use winit::event::{Touch, TouchPhase, WindowEvent};
use crate::graphics::Vertex;

const BOTTOM_TAB_BAR_HEIGHT: f32 = 0.2;
const SECONDARY_COLOR: [f32; 4] = [84./255., 33./255., 32./255., 1.];

#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum Kind {
    None,
    Terrain,
    Entities
}

pub struct UI {
    pub kind_selected: Kind,
    touch: Option<Touch>
}
impl UI {
    pub fn new() -> Self {
        Self {
            kind_selected: Kind::Entities,
            touch: None
        }
    }
    // Returns true if event was handled by UI
    pub fn window_event(&mut self, event: &WindowEvent) -> bool {
        match event {
            WindowEvent::Touch(ref t) => {
                match t.phase {
                    TouchPhase::Started => {
                        if !self.touch.is_some() {
                            self.touch = Some(*t);
                            true
                        } else {
                            false
                        }
                    },
                    TouchPhase::Moved => {
                        if let Some(old_t) = self.touch {
                            if old_t.id == t.id {
                                // TODO
                                true
                            } else {
                                false
                            }
                        } else {
                            false
                        }
                    },
                    TouchPhase::Cancelled | TouchPhase::Ended => {
                        if let Some(old_t) = self.touch {
                            if old_t.id == t.id {
                                self.touch = None;
                                true
                            } else {
                                false
                            }
                        } else {
                            false
                        }
                    }
                }
            },
            _ => false
        }
    }
    pub fn render(&self, vertices: &mut Vec<Vertex>, indices: &mut Vec<u32>) {
        let vs = [
            // Terrain
            Vertex { color: SECONDARY_COLOR, pos: [-1., -1.+(BOTTOM_TAB_BAR_HEIGHT*2.)], effect: 0 },
            Vertex { color: SECONDARY_COLOR, pos: [-1., -1.], effect: 0 },
            Vertex { color: SECONDARY_COLOR, pos: [0., -1.], effect: 0 },
            Vertex { color: SECONDARY_COLOR, pos: [0., -1.+(BOTTOM_TAB_BAR_HEIGHT*2.)], effect: 0 },

            // Entities
            // 3,
            // 2,
            Vertex { color: SECONDARY_COLOR, pos: [1., -1.], effect: 0 },
            Vertex { color: SECONDARY_COLOR, pos: [1., -1.+(BOTTOM_TAB_BAR_HEIGHT*2.)], effect: 0 }
        ];
        let ids = [
            0,1,2,
            2,3,0,
            3,2,4,
            4,5,3
        ];
        let i = vertices.len() as u32;
        vertices.extend_from_slice(&vs);
        indices.extend_from_slice(&ids.map(|id| id+i));
    }
}