zenith-foundation 0.1.0

//! 统一错误类型与错误处理规范
//!
//! 本模块定义 Zenith 框架的统一错误类型，
//! 所有错误都必须携带上下文信息，禁止返回裸错误。

use std::fmt;

/// 核心错误类型
#[derive(Debug, thiserror::Error)]
pub enum CoreError {
    /// 资源配额超限
    #[error("quota exceeded: limit={limit}, requested={requested}, resource={resource}")]
    QuotaExceeded {
        /// 资源类型
        resource: &'static str,
        /// 配额上限
        limit: u64,
        /// 请求数量
        requested: u64,
    },

    /// 资源未找到
    #[error("resource not found: id={id}, type={resource_type}")]
    ResourceNotFound {
        /// 资源ID
        id: u64,
        /// 资源类型
        resource_type: &'static str,
    },

    /// 资源已存在（重复创建）
    #[error("resource already exists: id={id}, type={resource_type}")]
    ResourceAlreadyExists {
        /// 资源ID
        id: u64,
        /// 资源类型
        resource_type: &'static str,
    },

    /// 资源已损坏
    #[error("resource poisoned: id={id}, reason={reason}")]
    ResourcePoisoned {
        /// 资源ID
        id: u64,
        /// 损坏原因
        reason: String,
    },

    /// 所有权错误
    #[error("ownership violation: expected={expected}, actual={actual}")]
    OwnershipViolation {
        /// 期望的所有者
        expected: &'static str,
        /// 实际的所有者
        actual: &'static str,
    },

    /// 地址范围无效
    #[error("invalid address range: addr={addr:x}, len={len}, max={max:x}")]
    InvalidAddressRange {
        /// 起始地址
        addr: u64,
        /// 长度
        len: u64,
        /// 最大地址
        max: u64,
    },

    /// 算术溢出
    #[error("arithmetic overflow: operation={op}, a={a}, b={b}")]
    ArithmeticOverflow {
        /// 操作符
        op: &'static str,
        /// 操作数a
        a: u64,
        /// 操作数b
        b: u64,
    },

    /// 状态冲突
    #[error("state conflict: current={current}, expected={expected}")]
    StateConflict {
        /// 当前状态
        current: String,
        /// 期望状态
        expected: String,
    },

    /// 无效配置
    #[error("invalid config: {field} — {reason}")]
    InvalidConfig {
        /// 配置字段名
        field: &'static str,
        /// 原因
        reason: &'static str,
    },

    /// 内部错误
    #[error("internal error: {0}")]
    Internal(String),

    /// 未知错误
    #[error("unknown error: {0}")]
    Unknown(String),
}

/// 核心结果类型
pub type CoreResult<T> = Result<T, CoreError>;

impl CoreError {
    /// 创建配额超限错误
    pub fn quota_exceeded(resource: &'static str, limit: u64, requested: u64) -> Self {
        CoreError::QuotaExceeded {
            resource,
            limit,
            requested,
        }
    }

    /// 创建资源未找到错误
    pub fn resource_not_found(id: u64, resource_type: &'static str) -> Self {
        CoreError::ResourceNotFound { id, resource_type }
    }

    /// 创建资源已存在错误
    pub fn resource_already_exists(id: u64, resource_type: &'static str) -> Self {
        CoreError::ResourceAlreadyExists {
            id,
            resource_type,
        }
    }

    /// 创建资源损坏错误
    pub fn resource_poisoned(id: u64, reason: impl Into<String>) -> Self {
        CoreError::ResourcePoisoned {
            id,
            reason: reason.into(),
        }
    }

    /// 创建所有权违规错误
    pub fn ownership_violation(expected: &'static str, actual: &'static str) -> Self {
        CoreError::OwnershipViolation { expected, actual }
    }

    /// 创建地址范围无效错误
    pub fn invalid_address_range(addr: u64, len: u64, max: u64) -> Self {
        CoreError::InvalidAddressRange { addr, len, max }
    }

    /// 创建算术溢出错误
    pub fn arithmetic_overflow(op: &'static str, a: u64, b: u64) -> Self {
        CoreError::ArithmeticOverflow { op, a, b }
    }

    /// 创建状态冲突错误
    pub fn state_conflict(current: impl Into<String>, expected: impl Into<String>) -> Self {
        CoreError::StateConflict {
            current: current.into(),
            expected: expected.into(),
        }
    }

    /// 创建无效配置错误
    pub fn invalid_config(field: &'static str, reason: &'static str) -> Self {
        CoreError::InvalidConfig { field, reason }
    }

    /// 创建内部错误
    pub fn internal(msg: impl Into<String>) -> Self {
        CoreError::Internal(msg.into())
    }

    /// 创建未知错误
    pub fn unknown(msg: impl Into<String>) -> Self {
        CoreError::Unknown(msg.into())
    }
}

/// 可记录的错误特征
pub trait LoggableError: fmt::Display {
    /// 是否为可恢复错误
    fn is_recoverable(&self) -> bool;

