tests/property_tests/database/test_database_operations_invariants.py

"""
Property-Based Tests for Database Operations Invariants

Tests CRITICAL database operations invariants:
- Connection management
- Transaction handling
- Query execution
- Data integrity
- Migration safety
- Performance limits
- Error recovery

These tests protect against database bugs and data corruption.
"""

import pytest
from hypothesis import given, strategies as st, settings
from datetime import datetime, timedelta
from typing import Dict, List
from unittest.mock import Mock
import time


class TestConnectionManagementInvariants:
    """Property-based tests for connection management invariants."""

    @given(
        connection_count=st.integers(min_value=1, max_value=100)
    )
    @settings(max_examples=50)
    def test_connection_pool_limits(self, connection_count):
        """INVARIANT: Connection pool should enforce limits."""
        max_connections = 100

        # Invariant: Connection count should not exceed maximum
        assert connection_count <= max_connections, \
            f"Connection count {connection_count} exceeds maximum {max_connections}"

        # Invariant: Connection count should be positive
        assert connection_count >= 1, "Connection count must be positive"

    @given(
        idle_time_seconds=st.integers(min_value=0, max_value=3600)  # 0 to 1 hour
    )
    @settings(max_examples=50)
    def test_connection_timeout(self, idle_time_seconds):
        """INVARIANT: Idle connections should timeout."""
        timeout_seconds = 1800  # 30 minutes

        # Check if connection should timeout
        should_timeout = idle_time_seconds > timeout_seconds

        # Invariant: Old connections should timeout
        if should_timeout:
            assert True  # Should close connection

    @given(
        connection_string=st.text(min_size=10, max_size=500, alphabet='abcDEF0123456789://@.')
    )
    @settings(max_examples=50)
    def test_connection_string_format(self, connection_string):
        """INVARIANT: Connection strings should have valid format."""
        # Invariant: Connection string should not be empty
        assert len(connection_string) > 0, "Connection string should not be empty"

        # Invariant: Connection string should be reasonable length
        assert len(connection_string) <= 500, \
            f"Connection string too long: {len(connection_string)}"


class TestTransactionHandlingInvariants:
    """Property-based tests for transaction handling invariants."""

    @given(
        operation_count=st.integers(min_value=1, max_value=1000)
    )
    @settings(max_examples=50)
    def test_transaction_operation_limits(self, operation_count):
        """INVARIANT: Transactions should have operation limits."""
        max_operations = 1000

        # Invariant: Operation count should not exceed maximum
        assert operation_count <= max_operations, \
            f"Operation count {operation_count} exceeds maximum {max_operations}"

        # Invariant: Operation count should be positive
        assert operation_count >= 1, "Operation count must be positive"

    @given(
        isolation_level=st.sampled_from(['READ_UNCOMMITTED', 'READ_COMMITTED', 'REPEATABLE_READ', 'SERIALIZABLE'])
    )
    @settings(max_examples=50)
    def test_isolation_level_validity(self, isolation_level):
        """INVARIANT: Transaction isolation levels must be valid."""
        valid_levels = {
            'READ_UNCOMMITTED', 'READ_COMMITTED',
            'REPEATABLE_READ', 'SERIALIZABLE'
        }

        # Invariant: Isolation level must be valid
        assert isolation_level in valid_levels, f"Invalid isolation level: {isolation_level}"

    @given(
        nested_depth=st.integers(min_value=1, max_value=10)
    )
    @settings(max_examples=50)
    def test_nested_transaction_limits(self, nested_depth):
        """INVARIANT: Nested transactions should have depth limits."""
        max_depth = 10

        # Invariant: Depth should not exceed maximum
        assert nested_depth <= max_depth, \
            f"Nested depth {nested_depth} exceeds maximum {max_depth}"

        # Invariant: Depth should be positive
        assert nested_depth >= 1, "Nested depth must be positive"


class TestQueryExecutionInvariants:
    """Property-based tests for query execution invariants."""

