use std::{collections::HashMap, ops::Deref};

use lyra_ecs::{world::World, system::IntoSystem};

use crate::plugin::Plugin;

use super::{Button, KeyCode, InputButtons};

#[allow(dead_code)]
#[derive(Debug, Clone, Copy, Eq, PartialEq, Ord, PartialOrd, Hash)]
pub enum GamepadFormat {
    DualAxis,
    Joystick,
}

#[allow(dead_code)]
#[derive(Debug, Clone, Copy, Eq, PartialEq, Ord, PartialOrd, Hash)]
pub enum GamepadButton {
    FaceBottom,
    FaceLeft,
    FaceRight,
    FaceTop,
    VirtualConfirm,
    VirtualDeny,
    LThumbstick,
    RThumbstick,
    DPadUp,
    DPadDown,
    DPadLeft,
    DPadRight,
    LShoulder,
    RShoulder,
    LTrigger,
    RTrigger,
    Special,
    LSpecial,
    RSpecial,
}

#[allow(dead_code)]
#[derive(Debug, Clone, Copy, Eq, PartialEq, Ord, PartialOrd, Hash)]
pub enum GamepadAxis {
    LThumbstickX,
    LThumbstickY,
    RThumbstickX,
    RThumbstickY,
    LTrigger,
    RTrigger,
}

#[allow(dead_code)]
#[derive(Debug, Clone, Copy, Eq, PartialEq, Ord, PartialOrd, Hash)]
pub enum GamepadInput {
    Button(GamepadButton),
    Axis(GamepadAxis),
}

#[allow(dead_code)]
#[derive(Debug, Clone, Copy, Eq, PartialEq, Ord, PartialOrd, Hash)]
pub enum ActionSource {
    Keyboard(KeyCode),
    Gamepad(GamepadFormat, GamepadInput),
}

impl ActionSource {
    /// Convert this Source into a Binding. Uses a default Binding modifier value of `1.0`.
    pub fn into_binding(self) -> Binding {
        Binding::from_source(self)
    }

    /// Convert this Source into a Binding, setting the modifier.
    pub fn into_binding_modifier(self, modifier: f32) -> Binding {
        Binding::from_source_modifier(self, modifier)
    }
}

#[derive(Clone, Debug)]
pub struct Binding {
    pub source: ActionSource,
    pub modifier: f32,
}

impl Binding {
    /// Create a binding from a Source. Uses a default value of `1.0` as the modifier.
    pub fn from_source(source: ActionSource) -> Self {
        Self {
            source,
            modifier: 1.0,
        }
    }

    /// Create a binding from a Source, with a modifier
    pub fn from_source_modifier(source: ActionSource, modifier: f32) -> Self {
        Self {
            source,
            modifier,
        }
    }
}

#[derive(Debug, Clone, Copy, PartialEq)]
pub enum ActionState {
    /// No input is being given by the user for the button/axis.
    Idle,
    /// The button is pressed
    Pressed(f32),
    /// The button was just pressed
    JustPressed(f32),
    /// The button was just released
    JustReleased,
    
    //Released,
    /// The axis moved
    Axis(f32),
    /// Some other state with a modifier
    Other(f32),
}

#[derive(Debug, Clone, Copy, Eq, PartialEq, Ord, PartialOrd, Hash)]
pub enum ActionKind {
    Button,
    Axis
}

#[derive(Clone, Debug)]
pub struct Action {
    pub kind: ActionKind,
    pub state: ActionState,
}

impl Action {
    pub fn new(kind: ActionKind) -> Self {
        Self {
            kind,
            state: ActionState::Idle,
        }
    }
}

#[derive(Debug, Default, Clone, Copy, Eq, PartialEq, Ord, PartialOrd, Hash)]
pub struct LayoutId(u32);

impl From<u32> for LayoutId {
    fn from(value: u32) -> Self {
        Self(value)
    }
}