    /// 是否为安全相关错误
    fn is_security_related(&self) -> bool;

    /// 获取错误严重级别
    fn severity(&self) -> ErrorSeverity;
}

/// 错误严重级别（全 workspace 唯一定义）
///
/// 四级语义与其他平台错误体系的映射：
/// `Info`/`Warning`/`Error` 同名对应；`Critical` 即致命级
/// （等同部分平台错误体系中的 `Fatal`：系统不可用、不可恢复）。
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum ErrorSeverity {
    /// 信息级别（可恢复）
    Info,
    /// 警告级别（需要关注）
    Warning,
    /// 错误级别（操作失败）
    Error,
    /// 严重错误（致命级，等同 `Fatal`：系统不可用）
    Critical,
}

impl LoggableError for CoreError {
    fn is_recoverable(&self) -> bool {
        matches!(
            self,
            CoreError::QuotaExceeded { .. }
                | CoreError::ResourceNotFound { .. }
                | CoreError::ResourceAlreadyExists { .. }
        )
    }

    fn is_security_related(&self) -> bool {
        matches!(
            self,
            CoreError::OwnershipViolation { .. } | CoreError::InvalidAddressRange { .. }
        )
    }

    fn severity(&self) -> ErrorSeverity {
        match self {
            CoreError::OwnershipViolation { .. } => ErrorSeverity::Critical,
            CoreError::ResourcePoisoned { .. } => ErrorSeverity::Critical,
            CoreError::InvalidAddressRange { .. } => ErrorSeverity::Error,
            CoreError::ArithmeticOverflow { .. } => ErrorSeverity::Error,
            CoreError::StateConflict { .. } => ErrorSeverity::Warning,
            CoreError::InvalidConfig { .. } => ErrorSeverity::Warning,
            CoreError::QuotaExceeded { .. } => ErrorSeverity::Warning,
            CoreError::ResourceAlreadyExists { .. } => ErrorSeverity::Warning,
            CoreError::ResourceNotFound { .. } => ErrorSeverity::Info,
            CoreError::Internal(_) => ErrorSeverity::Error,
            CoreError::Unknown(_) => ErrorSeverity::Error,
        }
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn test_quota_exceeded_error() {
        let err = CoreError::quota_exceeded("frame", 1024, 2048);
        assert!(err.is_recoverable());
        assert!(!err.is_security_related());
        assert_eq!(err.severity(), ErrorSeverity::Warning);
        assert!(err.to_string().contains("frame"));
    }

    #[test]
    fn test_ownership_violation_error() {
        let err = CoreError::ownership_violation("pool", "other");
        assert!(!err.is_recoverable());
        assert!(err.is_security_related());
        assert_eq!(err.severity(), ErrorSeverity::Critical);
    }

    #[test]
    fn test_invalid_address_range_error() {
        let err = CoreError::invalid_address_range(0x1000, 256, 0x2000);
        assert!(!err.is_recoverable());
        assert!(err.is_security_related());
        assert_eq!(err.severity(), ErrorSeverity::Error);
    }

    #[test]
    fn test_arithmetic_overflow_error() {
        let err = CoreError::arithmetic_overflow("add", u64::MAX, 1);
        assert_eq!(err.severity(), ErrorSeverity::Error);
    }

    #[test]
    fn test_state_conflict_error() {
        let err = CoreError::state_conflict("active", "idle");
        assert_eq!(err.severity(), ErrorSeverity::Warning);
    }

    #[test]
    fn test_internal_error() {
        let err = CoreError::internal("something went wrong");
        assert_eq!(err.severity(), ErrorSeverity::Error);
    }

    // ===== CoreError 所有变体构造函数和 Display 输出 =====

    #[test]
    fn test_quota_exceeded_display() {
        let err = CoreError::quota_exceeded("memory", 1024, 2048);
        let msg = err.to_string();
        assert!(msg.contains("quota exceeded"));
        assert!(msg.contains("memory"));
        assert!(msg.contains("1024"));
        assert!(msg.contains("2048"));
    }

    #[test]
    fn test_resource_not_found_constructor_and_display() {
        let err = CoreError::resource_not_found(42, "frame");
        assert!(err.is_recoverable());
        assert!(!err.is_security_related());
        assert_eq!(err.severity(), ErrorSeverity::Info);

        let msg = err.to_string();
        assert!(msg.contains("resource not found"));
        assert!(msg.contains("42"));
        assert!(msg.contains("frame"));
    }

    #[test]
    fn test_resource_already_exists_constructor_and_display() {
        let err = CoreError::resource_already_exists(7, "connection");
        assert!(err.is_recoverable());
        assert!(!err.is_security_related());
        assert_eq!(err.severity(), ErrorSeverity::Warning);

        let msg = err.to_string();
        assert!(msg.contains("resource already exists"));
        assert!(msg.contains("7"));
        assert!(msg.contains("connection"));
    }

