/*
 * Copyright (C) 2022 Umut İnan Erdoğan <umutinanerdogan@pm.me>
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at https://mozilla.org/MPL/2.0/.
 */

use std::cell::RefCell;
use std::collections::HashMap;
use std::rc::Rc;
use raw_window_handle::HasRawWindowHandle;
use winit::{
    event_loop::EventLoopWindowTarget,
    window::{Window as WinitWindow, WindowBuilder as WinitWindowBuilder},
};
use winit::dpi::PhysicalSize;
use winit::error::OsError;
use winit::window::WindowId;
use abletk_common::color::Color;
use abletk_common::Renderer;
use crate::context::Context;
use crate::event::window::Event;
use crate::widget::Widget;

pub struct Window {
    window: WinitWindow,
    events: HashMap<Event, Vec<fn(&mut Context, &mut Window)>>,
    root: Box<dyn Widget>,
    ctx: Rc<RefCell<Context>>,
    renderer: Renderer,
    background: Color,
}

impl Window {
    pub fn new<S: Into<String>>(
        ctx: Rc<RefCell<Context>>,
        root: Box<dyn Widget>,
        event_loop: &EventLoopWindowTarget<()>,
        events: HashMap<Event, Vec<fn(&mut Context, &mut Window)>>,
        always_on_top: bool,
        background: Color,
        decorations: bool,
        maximized: bool,
        resizable: bool,
        title: S,
        transparent: bool,
        visible: bool,
    ) -> Result<Self, OsError> {
        let window = WinitWindowBuilder::new()
            .with_always_on_top(always_on_top)
            .with_decorations(decorations)
            .with_maximized(maximized)
            .with_resizable(resizable)
            .with_title(title)
            .with_transparent(transparent)
            .with_visible(visible)
            .build(event_loop)?;

        Ok(Self {
            renderer: Renderer::new(window.raw_window_handle()),
            window,
            background,
            events,
            root,
            ctx,
        })
    }

    pub fn builder<W: Widget + 'static>(root: W) -> WindowBuilder {
        WindowBuilder::new(root)
    }

    pub fn render(&mut self) {
        let position = self.root.position();
        eprintln!("Rendering window with id {:?}", self.id());
        eprintln!("Root widget position: {position:?}");

        self.renderer.begin_draw();
        self.renderer.clear(self.background);
        self.renderer.position_at(position.x(), position.y());
        self.root.draw(&mut self.renderer);
        self.renderer.end_draw()
    }

    pub fn set_always_on_top(&self, value: bool) {
        self.window.set_always_on_top(value)
    }

    pub fn focus(&self) {
        self.window.focus_window()
    }

    pub fn redraw(&self) {
        self.window.request_redraw()
    }

    pub fn set_title<S: AsRef<str> + Into<String>>(&mut self, title: S) {
        self.window.set_title(title.as_ref())
    }

    pub(crate) fn emit_event(&mut self, event: Event) {
        if let Some(handlers) = self.events.get(&event) {
            let ctx = self.ctx.clone();
            let ctx = &mut ctx.borrow_mut();
            handlers.clone().iter().for_each(|handler| handler(ctx, self))
        }
    }

    pub(crate) fn id(&self) -> WindowId {
        self.window.id()
    }

    pub(crate) fn resized(&mut self, size: PhysicalSize<u32>) {
        self.renderer.resized(size.width, size.height)
    }
}

pub struct WindowBuilder {
    events: HashMap<Event, Vec<fn(&mut Context, &mut Window)>>,
    always_on_top: bool,
    background: Option<Color>,
    decorations: bool,
    maximized: bool,
    resizable: bool,
    title: Option<String>,
    transparent: bool,
    visible: bool,
    root: Box<dyn Widget>,
}

impl WindowBuilder {
    pub fn new<W: Widget + 'static>(root: W) -> Self {
        Self {
            events: Default::default(),
            always_on_top: false,
            background: None,
            decorations: true,
            maximized: false,
            resizable: true,
            title: None,
            transparent: false,
            visible: true,
            root: Box::new(root),
        }
    }

    pub fn on_event(mut self,
        event: Event,
        handler: fn(&mut Context, &mut Window),
    ) -> Self {
        if let Some(handlers) = self.events.get_mut(&event) {
            handlers.push(handler);
        } else {
            self.events.insert(event, vec![handler]);
        }

        self
    }

    pub fn always_on_top(mut self, value: bool) -> Self {
        self.always_on_top = value;
        self
    }

    pub fn background(mut self, value: Color) -> Self {
        self.background = Some(value);
        self
    }

    pub fn decorations(mut self, value: bool) -> Self {
        self.decorations = value;
        self
    }

    pub fn maximized(mut self, value: bool) -> Self {
        self.maximized = value;
        self
    }

    pub fn resizable(mut self, value: bool) -> Self {
        self.resizable = value;
        self
    }

    pub fn title<S: Into<String>>(mut self, value: S) -> Self {
        self.title = Some(value.into());
        self
    }

    pub fn transparent(mut self, value: bool) -> Self {
        self.transparent = value;
        self
    }

    pub fn visible(mut self, value: bool) -> Self {
        self.visible = value;
        self
    }

    pub fn build(self,
        ctx: Rc<RefCell<Context>>,
        event_loop: &EventLoopWindowTarget<()>
    ) -> Result<Window, OsError> {
        Window::new(
            ctx,
            self.root,
            event_loop,
            self.events,
            // todo: make this the application name
            self.always_on_top,
            self.background.unwrap_or(Color(1.0, 1.0, 1.0, 1.0)),
            self.decorations,
            self.maximized,
            self.resizable,
            self.title.unwrap_or("AbleTK Window".into()),
            self.transparent,
            self.visible,
        )
    }
}