use serde::Serialize;
use std::fs::DirEntry;
use std::{io, env};
use rocket::serde::json::Json;

#[derive(Serialize)]
pub struct Category {
    name: String,
    // NOTE: this is simply a URI pathname
    // EXAMPLE: /thumbnail/<category>/.thumbnail.png
    thumbnail: String
}

#[derive(Serialize)]
struct List {
    categories: Vec<Category>
}
fn get_category_dirs(path: &str) -> std::io::Result<Vec<DirEntry>> {
    let path = std::path::Path::new(path);
    if !path.is_dir() {
        let e = io::Error::new(io::ErrorKind::NotFound, "Unable to open");
        return Err(e);
    }

    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()
    };

    let mut cats: Vec<Category> = Vec::new();
    if let Ok(dirs) = get_category_dirs(&dir) {
        // Let's just assume that each item in this directory is a folder
        // That way we can do this blindly without 9999 allocs
        for d in dirs {
            let name = d.file_name().to_string_lossy().to_string();
            let thumbnail = format!("/thumbnail/{}/category-thumbnail.jpg", name);
            cats.push(Category {name, thumbnail});
        }
    }
    Json(cats)
}