use common::message::{Request, Response};
use sdk::vanadium_client::{VAppClient, VAppExecutionError};

use sdk::comm::SendMessageError;

pub use sdk::{transport, vanadium_client};

#[derive(Debug)]
pub enum AtprotoAppClientError {
    VAppExecutionError(VAppExecutionError),
    SendMessageError(SendMessageError),
    InvalidResponse(&'static str),
    GenericError(&'static str),
}

impl From<VAppExecutionError> for AtprotoAppClientError {
    fn from(e: VAppExecutionError) -> Self {
        Self::VAppExecutionError(e)
    }
}

impl From<SendMessageError> for AtprotoAppClientError {
    fn from(e: SendMessageError) -> Self {
        Self::SendMessageError(e)
    }
}

impl From<&'static str> for AtprotoAppClientError {
    fn from(e: &'static str) -> Self {
        Self::GenericError(e)
    }
}

impl std::fmt::Display for AtprotoAppClientError {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        match self {
            AtprotoAppClientError::VAppExecutionError(e) => write!(f, "VAppExecutionError: {}", e),
            AtprotoAppClientError::SendMessageError(e) => write!(f, "SendMessageError: {}", e),
            AtprotoAppClientError::InvalidResponse(e) => write!(f, "InvalidResponse: {}", e),
            AtprotoAppClientError::GenericError(e) => write!(f, "GenericError: {}", e),
        }
    }
}

impl std::error::Error for AtprotoAppClientError {
    fn source(&self) -> Option<&(dyn std::error::Error + 'static)> {
        match self {
            AtprotoAppClientError::VAppExecutionError(e) => Some(e),
            AtprotoAppClientError::SendMessageError(e) => Some(e),
            AtprotoAppClientError::InvalidResponse(_) => None,
            AtprotoAppClientError::GenericError(_) => None,
        }
    }
}

pub struct AtprotoAppClient {
    app_client: Box<dyn VAppClient + Send + Sync>,
}

impl<'a> AtprotoAppClient {
    pub fn new(app_client: Box<dyn VAppClient + Send + Sync>) -> Self {
        Self { app_client }
    }

    async fn send_message(&mut self, out: &[u8]) -> Result<Vec<u8>, AtprotoAppClientError> {
        sdk::comm::send_message(&mut self.app_client, out)
            .await
            .map_err(AtprotoAppClientError::from)
    }

    async fn parse_response(response_raw: &'a [u8]) -> Result<Response, AtprotoAppClientError> {
        let resp: Response = postcard::from_bytes(response_raw)
            .map_err(|_| AtprotoAppClientError::GenericError("Failed to parse response"))?;
        Ok(resp)
    }

    pub async fn get_did_key(
        &mut self,
        index: u32,
        display: bool,
    ) -> Result<Vec<u8>, AtprotoAppClientError> {
        let msg = postcard::to_allocvec(&Request::GetDidKey { index, display })
            .map_err(|_| AtprotoAppClientError::GenericError("Failed to serialize Exit request"))?;

        let response_raw = self.send_message(&msg).await?;
        match Self::parse_response(&response_raw).await? {
            Response::DidKey(key) => Ok(key),
            _ => Err(AtprotoAppClientError::InvalidResponse("Invalid response")),
        }
    }

    pub async fn exit(&mut self) -> Result<i32, AtprotoAppClientError> {
        let msg = postcard::to_allocvec(&Request::Exit)
            .map_err(|_| AtprotoAppClientError::GenericError("Failed to serialize Exit request"))?;
        let response_raw = self.send_message(&msg).await?;

        match Self::parse_response(&response_raw).await {
            Ok(_) => Err(AtprotoAppClientError::InvalidResponse(
                "Exit message shouldn't return!",
            )),
            Err(e) => match e {
                AtprotoAppClientError::VAppExecutionError(VAppExecutionError::AppExited(
                    status,
                )) => Ok(status),
                e => {
                    println!("Unexpected error on exit: {:?}", e);
                    Err(AtprotoAppClientError::InvalidResponse(
                        "Unexpected error on exit",
                    ))
                }
            },
        }
    }
}