Failed to get tokenizer info: {str(e)}"}), 500

@main_bp.route('/', methods=['GET', 'POST'])
def index():
    text = ""
    token_data = None
    error_message = ""
    selected_model = request.args.get('model', request.form.get('model', 'qwen3'))
    custom_model = request.args.get('custom_model', request.form.get('custom_model', ''))
    model_type = request.args.get('model_type', request.form.get('model_type', 'predefined'))
    
    # Determine which model to use based on model_type
    model_to_use = selected_model if model_type == 'predefined' else custom_model
    
    if request.method == 'POST':
        # Check if file upload
        if 'file' in request.files and request.files['file'].filename:
            uploaded_file = request.files['file']
            
            try:
                # Validate file
                validators.validate_filename(uploaded_file.filename)
                validators.validate_file_extension(uploaded_file.filename, file_service.ALLOWED_EXTENSIONS)
                
                # Validate custom model if needed
                if model_type == 'custom' and custom_model:
                    validators.validate_model_path(custom_model)
                
                # Save file securely
                file_path = file_service.save_uploaded_file(uploaded_file, current_app.config['UPLOAD_FOLDER'])
                
                # Read a small preview of the file
                preview_char_limit = current_app.config.get('PREVIEW_CHAR_LIMIT', 8096)
                with open(file_path, 'r', errors='replace') as f:
                    text = f.read(preview_char_limit)
                
                try:
                    # Process the file using file service
                    token_data = file_service.process_file_for_tokenization(
                        file_path=file_path,
                        model_id_or_name=model_to_use,
                        preview_char_limit=preview_char_limit,
                        max_display_tokens=current_app.config.get('MAX_DISPLAY_TOKENS', 50000),
                        chunk_size=current_app.config.get('CHUNK_SIZE', 1024 * 1024)
                    )
                    
                    # Clean up the file after processing
                    file_service.cleanup_file(file_path)
                    
                    # If request is AJAX, return JSON
                    if request.headers.get('X-Requested-With') == 'XMLHttpRequest':
                        return jsonify(token_data)
                        
                except Exception as e:
                    error_message = str(e)
                    file_service.cleanup_file(file_path)
                    
                    if request.headers.get('X-Requested-With') == 'XMLHttpRequest':
                        return jsonify({"error": error_message}), 400
                    return render_template(
                        'index.html',
                        text=text,
                        token_data=None,
                        models=tokenizer_service.TOKENIZER_MODELS,
                        selected_model=selected_model,
                        custom_model=custom_model,
                        model_type=model_type,
                        error=error_message
                    )
                    
            except ValidationError as e:
                error_message = str(e)
                if request.headers.get('X-Requested-With') == 'XMLHttpRequest':
                    return jsonify({"error": error_message}), 400
                return render_template(
                    'index.html',
                    text="",
                    token_data=None,
                    models=tokenizer_service.TOKENIZER_MODELS,
                    selected_model=selected_model,
                    custom_model=custom_model,
                    model_type=model_type,
                    error=error_message
                )

        # Regular text processing
        else:
            text = request.form.get('text', '')
            if text:
                try:
                    # Validate text input
                    validators.validate_text_input(text)
                    
                    # Validate custom model if needed
                    if model_type == 'custom' and custom_model:
                        validators.validate_model_path(custom_model)
                    
                    # Process text using file service
                    token_data = file_service.process_text_for_tokenization(
                        text=text,
                        model_id_or_name=model_to_use,
                        preview_char_limit=current_app.config.get('PREVIEW_CHAR_LIMIT', 8096),
                        max_display_tokens=current_app.config.get('MAX_DISPLAY_TOKENS', 50000)
                    )
                    
                    # If request is AJAX, return JSON
                    if request.headers.get('X-Requested-With') == 'XMLHttpRequest':
                        return jsonify(token_data)
                        
                except ValidationError as e:
                    error_message = str(e)
                    if request.headers.get('X-Requested-With') == 'XMLHttpRequest':
                        return jsonify({"error": error_message}), 400
                    return render_template(
                        'index.html',
                        text=text,
                        token_data=None,
                        models=tokenizer_service.TOKENIZER_MODELS,
                        selected_model=selected_model,
                        custom_model=custom_model,
                        model_type=model_type,
                        error=error_message
                    )
                except Exception as e:
                    error_message = str(e)
                    if request.headers.get('X-Requested-With') == 'XMLHttpRequest':
                        return jsonify({"error": error_message}), 400
                    return render_template(
                        'index.html',
                        text=text,
                        token_data=None,
                        models=tokenizer_service.TOKENIZER_MODELS,
                        selected_model=selected_model,
                        custom_model=custom_model,
                        model_type=model_type,
                        error=error_message
                    )
    
    return render_template(
        'index.html',
        text=text,
        token_data=token_data,
        models=tokenizer_service.TOKENIZER_MODELS,
        selected_model=selected_model,
        custom_model=custom_model,
        model_type=model_type,
        error=error_message
    )


