"""
Templates API Blueprint

Provides REST endpoints for workflow template management.
"""

from flask import Blueprint, request, jsonify
import logging

import sys
import os
sys.path.append(os.path.dirname(os.path.dirname(os.path.abspath(__file__))))

from services.template_service import TemplateService
from services.serialization import WorkflowSerializer
from api.errors import handle_api_error

templates_bp = Blueprint('templates', __name__)
logger = logging.getLogger(__name__)

# Initialize services
template_service = TemplateService()
workflow_serializer = WorkflowSerializer()

@templates_bp.route('/', methods=['GET'])
def list_templates():
    """List all templates with optional filtering"""
    try:
        # Get query parameters
        category = request.args.get('category')
        difficulty = request.args.get('difficulty')
        
        # Get templates
        templates = template_service.list_templates(category=category, difficulty=difficulty)
        
        # Convert to dict format
        result = []
        for template in templates:
            template_dict = template.to_dict()
            # Remove the full workflow from list view for performance
            template_dict.pop('workflow', None)
            result.append(template_dict)
        
        return jsonify({
            'templates': result,
            'count': len(result)
        })
        
    except Exception as e:
        logger.error(f"Error listing templates: {e}")
        return handle_api_error(e)

@templates_bp.route('/', methods=['POST'])
def create_template():
    """Create a new template"""
    try:
        data = request.get_json()
        
        if not data:
            return jsonify({'error': 'No data provided'}), 400
        
        # Create template
        template = template_service.create_template(data)
        
        logger.info(f"Created template: {template.id}")
        return jsonify(template.to_dict()), 201
        
    except ValueError as e:
        logger.warning(f"Template validation error: {e}")
        return jsonify({'error': str(e)}), 400
    except Exception as e:
        logger.error(f"Error creating template: {e}")
        return handle_api_error(e)

@templates_bp.route('/<template_id>', methods=['GET'])
def get_template(template_id):
    """Get a specific template"""
    try:
        template = template_service.get_template(template_id)
        
        if not template:
            return jsonify({'error': 'Template not found'}), 404
        
        return jsonify(template.to_dict())
        
    except Exception as e:
        logger.error(f"Error getting template {template_id}: {e}")
        return handle_api_error(e)

@templates_bp.route('/<template_id>', methods=['PUT'])
def update_template(template_id):
    """Update an existing template"""
    try:
        data = request.get_json()
        
        if not data:
            return jsonify({'error': 'No data provided'}), 400
        
        template = template_service.update_template(template_id, data)
        
        if not template:
            return jsonify({'error': 'Template not found'}), 404
        
        logger.info(f"Updated template: {template_id}")
        return jsonify(template.to_dict())
        
    except ValueError as e:
        logger.warning(f"Template validation error: {e}")
        return jsonify({'error': str(e)}), 400
    except Exception as e:
        logger.error(f"Error updating template {template_id}: {e}")
        return handle_api_error(e)

@templates_bp.route('/<template_id>', methods=['DELETE'])
def delete_template(template_id):
    """Delete a template"""
    try:
        success = template_service.delete_template(template_id)
        
        if not success:
            return jsonify({'error': 'Template not found'}), 404
        
        logger.info(f"Deleted template: {template_id}")
        return jsonify({'message': 'Template deleted successfully'})
        
    except Exception as e:
        logger.error(f"Error deleting template {template_id}: {e}")
        return handle_api_error(e)

@templates_bp.route('/<template_id>/instantiate', methods=['POST'])
def instantiate_template(template_id):
    """Create a workflow from a template"""
    try:
        data = request.get_json()
        
        if not data:
            return jsonify({'error': 'No data provided'}), 400
        
        # Extract parameters
        parameters = data.get('parameters', {})
        workflow_name = data.get('name', f'Workflow from template {template_id}')
        created_by = data.get('created_by', 'user')
        
        # Create workflow instance
        workflow = template_service.instantiate_template(
            template_id, parameters, workflow_name, created_by
        )
        
        if not workflow:
            return jsonify({'error': 'Template not found'}), 404
        
        # Save the workflow
        workflow_data = workflow_serializer.serialize(workflow)
        workflow_id = workflow_serializer.save_workflow(workflow_data)
        
        logger.info(f"Instantiated template {template_id} as workflow {workflow_id}")
        return jsonify({
            'workflow_id': workflow_id,
            'workflow': workflow.to_dict()
        }), 201
        
    except ValueError as e:
        logger.warning(f"Template instantiation error: {e}")
        return jsonify({'error': str(e)}), 400
    except Exception as e:
        logger.error(f"Error instantiating template {template_id}: {e}")
        return handle_api_error(e)

@templates_bp.route('/from-workflow', methods=['POST'])
def create_template_from_workflow():
    """Create a template from an existing workflow"""
    try:
        data = request.get_json()
        
        if not data:
            return jsonify({'error': 'No data provided'}), 400
        
        # Extract required fields
        workflow_id = data.get('workflow_id')
        template_name = data.get('template_name')
        template_description = data.get('template_description')
        category = data.get('category', 'Custom')
        parameters = data.get('parameters', [])
        
        if not all([workflow_id, template_name, template_description]):
            return jsonify({
                'error': 'workflow_id, template_name, and template_description are required'
            }), 400
        
        # Load the workflow
        workflow_data = workflow_serializer.load_workflow(workflow_id)
        if not workflow_data:
            return jsonify({'error': 'Workflow not found'}), 404
        
        workflow = workflow_serializer.deserialize(workflow_data)
        
        # Create template
        template = template_service.create_template_from_workflow(
            workflow, template_name, template_description, category, parameters
        )
        
        logger.info(f"Created template {template.id} from workflow {workflow_id}")
        return jsonify(template.to_dict()), 201
        
    except ValueError as e:
        logger.warning(f"Template creation error: {e}")
        return jsonify({'error': str(e)}), 400
    except Exception as e:
        logger.error(f"Error creating template from workflow: {e}")
        return handle_api_error(e)

@templates_bp.route('/categories', methods=['GET'])
def get_template_categories():
    """Get all available template categories"""
    try:
        templates = template_service.list_templates()
        categories = list(set(template.category for template in templates))
        categories.sort()
        
        return jsonify({
            'categories': categories
        })
        
    except Exception as e:
        logger.error(f"Error getting template categories: {e}")
        return handle_api_error(e)