use std::sync::atomic::{AtomicBool, Ordering};
use std::sync::Arc;

use parking_lot::RwLock;

use crate::dynamic_data::Pokemon;
use crate::dynamic_data::ScriptContainer;
use crate::dynamic_data::{LearnedMove, ScriptWrapper};
use crate::dynamic_data::{ScriptSource, ScriptSourceData};

/// The data on a turn choice that should be contained in every turn choice, regardless of type.
#[derive(Debug)]
struct CommonChoiceData {
    /// The user of the turn choice
    user: Arc<Pokemon>,
    /// The speed of the user at the beginning of the turn.
    speed: u32,
    /// This random value is set at the beginning of the turn. It is used for tie breaking of the
    /// turn order in a predictable way, regardless of implementation and hardware.
    random_value: u32,
    /// Whether or not the choice has failed. A failed choice will stop running, and execute special
    /// fail handling during turn execution.
    has_failed: AtomicBool,
    /// The data we can use to retrieve scripts that are affecting this choice. This will be written
    /// to once: when we need to initialize it. After that, this is only used to read. To prevent a
    /// read while we're writing to it, this is a RwLock.
    script_source_data: RwLock<ScriptSourceData>,
}

/// This enum defines a single choice for a Pokemon for a battle turn.
#[derive(Debug)]
#[cfg_attr(feature = "wasm", derive(unique_type_id_derive::UniqueTypeId))]
pub enum TurnChoice {
    /// A move choice tells a Pokemon to use a move on a target for this turn.
    Move(MoveChoice),
    /// An item choice tells a Pokemon to use an item.
    Item(ItemChoice),
    /// A switch choice tells a Pokemon to switch with another Pokemon from the party.
    Switch(SwitchChoice),
    /// A flee choice tells a Pokemon to flee from battle.
    Flee(FleeChoice),
    /// A pass choice tells the user to do nothing that turn.
    Pass(PassChoice),
}

impl TurnChoice {
    /// The shared choice data between each of the different turn choices.
    fn choice_data(&self) -> &CommonChoiceData {
        match self {
            TurnChoice::Move(data) => &data.choice_data,
            TurnChoice::Item(data) => &data.choice_data,
            TurnChoice::Switch(data) => &data.choice_data,
            TurnChoice::Flee(data) => &data.choice_data,
            TurnChoice::Pass(data) => &data.choice_data,
        }
    }
    /// The shared choice data between each of the different turn choices.
    fn choice_data_mut(&mut self) -> &mut Box<CommonChoiceData> {
        match self {
            TurnChoice::Move(data) => &mut data.choice_data,
            TurnChoice::Item(data) => &mut data.choice_data,
            TurnChoice::Switch(data) => &mut data.choice_data,
            TurnChoice::Flee(data) => &mut data.choice_data,
            TurnChoice::Pass(data) => &mut data.choice_data,
        }
    }

    /// Get the user of the given choice.
    pub fn user(&self) -> &Arc<Pokemon> {
        &self.choice_data().user
    }

    /// Get the speed of the user for the choice. Note that this speed is the speed of the Pokemon
    /// at the start of the turn!
    pub fn speed(&self) -> u32 {
        self.choice_data().speed
    }

    /// Get the mutable speed of the user for the choice. Note that this speed is the speed of the Pokemon
    /// at the start of the turn!
    pub fn speed_mut(&mut self) -> &mut u32 {
        &mut self.choice_data_mut().speed
    }

    /// Gets whether or not the choice has failed. If we notice this when we execute the choice, we
    /// will not execute it.
    pub fn has_failed(&self) -> bool {
        self.choice_data().has_failed.load(Ordering::SeqCst)
    }

    /// Fails the choice. This will prevent it from executing and run a specific fail handling during
    /// execution. Note that this can not be undone.
    pub fn fail(&self) {
        self.choice_data().has_failed.store(true, Ordering::SeqCst)
    }

