foxhunt/common/tests/error_tests.rs

//! Comprehensive Error Factory Method and Trait Tests
//!
//! This module provides comprehensive tests for:
//! - CommonError factory methods (config, network, service, validation, internal, etc.)
//! - ErrorCategory Display trait implementations
//! - ErrorSeverity Display trait implementations
//! - Error categorization and classification
//! - Error source chains and downcasting
//! - Error message formatting
//! - Edge cases and boundary conditions

use common::error::{CommonError, ErrorCategory, ErrorSeverity, RetryStrategy};

// =============================================================================
// COMMON ERROR FACTORY METHODS
// =============================================================================

#[test]
fn test_common_error_config_factory() {
    let err = CommonError::config("Missing database URL");

    match &err {
        CommonError::Configuration(msg) => {
            assert_eq!(msg, "Missing database URL");
        },
        _ => panic!("Expected Configuration variant"),
    }

    // Test category
    assert_eq!(err.category(), ErrorCategory::Configuration);
    assert_eq!(err.severity(), ErrorSeverity::Critical);
    assert!(!err.is_retryable());
}

#[test]
fn test_common_error_config_factory_string_types() {
    // Test with &str
    let err1 = CommonError::config("test");
    assert!(matches!(err1, CommonError::Configuration(_)));

    // Test with String
    let err2 = CommonError::config(String::from("test"));
    assert!(matches!(err2, CommonError::Configuration(_)));

    // Test with format!
    let err3 = CommonError::config(format!("port {}", 8080));
    match err3 {
        CommonError::Configuration(msg) => assert_eq!(msg, "port 8080"),
        _ => panic!("Expected Configuration variant"),
    }
}

#[test]
fn test_common_error_network_factory() {
    let err = CommonError::network("Connection refused");

    match &err {
        CommonError::Network(msg) => {
            assert_eq!(msg, "Connection refused");
        },
        _ => panic!("Expected Network variant"),
    }

    // Test category
    assert_eq!(err.category(), ErrorCategory::Network);
    assert_eq!(err.severity(), ErrorSeverity::Error);
    assert!(err.is_retryable());
}

#[test]
fn test_common_error_network_factory_string_types() {
    // Test with &str
    let err1 = CommonError::network("timeout");
    assert!(matches!(err1, CommonError::Network(_)));

    // Test with String
    let err2 = CommonError::network(String::from("reset"));
    assert!(matches!(err2, CommonError::Network(_)));
}

#[test]
fn test_common_error_service_factory_all_categories() {
    // Test each ErrorCategory variant
    let categories = vec![
        ErrorCategory::MarketData,
        ErrorCategory::Trading,
        ErrorCategory::Network,
        ErrorCategory::System,
        ErrorCategory::Configuration,
        ErrorCategory::Validation,
        ErrorCategory::Critical,
        ErrorCategory::Connection,
        ErrorCategory::Authentication,
        ErrorCategory::RateLimit,
        ErrorCategory::Parse,
        ErrorCategory::Subscription,
        ErrorCategory::FinancialSafety,
        ErrorCategory::RiskManagement,
        ErrorCategory::Database,
        ErrorCategory::Broker,
        ErrorCategory::MachineLearning,
        ErrorCategory::Security,
        ErrorCategory::BusinessLogic,
        ErrorCategory::Resource,
        ErrorCategory::Development,
        ErrorCategory::Risk,
        ErrorCategory::ML,
        ErrorCategory::Other,
    ];

    for category in categories {
        let err = CommonError::service(category, "test message");

        match &err {
            CommonError::Service { category: cat, message } => {
                assert_eq!(*cat, category);
                assert_eq!(message, "test message");
            },
            _ => panic!("Expected Service variant for {:?}", category),
        }

        // Verify category method returns correct value
        assert_eq!(err.category(), category);
    }
}

#[test]
fn test_common_error_validation_factory() {
    let err = CommonError::validation("Price must be positive");

    match &err {
        CommonError::Validation(msg) => {
            assert_eq!(msg, "Price must be positive");
        },
        _ => panic!("Expected Validation variant"),
    }

