use imgui_sys;
use std::marker::PhantomData;
use std::ptr;

use super::{ImStr, Ui};

#[must_use]
pub struct Menu<'ui, 'p> {
    label: ImStr<'p>,
    enabled: bool,
    _phantom: PhantomData<&'ui Ui<'ui>>,
}

impl<'ui, 'p> Menu<'ui, 'p> {
    pub fn new(label: ImStr<'p>) -> Self {
        Menu {
            label: label,
            enabled: true,
            _phantom: PhantomData,
        }
    }
    #[inline]
    pub fn enabled(mut self, enabled: bool) -> Self {
        self.enabled = enabled;
        self
    }
    pub fn build<F: FnOnce()>(self, f: F) {
        let render = unsafe { imgui_sys::igBeginMenu(self.label.as_ptr(), self.enabled) };
        if render {
            f();
            unsafe { imgui_sys::igEndMenu() };
        }
    }
}

#[must_use]
pub struct MenuItem<'ui, 'p> {
    label: ImStr<'p>,
    shortcut: Option<ImStr<'p>>,
    selected: Option<&'p mut bool>,
    enabled: bool,
    _phantom: PhantomData<&'ui Ui<'ui>>,
}

impl<'ui, 'p> MenuItem<'ui, 'p> {
    pub fn new(label: ImStr<'p>) -> Self {
        MenuItem {
            label: label,
            shortcut: None,
            selected: None,
            enabled: true,
            _phantom: PhantomData,
        }
    }
    #[inline]
    pub fn shortcut(mut self, shortcut: ImStr<'p>) -> Self {
        self.shortcut = Some(shortcut);
        self
    }
    #[inline]
    pub fn selected(mut self, selected: &'p mut bool) -> Self {
        self.selected = Some(selected);
        self
    }
    #[inline]
    pub fn enabled(mut self, enabled: bool) -> Self {
        self.enabled = enabled;
        self
    }
    pub fn build(self) -> bool {
        let label = self.label.as_ptr();
        let shortcut = self.shortcut.map(|x| x.as_ptr()).unwrap_or(ptr::null());
        let selected = self.selected.map(|x| x as *mut bool).unwrap_or(ptr::null_mut());
        let enabled = self.enabled;
        unsafe { imgui_sys::igMenuItemPtr(label, shortcut, selected, enabled) }
    }
}