// file: crates/common/game-assets-lib/src/resolver.rs
// version: 1

/// Resolves logical asset URIs against separate common and game roots.
#[derive(Clone, Debug, Eq, PartialEq)]
pub struct AssetResolver {
    common_root: std::path::PathBuf,
    game_root: std::path::PathBuf,
}

impl AssetResolver {
    /// Creates a resolver from physical common and game asset roots.
    #[must_use]
    pub fn new(common_root: impl Into<std::path::PathBuf>, game_root: impl Into<std::path::PathBuf>) -> Self {
        return Self { common_root: common_root.into(), game_root: game_root.into() };
    }

    /// Resolves `common://` or `game://` URI into a physical path without touching the filesystem.
    pub fn resolve(&self, uri: &str) -> Result<std::path::PathBuf, crate::AssetError> {
        let (root, relative) = if let Some(relative) = uri.strip_prefix("common://") {
            (&self.common_root, relative)
        } else if let Some(relative) = uri.strip_prefix("game://") {
            (&self.game_root, relative)
        } else {
            return Err(crate::AssetError::UnsupportedScheme);
        };
        if relative.is_empty() {
            return Err(crate::AssetError::EmptyPath);
        }
        let relative_path = std::path::Path::new(relative);
        if relative_path.is_absolute() || relative.contains('\\') {
            return Err(crate::AssetError::InvalidPath);
        }
        for component in relative_path.components() {
            if !matches!(component, std::path::Component::Normal(_)) {
                return Err(crate::AssetError::InvalidPath);
            }
        }
        return Ok(root.join(relative_path));
    }
}

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