    /// The random value of a turn choice gets set during the start of a choice, and is used for tie
    /// breaking of turn executions. This means that choices get executed with a predictable order,
    /// regardless of implementation details.
    pub(crate) fn random_value(&self) -> u32 {
        self.choice_data().random_value
    }

    /// This sets the above random value.
    pub(crate) fn set_random_value(&mut self, val: u32) {
        self.choice_data_mut().random_value = val;
    }

    /// Helper function to get the move choice data from a turn. Note that this will panic if not
    /// used on a move choice.
    pub(crate) fn get_move_turn_data(&self) -> &MoveChoice {
        if let TurnChoice::Move(data) = self {
            return data;
        }
        panic!("Invalid turn choice");
    }
}

impl ScriptSource for TurnChoice {
    fn get_script_count(&self) -> usize {
        match self {
            TurnChoice::Move(data) => data.get_script_count(),
            TurnChoice::Item(data) => data.get_script_count(),
            TurnChoice::Switch(data) => data.get_script_count(),
            TurnChoice::Flee(data) => data.get_script_count(),
            TurnChoice::Pass(data) => data.get_script_count(),
        }
    }

    fn get_script_source_data(&self) -> &RwLock<ScriptSourceData> {
        match self {
            TurnChoice::Move(data) => data.get_script_source_data(),
            TurnChoice::Item(data) => data.get_script_source_data(),
            TurnChoice::Switch(data) => data.get_script_source_data(),
            TurnChoice::Flee(data) => data.get_script_source_data(),
            TurnChoice::Pass(data) => data.get_script_source_data(),
        }
    }

    fn get_own_scripts(&self, scripts: &mut Vec<ScriptWrapper>) {
        match self {
            TurnChoice::Move(data) => data.get_own_scripts(scripts),
            TurnChoice::Item(data) => data.get_own_scripts(scripts),
            TurnChoice::Switch(data) => data.get_own_scripts(scripts),
            TurnChoice::Flee(data) => data.get_own_scripts(scripts),
            TurnChoice::Pass(data) => data.get_own_scripts(scripts),
        }
    }

    fn collect_scripts(&self, scripts: &mut Vec<ScriptWrapper>) {
        match self {
            TurnChoice::Move(data) => data.collect_scripts(scripts),
            TurnChoice::Item(data) => data.collect_scripts(scripts),
            TurnChoice::Switch(data) => data.collect_scripts(scripts),
            TurnChoice::Flee(data) => data.collect_scripts(scripts),
            TurnChoice::Pass(data) => data.collect_scripts(scripts),
        }
    }
}

/// The data attached to a move choice.
#[derive(Debug)]
pub struct MoveChoice {
    /// The move that is used for this choice.
    used_move: Arc<LearnedMove>,
    /// The side this move is aimed at.
    target_side: u8,
    /// The index of the Pokemon on the side we're aiming at.
    target_index: u8,
    /// The move script.
    script: ScriptContainer,
    /// The priority of the move choice at the beginning of the turn.
    priority: i8,
    /// The common turn choice data.
    choice_data: Box<CommonChoiceData>,
}

impl MoveChoice {
    /// Initializes the data for a new move choice.
    pub fn new(user: Arc<Pokemon>, used_move: Arc<LearnedMove>, target_side: u8, target_index: u8) -> Self {
        Self {
            used_move,
            target_side,
            target_index,
            script: Default::default(),
            priority: 0,
            choice_data: Box::new(CommonChoiceData {
                user,
                speed: 0,
                random_value: 0,
                has_failed: Default::default(),
                script_source_data: Default::default(),
            }),
        }
    }

    /// The actual learned move on the Pokemon we use for this choice.
    pub fn used_move(&self) -> &Arc<LearnedMove> {
        &self.used_move
    }

