// file: crates/knowledge-domain-lib/src/source.rs
// version: 3

//! Source identities independent of repository and forge providers.

/// Error returned when constructing an invalid source identifier.
#[derive(Clone, Copy, Debug, Eq, PartialEq)]
pub enum SourceIdError {
    /// The identifier is empty or contains only whitespace.
    Empty,
}

impl std::fmt::Display for crate::SourceIdError {
    fn fmt(&self, formatter: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        match self {
            crate::SourceIdError::Empty => return formatter.write_str("source identifier must not be empty"),
        }
    }
}

impl std::error::Error for crate::SourceIdError {}

/// Stable logical identifier of one configured content source.
#[derive(Clone, Debug, Eq, Hash, PartialEq)]
pub struct SourceId(String);

impl crate::SourceId {
    /// Build a source identifier without imposing a fixed repository count or provider syntax.
    pub fn new(value: &str) -> Result<crate::SourceId, crate::SourceIdError> {
        if value.trim().is_empty() {
            return Err(crate::SourceIdError::Empty);
        }
        return Ok(Self(value.to_owned()));
    }

    /// Return the identifier as text.
    pub fn as_str(&self) -> &str {
        return self.0.as_str();
    }
}

/// One logical content source associated with a semantic family.
#[derive(Clone, Debug, Eq, PartialEq)]
pub struct ContentSource {
    id: crate::SourceId,
    family: crate::ContentFamily,
}

impl crate::ContentSource {
    /// Build a content source from a textual source identifier.
    pub fn new(id: &str, family: crate::ContentFamily) -> Result<crate::ContentSource, crate::SourceIdError> {
        let source_id = match crate::SourceId::new(id) {
            Ok(value) => value,
            Err(error) => return Err(error),
        };
        return Ok(crate::ContentSource { id: source_id, family });
    }

    /// Return the logical source identifier.
    pub fn id(&self) -> &crate::SourceId {
        return &self.id;
    }

    /// Return the semantic content family.
    pub fn family(&self) -> crate::ContentFamily {
        return self.family;
    }
}

#[cfg(test)]
#[path = "../unit_tests/source.rs"]
mod tests;