monorepo/file-service/src/store/thumbnail.rs

use image::imageops::FilterType;
use std::fs::remove_file;
use std::path::{Path, PathBuf};

use super::{ReadFileError, WriteFileError};

#[derive(Clone, Debug, PartialEq)]
pub struct Thumbnail {
    pub path: PathBuf,
}

impl Thumbnail {
    pub fn open(
        origin_path: PathBuf,
        thumbnail_path: PathBuf,
    ) -> Result<Thumbnail, WriteFileError> {
        let s = Thumbnail {
            path: PathBuf::from(thumbnail_path),
        };

        if !s.path.exists() {
            let img = image::open(&origin_path)?;
            let tn = img.resize(640, 640, FilterType::Nearest);
            tn.save(&s.path)?;
        }

        Ok(s)
    }

    /*
    pub fn from_path(path: &Path) -> Result<Thumbnail, ReadFileError> {
        let id = path
            .file_name()
            .map(|s| String::from(s.to_string_lossy()))
            .ok_or(ReadFileError::NotAnImage(PathBuf::from(path)))?;

        let path = path
            .parent()
            .ok_or(ReadFileError::FileNotFound(PathBuf::from(path)))?;

        Thumbnail::open(&id, root)
    }
    */

    /*
    fn thumbnail_path(id: &str, root: &Path) -> PathBuf {
        let mut path = PathBuf::from(root);
        path.push(".thumbnails");
        path.push(id.clone());
        path
    }
    */

    pub fn stream(&self) -> Result<std::fs::File, ReadFileError> {
        std::fs::File::open(self.path.clone()).map_err(|err| {
            if err.kind() == std::io::ErrorKind::NotFound {
                ReadFileError::FileNotFound
            } else {
                ReadFileError::from(err)
            }
        })
    }

    pub fn delete(self) -> Result<(), WriteFileError> {
        remove_file(self.path).map_err(WriteFileError::from)
    }
}

#[cfg(test)]
mod test {
    use super::*;
    use crate::store::utils::FileCleanup;

    #[test]
    fn it_creates_a_thumbnail_if_one_does_not_exist() {
        let _ = FileCleanup(PathBuf::from("var/rawr.tn.png"));
        let _ = Thumbnail::open(
            PathBuf::from("fixtures/rawr.png"),
            PathBuf::from("var/rawr.tn.png"),
        )
        .expect("thumbnail open must work");
        assert!(Path::new("var/rawr.tn.png").is_file());
    }
}