noosphere-cli 0.17.0

//! Helpers for dealing with translation between slugs and files

use std::str::FromStr;

use anyhow::Result;
use noosphere_core::data::{ContentType, Header, MemoIpld};

/// Given a [MemoIpld], attempt to infer a file extension. A 'File-Extension' header
/// will be used (if present); otherwise, the extension will be inferred from
/// the 'Content-Type' header (again, if present).
pub fn infer_file_extension(memo: &MemoIpld) -> Result<Option<String>> {
    if let Some(extension) = memo.get_first_header(&Header::FileExtension) {
        return Ok(Some(extension));
    }

    Ok(match memo.content_type() {
        Some(content_type) => match content_type {
            ContentType::Subtext => Some("subtext".into()),
            ContentType::Sphere => Some("sphere".into()),
            ContentType::Bytes => None,
            ContentType::Unknown(content_type) => {
                match mime_guess::get_mime_extensions_str(&content_type) {
                    Some(extensions) => extensions.first().map(|str| String::from(*str)),
                    None => None,
                }
            }
            ContentType::Cbor => Some("json".into()),
            ContentType::Json => Some("cbor".into()),
            ContentType::Text => Some("txt".into()),
        },
        None => {
            warn!("No content type specified; cannot infer a file extension");
            None
        }
    })
}

/// Given a file extension, infer its mime
pub async fn infer_content_type(extension: &str) -> Result<ContentType> {
    // TODO(#558): User-specified/customized extension->mime mapping
    Ok(match extension {
        "subtext" => ContentType::Subtext,
        "sphere" => ContentType::Sphere,
        _ => ContentType::from_str(
            mime_guess::from_ext(extension)
                .first_raw()
                .unwrap_or("raw/bytes"),
        )?,
    })
}