use super::objlist::PyList;
use super::objstr;
use super::objtype;
use crate::obj::objproperty::PropertyBuilder;
use crate::pyobject::{
    AttributeProtocol, DictProtocol, IdProtocol, PyAttributes, PyContext, PyFuncArgs, PyObjectRef,
    PyRef, PyResult, PyValue, TypeProtocol,
};
use crate::vm::VirtualMachine;

#[derive(Clone, Debug)]
pub struct PyInstance;

impl PyValue for PyInstance {
    fn required_type(_ctx: &PyContext) -> PyObjectRef {
        panic!("no specific type for PyInstance, don't type check me")
    }
}

pub type PyInstanceRef = PyRef<PyInstance>;

pub fn new_instance(vm: &mut VirtualMachine, mut args: PyFuncArgs) -> PyResult {
    // more or less __new__ operator
    let type_ref = args.shift();
    let obj = vm.ctx.new_instance(type_ref.clone(), None);
    Ok(obj)
}

fn object_eq(vm: &mut VirtualMachine, args: PyFuncArgs) -> PyResult {
    arg_check!(
        vm,
        args,
        required = [(_zelf, Some(vm.ctx.object())), (_other, None)]
    );
    Ok(vm.ctx.not_implemented())
}

fn object_ne(vm: &mut VirtualMachine, args: PyFuncArgs) -> PyResult {
    arg_check!(
        vm,
        args,
        required = [(_zelf, Some(vm.ctx.object())), (_other, None)]
    );

    Ok(vm.ctx.not_implemented())
}

fn object_lt(vm: &mut VirtualMachine, args: PyFuncArgs) -> PyResult {
    arg_check!(
        vm,
        args,
        required = [(_zelf, Some(vm.ctx.object())), (_other, None)]
    );

    Ok(vm.ctx.not_implemented())
}

fn object_le(vm: &mut VirtualMachine, args: PyFuncArgs) -> PyResult {
    arg_check!(
        vm,
        args,
        required = [(_zelf, Some(vm.ctx.object())), (_other, None)]
    );

    Ok(vm.ctx.not_implemented())
}

fn object_gt(vm: &mut VirtualMachine, args: PyFuncArgs) -> PyResult {
    arg_check!(
        vm,
        args,
        required = [(_zelf, Some(vm.ctx.object())), (_other, None)]
    );

    Ok(vm.ctx.not_implemented())
}

fn object_ge(vm: &mut VirtualMachine, args: PyFuncArgs) -> PyResult {
    arg_check!(
        vm,
        args,
        required = [(_zelf, Some(vm.ctx.object())), (_other, None)]
    );

    Ok(vm.ctx.not_implemented())
}

fn object_hash(vm: &mut VirtualMachine, args: PyFuncArgs) -> PyResult {
    arg_check!(vm, args, required = [(_zelf, Some(vm.ctx.object()))]);

    // For now default to non hashable
    Err(vm.new_type_error("unhashable type".to_string()))
}

// TODO: is object the right place for delattr?
fn object_delattr(vm: &mut VirtualMachine, args: PyFuncArgs) -> PyResult {
    arg_check!(
        vm,
        args,
        required = [
            (zelf, Some(vm.ctx.object())),
            (attr, Some(vm.ctx.str_type()))
        ]
    );

    match zelf.dict {
        Some(ref dict) => {
            let attr_name = objstr::get_value(attr);
            dict.borrow_mut().remove(&attr_name);
            Ok(vm.get_none())
        }
        None => Err(vm.new_type_error("TypeError: no dictionary.".to_string())),
    }
}

fn object_str(vm: &mut VirtualMachine, args: PyFuncArgs) -> PyResult {
    arg_check!(vm, args, required = [(zelf, Some(vm.ctx.object()))]);
    vm.call_method(zelf, "__repr__", vec![])
}

fn object_repr(vm: &mut VirtualMachine, args: PyFuncArgs) -> PyResult {
    arg_check!(vm, args, required = [(obj, Some(vm.ctx.object()))]);
    let type_name = objtype::get_type_name(&obj.typ());
    let address = obj.get_id();
    Ok(vm.new_str(format!("<{} object at 0x{:x}>", type_name, address)))
}

pub fn object_dir(obj: PyObjectRef, vm: &mut VirtualMachine) -> PyList {
    let attributes = get_attributes(&obj);
    let attributes: Vec<PyObjectRef> = attributes
        .keys()
        .map(|k| vm.ctx.new_str(k.to_string()))
        .collect();
    PyList::from(attributes)
}