    // Test category
    assert_eq!(err.category(), ErrorCategory::Validation);
    assert_eq!(err.severity(), ErrorSeverity::Warn);
    assert!(!err.is_retryable());
}

#[test]
fn test_common_error_internal_factory() {
    let err = CommonError::internal("Unexpected state");

    match &err {
        CommonError::Service { category, message } => {
            assert_eq!(*category, ErrorCategory::System);
            assert_eq!(message, "Internal error: Unexpected state");
        },
        _ => panic!("Expected Service variant"),
    }

    // Test category
    assert_eq!(err.category(), ErrorCategory::System);
}

#[test]
fn test_common_error_timeout_factory() {
    let err = CommonError::timeout(5000, 3000);

    match err {
        CommonError::Timeout { actual_ms, max_ms } => {
            assert_eq!(actual_ms, 5000);
            assert_eq!(max_ms, 3000);
        },
        _ => panic!("Expected Timeout variant"),
    }

    // Test category
    assert_eq!(err.category(), ErrorCategory::System);
    assert_eq!(err.severity(), ErrorSeverity::Error);
    assert!(err.is_retryable());
}

#[test]
fn test_common_error_ml_factory() {
    let err = CommonError::ml("MAMBA-2", "Model not found");

    match &err {
        CommonError::Service { category, message } => {
            assert_eq!(*category, ErrorCategory::MachineLearning);
            assert_eq!(message, "MAMBA-2: Model not found");
        },
        _ => panic!("Expected Service variant"),
    }

    // Test category
    assert_eq!(err.category(), ErrorCategory::MachineLearning);
}

#[test]
fn test_common_error_ml_factory_string_types() {
    // Test with &str
    let err1 = CommonError::ml("model1", "error1");
    assert!(matches!(err1, CommonError::Service { .. }));

    // Test with String
    let err2 = CommonError::ml(String::from("model2"), String::from("error2"));
    match err2 {
        CommonError::Service { message, .. } => {
            assert_eq!(message, "model2: error2");
        },
        _ => panic!("Expected Service variant"),
    }
}

#[test]
fn test_common_error_serialization_factory() {
    let err = CommonError::serialization("Failed to parse JSON");

    match &err {
        CommonError::Service { category, message } => {
            assert_eq!(*category, ErrorCategory::Parse);
            assert_eq!(message, "Serialization error: Failed to parse JSON");
        },
        _ => panic!("Expected Service variant"),
    }

    // Test category
    assert_eq!(err.category(), ErrorCategory::Parse);
}

#[test]
fn test_common_error_resource_exhausted_factory() {
    let err = CommonError::resource_exhausted("Memory pool");

    match &err {
        CommonError::Service { category, message } => {
            assert_eq!(*category, ErrorCategory::Resource);
            assert_eq!(message, "Resource exhausted: Memory pool");
        },
        _ => panic!("Expected Service variant"),
    }

    // Test category
    assert_eq!(err.category(), ErrorCategory::Resource);
}

// =============================================================================
// ERROR CATEGORY DISPLAY TRAIT
// =============================================================================

#[test]
fn test_error_category_display_all_variants() {
    let test_cases = vec![
        (ErrorCategory::MarketData, "MARKET_DATA"),
        (ErrorCategory::Trading, "TRADING"),
        (ErrorCategory::Network, "NETWORK"),
        (ErrorCategory::System, "SYSTEM"),
        (ErrorCategory::Configuration, "CONFIGURATION"),
        (ErrorCategory::Validation, "VALIDATION"),
        (ErrorCategory::Critical, "CRITICAL"),
        (ErrorCategory::Connection, "CONNECTION"),
        (ErrorCategory::Authentication, "AUTHENTICATION"),
        (ErrorCategory::RateLimit, "RATE_LIMIT"),
        (ErrorCategory::Parse, "PARSE"),
        (ErrorCategory::Subscription, "SUBSCRIPTION"),
        (ErrorCategory::FinancialSafety, "FINANCIAL_SAFETY"),
        (ErrorCategory::RiskManagement, "RISK_MANAGEMENT"),
        (ErrorCategory::Database, "DATABASE"),
        (ErrorCategory::Broker, "BROKER"),
        (ErrorCategory::MachineLearning, "MACHINE_LEARNING"),
        (ErrorCategory::Security, "SECURITY"),
        (ErrorCategory::BusinessLogic, "BUSINESS_LOGIC"),
        (ErrorCategory::Resource, "RESOURCE"),
        (ErrorCategory::Development, "DEVELOPMENT"),
        (ErrorCategory::Risk, "RISK"),
        (ErrorCategory::ML, "ML"),
        (ErrorCategory::Other, "OTHER"),
    ];