    /// The target side the move is aimed at.
    pub fn target_side(&self) -> u8 {
        self.target_side
    }
    /// The Pokemon index on the side we're aiming at.
    pub fn target_index(&self) -> u8 {
        self.target_index
    }
    /// The priority of the move choice at the beginning of the turn.
    pub fn priority(&self) -> i8 {
        self.priority
    }
    /// The priority of the move choice at the beginning of the turn.
    pub fn priority_mut(&mut self) -> &mut i8 {
        &mut self.priority
    }
    /// The user of the choice.
    pub fn user(&self) -> &Arc<Pokemon> {
        &self.choice_data.user
    }
    /// The move script of the choice.
    pub fn script(&self) -> &ScriptContainer {
        &self.script
    }
}

impl ScriptSource for MoveChoice {
    fn get_script_count(&self) -> usize {
        1 + self.choice_data.user.get_script_count()
    }

    fn get_script_source_data(&self) -> &RwLock<ScriptSourceData> {
        &self.choice_data.script_source_data
    }

    fn get_own_scripts(&self, scripts: &mut Vec<ScriptWrapper>) {
        scripts.push((&self.script).into());
    }

    fn collect_scripts(&self, scripts: &mut Vec<ScriptWrapper>) {
        self.get_own_scripts(scripts);
        self.choice_data.user.collect_scripts(scripts);
    }
}

/// The data given when we select an item choice.
#[derive(Debug)]
pub struct ItemChoice {
    /// The shared data of all turn choices.
    choice_data: Box<CommonChoiceData>,
}

impl ItemChoice {
    /// Initialised a new item choice.
    pub fn new(user: Arc<Pokemon>) -> Self {
        Self {
            choice_data: Box::new(CommonChoiceData {
                user,
                speed: 0,
                random_value: 0,
                has_failed: Default::default(),
                script_source_data: Default::default(),
            }),
        }
    }
}

impl ScriptSource for ItemChoice {
    fn get_script_count(&self) -> usize {
        0
    }

    fn get_script_source_data(&self) -> &RwLock<ScriptSourceData> {
        &self.choice_data.script_source_data
    }

    fn get_own_scripts(&self, _scripts: &mut Vec<ScriptWrapper>) {}

    fn collect_scripts(&self, scripts: &mut Vec<ScriptWrapper>) {
        self.choice_data.user.collect_scripts(scripts);
    }
}

/// The data given when we select a switch choice.
#[derive(Debug)]
pub struct SwitchChoice {
    /// The shared data of all turn choices.
    choice_data: Box<CommonChoiceData>,
}

impl SwitchChoice {
    /// Initialise the turn choice data.
    pub fn new(user: Arc<Pokemon>) -> Self {
        Self {
            choice_data: Box::new(CommonChoiceData {
                user,
                speed: 0,
                random_value: 0,
                has_failed: Default::default(),
                script_source_data: Default::default(),
            }),
        }
    }
}

impl ScriptSource for SwitchChoice {
    fn get_script_count(&self) -> usize {
        0
    }

    fn get_script_source_data(&self) -> &RwLock<ScriptSourceData> {
        &self.choice_data.script_source_data
    }

    fn get_own_scripts(&self, _scripts: &mut Vec<ScriptWrapper>) {}

    fn collect_scripts(&self, scripts: &mut Vec<ScriptWrapper>) {
        self.choice_data.user.collect_scripts(scripts);
    }
}

/// The data given when we select a flee choice.
#[derive(Debug)]
pub struct FleeChoice {
    /// The common data all turn choices share.
    choice_data: Box<CommonChoiceData>,
}

impl FleeChoice {
    /// Initialises a new flee choice.
    pub fn new(user: Arc<Pokemon>) -> Self {
        Self {
            choice_data: Box::new(CommonChoiceData {
                user,
                speed: 0,
                random_value: 0,
                has_failed: Default::default(),
                script_source_data: Default::default(),
            }),
        }
    }
}

impl ScriptSource for FleeChoice {
    fn get_script_count(&self) -> usize {
        0
    }

    fn get_script_source_data(&self) -> &RwLock<ScriptSourceData> {
        &self.choice_data.script_source_data
    }

    fn get_own_scripts(&self, _scripts: &mut Vec<ScriptWrapper>) {}

    fn collect_scripts(&self, scripts: &mut Vec<ScriptWrapper>) {
        self.choice_data.user.collect_scripts(scripts);
    }
}