#[derive(Clone, Default)]
pub struct Layout {
    mappings: HashMap<ActionMappingId, ActionMapping>,
    active_mapping: ActionMappingId,
}

impl Layout {
    pub fn new() -> Self {
        Self::default()
    }

    pub fn add_mapping(&mut self, mapping: ActionMapping) -> &mut Self {
        self.mappings.insert(mapping.id, mapping);

        self
    }
}

#[derive(Debug, Default, Clone, Copy, Eq, PartialEq, Ord, PartialOrd, Hash)]
pub struct ActionMappingId(u32);

impl From<u32> for ActionMappingId {
    fn from(value: u32) -> Self {
        Self(value)
    }
}

#[derive(Clone)]
pub struct ActionMapping {
    layout: LayoutId,
    id: ActionMappingId,
    action_binds: HashMap<String, Vec<Binding>>,
}

impl ActionMapping {
    pub fn new(layout: LayoutId, id: ActionMappingId) -> Self {
        Self {
            layout,
            id,
            action_binds: HashMap::new(),
        }
    }

    /// Creates a binding for the action.
    /// 
    /// If the action is not in this layout, this will panic!
    /// 
    /// Parameters:
    /// * `action_label` - The label corresponding to the action in this Layout.
    /// * `bind` - The Binding to add to the Action.
    pub fn bind(mut self, action_label: &str, bindings: &[Binding]) -> Self {
        let mut bindings = bindings.to_vec();

        let action_binds = self.action_binds.entry(action_label.to_string()).or_default();
        action_binds.append(&mut bindings);

        self
    }

    /// Creates multiple binding for the action.
    /// 
    /// If the action is not in this layout, this will panic!
    /// 
    /// Parameters:
    /// * `action_label` - The label corresponding to the action in this Layout.
    /// * `bindings` - The list of Bindings to add to the Action.
    /* pub fn add_bindings(&mut self, action_label: String, bindings: &[Binding]) -> &mut Self {
        let mut bindings = bindings.to_vec();
        let action_binds = self.action_binds.entry(action_label)
            .or_insert_with(Vec::new);
        action_binds.append(&mut bindings);

        self
    } */

    pub fn finish(self) -> Self {
        self
    }
}

#[derive(Clone, Default)]
pub struct ActionHandler {
    pub actions: HashMap<String, Action>,
    pub layouts: HashMap<LayoutId, Layout>,
    pub current_layout: LayoutId,
    pub current_mapping: ActionMappingId,
}

impl ActionHandler {
    pub fn new() -> Self {
        Self::default()
    }

    pub fn add_layout(mut self, id: LayoutId) -> Self {
        self.layouts.insert(id, Layout::new());

        self
    }

    pub fn add_action(mut self, label: &str, action: Action) -> Self {
        self.actions.insert(label.to_string(), action);

        self
    }

    pub fn add_mapping(mut self, mapping: ActionMapping) -> Self {
        let layout = self.layouts.get_mut(&mapping.layout).unwrap();
        layout.add_mapping(mapping);

        self
    }

    /// Returns true if the action is pressed (or was just pressed).
    /// 
    /// This will panic if the action name does not correspond to an action.
    pub fn is_action_pressed(&self, action_name: &str) -> bool {
        let action = self.actions.get(action_name)
            .unwrap_or_else(|| panic!("Action {action_name} was not found"));

        matches!(action.state, ActionState::Pressed(_) | ActionState::JustPressed(_))
    }

