use fluent::{FluentError};
use fluent_syntax::parser::ParserError;
use std::error::Error;
use std::fmt;
use unic_langid::LanguageIdentifier;

#[derive(Debug)]
pub enum I18nError {
    InvalidLanguage,
    LanguageResourceFailed(Vec<ParserError>),
    BundleLoadFailed(Vec<FluentError>),
    TemplateError(String),
    MissingTranslation {
        locale: LanguageIdentifier,
        message_id: String,
    },
}

impl fmt::Display for I18nError {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        match self {
            I18nError::InvalidLanguage => write!(f, "Invalid language identifier"),
            I18nError::LanguageResourceFailed(errors) => {
                write!(f, "Failed to parse language resource: {:?}", errors)
            }
            I18nError::BundleLoadFailed(errors) => {
                write!(f, "Failed to load bundle: {:?}", errors)
            }
            I18nError::TemplateError(msg) => write!(f, "Template error: {}", msg),
            I18nError::MissingTranslation { locale, message_id } => {
                write!(f, "Missing translation for '{}' in locale '{}'", message_id, locale)
            }
        }
    }
}

impl Error for I18nError {}