//! Centralized error definitions for atproto-calendar-import
//!
//! All errors follow the format: `error-atproto-calendar-<domain>-<code> <msg>: <details>`

use thiserror::Error;

#[derive(Debug, Error)]
pub enum CalendarImportError {
    // Authentication errors (1xx)
    #[error("error-atproto-calendar-auth-101 OAuth2 token retrieval failed: {0}")]
    OAuth2TokenFailed(String),
    
    #[error("error-atproto-calendar-auth-102 Invalid access token: {0}")]
    InvalidAccessToken(String),
    
    #[error("error-atproto-calendar-auth-103 Token refresh failed: {0}")]
    TokenRefreshFailed(String),
    
    #[error("error-atproto-calendar-auth-104 AT Protocol authentication failed: {0}")]
    AtProtocolAuthFailed(String),
    
    // Import errors (2xx)
    #[error("error-atproto-calendar-import-201 Google Calendar API request failed: {0}")]
    GoogleApiError(String),
    
    #[error("error-atproto-calendar-import-202 Outlook Graph API request failed: {0}")]
    OutlookApiError(String),
    
    #[error("error-atproto-calendar-import-203 Failed to parse calendar event: {0}")]
    EventParseError(String),
    
    #[error("error-atproto-calendar-import-204 Network request failed: {0}")]
    NetworkError(String),
    
    #[error("error-atproto-calendar-import-205 Rate limit exceeded for provider: {0}")]
    RateLimitExceeded(String),
    
    // Transform errors (3xx)
    #[error("error-atproto-calendar-transform-301 Invalid datetime format: {0}")]
    InvalidDateTimeFormat(String),
    
    #[error("error-atproto-calendar-transform-302 Missing required field: {0}")]
    MissingRequiredField(String),
    
    #[error("error-atproto-calendar-transform-303 Field validation failed: {field} - {reason}")]
    FieldValidationError { field: String, reason: String },
    
    #[error("error-atproto-calendar-transform-304 Event serialization failed: {0}")]
    SerializationError(String),
    
    // PDS errors (4xx)
    #[error("error-atproto-calendar-pds-401 Failed to connect to PDS: {0}")]
    PdsConnectionError(String),
    
    #[error("error-atproto-calendar-pds-402 Failed to write record to repository: {0}")]
    PdsWriteError(String),
    
    #[error("error-atproto-calendar-pds-403 Repository not found: {0}")]
    RepositoryNotFound(String),
    
    #[error("error-atproto-calendar-pds-404 Invalid collection name: {0}")]
    InvalidCollection(String),
    
    #[error("error-atproto-calendar-pds-405 Record validation failed: {0}")]
    RecordValidationError(String),
    
    // Deduplication errors (5xx)
    #[error("error-atproto-calendar-dedup-501 Failed to access cache: {0}")]
    CacheAccessError(String),
    
    #[error("error-atproto-calendar-dedup-502 Hash generation failed: {0}")]
    HashGenerationError(String),
    
    #[error("error-atproto-calendar-dedup-503 Cache corruption detected: {0}")]
    CacheCorruption(String),
    
    // Configuration errors (6xx)
    #[error("error-atproto-calendar-config-601 Missing environment variable: {0}")]
    MissingEnvironmentVariable(String),
    
    #[error("error-atproto-calendar-config-602 Invalid configuration value: {key} - {reason}")]
    InvalidConfigValue { key: String, reason: String },
    
    #[error("error-atproto-calendar-config-603 Configuration file not found: {0}")]
    ConfigFileNotFound(String),
    
    // General errors (9xx)
    #[error("error-atproto-calendar-general-901 Internal error: {0}")]
    InternalError(String),
    
    #[error("error-atproto-calendar-general-902 Operation timeout: {0}")]
    TimeoutError(String),
    
    #[error("error-atproto-calendar-general-903 Feature not implemented: {0}")]
    NotImplemented(String),
}

impl From<reqwest::Error> for CalendarImportError {
    fn from(error: reqwest::Error) -> Self {
        CalendarImportError::NetworkError(error.to_string())
    }
}

impl From<serde_json::Error> for CalendarImportError {
    fn from(error: serde_json::Error) -> Self {
        CalendarImportError::SerializationError(error.to_string())
    }
}

impl From<chrono::ParseError> for CalendarImportError {
    fn from(error: chrono::ParseError) -> Self {
        CalendarImportError::InvalidDateTimeFormat(error.to_string())
    }
}

impl From<std::env::VarError> for CalendarImportError {
    fn from(error: std::env::VarError) -> Self {
        match error {
            std::env::VarError::NotPresent => {
                CalendarImportError::MissingEnvironmentVariable("Variable not set".to_string())
            }
            std::env::VarError::NotUnicode(_) => {
                CalendarImportError::InvalidConfigValue {
                    key: "environment_variable".to_string(),
                    reason: "Contains invalid Unicode".to_string(),
                }
            }
        }
    }
}

impl From<anyhow::Error> for CalendarImportError {
    fn from(error: anyhow::Error) -> Self {
        CalendarImportError::InternalError(error.to_string())
    }
}

/// Result type alias for this crate
pub type Result<T> = std::result::Result<T, CalendarImportError>;