"""
Database Schema Generator Agent

Generates database schemas, table definitions, and relationships
for various database systems.
"""

from typing import Any, Dict, List
from agents.base import BaseAgent


class DatabaseSchemaGeneratorAgent(BaseAgent):
    """
    Generates database schemas and table definitions.

    Supports:
    - PostgreSQL
    - MySQL
    - SQLite
    - MongoDB
    - Redis
    - Relationships and indexes
    """

    def __init__(self):
        super().__init__(
            name='database-schema-generator',
            description='Generate database schemas and table definitions',
            category='engineering',
            version='1.0.0',
            tags=['database', 'schema', 'sql', 'nosql', 'data-modeling']
        )

    async def execute(self, params: Dict[str, Any]) -> Dict[str, Any]:
        """
        Generate database schema.

        Args:
            params: {
                'database_type': 'postgresql|mysql|sqlite|mongodb|redis',
                'schema_definition': Dict,  # Schema specification
                'options': {
                    'add_timestamps': bool,
                    'add_soft_delete': bool,
                    'add_indexes': bool,
                    'add_constraints': bool,
                    'add_triggers': bool,
                    'normalize': bool
                }
            }

        Returns:
            {
                'status': 'success|failed',
                'tables_generated': List[Dict],
                'relationships': List[Dict],
                'indexes': List[Dict],
                'constraints': List[Dict],
                'schema_file': str,
                'migration_file': str
            }
        """
        database_type = params.get('database_type', 'postgresql')
        schema_definition = params.get('schema_definition', {})
        options = params.get('options', {})

        self.logger.info(f"Generating schema for {database_type}")

        # Mock schema generation
        tables = [
            {
                'name': 'users',
                'columns': [
                    {'name': 'id', 'type': 'UUID', 'primary_key': True},
                    {'name': 'email', 'type': 'VARCHAR(255)', 'unique': True, 'nullable': False},
                    {'name': 'username', 'type': 'VARCHAR(100)', 'unique': True, 'nullable': False},
                    {'name': 'password_hash', 'type': 'VARCHAR(255)', 'nullable': False},
                    {'name': 'first_name', 'type': 'VARCHAR(100)', 'nullable': True},
                    {'name': 'last_name', 'type': 'VARCHAR(100)', 'nullable': True},
                    {'name': 'is_active', 'type': 'BOOLEAN', 'default': True},
                    {'name': 'created_at', 'type': 'TIMESTAMP', 'default': 'NOW()'},
                    {'name': 'updated_at', 'type': 'TIMESTAMP', 'default': 'NOW()'},
                    {'name': 'deleted_at', 'type': 'TIMESTAMP', 'nullable': True}
                ],
                'indexes': ['email', 'username', 'created_at']
            },
            {
                'name': 'products',
                'columns': [
                    {'name': 'id', 'type': 'UUID', 'primary_key': True},
                    {'name': 'name', 'type': 'VARCHAR(255)', 'nullable': False},
                    {'name': 'description', 'type': 'TEXT', 'nullable': True},
                    {'name': 'price', 'type': 'DECIMAL(10,2)', 'nullable': False},
                    {'name': 'stock', 'type': 'INTEGER', 'default': 0},
                    {'name': 'category_id', 'type': 'UUID', 'foreign_key': 'categories.id'},
                    {'name': 'created_at', 'type': 'TIMESTAMP', 'default': 'NOW()'},
                    {'name': 'updated_at', 'type': 'TIMESTAMP', 'default': 'NOW()'}
                ],
                'indexes': ['category_id', 'name', 'price']
            },
            {
                'name': 'orders',
                'columns': [
                    {'name': 'id', 'type': 'UUID', 'primary_key': True},
                    {'name': 'user_id', 'type': 'UUID', 'foreign_key': 'users.id'},
                    {'name': 'status', 'type': 'VARCHAR(50)', 'nullable': False},
                    {'name': 'total_amount', 'type': 'DECIMAL(10,2)', 'nullable': False},
                    {'name': 'created_at', 'type': 'TIMESTAMP', 'default': 'NOW()'},
                    {'name': 'updated_at', 'type': 'TIMESTAMP', 'default': 'NOW()'}
                ],
                'indexes': ['user_id', 'status', 'created_at']
            }
        ]

        relationships = [
            {
                'from_table': 'products',
                'to_table': 'categories',
                'type': 'many_to_one',
                'foreign_key': 'category_id',
                'on_delete': 'CASCADE'
            },
            {
                'from_table': 'orders',
                'to_table': 'users',
                'type': 'many_to_one',
                'foreign_key': 'user_id',
                'on_delete': 'RESTRICT'
            },
            {
                'from_table': 'order_items',
                'to_table': 'orders',
                'type': 'many_to_one',
                'foreign_key': 'order_id',
                'on_delete': 'CASCADE'
            },
            {
                'from_table': 'order_items',
                'to_table': 'products',
                'type': 'many_to_one',
                'foreign_key': 'product_id',
                'on_delete': 'RESTRICT'
            }
        ]

        indexes = [
            {'table': 'users', 'columns': ['email'], 'unique': True},
            {'table': 'users', 'columns': ['username'], 'unique': True},
            {'table': 'products', 'columns': ['category_id', 'name']},
            {'table': 'orders', 'columns': ['user_id', 'created_at']}
        ]

        constraints = [
            {
                'table': 'users',
                'type': 'CHECK',
                'condition': "email LIKE '%@%'"
            },
            {
                'table': 'products',
                'type': 'CHECK',
                'condition': 'price >= 0'
            },
            {
                'table': 'orders',
                'type': 'CHECK',
                'condition': 'total_amount >= 0'
            }
        ]

        return {
            'status': 'success',
            'database_type': database_type,
            'tables_generated': tables,
            'total_tables': len(tables),
            'total_columns': sum(len(t['columns']) for t in tables),
            'relationships': relationships,
            'indexes': indexes,
            'constraints': constraints,
            'schema_file': f'schema/{database_type}_schema.sql',
            'migration_file': f'migrations/001_initial_schema.sql',
            'features': {
                'timestamps': options.get('add_timestamps', True),
                'soft_delete': options.get('add_soft_delete', True),
                'indexes': options.get('add_indexes', True),
                'constraints': options.get('add_constraints', True),
                'foreign_keys': True,
                'check_constraints': True
            },
            'normalization_level': '3NF',
            'estimated_size': '50MB initial',
            'next_steps': [
                'Review schema design',
                'Create database migration',
                'Generate ORM models',
                'Add seed data',
                'Set up backups'
            ]
        }

    def validate_params(self, params: Dict[str, Any]) -> bool:
        """Validate schema generation parameters."""
        valid_databases = ['postgresql', 'mysql', 'sqlite', 'mongodb', 'redis']
        database_type = params.get('database_type', 'postgresql')

        if database_type not in valid_databases:
            self.logger.error(f"Unsupported database: {database_type}")
            return False

        return True
