/// ACC-1643 错误类型定义

use std::fmt;

#[derive(Debug, Clone)]
pub enum Acc1643Error {
    /// 未授权操作
    Unauthorized {
        operator: String,
        required_role: String,
    },
    
    /// 文档不存在
    DocumentNotFound {
        doc_id: String,
    },
    
    /// 文档类型无效
    InvalidDocumentType {
        doc_type: String,
    },
    
    /// 文档已存在
    DocumentAlreadyExists {
        doc_id: String,
    },
    
    /// 文档验证失败
    DocumentVerificationFailed {
        doc_id: String,
        reason: String,
    },
    
    /// 文档版本冲突
    VersionConflict {
        doc_id: String,
        expected_version: u64,
        actual_version: u64,
    },
    
    /// Merkle证明无效
    InvalidMerkleProof,
    
    /// 宪法收据无效
    InvalidConstitutionalReceipt {
        receipt_hash: String,
    },
}

impl fmt::Display for Acc1643Error {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        match self {
            Acc1643Error::Unauthorized { operator, required_role } => {
                write!(f, "Unauthorized: {} requires role {}", operator, required_role)
            }
            Acc1643Error::DocumentNotFound { doc_id } => {
                write!(f, "Document not found: {}", doc_id)
            }
            Acc1643Error::InvalidDocumentType { doc_type } => {
                write!(f, "Invalid document type: {}", doc_type)
            }
            Acc1643Error::DocumentAlreadyExists { doc_id } => {
                write!(f, "Document already exists: {}", doc_id)
            }
            Acc1643Error::DocumentVerificationFailed { doc_id, reason } => {
                write!(f, "Document verification failed for {}: {}", doc_id, reason)
            }
            Acc1643Error::VersionConflict { doc_id, expected_version, actual_version } => {
                write!(
                    f,
                    "Version conflict for {}: expected {}, got {}",
                    doc_id, expected_version, actual_version
                )
            }
            Acc1643Error::InvalidMerkleProof => {
                write!(f, "Invalid Merkle proof")
            }
            Acc1643Error::InvalidConstitutionalReceipt { receipt_hash } => {
                write!(f, "Invalid constitutional receipt: {}", receipt_hash)
            }
        }
    }
}

impl std::error::Error for Acc1643Error {}

pub type Result<T> = std::result::Result<T, Acc1643Error>;