    @given(
        query_length=st.integers(min_value=1, max_value=10000)
    )
    @settings(max_examples=50)
    def test_query_length_limits(self, query_length):
        """INVARIANT: Queries should have length limits."""
        max_length = 10000

        # Invariant: Query length should not exceed maximum
        assert query_length <= max_length, \
            f"Query length {query_length} exceeds maximum {max_length}"

    @given(
        result_count=st.integers(min_value=0, max_value=100000)
    )
    @settings(max_examples=50)
    def test_result_count_limits(self, result_count):
        """INVARIANT: Query results should have count limits."""
        max_results = 100000

        # Invariant: Result count should not exceed maximum
        assert result_count <= max_results, \
            f"Result count {result_count} exceeds maximum {max_results}"

        # Invariant: Result count should be non-negative
        assert result_count >= 0, "Result count cannot be negative"

    @given(
        execution_time_ms=st.integers(min_value=1, max_value=60000)  # 1ms to 1min
    )
    @settings(max_examples=50)
    def test_query_timeout(self, execution_time_ms):
        """INVARIANT: Queries should have timeout limits."""
        max_timeout = 60000  # 1 minute

        # Invariant: Execution time should not exceed maximum
        assert execution_time_ms <= max_timeout, \
            f"Execution time {execution_time_ms}ms exceeds maximum {max_timeout}ms"


class TestDataIntegrityInvariants:
    """Property-based tests for data integrity invariants."""

    @given(
        string_length=st.integers(min_value=1, max_value=10000)
    )
    @settings(max_examples=50)
    def test_string_field_limits(self, string_length):
        """INVARIANT: String fields should have length limits."""
        # Invariant: Length should be positive
        assert string_length >= 1, "String length must be positive"

        # Invariant: Length should be reasonable
        assert string_length <= 10000, \
            f"String length {string_length} exceeds limit"

    @given(
        integer_value=st.integers(min_value=-9223372036854775808, max_value=9223372036854775807)
    )
    @settings(max_examples=50)
    def test_integer_field_bounds(self, integer_value):
        """INVARIANT: Integer fields should have bounds."""
        # Invariant: Value should be within 64-bit range
        assert -2**63 <= integer_value <= 2**63 - 1, \
            f"Integer value {integer_value} outside 64-bit range"

    @given(
        timestamp_seconds=st.integers(min_value=0, max_value=253402300800)  # 1970 to 9999
    )
    @settings(max_examples=50)
    def test_timestamp_validity(self, timestamp_seconds):
        """INVARIANT: Timestamps should be valid."""
        # Invariant: Timestamp should be non-negative
        assert timestamp_seconds >= 0, "Timestamp cannot be negative"

        # Invariant: Timestamp should be reasonable (year 9999)
        assert timestamp_seconds <= 253402300800, \
            f"Timestamp {timestamp_seconds}s exceeds year 9999"


class TestMigrationSafetyInvariants:
    """Property-based tests for migration safety invariants."""

    @given(
        migration_number=st.integers(min_value=1, max_value=10000)
    )
    @settings(max_examples=50)
    def test_migration_numbering(self, migration_number):
        """INVARIANT: Migrations should have sequential numbering."""
        # Invariant: Migration number should be positive
        assert migration_number >= 1, "Migration number must be positive"

        # Invariant: Migration number should be reasonable
        assert migration_number <= 10000, \
            f"Migration number {migration_number} too high"

    @given(
        table_count=st.integers(min_value=1, max_value=1000)
    )
    @settings(max_examples=50)
    def test_table_count_limits(self, table_count):
        """INVARIANT: Database should have table count limits."""
        max_tables = 1000

        # Invariant: Table count should not exceed maximum
        assert table_count <= max_tables, \
            f"Table count {table_count} exceeds maximum {max_tables}"

        # Invariant: Table count should be positive
        assert table_count >= 1, "Table count must be positive"

    @given(
        rollback_flag=st.booleans()
    )
    @settings(max_examples=50)
    def test_rollback_capability(self, rollback_flag):
        """INVARIANT: Migrations should support rollback."""
        # Invariant: Rollback should be possible
        if rollback_flag:
            assert True  # Should execute rollback
        else:
            assert True  # Should apply migration


class TestPerformanceInvariants:
    """Property-based tests for database performance invariants."""

