/// A bunch of syntax sugar too make strongly typed sessions for Axum's sessions store
use crate::error_response;
use axum::extract::FromRequestParts;
use axum::http::StatusCode;
use axum::http::request::Parts;
use axum::response::Response;
use serde::{Deserialize, Serialize};
use std::collections::HashMap;
use std::fmt;
use tower_sessions::Session;

#[derive(Debug, Deserialize, Serialize, Clone)]
pub enum FlashMessage {
    Success(String),
    Error(String),
}

/// THis is the actual session store for axum sessions
#[derive(Debug, Deserialize, Serialize)]
struct SessionData {
    did: Option<String>,

    flash_message: HashMap<String, FlashMessage>,
}

impl Default for SessionData {
    fn default() -> Self {
        Self {
            did: None,
            flash_message: HashMap::new(),
        }
    }
}

pub struct AxumSessionStore {
    session: Session,
    data: SessionData,
}

/// How you actually interact with the session store
impl AxumSessionStore {
    const SESSION_DATA_KEY: &'static str = "session.data";

    pub fn _logged_in(&self) -> bool {
        self.data.did.is_some()
    }

    pub async fn set_did(&mut self, did: String) -> Result<(), tower_sessions::session::Error> {
        self.data.did = Some(did);
        Self::update_session(&self.session, &self.data).await
    }

    pub fn get_did(&self) -> Option<String> {
        self.data.did.clone()
    }

    ///Gets the message as well as removes it from the session
    pub async fn get_flash_message(
        &mut self,
        key: &str,
    ) -> Result<Option<FlashMessage>, tower_sessions::session::Error> {
        let message = self.data.flash_message.get(key).cloned();
        if message.is_some() {
            self.data.flash_message.remove(key);
            Self::update_session(&self.session, &self.data).await?
        }
        Ok(message)
    }

    pub async fn set_flash_message(
        &mut self,
        key: &str,
        message: FlashMessage,
    ) -> Result<(), tower_sessions::session::Error> {
        self.data.flash_message.insert(key.to_string(), message);
        Self::update_session(&self.session, &self.data).await
    }

    /// Make sure to call this or your session won't actually be saved
    async fn update_session(
        session: &Session,
        session_data: &SessionData,
    ) -> Result<(), tower_sessions::session::Error> {
        session.insert(Self::SESSION_DATA_KEY, session_data).await
    }
}

impl fmt::Display for AxumSessionStore {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        f.debug_struct("SessionStore")
            .field("did", &self.data.did)
            .finish()
    }
}

impl<S> FromRequestParts<S> for AxumSessionStore
where
    S: Send + Sync,
{
    type Rejection = (StatusCode, &'static str);

    async fn from_request_parts(req: &mut Parts, state: &S) -> Result<Self, Self::Rejection> {
        let session = Session::from_request_parts(req, state).await?;

        let data: SessionData = session
            .get(Self::SESSION_DATA_KEY)
            .await
            .unwrap()
            .unwrap_or_default();

        Ok(Self { session, data })
    }
}

/// Helper wrapper for handling http responses if theres an error
pub async fn set_flash_message(
    session: &mut AxumSessionStore,
    key: &str,
    flash_message: FlashMessage,
) -> Result<(), Response> {
    session
        .set_flash_message(key, flash_message)
        .await
        .map_err(|err| {
            log::error!("Error setting flash message: {err}");
            error_response(
                StatusCode::INTERNAL_SERVER_ERROR,
                "Error setting flash message",
            )
        })
}

/// Helper wrapper for handling http responses if theres an error
pub async fn get_flash_message(
    session: &mut AxumSessionStore,
    key: &str,
) -> Result<Option<FlashMessage>, Response> {
    match session.get_flash_message(key).await {
        Ok(message) => Ok(message),
        Err(err) => {
            log::error!("Error getting flash message: {err}");
            Err(error_response(
                StatusCode::INTERNAL_SERVER_ERROR,
                "Error getting flash message",
            ))
        }
    }
}