use piston::input::{Button, Event, Input, Motion, ButtonState as PButtonState};

use serde::{Serialize, Deserialize};

use crate::types::{InputTypeFlags, InputCause, ButtonState, ProcessingResult};
use crate::{Schema, ToEventType, EventType};

#[derive(Serialize, Deserialize)]
pub struct SchemaPiston<TUserAction>
where TUserAction: Clone + Serialize,
{
    schema: Schema<Event, usize, TUserAction>,
}

/// Schema implementation using the Piston backend
impl<TUserAction> SchemaPiston<TUserAction>
where TUserAction: Clone + Serialize,
{
    /// Create a new Schema with given name
    pub fn new(name: &str) -> Self {
        SchemaPiston {
            schema: Schema::new(name)
        }
    }

    /// Assigns assigns the controller from next registered input event
    /// to this schema if it passes through the input flags
    pub fn assign_controller(&mut self, event: &Event, iaf: InputTypeFlags) -> bool {
        self.schema.assign_controller(event, iaf)
    }

    /// Assigns specified user action to the next registered event from piston
    pub fn assign_input(&mut self, event: &Event, action: TUserAction, iaf: InputTypeFlags) -> bool {
        self.schema.assign_input(event, action, iaf)
    }

    /// Main event processing hook. Will result in ProcessingResult for user's action if
    /// a mapping is withing the schema for the given event.
    pub fn process_event(&mut self, event: &Event) -> Option<ProcessingResult<TUserAction>> {
        self.schema.process_event(event)
    }

    /// Assigns a player_id to this schema
    pub fn set_player_id(&mut self, player_id: Option<usize>) {
        self.schema.set_player_id(player_id);
    }

    /// Returns the current player_id (or None if not assigned)
    pub fn player_id(&self) -> Option<usize> {
        self.schema.player_id
    }

    /// Returns the currently assigned controller (or None if not assigned)
    /// *NOTE* keyboard and mouse have no controller ID by definition in piston
    pub fn controller_id(&self) -> Option<usize> {
        self.schema.controller_id
    }
}

impl ToEventType<usize> for Event
{
    fn to_raw(&self) -> Option<EventType> {
        match self {
            Event::Input(input) => match input {
                Input::Button(args) => match args.button {
                    Button::Keyboard(v) => Some(EventType::new(1, v as u64)),
                    Button::Mouse(v) => Some(EventType::new(2, v as u64)),
                    _ => None
                },
                Input::Move(args) => match args {
                    Motion::ControllerAxis(v) => Some(EventType::new(3, u64::from(v.axis))),
                    Motion::MouseCursor(_, _) => Some(EventType::new(4, 0)), // we only care that it's mouse move here
                    _ => None
                },
                _ => None
            }
            _ => None,
        }
    }

    fn controller_id(&self) -> Option<usize> {
        match self {
            Event::Input(input) => match input {
                Input::Move(args) => match args {
                    Motion::ControllerAxis(c) => Some(c.id as usize),
                    _ => None,
                },
                Input::Button(args) => match args.button {
                    Button::Controller(c) => Some(c.id as usize),
                    Button::Hat(c) => Some(c.id as usize),
                    _ => None,
                }
                _ => None,
            },
            _ => None,
        }
    }

    fn filter_for_assignment(&self, iaf: InputTypeFlags) -> bool {
        match self {
            Event::Input(input) => match input {
                Input::Button(args) => match args.state {
                    PButtonState::Press => match args.button {
                        Button::Keyboard(_) => iaf.intersects(InputTypeFlags::Key),
                        Button::Controller(_) | // any non key button here
                            Button::Mouse(_) |
                            Button::Hat(_) => iaf.intersects(InputTypeFlags::Button)
                    },
                    PButtonState::Release => false, // do not assign from release
                },
                Input::Move(args) => match args {
                    Motion::MouseCursor(_, _) => iaf.contains(InputTypeFlags::MouseMove),
                    Motion::MouseRelative(_, _) => iaf.contains(InputTypeFlags::MouseMove),
                    Motion::MouseScroll(_, _) => false, // TODO: add proper mouse scroll support to prongs
                    Motion::ControllerAxis(_) => iaf.contains(InputTypeFlags::Axis),
                    Motion::Touch(_) => false, // TODO: add touch support to prongs
                }
                _ => iaf.contains(InputTypeFlags::Other),
            },
            _ => false,
        }
    }

    fn get_cause(&self) -> Option<InputCause> {
        match self {
            Event::Input(input) => match input {
                Input::Button(args) => match args.state {
                    PButtonState::Press => Some(InputCause::Button(ButtonState::Pressed)),
                    PButtonState::Release => Some(InputCause::Button(ButtonState::Released)),
                },
                Input::Move(args) => match args {
                    Motion::MouseCursor(x, y) => Some(InputCause::Motion(*x, *y)),
                    Motion::MouseRelative(_, _) => None,
                    Motion::MouseScroll(_, _) => None,
                    Motion::ControllerAxis(_) => None, // InputCause::Axis(), TODO
                    Motion::Touch(_) => None, // TODO: add touch support to prongs
                }
                _ => None,
            },
            _ => None,
        }
    }    
}