* /api/categories/<cat> is now working properly

Output should be correct for the frontend

api/src/category.rs

@@ -0,0 +1,81 @@
+use base64;
+use serde::Serialize;
+use std::fs::DirEntry;
+use std::{io, env};
+use rocket::serde::json::Json;
+
+#[derive(Serialize)]
+pub struct Category {
+    name: String,
+    thumbnail: Option<String>
+}
+
+#[derive(Serialize)]
+struct List {
+    categories: Vec<Category>
+}
+
+
+
+fn get_category_metadata(entry: DirEntry) -> io::Result<(String, Option<String>)> {
+    use std::io::Read;
+    let name = entry.file_name().to_string_lossy().to_string();
+    let mut p = entry.path(); p.push(".thumbnail.jpg");
+    if p.is_file() {
+        let mut buf = Vec::new();
+        let mut file = std::fs::File::open(p)?;
+        file.read_to_end(&mut buf)?;
+
+        let nail = base64::encode(buf).to_string();
+        return match nail.len() {
+            0 => Ok((name, None)),
+            _ => Ok((name, Some(nail)))
+        };
+    }
+    return Ok((String::new(), None));
+}
+
+fn get_category_dirs(path: &str) -> std::io::Result<Vec<DirEntry>> {
+    let path = std::path::Path::new(path);
+    if !path.is_dir() {
+        panic!("<{:?}> is not a valid directory", path);
+    }
+
+    let mut ret: Vec<DirEntry> = Vec::new();
+    for entry in std::fs::read_dir(path)? {
+        if let Ok(entry) = entry {
+            ret.push(entry)
+        }
+    }
+    return Ok(ret);
+}
+
+#[get("/categories")]
+pub fn list() -> Json<Vec<Category>> {
+    // WARN: misconfigured servers are just going to get shafted and serve up
+    // a tonne of 500's
+    let dir = match env::var("CLIPS_DIR") {
+        Ok(val) => val,
+        Err(_) => "/media/clips/".to_string()
+    };
+    match get_category_dirs(&dir) {
+        Ok(entries) => { 
+            let mut cats: Vec<Category> = Vec::new();
+            for ent in entries {
+                match get_category_metadata(ent) {
+                    Ok((name, thumbnail)) => {
+                        cats.push(Category {name, thumbnail});
+                    },
+                    _  => continue
+                }
+                
+            }
+            return Json(cats);
+        },
+        Err(e) => {
+            eprintln!("ERROR: {}", e);
+        }
+    }
+    Json(Vec::new())
+}
+