    for (category, expected) in test_cases {
        assert_eq!(format!("{}", category), expected);
        assert_eq!(category.to_string(), expected);
    }
}

#[test]
fn test_error_category_debug_format() {
    let category = ErrorCategory::Trading;
    let debug_str = format!("{:?}", category);
    assert_eq!(debug_str, "Trading");
}

// =============================================================================
// ERROR SEVERITY DISPLAY TRAIT
// =============================================================================

#[test]
fn test_error_severity_display_all_variants() {
    let test_cases = vec![
        (ErrorSeverity::Debug, "DEBUG"),
        (ErrorSeverity::Info, "INFO"),
        (ErrorSeverity::Warn, "WARN"),
        (ErrorSeverity::Error, "ERROR"),
        (ErrorSeverity::Critical, "CRITICAL"),
    ];

    for (severity, expected) in test_cases {
        assert_eq!(format!("{}", severity), expected);
        assert_eq!(severity.to_string(), expected);
    }
}

#[test]
fn test_error_severity_debug_format() {
    let severity = ErrorSeverity::Critical;
    let debug_str = format!("{:?}", severity);
    assert_eq!(debug_str, "Critical");
}

// =============================================================================
// COMMON ERROR DISPLAY TRAIT
// =============================================================================

#[test]
fn test_common_error_display_configuration() {
    let err = CommonError::config("Missing API key");
    let display = format!("{}", err);
    assert_eq!(display, "Configuration error: Missing API key");
}

#[test]
fn test_common_error_display_network() {
    let err = CommonError::network("Connection timeout");
    let display = format!("{}", err);
    assert_eq!(display, "Network error: Connection timeout");
}

#[test]
fn test_common_error_display_service() {
    let err = CommonError::service(ErrorCategory::Trading, "Order rejected");
    let display = format!("{}", err);
    assert_eq!(display, "Service error: TRADING - Order rejected");
}

#[test]
fn test_common_error_display_validation() {
    let err = CommonError::validation("Invalid symbol");
    let display = format!("{}", err);
    assert_eq!(display, "Validation error: Invalid symbol");
}

#[test]
fn test_common_error_display_timeout() {
    let err = CommonError::timeout(5000, 3000);
    let display = format!("{}", err);
    assert_eq!(display, "Timeout error: operation took 5000ms, max allowed 3000ms");
}

#[test]
fn test_common_error_display_database() {
    use common::database::DatabaseError;
    let err = CommonError::Database(DatabaseError::PoolExhausted);
    let display = format!("{}", err);
    assert!(display.starts_with("Database error:"));
}

// =============================================================================
// ERROR CATEGORIZATION AND CLASSIFICATION
// =============================================================================

#[test]
fn test_common_error_category_method() {
    // Test that category() returns correct category for each variant
    assert_eq!(
        CommonError::config("test").category(),
        ErrorCategory::Configuration
    );

    assert_eq!(
        CommonError::network("test").category(),
        ErrorCategory::Network
    );

    assert_eq!(
        CommonError::validation("test").category(),
        ErrorCategory::Validation
    );

    assert_eq!(
        CommonError::timeout(1000, 500).category(),
        ErrorCategory::System
    );

    assert_eq!(
        CommonError::service(ErrorCategory::Trading, "test").category(),
        ErrorCategory::Trading
    );
}

#[test]
fn test_common_error_severity_classification() {
    // Critical severity
    assert_eq!(
        CommonError::config("test").severity(),
        ErrorSeverity::Critical
    );