/// The data given when we select a pass choice.
#[derive(Debug)]
pub struct PassChoice {
    /// The common data of all turn choices.
    choice_data: Box<CommonChoiceData>,
}

impl PassChoice {
    /// Initialised a new pass choice.
    pub fn new(user: Arc<Pokemon>) -> Self {
        Self {
            choice_data: Box::new(CommonChoiceData {
                user,
                speed: 0,
                random_value: 0,
                has_failed: Default::default(),
                script_source_data: Default::default(),
            }),
        }
    }
}

impl ScriptSource for PassChoice {
    fn get_script_count(&self) -> usize {
        0
    }

    fn get_script_source_data(&self) -> &RwLock<ScriptSourceData> {
        &self.choice_data.script_source_data
    }

    fn get_own_scripts(&self, _scripts: &mut Vec<ScriptWrapper>) {}

    fn collect_scripts(&self, scripts: &mut Vec<ScriptWrapper>) {
        self.choice_data.user.collect_scripts(scripts);
    }
}

impl PartialEq<Self> for TurnChoice {
    fn eq(&self, other: &Self) -> bool {
        std::ptr::eq(self, other)
    }
}

impl Eq for TurnChoice {}

impl PartialOrd for TurnChoice {
    fn partial_cmp(&self, other: &Self) -> Option<std::cmp::Ordering> {
        Some(self.cmp(other))
    }
}

impl Ord for TurnChoice {
    fn cmp(&self, other: &Self) -> std::cmp::Ordering {
        match self {
            TurnChoice::Move(data) => {
                if let TurnChoice::Move(other_data) = other {
                    let priority_compare = data.priority.cmp(&other_data.priority);
                    if priority_compare != std::cmp::Ordering::Equal {
                        return priority_compare;
                    }
                    let speed_compare = self.speed().cmp(&other.speed());
                    if speed_compare != std::cmp::Ordering::Equal {
                        return speed_compare;
                    }
                    return self.random_value().cmp(&other.random_value());
                }
                std::cmp::Ordering::Greater
            }
            TurnChoice::Item { .. } => {
                if let TurnChoice::Move { .. } = other {
                    return std::cmp::Ordering::Less;
                }
                if let TurnChoice::Item { .. } = other {
                    let speed_compare = self.speed().cmp(&other.speed());
                    if speed_compare != std::cmp::Ordering::Equal {
                        return speed_compare;
                    }
                    return self.random_value().cmp(&other.random_value());
                }
                std::cmp::Ordering::Greater
            }
            TurnChoice::Switch { .. } => {
                if let TurnChoice::Move { .. } = other {
                    return std::cmp::Ordering::Less;
                }
                if let TurnChoice::Item { .. } = other {
                    return std::cmp::Ordering::Less;
                }
                if let TurnChoice::Switch { .. } = other {
                    let speed_compare = self.speed().cmp(&other.speed());
                    if speed_compare != std::cmp::Ordering::Equal {
                        return speed_compare;
                    }
                    return self.random_value().cmp(&other.random_value());
                }
                std::cmp::Ordering::Greater
            }
            TurnChoice::Flee { .. } => {
                if let TurnChoice::Flee { .. } = other {
                    let speed_compare = self.speed().cmp(&other.speed());
                    if speed_compare != std::cmp::Ordering::Equal {
                        return speed_compare;
                    }
                    return self.random_value().cmp(&other.random_value());
                }
                std::cmp::Ordering::Less
            }
            TurnChoice::Pass(..) => std::cmp::Ordering::Less,
        }
    }
}