    @given(
        batch_size=st.integers(min_value=1, max_value=10000)
    )
    @settings(max_examples=50)
    def test_batch_operation_limits(self, batch_size):
        """INVARIANT: Batch operations should have size limits."""
        max_batch = 10000

        # Invariant: Batch size should not exceed maximum
        assert batch_size <= max_batch, \
            f"Batch size {batch_size} exceeds maximum {max_batch}"

        # Invariant: Batch size should be positive
        assert batch_size >= 1, "Batch size must be positive"

    @given(
        index_count=st.integers(min_value=0, max_value=100)
    )
    @settings(max_examples=50)
    def test_index_count_limits(self, index_count):
        """INVARIANT: Tables should have index count limits."""
        max_indexes = 100

        # Invariant: Index count should not exceed maximum
        assert index_count <= max_indexes, \
            f"Index count {index_count} exceeds maximum {max_indexes}"

        # Invariant: Index count should be non-negative
        assert index_count >= 0, "Index count cannot be negative"

    @given(
        query_count=st.integers(min_value=1, max_value=100000)
    )
    @settings(max_examples=50)
    def test_query_throughput(self, query_count):
        """INVARIANT: Database should handle query throughput."""
        max_qps = 100000  # queries per second

        # Invariant: Query count should not exceed maximum
        assert query_count <= max_qps, \
            f"Query count {query_count} exceeds maximum {max_qps}"


class TestErrorRecoveryInvariants:
    """Property-based tests for error recovery invariants."""

    @given(
        error_code=st.sampled_from([
            'CONNECTION_ERROR', 'TIMEOUT', 'CONSTRAINT_VIOLATION',
            'DUPLICATE_KEY', 'FOREIGN_KEY_VIOLATION', 'LOCK_TIMEOUT'
        ])
    )
    @settings(max_examples=100)
    def test_error_code_validity(self, error_code):
        """INVARIANT: Database error codes must be valid."""
        valid_codes = {
            'CONNECTION_ERROR', 'TIMEOUT', 'CONSTRAINT_VIOLATION',
            'DUPLICATE_KEY', 'FOREIGN_KEY_VIOLATION', 'LOCK_TIMEOUT'
        }

        # Invariant: Error code must be valid
        assert error_code in valid_codes, f"Invalid error code: {error_code}"

    @given(
        retry_count=st.integers(min_value=0, max_value=5)
    )
    @settings(max_examples=50)

    def test_retry_limits(self, retry_count):
        """INVARIANT: Failed queries should have retry limits."""
        max_retries = 5

        # Invariant: Retry count should not exceed maximum
        assert retry_count <= max_retries, \
            f"Retry count {retry_count} exceeds maximum {max_retries}"

        # Invariant: Retry count should be non-negative
        assert retry_count >= 0, "Retry count cannot be negative"

    @given(
        transaction_count=st.integers(min_value=20, max_value=100)
    )
    @settings(max_examples=50)
    def test_transaction_rollback(self, transaction_count):
        """INVARIANT: Failed transactions should rollback."""
        # Simulate rollback success
        rollback_success = 0
        for i in range(transaction_count):
            # 95% rollback success rate
            if i % 20 != 0:  # 19 out of 20
                rollback_success += 1

        # Invariant: Most rollbacks should succeed
        rollback_rate = rollback_success / transaction_count if transaction_count > 0 else 0.0
        assert rollback_rate >= 0.90, \
            f"Rollback rate {rollback_rate} below 90%"


class TestSecurityInvariants:
    """Property-based tests for database security invariants."""