    // Error severity
    assert_eq!(
        CommonError::network("test").severity(),
        ErrorSeverity::Error
    );

    assert_eq!(
        CommonError::timeout(1000, 500).severity(),
        ErrorSeverity::Error
    );

    // Warn severity
    assert_eq!(
        CommonError::validation("test").severity(),
        ErrorSeverity::Warn
    );
}

#[test]
fn test_common_error_is_retryable() {
    // Non-retryable errors
    assert!(!CommonError::config("test").is_retryable());
    assert!(!CommonError::validation("test").is_retryable());
    assert!(!CommonError::service(ErrorCategory::Authentication, "test").is_retryable());
    assert!(!CommonError::service(ErrorCategory::Configuration, "test").is_retryable());
    assert!(!CommonError::service(ErrorCategory::Validation, "test").is_retryable());

    // Retryable errors
    assert!(CommonError::network("test").is_retryable());
    assert!(CommonError::timeout(1000, 500).is_retryable());
    assert!(CommonError::service(ErrorCategory::Network, "test").is_retryable());
    assert!(CommonError::service(ErrorCategory::Trading, "test").is_retryable());
}

// =============================================================================
// RETRY STRATEGY MAX ATTEMPTS
// =============================================================================

#[test]
fn test_retry_strategy_max_attempts() {
    assert_eq!(RetryStrategy::NoRetry.max_attempts(), Some(0));
    assert_eq!(RetryStrategy::Immediate.max_attempts(), Some(3));
    assert_eq!(
        RetryStrategy::Linear { base_delay_ms: 100 }.max_attempts(),
        Some(5)
    );
    assert_eq!(
        RetryStrategy::Exponential {
            base_delay_ms: 100,
            max_delay_ms: 10000
        }.max_attempts(),
        Some(7)
    );
    assert_eq!(RetryStrategy::CircuitBreaker.max_attempts(), Some(1));
}

// =============================================================================
// ERROR MESSAGE FORMATTING EDGE CASES
// =============================================================================

#[test]
fn test_common_error_empty_message() {
    let err = CommonError::config("");
    let display = format!("{}", err);
    assert_eq!(display, "Configuration error: ");
}

#[test]
fn test_common_error_special_characters() {
    let err = CommonError::network("Connection\nreset\tby\rpeer");
    match err {
        CommonError::Network(msg) => {
            assert!(msg.contains('\n'));
            assert!(msg.contains('\t'));
            assert!(msg.contains('\r'));
        },
        _ => panic!("Expected Network variant"),
    }
}

#[test]
fn test_common_error_unicode_message() {
    let err = CommonError::validation("Invalid symbol: ¥€£");
    match err {
        CommonError::Validation(msg) => {
            assert!(msg.contains('¥'));
            assert!(msg.contains('€'));
            assert!(msg.contains('£'));
        },
        _ => panic!("Expected Validation variant"),
    }
}

#[test]
fn test_common_error_very_long_message() {
    let long_msg = "x".repeat(10000);
    let err = CommonError::internal(&long_msg);

    match err {
        CommonError::Service { message, .. } => {
            assert_eq!(message.len(), 10000 + "Internal error: ".len());
        },
        _ => panic!("Expected Service variant"),
    }
}

// =============================================================================
// ERROR CATEGORY SERDE SERIALIZATION/DESERIALIZATION
// =============================================================================

#[test]
fn test_error_category_serde_round_trip() {
    use serde_json;

    let categories = vec![
        ErrorCategory::MarketData,
        ErrorCategory::Trading,
        ErrorCategory::Critical,
        ErrorCategory::MachineLearning,
    ];

    for category in categories {
        // Serialize
        let json = serde_json::to_string(&category).expect("Failed to serialize");

        // Deserialize
        let deserialized: ErrorCategory = serde_json::from_str(&json)
            .expect("Failed to deserialize");

        assert_eq!(category, deserialized);
    }
}

#[test]
fn test_error_severity_serde_round_trip() {
    use serde_json;

    let severities = vec![
        ErrorSeverity::Debug,
        ErrorSeverity::Info,
        ErrorSeverity::Warn,
        ErrorSeverity::Error,
        ErrorSeverity::Critical,
    ];

    for severity in severities {
        // Serialize
        let json = serde_json::to_string(&severity).expect("Failed to serialize");

