use serde::Serialize;
use std::fs::DirEntry;
use std::path::Path;
use std::io;
use rocket::serde::json::Json;
use crate::common::{get_clips_dir, thumbs_dir};

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

/// Returns a vector of category directories
pub fn get_category_dirs(path: &str) -> std::io::Result<Vec<DirEntry>> {
    let path = std::path::Path::new(path);
    // Trying to ignore non-directory entries
    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)?).flatten() {
        if entry.path().is_dir() {
            ret.push(entry)
        }
    }
    Ok(ret)
}

/// Will return the path to a category's thumb nail assuming it exists.
/// If nothing is found then it gives back the URI path to a not-found image
pub fn get_category_thumbnail(category: &str) -> std::io::Result<String> {
    let pathname = format!("{}/{}", thumbs_dir(), &category);
    let path = Path::new(&pathname);
    // Assume directory as we're only called from "safe" places
    let item = path.read_dir()?.find(|file| {
        if let Ok(file) = file {
            let name = file.file_name().into_string().unwrap();
            name == "category-thumbnail.jpg"
        } else {
            false
        }
    });

    return Ok(match item {
        Some(name) => {
            let name = name.unwrap().file_name().into_string().unwrap();
            format!("/thumbnail/{}/{}", category, name)
        },
        None => "/static/cantfindshit.jpg".to_string()
    })
}

/// WARN: misconfigured servers are just going to get shafted and serve up
/// a tonne of 500's
#[get("/categories")]
pub fn list() -> Json<Vec<Category>> {
    let dir = get_clips_dir();

    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 = match get_category_thumbnail(&name) {
                Ok(s) => s,
                _ => "/static/cantfindshit.jpg".to_string()
            };
            cats.push(Category {name, thumbnail});
        }
    }
    Json(cats)
}