1 files changed, 66 insertions, 0 deletions
diff --git a/dichroism/src/image_service.rs b/dichroism/src/image_service.rs
new file mode 100644
index 0000000..b33d5c8
--- /dev/null
+++ b/dichroism/src/image_service.rs
@@ -0,0 +1,66 @@
+use crate::config::CONFIG_INSTANCE;
+use crate::constants::{PHOTO_BASE_XY, PHOTO_FULLSIZE_XY, PHOTO_THUMBNAIL_XY};
+use crate::error::DichroismError;
+use crate::models::{Photo, PhotoSet};
+use crate::result::Result;
+use base64::decode;
+use image::imageops::FilterType;
+use image::DynamicImage;
+use image::GenericImageView;
+use once_cell::sync::Lazy;
+use regex::Regex;
+use std::path::PathBuf;
+use uuid::Uuid;
+
+static DATA_URI_RE: Lazy<Regex> = Lazy::new(|| {
+    Regex::new("^data:image/(png|jpeg);base64,(?P<data>.+)")
+        .expect("Couldn't parse data URI Regex.")
+});
+
+// TODO: should be async so server threads don't block on FS access
+pub fn generate_photo_set(uri: &str) -> Result<PhotoSet> {
+    let data = DATA_URI_RE
+        .captures(uri)
+        .ok_or(DichroismError::UriDataExtract)?
+        .name("data")
+        .ok_or(DichroismError::UriDataExtract)?
+        .as_str();
+    let original = image::load_from_memory(&decode(data)?)?;
+    let fullsize = original.resize(PHOTO_FULLSIZE_XY, PHOTO_FULLSIZE_XY, FilterType::Lanczos3);
+    let base = original.resize(PHOTO_BASE_XY, PHOTO_BASE_XY, FilterType::Lanczos3);
+
+    let (width, height) = original.dimensions();
+    let thumbnail = if width > height {
+        let offset = (width - height) / 2;
+        original.crop_imm(offset, 0, width - offset * 2, height)
+    } else {
+        let offset = (height - width) / 2;
+        original.crop_imm(0, offset, width, height - offset * 2)
+    }
+    .resize(PHOTO_THUMBNAIL_XY, PHOTO_THUMBNAIL_XY, FilterType::Lanczos3);
+
+    Ok(PhotoSet {
+        id: None,
+        original: generate_photo(&original)?,
+        fullsize: generate_photo(&fullsize)?,
+        base: generate_photo(&base)?,
+        thumbnail: generate_photo(&thumbnail)?,
+    })
+}
+
+pub fn generate_photo(image: &DynamicImage) -> Result<Photo> {
+    let base_name = Uuid::new_v3(&Uuid::NAMESPACE_OID, &image.to_bytes())
+        .to_hyphenated()
+        .to_string();
+    let mut path = PathBuf::from(&CONFIG_INSTANCE.img_root);
+    path.push(base_name);
+    path.set_extension("jpg");
+    image.save(&path)?;
+
+    let id = path
+        .file_name()
+        .ok_or(DichroismError::ImageWrite)?
+        .to_str()
+        .ok_or(DichroismError::ImageWrite)?;
+    Ok(Photo::new(String::from(id)))
+}