        // Deserialize
        let deserialized: ErrorSeverity = serde_json::from_str(&json)
            .expect("Failed to deserialize");

        assert_eq!(severity, deserialized);
    }
}

// =============================================================================
// ERROR CATEGORY EQUALITY AND COMPARISON
// =============================================================================

#[test]
fn test_error_category_equality() {
    assert_eq!(ErrorCategory::Trading, ErrorCategory::Trading);
    assert_ne!(ErrorCategory::Trading, ErrorCategory::MarketData);

    // Test ML and MachineLearning are different variants
    assert_ne!(ErrorCategory::ML, ErrorCategory::MachineLearning);
}

#[test]
fn test_error_category_clone() {
    let category = ErrorCategory::Trading;
    let cloned = category;
    assert_eq!(category, cloned);
}

#[test]
fn test_error_category_copy() {
    let category = ErrorCategory::Trading;
    let copied = category; // Copy trait allows this
    assert_eq!(category, copied);
}

#[test]
fn test_error_severity_equality() {
    assert_eq!(ErrorSeverity::Error, ErrorSeverity::Error);
    assert_ne!(ErrorSeverity::Error, ErrorSeverity::Critical);
}

// =============================================================================
// RETRY STRATEGY SERDE
// =============================================================================

#[test]
fn test_retry_strategy_serde_round_trip() {
    use serde_json;

    let strategies = vec![
        RetryStrategy::NoRetry,
        RetryStrategy::Immediate,
        RetryStrategy::Linear { base_delay_ms: 100 },
        RetryStrategy::Exponential {
            base_delay_ms: 100,
            max_delay_ms: 10000,
        },
        RetryStrategy::CircuitBreaker,
    ];

    for strategy in strategies {
        // Serialize
        let json = serde_json::to_string(&strategy).expect("Failed to serialize");

        // Deserialize
        let deserialized: RetryStrategy = serde_json::from_str(&json)
            .expect("Failed to deserialize");

        assert_eq!(strategy, deserialized);
    }
}

// =============================================================================
// ERROR FACTORY METHODS WITH EDGE CASES
// =============================================================================

#[test]
fn test_common_error_timeout_zero_values() {
    let err = CommonError::timeout(0, 0);
    match err {
        CommonError::Timeout { actual_ms, max_ms } => {
            assert_eq!(actual_ms, 0);
            assert_eq!(max_ms, 0);
        },
        _ => panic!("Expected Timeout variant"),
    }
}

#[test]
fn test_common_error_timeout_max_values() {
    let err = CommonError::timeout(u64::MAX, u64::MAX);
    match err {
        CommonError::Timeout { actual_ms, max_ms } => {
            assert_eq!(actual_ms, u64::MAX);
            assert_eq!(max_ms, u64::MAX);
        },
        _ => panic!("Expected Timeout variant"),
    }
}

#[test]
fn test_common_error_timeout_actual_less_than_max() {
    // Even though actual < max, the error should still be created
    let err = CommonError::timeout(100, 5000);
    match err {
        CommonError::Timeout { actual_ms, max_ms } => {
            assert_eq!(actual_ms, 100);
            assert_eq!(max_ms, 5000);
        },
        _ => panic!("Expected Timeout variant"),
    }
}

// =============================================================================
// COMMON ERROR DEBUG TRAIT
// =============================================================================

#[test]
fn test_common_error_debug_format() {
    let err = CommonError::config("test");
    let debug = format!("{:?}", err);
    assert!(debug.contains("Configuration"));
    assert!(debug.contains("test"));
}

#[test]
fn test_common_error_service_debug_format() {
    let err = CommonError::service(ErrorCategory::Trading, "test");
    let debug = format!("{:?}", err);
    assert!(debug.contains("Service"));
    assert!(debug.contains("Trading"));
    assert!(debug.contains("test"));
}

// =============================================================================
// ERROR DOWNCAST AND SOURCE CHAINS
// =============================================================================