    /// Returns true if the action was just pressed.
    /// 
    /// This will panic if the action name does not correspond to an action.
    pub fn was_action_just_pressed(&self, action_name: &str) -> bool {
        let action = self.actions.get(action_name)
            .unwrap_or_else(|| panic!("Action {action_name} was not found"));

        matches!(action.state, ActionState::JustPressed(_))
    }

    /// Returns true if the action was just released.
    /// 
    /// This will panic if the action name does not correspond to an action.
    pub fn was_action_just_released(&self, action_name: &str) -> bool {
        let action = self.actions.get(action_name)
            .unwrap_or_else(|| panic!("Action {action_name} was not found"));

        matches!(action.state, ActionState::JustReleased)
    }

    /// Returns an action's state.
    /// 
    /// This will panic if the action name does not correspond to an action.
    pub fn get_action_state(&self, action_name: &str) -> ActionState {
        let action = self.actions.get(action_name)
            .unwrap_or_else(|| panic!("Action {action_name} was not found"));

        action.state
    }

    /// Returns the action's modifier if it is pressed (or was just pressed).
    /// Returns `None` if the action's state is not `ActionState::Pressed` or `ActionState::JustPressed`.
    /// 
    /// This will panic if the action name does not correspond to an action.
    pub fn get_pressed_modifier(&self, action_name: &str) -> Option<f32> {
        let action = self.actions.get(action_name)
            .unwrap_or_else(|| panic!("Action {action_name} was not found"));

        match action.state {
            ActionState::Pressed(v) | ActionState::JustPressed(v) => Some(v),
            _ => None,
        }
    }

    /// Returns the action's modifier if it was just pressed.
    /// Returns `None` if the action's state is not `ActionState::JustPressed`.
    /// 
    /// This will panic if the action name does not correspond to an action.
    pub fn get_just_pressed_modifier(&self, action_name: &str) -> Option<f32> {
        let action = self.actions.get(action_name)
            .unwrap_or_else(|| panic!("Action {action_name} was not found"));

        match action.state {
            ActionState::JustPressed(v) => Some(v),
            _ => None,
        }
    }
    
    /// Returns the action's modifier if its an updated axis.
    /// Returns `None` if the action's state is not `ActionState::Axis`.
    /// 
    /// This will panic if the action name does not correspond to an action.
    pub fn get_axis_modifier(&self, action_name: &str) -> Option<f32> {
        let action = self.actions.get(action_name)
            .unwrap_or_else(|| panic!("Action {action_name} was not found"));

        match action.state {
            ActionState::Axis(v) => Some(v),
            _ => None,
        }
    }
}

fn actions_system(world: &mut World) -> anyhow::Result<()> {
    let keys = world.try_get_resource::<InputButtons<KeyCode>>()
        .map(|r| r.deref().clone());

    if let Some(keys) = keys {
        let mut handler = world.try_get_resource_mut::<ActionHandler>()
            .expect("No Input Action handler was created in the world!");

        let layout = handler.layouts.get(&handler.current_layout).expect("No active layout");
        let mapping = layout.mappings.get(&layout.active_mapping).expect("No active mapping");
        
        for (action_name, binds) in mapping.action_binds.clone().iter() { // TODO: dont clone
            let mut new_state = None;

            for bind in binds.iter() {
                match bind.source {
                    ActionSource::Keyboard(key) => {
                        // JustPressed needs to be first, since is_pressed includes buttons that
                        // were just pressed.
                        if keys.was_just_pressed(key) {
                            new_state = Some(ActionState::JustPressed(bind.modifier));
                        } else if keys.is_pressed(key) {
                            new_state = Some(ActionState::Pressed(bind.modifier));
                        }
                    },
                    ActionSource::Gamepad(_, _) => todo!(),
                }
            }

            let action = handler.actions.get_mut(action_name).expect("Action name for binding is invalid!");

            if let Some(new_state) = new_state {
                action.state = new_state;
            } else {
                match action.state {
                    ActionState::Idle => {},
                    ActionState::JustReleased => action.state = ActionState::Idle,
                    _ => action.state = ActionState::JustReleased,
                }
            }
        }
    }

    Ok(())
}

#[derive(Default, Clone, Copy)]
pub struct InputActionPlugin;

impl Plugin for InputActionPlugin {
    fn setup(&self, game: &mut crate::game::Game) {
        game.with_system("input_actions", actions_system.into_system(), &[]);
    }
}