use bencher::{benchmark_group, benchmark_main, Bencher};

use rusty_v8 as v8;
use std::convert::TryFrom;

use serde::Deserialize;

use serde_v8::utils::{js_exec, v8_do};

#[derive(Debug, Deserialize, PartialEq)]
struct MathOp {
  arg1: u64,
  arg2: u64,
  operator: Option<String>,
}

fn dedo(
  code: &str,
  f: impl FnOnce(&mut v8::HandleScope, v8::Local<v8::Value>),
) {
  v8_do(|| {
    let isolate = &mut v8::Isolate::new(v8::CreateParams::default());
    let handle_scope = &mut v8::HandleScope::new(isolate);
    let context = v8::Context::new(handle_scope);
    let scope = &mut v8::ContextScope::new(handle_scope, context);
    let v = js_exec(scope, code);

    f(scope, v);
  })
}

fn dedo_json(code: &str, f: impl FnOnce(String)) {
  let code = format!("JSON.stringify({})", code);
  dedo(&code[..], |scope, v| {
    let s: String = serde_v8::from_v8(scope, v).unwrap();
    f(s);
  })
}

fn de_struct_v8(b: &mut Bencher) {
  dedo("({arg1: 10, arg2: 123 })", |scope, obj| {
    let mut total = 0;
    b.iter(move || {
      let op: MathOp = serde_v8::from_v8(scope, obj).unwrap();
      total = total + op.arg1 + op.arg2;
    });
  });
}

fn de_struct_v8_opt(b: &mut Bencher) {
  dedo("({arg1: 10, arg2: 123 })", |scope, v| {
    let k_arg1 = v8::String::new(scope, "arg1").unwrap().into();
    let k_arg2 = v8::String::new(scope, "arg2").unwrap().into();
    let obj = v8::Local::<v8::Object>::try_from(v).unwrap();
    let mut total = 0;
    b.iter(move || {
      let v_arg1 = obj.get(scope, k_arg1).unwrap();
      let v_arg2 = obj.get(scope, k_arg2).unwrap();
      let op = MathOp {
        arg1: serde_v8::from_v8(scope, v_arg1).unwrap(),
        arg2: serde_v8::from_v8(scope, v_arg2).unwrap(),
        operator: None,
      };
      total = total + op.arg1 + op.arg2;
    });
  });
}

fn de_struct_json(b: &mut Bencher) {
  dedo_json("({arg1: 10, arg2: 123 })", |s| {
    let mut total = 0;
    b.iter(move || {
      let op: MathOp = serde_json::from_str(&s).unwrap();
      total = total + op.arg1 + op.arg2;
    });
  });
}

fn de_struct_json_deopt(b: &mut Bencher) {
  // JSON.stringify() in loop (semi-simulating ABI loop)
  dedo("({arg1: 10, arg2: 123 })", |scope, obj| {
    let mut total = 0;
    b.iter(move || {
      let mut scope = v8::HandleScope::new(scope);
      let s = v8::json::stringify(&mut scope, obj).unwrap();
      let rs = s.to_rust_string_lossy(&mut scope);
      let op: MathOp = serde_json::from_str(&rs).unwrap();
      total = total + op.arg1 + op.arg2;
    });
  });
}

macro_rules! dualbench {
  ($v8_fn:ident, $json_fn:ident, $src:expr, $t:ty) => {
    fn $v8_fn(b: &mut Bencher) {
      dedo($src, |scope, v| {
        b.iter(move || {
          let _: $t = serde_v8::from_v8(scope, v).unwrap();
        });
      });
    }

    fn $json_fn(b: &mut Bencher) {
      dedo_json($src, |s| {
        b.iter(move || {
          let _: $t = serde_json::from_str(&s).unwrap();
        });
      });
    }
  };
}

dualbench!(de_bool_v8, de_bool_json, "true", bool);
dualbench!(de_int_v8, de_int_json, "12345", u32);
dualbench!(
  de_array_v8,
  de_array_json,
  "[1,2,3,4,5,6,7,8,9,10]",
  Vec<u32>
);
dualbench!(de_str_v8, de_str_json, "'hello world'", String);
dualbench!(de_tuple_v8, de_tuple_json, "[1,false]", (u8, bool));

fn de_tuple_v8_opt(b: &mut Bencher) {
  dedo("[1,false]", |scope, obj| {
    let arr = v8::Local::<v8::Array>::try_from(obj).unwrap();
    let obj = v8::Local::<v8::Object>::from(arr);

    b.iter(move || {
      let v1 = obj.get_index(scope, 0).unwrap();
      let v2 = obj.get_index(scope, 1).unwrap();
      let _: (u8, bool) = (
        serde_v8::from_v8(scope, v1).unwrap(),
        serde_v8::from_v8(scope, v2).unwrap(),
      );
    });
  });
}

benchmark_group!(
  benches,
  de_struct_v8,
  de_struct_v8_opt,
  de_struct_json,
  de_struct_json_deopt,
  de_bool_v8,
  de_bool_json,
  de_int_v8,
  de_int_json,
  de_array_v8,
  de_array_json,
  de_str_v8,
  de_str_json,
  de_tuple_v8,
  de_tuple_json,
  de_tuple_v8_opt,
);

benchmark_main!(benches);