"""
Template Data Models

Contains data models for workflow templates and template parameters.
"""

from dataclasses import dataclass, field
from datetime import datetime
from enum import Enum
from typing import Any, Dict, List, Optional
from uuid import uuid4

from .visual_workflow import VisualWorkflow, ParameterType


class TemplateDifficulty(Enum):
    """Difficulty levels for templates"""
    BEGINNER = 'beginner'
    INTERMEDIATE = 'intermediate'
    ADVANCED = 'advanced'


@dataclass
class TemplateParameter:
    """Configurable parameter for a template"""
    name: str
    type: ParameterType
    description: str
    default_value: Optional[Any] = None
    
    # Mapping to workflow nodes
    node_id: str = ""
    parameter_name: str = ""
    
    # UI hints
    label: str = ""
    placeholder: Optional[str] = None
    required: bool = True
    
    def to_dict(self) -> Dict[str, Any]:
        return {
            'name': self.name,
            'type': self.type.value,
            'description': self.description,
            'default_value': self.default_value,
            'node_id': self.node_id,
            'parameter_name': self.parameter_name,
            'label': self.label,
            'placeholder': self.placeholder,
            'required': self.required
        }
    
    @classmethod
    def from_dict(cls, data: Dict[str, Any]) -> 'TemplateParameter':
        return cls(
            name=data['name'],
            type=ParameterType(data['type']),
            description=data['description'],
            default_value=data.get('default_value'),
            node_id=data.get('node_id', ''),
            parameter_name=data.get('parameter_name', ''),
            label=data.get('label', ''),
            placeholder=data.get('placeholder'),
            required=data.get('required', True)
        )


@dataclass
class WorkflowTemplate:
    """Template for creating workflows"""
    id: str
    name: str
    description: str
    category: str
    
    # Template workflow structure
    workflow: VisualWorkflow
    
    # Configurable parameters
    parameters: List[TemplateParameter] = field(default_factory=list)
    
    # Metadata
    tags: List[str] = field(default_factory=list)
    difficulty: TemplateDifficulty = TemplateDifficulty.BEGINNER
    estimated_time: int = 5  # minutes
    
    # Usage statistics
    usage_count: int = 0
    rating: float = 0.0
    
    # Timestamps
    created_at: datetime = field(default_factory=datetime.now)
    updated_at: datetime = field(default_factory=datetime.now)
    created_by: str = "system"
    
    def to_dict(self) -> Dict[str, Any]:
        return {
            'id': self.id,
            'name': self.name,
            'description': self.description,
            'category': self.category,
            'workflow': self.workflow.to_dict(),
            'parameters': [p.to_dict() for p in self.parameters],
            'tags': self.tags,
            'difficulty': self.difficulty.value,
            'estimated_time': self.estimated_time,
            'usage_count': self.usage_count,
            'rating': self.rating,
            'created_at': self.created_at.isoformat(),
            'updated_at': self.updated_at.isoformat(),
            'created_by': self.created_by
        }
    
    @classmethod
    def from_dict(cls, data: Dict[str, Any]) -> 'WorkflowTemplate':
        return cls(
            id=data['id'],
            name=data['name'],
            description=data['description'],
            category=data['category'],
            workflow=VisualWorkflow.from_dict(data['workflow']),
            parameters=[TemplateParameter.from_dict(p) for p in data.get('parameters', [])],
            tags=data.get('tags', []),
            difficulty=TemplateDifficulty(data.get('difficulty', 'beginner')),
            estimated_time=data.get('estimated_time', 5),
            usage_count=data.get('usage_count', 0),
            rating=data.get('rating', 0.0),
            created_at=datetime.fromisoformat(data.get('created_at', datetime.now().isoformat())),
            updated_at=datetime.fromisoformat(data.get('updated_at', datetime.now().isoformat())),
            created_by=data.get('created_by', 'system')
        )
    
    def instantiate(self, parameters: Dict[str, Any], workflow_name: str, created_by: str = "user") -> VisualWorkflow:
        """Create a new workflow instance from this template"""
        # Create a copy of the template workflow
        workflow_data = self.workflow.to_dict()
        
        # Generate new IDs
        workflow_data['id'] = str(uuid4())
        workflow_data['name'] = workflow_name
        workflow_data['created_at'] = datetime.now().isoformat()
        workflow_data['updated_at'] = datetime.now().isoformat()
        workflow_data['created_by'] = created_by
        workflow_data['is_template'] = False
        
        # Apply parameter substitutions
        for param in self.parameters:
            if param.name in parameters:
                value = parameters[param.name]
                
                # Find the target node and update its parameter
                for node_data in workflow_data['nodes']:
                    if node_data['id'] == param.node_id:
                        node_data['parameters'][param.parameter_name] = value
                        break
        
        # Generate new node and edge IDs to avoid conflicts
        node_id_mapping = {}
        for i, node_data in enumerate(workflow_data['nodes']):
            old_id = node_data['id']
            new_id = f"{workflow_data['id']}_node_{i}"
            node_id_mapping[old_id] = new_id
            node_data['id'] = new_id
        
        # Update edge references
        for edge_data in workflow_data['edges']:
            edge_data['id'] = str(uuid4())
            edge_data['source'] = node_id_mapping.get(edge_data['source'], edge_data['source'])
            edge_data['target'] = node_id_mapping.get(edge_data['target'], edge_data['target'])
        
        return VisualWorkflow.from_dict(workflow_data)
    
    def validate(self) -> List[str]:
        """Validate template structure"""
        errors = []
        
        # Basic validation
        if not self.id:
            errors.append("Template ID is required")
        if not self.name:
            errors.append("Template name is required")
        if not self.category:
            errors.append("Template category is required")
        
        # Validate workflow
        workflow_errors = self.workflow.validate()
        errors.extend([f"Workflow: {err}" for err in workflow_errors])
        
        # Validate parameters
        node_ids = {node.id for node in self.workflow.nodes}
        for param in self.parameters:
            if param.node_id and param.node_id not in node_ids:
                errors.append(f"Parameter {param.name} references non-existent node {param.node_id}")
        
        return errors


def generate_template_id() -> str:
    """Generate a unique template ID"""
    return f"template_{str(uuid4())[:8]}"