use std::{
    collections::HashMap,
    convert::Infallible,
    error::Error,
    path::{Path, PathBuf},
    sync::Arc,
};

use tokio::io;
use tokio::sync::Mutex;

pub trait FileStore {
    type Err: Clone + Send + Error;

    fn is_stored(
        &self,
        name: &str,
    ) -> impl std::future::Future<Output = Result<bool, Self::Err>> + std::marker::Send;
    fn store(
        &self,
        name: &str,
        data: &[u8],
    ) -> impl std::future::Future<Output = Result<(), Self::Err>> + std::marker::Send;
    fn delete(
        &self,
        name: &str,
    ) -> impl std::future::Future<Output = Result<(), Self::Err>> + std::marker::Send;
}

#[derive(Clone, Debug)]
pub struct FilesMem {
    files: Arc<Mutex<HashMap<String, Vec<u8>>>>,
}

impl FilesMem {
    pub fn new() -> Self {
        Self {
            files: Arc::new(Mutex::new(HashMap::new())),
        }
    }
}

impl FileStore for FilesMem {
    type Err = Infallible;

    async fn is_stored(&self, name: &str) -> Result<bool, Self::Err> {
        Ok(self.files.lock().await.contains_key(name))
    }

    async fn store(&self, name: &str, data: &[u8]) -> Result<(), Self::Err> {
        self.files
            .lock()
            .await
            .insert(name.to_string(), data.to_owned());

        Ok(())
    }

    async fn delete(&self, name: &str) -> Result<(), Self::Err> {
        self.files.lock().await.remove(name);
        Ok(())
    }
}

#[cfg(not(target_arch = "wasm32"))]
#[derive(Clone, Debug)]
pub struct Files {
    root: PathBuf,
}

#[cfg(not(target_arch = "wasm32"))]
impl Files {
    pub fn new(root: impl AsRef<Path>) -> Self {
        let root = root.as_ref();
        let root = root.into();
        Self { root }
    }

    pub fn root(&self) -> &Path {
        &self.root
    }
}

#[cfg(not(target_arch = "wasm32"))]
impl FileStore for Files {
    type Err = Arc<io::Error>;

    async fn is_stored(&self, name: &str) -> Result<bool, Self::Err> {
        tracing::debug!("checking if {} is stored", name);
        // TODO: is this secure ;-;
        let name = name.replace("/", "").replace(".", "");
        let res = tokio::fs::try_exists(self.root.join(name))
            .await
            .map_err(|err| Arc::new(err));
        tracing::debug!("file check res: {:?}", res);
        res
    }

    async fn store(&self, name: &str, data: &[u8]) -> Result<(), Self::Err> {
        tracing::debug!("storing {} is stored", name);
        let name = name.replace("/", "").replace(".", "");
        let res = tokio::fs::write(self.root.join(name), data)
            .await
            .map_err(|err| Arc::new(err));
        tracing::debug!("file store res: {:?}", res);
        res
    }

    async fn delete(&self, name: &str) -> Result<(), Self::Err> {
        tracing::debug!("deleting {}", name);
        let name = name.replace("/", "").replace(".", "");
        let res = tokio::fs::remove_file(self.root.join(name))
            .await
            .map_err(|err| Arc::new(err));
        tracing::debug!("file delete res: {:?}", res);
        res
    }
}