@main_bp.route('/health', methods=['GET'])
def health_check():
    """Basic health check endpoint."""
    import time
    import psutil
    from flask import __version__ as flask_version
    
    try:
        # Basic application status
        status = {
            "status": "healthy",
            "timestamp": int(time.time()),
            "version": "1.0.0",
            "flask_version": flask_version,
            "uptime": int(time.time()),  # Simple uptime since this request
        }
        
        return jsonify(status), 200
    except Exception as e:
        return jsonify({
            "status": "unhealthy",
            "error": str(e),
            "timestamp": int(time.time())
        }), 500


@main_bp.route('/health/detailed', methods=['GET'])
def detailed_health_check():
    """Detailed health check with system and service status."""
    import time
    import psutil
    import os
    from flask import __version__ as flask_version
    
    try:
        # System information
        cpu_percent = psutil.cpu_percent(interval=1)
        memory = psutil.virtual_memory()
        disk = psutil.disk_usage('/')
        
        # Check tokenizer service
        tokenizer_status = "healthy"
        tokenizer_cache_size = len(tokenizer_service.tokenizers) + len(tokenizer_service.custom_tokenizers)
        
        # Test basic tokenizer loading
        try:
            test_tokenizer, _, error = tokenizer_service.load_tokenizer('gpt2')
            if error:
                tokenizer_status = f"warning: {error}"
        except Exception as e:
            tokenizer_status = f"error: {str(e)}"
        
        # Check upload directory
        upload_folder = current_app.config.get('UPLOAD_FOLDER', '/tmp')
        upload_dir_exists = os.path.exists(upload_folder)
        upload_dir_writable = os.access(upload_folder, os.W_OK) if upload_dir_exists else False
        
        status = {
            "status": "healthy",
            "timestamp": int(time.time()),
            "version": "1.0.0",
            "flask_version": flask_version,
            "system": {
                "cpu_percent": round(cpu_percent, 1),
                "memory": {
                    "total": memory.total,
                    "available": memory.available,
                    "percent": memory.percent,
                    "used": memory.used
                },
                "disk": {
                    "total": disk.total,
                    "used": disk.used,
                    "free": disk.free,
                    "percent": round((disk.used / disk.total) * 100, 1)
                }
            },
            "services": {
                "tokenizer_service": {
                    "status": tokenizer_status,
                    "cached_tokenizers": tokenizer_cache_size,
                    "available_models": len(tokenizer_service.TOKENIZER_MODELS)
                },
                "file_service": {
                    "upload_directory": upload_folder,
                    "directory_exists": upload_dir_exists,
                    "directory_writable": upload_dir_writable,
                    "allowed_extensions": list(file_service.ALLOWED_EXTENSIONS)
                }
            },
            "configuration": {
                "max_content_length": current_app.config.get('MAX_CONTENT_LENGTH'),
                "cache_expiration": current_app.config.get('CACHE_EXPIRATION', 3600),
                "max_display_tokens": current_app.config.get('MAX_DISPLAY_TOKENS', 50000),
                "preview_char_limit": current_app.config.get('PREVIEW_CHAR_LIMIT', 8096)
            }
        }
        
        # Determine overall status
        overall_status = "healthy"
        if tokenizer_status.startswith("error"):
            overall_status = "unhealthy"
        elif tokenizer_status.startswith("warning") or not upload_dir_writable:
            overall_status = "degraded"
        
        status["status"] = overall_status
        
        return jsonify(status), 200 if overall_status == "healthy" else 503
        
    except Exception as e:
        return jsonify({
            "status": "unhealthy",
            "error": str(e),
            "timestamp": int(time.time())
        }), 500


@main_bp.route('/health/ready', methods=['GET'])
def readiness_check():
    """Readiness check - determines if the application is ready to serve requests."""
    try:
        # Check if core services are ready
        checks = {
            "tokenizer_service": False,
            "file_service": False,
            "configuration": False
        }
        
        # Test tokenizer service
        try:
            test_tokenizer, _, error = tokenizer_service.load_tokenizer('gpt2')
            checks["tokenizer_service"] = error is None
        except:
            checks["tokenizer_service"] = False
        
        # Test file service
        try:
            upload_folder = current_app.config.get('UPLOAD_FOLDER', '/tmp')
            checks["file_service"] = os.path.exists(upload_folder) and os.access(upload_folder, os.W_OK)
        except:
            checks["file_service"] = False
        
        # Check configuration
        required_configs = ['MAX_CONTENT_LENGTH', 'UPLOAD_FOLDER']
        checks["configuration"] = all(current_app.config.get(config) is not None for config in required_configs)
        
        all_ready = all(checks.values())
        
        return jsonify({
            "ready": all_ready,
            "checks": checks,
            "timestamp": int(time.time())
        }), 200 if all_ready else 503
        
    except Exception as e:
        return jsonify({
            "ready": False,
            "error": str(e),
            "timestamp": int(time.time())
        }), 500