use std::rc::Rc;

use anyhow::Result;
use cursive::Printer;
use cursive::Rect;
use cursive::View;
use cursive::XY;
use cursive::direction::Direction;
use cursive::event::Event;
use cursive::event::EventResult;
use cursive::event::Key;
use cursive::traits::Resizable;
use cursive::view::Nameable;
use cursive::view::Selector;
use cursive::view::SizeConstraint;
use cursive::view::ViewNotFound;
use cursive::views::NamedView;
use cursive::views::ResizedView;
use getset::{Getters, MutGetters};

use crate::bindings::BindingCaller;
use crate::bindings::Bindings;
use crate::tabs::*;
use crate::runtime::Runtime;

pub const MAIN_VIEW_NAME: &'static str = "main_view";

#[derive(Getters, MutGetters)]
pub struct MainView {
    rt: Rc<Runtime>,

    #[getset(get = "pub", get_mut = "pub")]
    tabs: crate::tabs::Tabs,

    bindings: Bindings,
    bindings_caller: Option<ResizedView<NamedView<BindingCaller>>>,
}

impl MainView {
    pub fn new(rt: Rc<Runtime>) -> Result<NamedView<Self>> {
        let default_query = rt.config().notmuch_default_query();
        let tabs = Tabs::new(default_query, rt.clone())?;
        let bindings = crate::bindings::get_bindings();

        Ok(MainView { rt, tabs, bindings, bindings_caller: None }.with_name(MAIN_VIEW_NAME))
    }

    pub fn get_current_tab(&self) -> Option<&cursive_multiplex::Mux> {
        if let Some(mux) = self.tabs.get_active_tab() {
            mux.downcast_ref::<cursive_multiplex::Mux>()
        } else {
            None
        }
    }

    pub fn get_current_mux(&self) -> Option<&Box<dyn cursive::View>> {
        if let Some(mux) = self.get_current_tab() {
            return mux.get_current_view()
        }

        None
    }

    pub fn get_current_tab_mut(&mut self) -> Option<&mut cursive_multiplex::Mux> {
        if let Some(mux) = self.tabs.get_active_tab_mut() {
            mux.downcast_mut::<cursive_multiplex::Mux>()
        } else {
            None
        }
    }

    pub fn get_current_mux_mut(&mut self) -> Option<&mut Box<dyn cursive::View>> {
        if let Some(mut mux) = self.get_current_tab_mut() {
            return mux.get_current_view_mut()
        }

        None
    }

}

impl View for MainView {
    fn draw(&self, printer: &Printer) {
        self.tabs.draw(printer);
        if let Some(caller) = self.bindings_caller.as_ref() {
            caller.draw(printer);
        }
    }

    fn layout(&mut self, xy: XY<usize>) {
        self.tabs.layout(xy)
    }

    fn needs_relayout(&self) -> bool {
        self.tabs.needs_relayout()
    }

    fn required_size(&mut self, constraint: XY<usize>) -> XY<usize> {
        self.tabs.required_size(constraint)
    }

    fn on_event(&mut self, e: Event) -> EventResult {
        debug!("Received event: {:?}", e);
        match self.bindings_caller.as_mut() {
            Some(caller) => match e {
                Event::Key(Key::Esc) => {
                    self.bindings_caller = None;
                    debug!("Escape. Resetting bindings caller.");
                    EventResult::Consumed(None)
                },
                other => {
                    debug!("Forwarding event to bindings caller");
                    caller.on_event(other)
                },
            },
            None => match e {
                Event::Char(':') => {
                    debug!(": -> Constructing bindings caller.");
                    self.bindings_caller = Some({
                        self.bindings.caller()
                            .with_name(crate::bindings::BINDINGS_CALLER)
                            .resized(SizeConstraint::Full, SizeConstraint::AtLeast(5))
                    });
                    EventResult::Consumed(None)
                },
                other => {
                    debug!("Forwarding event to tabs");
                    self.tabs.on_event(other)
                },
            }
        }
    }

    fn call_on_any<'a>(&mut self, s: &Selector, tpl: &'a mut (dyn FnMut(&mut (dyn View + 'static)) + 'a)) {
        self.tabs.call_on_any(s, tpl);
    }

    fn focus_view(&mut self, s: &Selector) -> Result<(), ViewNotFound> {
        self.tabs.focus_view(s)
    }

    fn take_focus(&mut self, source: Direction) -> bool {
        self.tabs.take_focus(source)
    }

    fn important_area(&self, view_size: XY<usize>) -> Rect {
        self.tabs.important_area(view_size)
    }

    fn type_name(&self) -> &'static str {
        self.tabs.type_name()
    }

}