// Copyright 2018-2020 the Deno authors. All rights reserved. MIT license.
use super::dispatch_json::{blocking_json, Deserialize, JsonOp, Value};
use crate::repl;
use crate::repl::Repl;
use crate::state::State;
use deno_core::CoreIsolate;
use deno_core::CoreIsolateState;
use deno_core::ErrBox;
use deno_core::ZeroCopyBuf;
use std::rc::Rc;
use std::sync::Arc;
use std::sync::Mutex;

pub fn init(i: &mut CoreIsolate, s: &Rc<State>) {
  i.register_op("op_repl_start", s.stateful_json_op2(op_repl_start));
  i.register_op("op_repl_readline", s.stateful_json_op2(op_repl_readline));
}

struct ReplResource(Arc<Mutex<Repl>>);

#[derive(Deserialize)]
#[serde(rename_all = "camelCase")]
struct ReplStartArgs {
  history_file: String,
}

fn op_repl_start(
  isolate_state: &mut CoreIsolateState,
  state: &Rc<State>,
  args: Value,
  _zero_copy: &mut [ZeroCopyBuf],
) -> Result<JsonOp, ErrBox> {
  let args: ReplStartArgs = serde_json::from_value(args)?;
  debug!("op_repl_start {}", args.history_file);
  let history_path =
    repl::history_path(&state.global_state.dir, &args.history_file);
  let repl = repl::Repl::new(history_path);
  let resource = ReplResource(Arc::new(Mutex::new(repl)));
  let mut resource_table = isolate_state.resource_table.borrow_mut();
  let rid = resource_table.add("repl", Box::new(resource));
  Ok(JsonOp::Sync(json!(rid)))
}

#[derive(Deserialize)]
struct ReplReadlineArgs {
  rid: i32,
  prompt: String,
}

fn op_repl_readline(
  isolate_state: &mut CoreIsolateState,
  _state: &Rc<State>,
  args: Value,
  _zero_copy: &mut [ZeroCopyBuf],
) -> Result<JsonOp, ErrBox> {
  let args: ReplReadlineArgs = serde_json::from_value(args)?;
  let rid = args.rid as u32;
  let prompt = args.prompt;
  debug!("op_repl_readline {} {}", rid, prompt);
  let resource_table = isolate_state.resource_table.borrow();
  let resource = resource_table
    .get::<ReplResource>(rid)
    .ok_or_else(ErrBox::bad_resource_id)?;
  let repl = resource.0.clone();

  blocking_json(false, move || {
    let line = repl.lock().unwrap().readline(&prompt)?;
    Ok(json!(line))
  })
}