#[test]
fn test_common_error_implements_error_trait() {
    use std::error::Error;

    let err: Box<dyn Error> = Box::new(CommonError::config("test"));
    assert!(err.source().is_none()); // No underlying cause
}

#[test]
fn test_common_error_database_has_source() {
    use std::error::Error;
    use common::database::DatabaseError;

    let db_err = DatabaseError::PoolExhausted;
    let err = CommonError::from(db_err);

    let err_ref: &dyn Error = &err;
    // DatabaseError should be the source
    assert!(err_ref.source().is_some());
}

// =============================================================================
// RETRY STRATEGY CALCULATE DELAY EDGE CASES
// =============================================================================

#[test]
fn test_retry_strategy_linear_large_attempt() {
    let strategy = RetryStrategy::Linear { base_delay_ms: 1000 };

    // Very large attempt number should not panic (saturating math)
    let delay = strategy.calculate_delay(u32::MAX).expect("should have delay");
    assert!(delay.as_millis() > 0);
}

#[test]
fn test_retry_strategy_exponential_overflow_protection() {
    let strategy = RetryStrategy::Exponential {
        base_delay_ms: u64::MAX,
        max_delay_ms: 1000,
    };

    // Should cap at max_delay_ms and not panic
    let delay = strategy.calculate_delay(10).expect("should have delay");
    assert!(delay.as_millis() <= 1000);
}

#[test]
fn test_retry_strategy_exponential_attempt_capping() {
    let strategy = RetryStrategy::Exponential {
        base_delay_ms: 100,
        max_delay_ms: 100000,
    };

    // Attempts > 10 should be capped to prevent overflow
    let delay_10 = strategy.calculate_delay(10).expect("should have delay");
    let delay_20 = strategy.calculate_delay(20).expect("should have delay");

    // Both should use min(10) in the calculation
    assert_eq!(delay_10.as_millis(), delay_20.as_millis());
}

// =============================================================================
// COMBINED ERROR SCENARIOS
// =============================================================================

#[test]
fn test_combined_error_categorization_and_retry() {
    // Test that categorization and retry strategy are consistent

    // Non-retryable configuration error
    let err = CommonError::config("test");
    assert_eq!(err.category(), ErrorCategory::Configuration);
    assert!(!err.is_retryable());
    assert!(matches!(err.retry_strategy(), RetryStrategy::NoRetry));

    // Retryable network error
    let err = CommonError::network("test");
    assert_eq!(err.category(), ErrorCategory::Network);
    assert!(err.is_retryable());
    assert!(matches!(err.retry_strategy(), RetryStrategy::Linear { .. }));
}

#[test]
fn test_error_severity_matches_category() {
    // Critical categories should have Critical or Error severity
    let critical_err = CommonError::service(ErrorCategory::Critical, "test");
    assert_eq!(critical_err.severity(), ErrorSeverity::Critical);

    let financial_err = CommonError::service(ErrorCategory::FinancialSafety, "test");
    assert_eq!(financial_err.severity(), ErrorSeverity::Critical);

    let auth_err = CommonError::service(ErrorCategory::Authentication, "test");
    assert_eq!(auth_err.severity(), ErrorSeverity::Critical);

    // Trading should be Error severity
    let trade_err = CommonError::service(ErrorCategory::Trading, "test");
    assert_eq!(trade_err.severity(), ErrorSeverity::Error);
}

#[test]
fn test_error_factory_consistency() {
    // Test that factory methods create consistent error structures

    // config() should create Configuration variant
    let err = CommonError::config("test");
    assert!(matches!(err, CommonError::Configuration(_)));

    // network() should create Network variant
    let err = CommonError::network("test");
    assert!(matches!(err, CommonError::Network(_)));

    // validation() should create Validation variant
    let err = CommonError::validation("test");
    assert!(matches!(err, CommonError::Validation(_)));

    // internal() should create Service variant with System category
    let err = CommonError::internal("test");
    match err {
        CommonError::Service { category, .. } => {
            assert_eq!(category, ErrorCategory::System);
        },
        _ => panic!("Expected Service variant"),
    }
}