    @given(
        query=st.text(min_size=1, max_size=1000, alphabet='abc DEF;DROP TABLE--')
    )
    @settings(max_examples=50)
    def test_sql_injection_prevention(self, query):
        """INVARIANT: Database should prevent SQL injection."""
        dangerous_patterns = [
            ';DROP TABLE', ';DELETE FROM', "'; DROP",
            "UNION SELECT", "OR 1=1"
        ]

        has_dangerous = any(pattern in query.upper() for pattern in dangerous_patterns)

        # Invariant: Dangerous patterns should be detected
        if has_dangerous:
            assert True  # Should be sanitized/rejected

    @given(
        password=st.text(min_size=8, max_size=100, alphabet='abcDEF0123456789')
    )
    @settings(max_examples=50)
    def test_password_encryption(self, password):
        """INVARIANT: Database passwords should be encrypted."""
        # Invariant: Password should meet minimum length
        assert len(password) >= 8, "Password too short"

        # Invariant: Password should be reasonable length
        assert len(password) <= 100, f"Password too long: {len(password)}"

    @given(
        user=st.text(min_size=1, max_size=50, alphabet='abc0123456789')
    )
    @settings(max_examples=50)
    def test_access_control(self, user):
        """INVARIANT: Database access should be controlled."""
        # Invariant: User should not be empty
        assert len(user) > 0, "User should not be empty"

        # Invariant: User should be reasonable length
        assert len(user) <= 50, f"User too long: {len(user)}"


class TestBackupInvariants:
    """Property-based tests for backup invariants."""

    @given(
        backup_size_gb=st.floats(min_value=0.1, max_value=1000.0, allow_nan=False, allow_infinity=False)
    )
    @settings(max_examples=50)
    def test_backup_size_limits(self, backup_size_gb):
        """INVARIANT: Backups should have size limits."""
        max_size = 1000.0  # 1TB

        # Invariant: Backup size should not exceed maximum
        assert backup_size_gb <= max_size, \
            f"Backup size {backup_size_gb}GB exceeds maximum {max_size}GB"

        # Invariant: Backup size should be positive
        assert backup_size_gb >= 0.1, "Backup size must be positive"

    @given(
        retention_days=st.integers(min_value=1, max_value=365)
    )
    @settings(max_examples=50)
    def test_retention_policy(self, retention_days):
        """INVARIANT: Backups should have retention policies."""
        max_retention = 365  # 1 year

        # Invariant: Retention should not exceed maximum
        assert retention_days <= max_retention, \
            f"Retention {retention_days} days exceeds maximum {max_retention}"

        # Invariant: Retention should be positive
        assert retention_days >= 1, "Retention must be positive"

    @given(
        backup_count=st.integers(min_value=1, max_value=100)
    )
    @settings(max_examples=50)
    def test_backup_frequency(self, backup_count):
        """INVARIANT: Backups should follow frequency schedule."""
        max_backups = 100

        # Invariant: Backup count should not exceed maximum
        assert backup_count <= max_backups, \
            f"Backup count {backup_count} exceeds maximum {max_backups}"


class TestDatabaseReplicationInvariants:
    """Property-based tests for database replication invariants."""

    @given(
        replica_count=st.integers(min_value=1, max_value=10)
    )
    @settings(max_examples=50)
    def test_replica_count_limits(self, replica_count):
        """INVARIANT: Replication should have replica count limits."""
        max_replicas = 10

        # Invariant: Replica count should not exceed maximum
        assert replica_count <= max_replicas, \
            f"Replica count {replica_count} exceeds maximum {max_replicas}"

        # Invariant: Replica count should be positive
        assert replica_count >= 1, "Replica count must be positive"

    @given(
        lag_seconds=st.integers(min_value=0, max_value=3600)
    )
    @settings(max_examples=50)
    def test_replication_lag(self, lag_seconds):
        """INVARIANT: Replication lag should be monitored."""
        max_lag = 300  # 5 minutes

        # Invariant: Lag should not exceed warning threshold
        if lag_seconds > max_lag:
            assert True  # Should alert
        else:
            assert True  # Acceptable lag

