//! Sbot type and associated methods.

use async_std::net::TcpStream;

use kuska_handshake::async_std::BoxStream;
use kuska_sodiumoxide::crypto::{auth, sign::ed25519};
use kuska_ssb::{
    api::{
        dto::{
            //content::{About, Post},
            content::{SubsetQuery, TypedMessage},
            CreateHistoryStreamIn,
        },
        ApiCaller,
    },
    discovery, keystore,
    keystore::OwnedIdentity,
    rpc::{RpcReader, RpcWriter},
};

use crate::error::GolgiError;
use crate::utils;

/// The Scuttlebutt identity, keys and configuration parameters for connecting to a local sbot
/// instance, as well as handles for calling RPC methods and receiving responses.
pub struct Sbot {
    id: String,
    public_key: ed25519::PublicKey,
    private_key: ed25519::SecretKey,
    address: String,
    // aka caps key (scuttleverse identifier)
    network_id: auth::Key,
    client: ApiCaller<TcpStream>,
    rpc_reader: RpcReader<TcpStream>,
}

impl Sbot {
    /// Initiate a connection with an sbot instance. Define the IP address, port and network key
    /// for the sbot, then retrieve the public key, private key (secret) and identity from the
    /// `.ssb-go/secret` file. Open a TCP stream to the sbot and perform the secret handshake. If successful, create a box stream and split it into a writer and reader. Return RPC handles to the sbot as part of the `struct` output.
    pub async fn init(ip_port: Option<String>, net_id: Option<String>) -> Result<Sbot, GolgiError> {
        let address = if ip_port.is_none() {
            "127.0.0.1:8008".to_string()
        } else {
            ip_port.unwrap()
        };

        let network_id = if net_id.is_none() {
            discovery::ssb_net_id()
        } else {
            auth::Key::from_slice(&hex::decode(net_id.unwrap()).unwrap()).unwrap()
        };

        let OwnedIdentity { pk, sk, id } = keystore::from_gosbot_local()
            .await
            .expect("couldn't read local secret");

        let socket = TcpStream::connect(&address)
            .await
            .map_err(|source| GolgiError::Io {
                source,
                context: "socket error; failed to initiate tcp stream connection".to_string(),
            })?;

        let handshake = kuska_handshake::async_std::handshake_client(
            &mut &socket,
            network_id.clone(),
            pk,
            sk.clone(),
            pk,
        )
        .await
        .map_err(GolgiError::Handshake)?;

        let (box_stream_read, box_stream_write) =
            BoxStream::from_handshake(socket.clone(), socket, handshake, 0x8000).split_read_write();

        let rpc_reader = RpcReader::new(box_stream_read);
        let client = ApiCaller::new(RpcWriter::new(box_stream_write));

        Ok(Self {
            id,
            public_key: pk,
            private_key: sk,
            address,
            network_id,
            client,
            rpc_reader,
        })
    }

    /// Call the `partialReplication getSubset` RPC method and return a vector
    /// of messages as KVTs (key, value, timestamp).
    // TODO: add args for `descending` and `page` (max number of msgs in response)
    pub async fn getsubset(&mut self, query: SubsetQuery) -> Result<String, GolgiError> {
        let req_id = self.client.getsubset_req_send(query).await?;

        utils::get_async(&mut self.rpc_reader, req_id, utils::getsubset_res_parse).await
    }

    /// Call the `whoami` RPC method and return an `id`.
    pub async fn whoami(&mut self) -> Result<String, GolgiError> {
        let req_id = self.client.whoami_req_send().await?;

        utils::get_async(&mut self.rpc_reader, req_id, utils::whoami_res_parse)
            .await
            .map(|whoami| whoami.id)
    }

    /// Call the `publish` RPC method and return a message reference.
    ///
    /// # Arguments
    ///
    /// * `msg` - A `TypedMessage` `enum` whose variants include `Pub`, `Post`, `Contact`, `About`,
    /// `Channel` and `Vote`. See the `kuska_ssb` documentation for further details such as field
    /// names and accepted values for each variant.
    pub async fn publish(&mut self, msg: TypedMessage) -> Result<String, GolgiError> {
        let req_id = self.client.publish_req_send(msg).await?;

        utils::get_async(&mut self.rpc_reader, req_id, utils::publish_res_parse).await
    }

    /// Wrapper for publish which constructs and publishes a post message appropriately from a string.
    ///
    /// # Arguments
    ///
    /// * `text` - A reference to a string slice which represents the text to be published in the post
    pub async fn publish_post(&mut self, text: &str) -> Result<String, GolgiError> {
        let msg = TypedMessage::Post {
            text: text.to_string(),
            mentions: None,
        };
        self.publish(msg).await
    }

    /// Wrapper for publish which constructs and publishes an about description message appropriately from a string.
    ///
    /// # Arguments
    ///
    /// * `description` - A reference to a string slice which represents the text to be published as an about description.
    pub async fn publish_description(&mut self, description: &str) -> Result<String, GolgiError> {
        let msg = TypedMessage::About {
            about: self.id.to_string(),
            name: None,
            title: None,
            branch: None,
            image: None,
            description: Some(description.to_string()),
            location: None,
            start_datetime: None,
        };
        self.publish(msg).await
    }

    /*
    pub async fn publish_post(&mut self, post: Post) -> Result<String, GolgiError> {
        let req_id = self.client.publish_req_send(post).await?;

        utils::get_async(&mut self.rpc_reader, req_id, utils::publish_res_parse).await
    }
    */

    /// Call the `createHistoryStream` RPC method and print the output.
    async fn create_history_stream(&mut self, id: String) -> Result<(), GolgiError> {
        let args = CreateHistoryStreamIn::new(id);
        let req_id = self.client.create_history_stream_req_send(&args).await?;
        // TODO: we should return a vector of messages instead of printing them
        utils::print_source_until_eof(&mut self.rpc_reader, req_id, utils::feed_res_parse).await
    }
}