#![feature(proc_macro, specialization, concat_idents)]

#[macro_use]
extern crate pyo3;

use pyo3::prelude::*;
use pyo3::{pyclass, pyfunction, pymodinit};

#[pyclass]
struct EmptyClass {}

fn sum_as_string(a: i64, b: i64) -> String {
    format!("{}", a + b).to_string()
}

#[pyfunction]
fn double(x: usize) -> usize {
    x * 2
}

/// This module is implemented in Rust.
#[pymodinit]
fn module_with_functions(py: Python, m: &PyModule) -> PyResult<()> {
    #[pyfn(m, "sum_as_string")]
    fn sum_as_string_py(_py: Python, a: i64, b: i64) -> PyResult<String> {
        let out = sum_as_string(a, b);
        return Ok(out);
    }

    #[pyfn(m, "no_parameters")]
    fn no_parameters() -> PyResult<usize> {
        return Ok(42);
    }

    m.add_class::<EmptyClass>().unwrap();

    m.add("foo", "bar").unwrap();

    m.add_function(wrap_function!(double)).unwrap();
    m.add("also_double", wrap_function!(double)(py)).unwrap();

    Ok(())
}

#[test]
#[cfg(Py_3)]
fn test_module_with_functions() {
    let gil = Python::acquire_gil();
    let py = gil.python();

    let d = PyDict::new(py);
    d.set_item("module_with_functions", unsafe {
        PyObject::from_owned_ptr(py, PyInit_module_with_functions())
    }).unwrap();

    let run = |code| py.run(code, None, Some(d)).unwrap();

    run("assert module_with_functions.__doc__ == 'This module is implemented in Rust.'");
    run("assert module_with_functions.sum_as_string(1, 2) == '3'");
    run("assert module_with_functions.no_parameters() == 42");
    run("assert module_with_functions.foo == 'bar'");
    run("assert module_with_functions.EmptyClass != None");
    run("assert module_with_functions.double(3) == 6");
    run("assert module_with_functions.also_double(3) == 6");
}

#[pymodinit(other_name)]
fn some_name(_: Python, _: &PyModule) -> PyResult<()> {
    Ok(())
}

#[test]
#[cfg(Py_3)]
fn test_module_renaming() {
    let gil = Python::acquire_gil();
    let py = gil.python();

    let d = PyDict::new(py);
    d.set_item("different_name", unsafe {
        PyObject::from_owned_ptr(py, PyInit_other_name())
    }).unwrap();

    py.run("assert different_name.__name__ == 'other_name'", None, Some(d)).unwrap();
}

#[test]
#[cfg(Py_3)]
fn test_module_from_code() {
    let gil = Python::acquire_gil();
    let py = gil.python();

    let adder_mod = PyModule::from_code(
        py,
        "def add(a,b):\n\treturn a+b",
        "adder_mod.py",
        "adder_mod",
    ).expect("Module code should be loaded");

    let add_func = adder_mod
        .get("add")
        .expect("Add fucntion should be in the module")
        .to_object(py);

    let ret_value: i32 = add_func
        .call1(py, (1, 2))
        .expect("A value should be returned")
        .extract(py)
        .expect("The value should be able to be converted to an i32");

    assert_eq!(ret_value, 3);
}