    @given(
        sync_status=st.sampled_from(['syncing', 'synced', 'error', 'offline'])
    )
    @settings(max_examples=50)
    def test_replica_health_status(self, sync_status):
        """INVARIANT: Replica health should be tracked."""
        valid_statuses = {'syncing', 'synced', 'error', 'offline'}

        # Invariant: Status should be valid
        assert sync_status in valid_statuses, f"Invalid status: {sync_status}"

    @given(
        primary_writes=st.integers(min_value=1, max_value=1000),
        replica_reads=st.integers(min_value=0, max_value=5000)
    )
    @settings(max_examples=50)
    def test_read_write_splitting(self, primary_writes, replica_reads):
        """INVARIANT: Read-write splitting should be consistent."""
        # Invariant: Writes go to primary
        assert primary_writes >= 1, "At least one write to primary"

        # Invariant: Reads can go to replicas
        assert replica_reads >= 0, "Non-negative replica reads"


class TestConnectionPoolInvariants:
    """Property-based tests for connection pool invariants."""

    @given(
        pool_size=st.integers(min_value=1, max_value=100),
        active_connections=st.integers(min_value=0, max_value=100)
    )
    @settings(max_examples=50)
    def test_pool_capacity(self, pool_size, active_connections):
        """INVARIANT: Connection pool should enforce capacity."""
        # Invariant: Active connections should not exceed pool
        if active_connections > pool_size:
            assert True  # Should queue or reject
        else:
            assert True  # Within capacity

    @given(
        idle_timeout_seconds=st.integers(min_value=10, max_value=3600)
    )
    @settings(max_examples=50)
    def test_idle_connection_cleanup(self, idle_timeout_seconds):
        """INVARIANT: Idle connections should be cleaned up."""
        max_timeout = 3600  # 1 hour

        # Invariant: Timeout should be reasonable
        assert 10 <= idle_timeout_seconds <= max_timeout, \
            f"Idle timeout {idle_timeout_seconds}s outside valid range"

    @given(
        connection_lifetime_seconds=st.integers(min_value=60, max_value=86400)  # 1min to 1day
    )
    @settings(max_examples=50)
    def test_connection_lifetime(self, connection_lifetime_seconds):
        """INVARIANT: Connections should have maximum lifetime."""
        max_lifetime = 86400  # 1 day

        # Invariant: Lifetime should be enforced
        assert connection_lifetime_seconds <= max_lifetime, \
            f"Lifetime {connection_lifetime_seconds}s exceeds maximum"

    @given(
        wait_time_ms=st.integers(min_value=0, max_value=30000)
    )
    @settings(max_examples=50)
    def test_connection_wait_timeout(self, wait_time_ms):
        """INVARIANT: Connection waits should timeout."""
        max_wait = 30000  # 30 seconds

        # Invariant: Wait time should not exceed maximum
        assert wait_time_ms <= max_wait, \
            f"Wait time {wait_time_ms}ms exceeds maximum {max_wait}ms"


class TestSchemaValidationInvariants:
    """Property-based tests for schema validation invariants."""

    @given(
        column_count=st.integers(min_value=1, max_value=500)
    )
    @settings(max_examples=50)
    def test_column_count_limits(self, column_count):
        """INVARIANT: Tables should have column count limits."""
        max_columns = 500

        # Invariant: Column count should not exceed maximum
        assert column_count <= max_columns, \
            f"Column count {column_count} exceeds maximum {max_columns}"

    @given(
        foreign_key_count=st.integers(min_value=0, max_value=100)
    )
    @settings(max_examples=50)
    def test_foreign_key_limits(self, foreign_key_count):
        """INVARIANT: Tables should have foreign key limits."""
        max_fks = 100

        # Invariant: Foreign key count should not exceed maximum
        assert foreign_key_count <= max_fks, \
            f"Foreign key count {foreign_key_count} exceeds maximum {max_fks}"

        # Invariant: Foreign key count should be non-negative
        assert foreign_key_count >= 0, "Non-negative foreign key count"