    #[test]
    fn test_resource_poisoned_constructor_and_display() {
        let err = CoreError::resource_poisoned(100, "corrupted data");
        assert!(!err.is_recoverable());
        assert!(!err.is_security_related());
        assert_eq!(err.severity(), ErrorSeverity::Critical);

        let msg = err.to_string();
        assert!(msg.contains("resource poisoned"));
        assert!(msg.contains("100"));
        assert!(msg.contains("corrupted data"));
    }

    #[test]
    fn test_ownership_violation_display() {
        let err = CoreError::ownership_violation("pool_a", "pool_b");
        let msg = err.to_string();
        assert!(msg.contains("ownership violation"));
        assert!(msg.contains("pool_a"));
        assert!(msg.contains("pool_b"));
    }

    #[test]
    fn test_invalid_address_range_display() {
        let err = CoreError::invalid_address_range(0x1000, 256, 0x2000);
        let msg = err.to_string();
        assert!(msg.contains("invalid address range"));
        assert!(msg.contains(&format!("{:x}", 0x1000)));
        assert!(msg.contains("256"));
    }

    #[test]
    fn test_arithmetic_overflow_display() {
        let err = CoreError::arithmetic_overflow("mul", 100, 200);
        let msg = err.to_string();
        assert!(msg.contains("arithmetic overflow"));
        assert!(msg.contains("mul"));
        assert!(msg.contains("100"));
        assert!(msg.contains("200"));
    }

    #[test]
    fn test_state_conflict_constructor_and_display() {
        let err = CoreError::state_conflict("running", "stopped");
        assert!(!err.is_recoverable());
        assert!(!err.is_security_related());
        assert_eq!(err.severity(), ErrorSeverity::Warning);

        let msg = err.to_string();
        assert!(msg.contains("state conflict"));
        assert!(msg.contains("running"));
        assert!(msg.contains("stopped"));
    }

    #[test]
    fn test_internal_error_constructor_and_display() {
        let err = CoreError::internal("fatal crash");
        assert!(!err.is_recoverable());
        assert!(!err.is_security_related());
        assert_eq!(err.severity(), ErrorSeverity::Error);

        let msg = err.to_string();
        assert!(msg.contains("internal error"));
        assert!(msg.contains("fatal crash"));
    }

    #[test]
    fn test_unknown_error_constructor_and_display() {
        let err = CoreError::unknown("mystery error");
        assert!(!err.is_recoverable());
        assert!(!err.is_security_related());
        assert_eq!(err.severity(), ErrorSeverity::Error);

        let msg = err.to_string();
        assert!(msg.contains("unknown error"));
        assert!(msg.contains("mystery error"));
    }

    // ===== ErrorSeverity 排序和比较 =====

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

    #[test]
    fn test_error_severity_clone_copy() {
        let s = ErrorSeverity::Warning;
        let s2 = s;
        assert_eq!(s, s2);
        let s3 = s;
        assert_eq!(s, s3);
    }

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

    // ===== is_recoverable / is_security_related 完整覆盖 =====

    #[test]
    fn test_all_recoverable_errors() {
        assert!(CoreError::quota_exceeded("mem", 0, 0).is_recoverable());
        assert!(CoreError::resource_not_found(0, "x").is_recoverable());
        assert!(CoreError::resource_already_exists(0, "x").is_recoverable());

        assert!(!CoreError::resource_poisoned(0, "x").is_recoverable());
        assert!(!CoreError::ownership_violation("a", "b").is_recoverable());
        assert!(!CoreError::invalid_address_range(0, 0, 0).is_recoverable());
        assert!(!CoreError::arithmetic_overflow("add", 0, 0).is_recoverable());
        assert!(!CoreError::state_conflict("a", "b").is_recoverable());
        assert!(!CoreError::internal("x").is_recoverable());
        assert!(!CoreError::unknown("x").is_recoverable());
    }

    #[test]
    fn test_all_security_related_errors() {
        assert!(CoreError::ownership_violation("a", "b").is_security_related());
        assert!(CoreError::invalid_address_range(0, 0, 0).is_security_related());

        assert!(!CoreError::quota_exceeded("mem", 0, 0).is_security_related());
        assert!(!CoreError::resource_not_found(0, "x").is_security_related());
        assert!(!CoreError::resource_already_exists(0, "x").is_security_related());
        assert!(!CoreError::resource_poisoned(0, "x").is_security_related());
        assert!(!CoreError::arithmetic_overflow("add", 0, 0).is_security_related());
        assert!(!CoreError::state_conflict("a", "b").is_security_related());
        assert!(!CoreError::internal("x").is_security_related());
        assert!(!CoreError::unknown("x").is_security_related());
    }

    // ===== LoggableError trait 对象安全测试 =====

    #[test]
    fn test_loggable_error_trait_object() {
        let err: Box<dyn LoggableError> = Box::new(CoreError::internal("test"));
        assert!(!err.is_recoverable());
        assert!(!err.is_security_related());
        assert_eq!(err.severity(), ErrorSeverity::Error);
        assert!(err.to_string().contains("internal error"));
    }
}