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())
}