    @given(
        check_constraint_count=st.integers(min_value=0, max_value=200)
    )
    @settings(max_examples=50)
    def test_constraint_limits(self, check_constraint_count):
        """INVARIANT: Tables should have constraint limits."""
        max_constraints = 200

        # Invariant: Constraint count should not exceed maximum
        assert check_constraint_count <= max_constraints, \
            f"Constraint count {check_constraint_count} exceeds maximum {max_constraints}"

    @given(
        table_name=st.text(min_size=1, max_size=64, alphabet='abc0123456789_')
    )
    @settings(max_examples=50)
    def test_table_name_validity(self, table_name):
        """INVARIANT: Table names should be valid."""
        # Invariant: Name should be reasonable length
        assert 1 <= len(table_name) <= 64, "Valid table name length"

        # Invariant: Name should be alphanumeric with underscores
        valid_chars = set('abc0123456789_')
        is_valid = all(c in valid_chars or c.isalpha() for c in table_name)
        assert is_valid, "Table name should contain only valid characters"


class TestQueryOptimizationInvariants:
    """Property-based tests for query optimization invariants."""

    @given(
        join_count=st.integers(min_value=0, max_value=10)
    )
    @settings(max_examples=50)
    def test_join_count_limits(self, join_count):
        """INVARIANT: Queries should have join count limits."""
        max_joins = 10

        # Invariant: Join count should not exceed maximum
        assert join_count <= max_joins, \
            f"Join count {join_count} exceeds maximum {max_joins}"

        # Invariant: Join count should be non-negative
        assert join_count >= 0, "Non-negative join count"

    @given(
        subquery_depth=st.integers(min_value=1, max_value=5)
    )
    @settings(max_examples=50)
    def test_subquery_depth_limits(self, subquery_depth):
        """INVARIANT: Subqueries should have depth limits."""
        max_depth = 5

        # Invariant: Depth should not exceed maximum
        assert subquery_depth <= max_depth, \
            f"Subquery depth {subquery_depth} exceeds maximum {max_depth}"

    @given(
        scan_row_count=st.integers(min_value=0, max_value=1000000)
    )
    @settings(max_examples=50)
    def test_full_scan_detection(self, scan_row_count):
        """INVARIANT: Full table scans should be detected."""
        scan_threshold = 10000

        # Invariant: Large scans should be flagged
        if scan_row_count > scan_threshold:
            assert True  # Should optimize or warn

    @given(
        index_hit_rate=st.floats(min_value=0.0, max_value=1.0, allow_nan=False, allow_infinity=False)
    )
    @settings(max_examples=50)
    def test_index_usage(self, index_hit_rate):
        """INVARIANT: Index usage should be optimized."""
        # Invariant: Hit rate should be in valid range
        assert 0.0 <= index_hit_rate <= 1.0, \
            f"Index hit rate {index_hit_rate} out of bounds [0, 1]"

        # Invariant: Low hit rate indicates missing index
        if index_hit_rate < 0.8:
            assert True  # Should investigate


class TestConcurrentDatabaseAccessInvariants:
    """Property-based tests for concurrent database access invariants."""

    @given(
        transaction_count=st.integers(min_value=1, max_value=1000),
        isolation_level=st.sampled_from(['READ_UNCOMMITTED', 'READ_COMMITTED', 'REPEATABLE_READ', 'SERIALIZABLE'])
    )
    @settings(max_examples=50)
    def test_concurrent_transactions(self, transaction_count, isolation_level):
        """INVARIANT: Concurrent transactions should be isolated."""
        # Invariant: Transaction count should be reasonable
        assert 1 <= transaction_count <= 1000, "Valid transaction count"

        # Invariant: Isolation level should be valid
        valid_levels = {'READ_UNCOMMITTED', 'READ_COMMITTED', 'REPEATABLE_READ', 'SERIALIZABLE'}
        assert isolation_level in valid_levels, f"Invalid isolation level: {isolation_level}"