fn object_format(vm: &mut VirtualMachine, args: PyFuncArgs) -> PyResult {
    arg_check!(
        vm,
        args,
        required = [
            (obj, Some(vm.ctx.object())),
            (format_spec, Some(vm.ctx.str_type()))
        ]
    );
    if objstr::get_value(format_spec).is_empty() {
        vm.to_str(obj)
    } else {
        Err(vm.new_type_error("unsupported format string passed to object.__format__".to_string()))
    }
}

pub fn init(context: &PyContext) {
    let object = &context.object;
    let object_doc = "The most base type";

    context.set_attr(&object, "__new__", context.new_rustfunc(new_instance));
    context.set_attr(&object, "__init__", context.new_rustfunc(object_init));
    context.set_attr(
        &object,
        "__class__",
        PropertyBuilder::new(context)
            .add_getter(object_class)
            .add_setter(object_class_setter)
            .create(),
    );
    context.set_attr(&object, "__eq__", context.new_rustfunc(object_eq));
    context.set_attr(&object, "__ne__", context.new_rustfunc(object_ne));
    context.set_attr(&object, "__lt__", context.new_rustfunc(object_lt));
    context.set_attr(&object, "__le__", context.new_rustfunc(object_le));
    context.set_attr(&object, "__gt__", context.new_rustfunc(object_gt));
    context.set_attr(&object, "__ge__", context.new_rustfunc(object_ge));
    context.set_attr(&object, "__delattr__", context.new_rustfunc(object_delattr));
    context.set_attr(&object, "__dict__", context.new_property(object_dict));
    context.set_attr(&object, "__dir__", context.new_rustfunc(object_dir));
    context.set_attr(&object, "__hash__", context.new_rustfunc(object_hash));
    context.set_attr(&object, "__str__", context.new_rustfunc(object_str));
    context.set_attr(&object, "__repr__", context.new_rustfunc(object_repr));
    context.set_attr(&object, "__format__", context.new_rustfunc(object_format));
    context.set_attr(
        &object,
        "__getattribute__",
        context.new_rustfunc(object_getattribute),
    );
    context.set_attr(&object, "__doc__", context.new_str(object_doc.to_string()));
}

fn object_init(vm: &mut VirtualMachine, _args: PyFuncArgs) -> PyResult {
    Ok(vm.ctx.none())
}

fn object_class(obj: PyObjectRef, _vm: &mut VirtualMachine) -> PyObjectRef {
    obj.typ()
}

fn object_class_setter(
    instance: PyObjectRef,
    _value: PyObjectRef,
    vm: &mut VirtualMachine,
) -> PyResult {
    let type_repr = vm.to_pystr(&instance.typ())?;
    Err(vm.new_type_error(format!("can't change class of type '{}'", type_repr)))
}

fn object_dict(vm: &mut VirtualMachine, args: PyFuncArgs) -> PyResult {
    if let Some(ref dict) = args.args[0].dict {
        let new_dict = vm.new_dict();
        for (attr, value) in dict.borrow().iter() {
            new_dict.set_item(&vm.ctx, &attr, value.clone());
        }
        Ok(new_dict)
    } else {
        Err(vm.new_type_error("TypeError: no dictionary.".to_string()))
    }
}

fn object_getattribute(vm: &mut VirtualMachine, args: PyFuncArgs) -> PyResult {
    arg_check!(
        vm,
        args,
        required = [
            (obj, Some(vm.ctx.object())),
            (name_str, Some(vm.ctx.str_type()))
        ]
    );
    let name = objstr::get_value(&name_str);
    trace!("object.__getattribute__({:?}, {:?})", obj, name);
    let cls = obj.typ();

    if let Some(attr) = cls.get_attr(&name) {
        let attr_class = attr.typ();
        if attr_class.has_attr("__set__") {
            if let Some(descriptor) = attr_class.get_attr("__get__") {
                return vm.invoke(descriptor, vec![attr, obj.clone(), cls]);
            }
        }
    }

    if let Some(obj_attr) = obj.get_attr(&name) {
        Ok(obj_attr)
    } else if let Some(attr) = cls.get_attr(&name) {
        vm.call_get_descriptor(attr, obj.clone())
    } else if let Some(getter) = cls.get_attr("__getattr__") {
        vm.invoke(getter, vec![cls, name_str.clone()])
    } else {
        Err(vm.new_attribute_error(format!("{} has no attribute '{}'", obj, name)))
    }
}

pub fn get_attributes(obj: &PyObjectRef) -> PyAttributes {
    // Get class attributes:
    let mut attributes = objtype::get_attributes(obj.type_pyref());

    // Get instance attributes:
    if let Some(dict) = &obj.dict {
        for (name, value) in dict.borrow().iter() {
            attributes.insert(name.to_string(), value.clone());
        }
    }

    attributes
}