use std::sync::Arc;

use nxmesh_proto::{AgentMessage, ConfigUpdate, MasterMessage, master_message::Payload};

use crate::service::master_handler::{MasterHandlerError, MessageResult};

#[async_trait::async_trait]
pub trait MasterMessageHandler: Send + Sync + 'static {
    async fn handle_master_message(&self, message: MasterMessage) -> MessageResult<()>;
}

#[async_trait::async_trait]
pub trait OnConfigUpdateHandler: Send + Sync + 'static {
    // Handle the config update message from master, write the config content to files, validate the new config and reload nginx
    async fn on_config_update(&self, config_info: ConfigUpdate) -> MessageResult<()>;
}

pub struct HandlerImpl<OCH>
where
    OCH: OnConfigUpdateHandler + ?Sized,
{
    on_config_update_handler: Arc<OCH>,
}

impl<OCH> HandlerImpl<OCH>
where
    OCH: OnConfigUpdateHandler + ?Sized,
{
    pub fn new(on_config_update_handler: Arc<OCH>) -> Self {
        Self {
            on_config_update_handler,
        }
    }
}

#[async_trait::async_trait]
impl<OCH> MasterMessageHandler for HandlerImpl<OCH>
where
    OCH: OnConfigUpdateHandler + ?Sized,
{
    async fn handle_master_message(&self, message: MasterMessage) -> MessageResult<()> {
        match message.payload {
            Some(Payload::ConfigUpdate(config_info)) => {
                self.on_config_update_handler
                    .on_config_update(config_info)
                    .await
            }
            Some(_) => {
                // We should never receive other types of messages from the master, but we should handle it anyway
                Err(MasterHandlerError::MessageHandlingError(
                    "Received unsupported master message type".to_string(),
                ))
            }
            None => {
                // This should never happen as the master should always send a valid message, but we should handle it anyway
                return Err(MasterHandlerError::MessageHandlingError(
                    "Received master message with empty payload".to_string(),
                ));
            }
        }
    }
}