    @given(
        lock_wait_time_ms=st.integers(min_value=0, max_value=60000)
    )
    @settings(max_examples=50)
    def test_lock_wait_timeout(self, lock_wait_time_ms):
        """INVARIANT: Lock waits should timeout."""
        max_wait = 60000  # 1 minute

        # Invariant: Wait time should not exceed maximum
        assert lock_wait_time_ms <= max_wait, \
            f"Lock wait {lock_wait_time_ms}ms exceeds maximum {max_wait}ms"

    @given(
        deadlock_count=st.integers(min_value=0, max_value=100)
    )
    @settings(max_examples=50)
    def test_deadlock_detection(self, deadlock_count):
        """INVARIANT: Deadlocks should be detected and resolved."""
        # Invariant: Deadlock count should be non-negative
        assert deadlock_count >= 0, "Non-negative deadlock count"

        # Invariant: Should detect and resolve deadlocks
        if deadlock_count > 0:
            assert True  # Should victimize one transaction

    @given(
        hot_table_access_count=st.integers(min_value=1, max_value=10000),
        total_access_count=st.integers(min_value=1, max_value=100000)
    )
    @settings(max_examples=50)
    def test_hotspot_detection(self, hot_table_access_count, total_access_count):
        """INVARIANT: Hot tables should be detected."""
        # Invariant: Access counts should be positive
        assert hot_table_access_count >= 1, "Positive hot table access"
        assert total_access_count >= 1, "Positive total access"

        # Calculate hotspot ratio (cap at 1.0 if hot > total)
        hotspot_ratio = min(1.0, hot_table_access_count / total_access_count if total_access_count > 0 else 0.0)

        # Invariant: Ratio should be in valid range
        assert 0.0 <= hotspot_ratio <= 1.0, f"Hotspot ratio {hotspot_ratio} out of bounds"

        # Invariant: High concentration indicates hotspot
        if hotspot_ratio > 0.5:
            assert True  # Should optimize access


class TestDataConsistencyInvariants:
    """Property-based tests for data consistency invariants."""

    @given(
        cascade_depth=st.integers(min_value=1, max_value=10)
    )
    @settings(max_examples=50)
    def test_cascade_delete_limits(self, cascade_depth):
        """INVARIANT: Cascade deletes should have depth limits."""
        max_depth = 10

        # Invariant: Depth should not exceed maximum
        assert cascade_depth <= max_depth, \
            f"Cascade depth {cascade_depth} exceeds maximum {max_depth}"

    @given(
        update_row_count=st.integers(min_value=1, max_value=100000)
    )
    @settings(max_examples=50)
    def test_bulk_update_limits(self, update_row_count):
        """INVARIANT: Bulk updates should have row count limits."""
        max_rows = 100000

        # Invariant: Row count should not exceed maximum
        assert update_row_count <= max_rows, \
            f"Update count {update_row_count} exceeds maximum {max_rows}"

    @given(
        trigger_chain_length=st.integers(min_value=1, max_value=20)
    )
    @settings(max_examples=50)
    def test_trigger_chain_limits(self, trigger_chain_length):
        """INVARIANT: Trigger chains should have length limits."""
        max_chain = 20

        # Invariant: Chain length should not exceed maximum
        assert trigger_chain_length <= max_chain, \
            f"Trigger chain {trigger_chain_length} exceeds maximum {max_chain}"

    @given(
        parent_rows=st.integers(min_value=1, max_value=1000),
        child_rows=st.integers(min_value=0, max_value=10000)
    )
    @settings(max_examples=50)
    def test_referential_integrity(self, parent_rows, child_rows):
        """INVARIANT: Referential integrity should be maintained."""
        # Invariant: Parent count should be positive
        assert parent_rows >= 1, "Positive parent row count"

        # Invariant: Child count should be non-negative
        assert child_rows >= 0, "Non-negative child row count"

        # Invariant: Orphaned children should be prevented
        if child_rows > 0:
            assert True  # Should validate parent exists