use core::{fmt::Display, num::NonZeroU8, ops::Not};

use rand::seq::SliceRandom;
use serde::{Deserialize, Serialize};

use crate::{
    diedto::DiedTo,
    error::GameError,
    game::{DateTime, Village},
    message::{CharacterIdentity, Identification, PublicIdentity, night::ActionPrompt},
    modifier::Modifier,
    player::{PlayerId, RoleChange},
    role::{Alignment, MAPLE_WOLF_ABSTAIN_LIMIT, PreviousGuardianAction, Role, RoleTitle},
};

type Result<T> = core::result::Result<T, GameError>;

#[derive(Debug, Clone, Copy, Serialize, Deserialize, PartialEq, Eq, Hash)]
pub struct CharacterId(uuid::Uuid);

impl CharacterId {
    pub fn new() -> Self {
        Self(uuid::Uuid::new_v4())
    }
    pub const fn from_u128(v: u128) -> Self {
        Self(uuid::Uuid::from_u128(v))
    }
}

impl Display for CharacterId {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        self.0.fmt(f)
    }
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct Character {
    player_id: PlayerId,
    identity: CharacterIdentity,
    role: Role,
    modifier: Option<Modifier>,
    died_to: Option<DiedTo>,
    role_changes: Vec<RoleChange>,
}

impl Character {
    pub fn new(
        Identification {
            player_id,
            public:
                PublicIdentity {
                    name,
                    pronouns,
                    number,
                },
        }: Identification,
        role: Role,
    ) -> Option<Self> {
        Some(Self {
            role,
            identity: CharacterIdentity {
                character_id: CharacterId::new(),
                name,
                pronouns,
                number: number?,
            },
            player_id,
            modifier: None,
            died_to: None,
            role_changes: Vec::new(),
        })
    }

    pub const fn is_power_role(&self) -> bool {
        match &self.role {
            Role::Scapegoat { .. } | Role::Villager => false,

            _ => true,
        }
    }

    pub fn identity(&self) -> CharacterIdentity {
        self.identity.clone()
    }

    pub fn name(&self) -> &str {
        self.identity.name.as_str()
    }

    pub const fn number(&self) -> NonZeroU8 {
        self.identity.number
    }

    pub const fn pronouns(&self) -> Option<&str> {
        match self.identity.pronouns.as_ref() {
            Some(p) => Some(p.as_str()),
            None => None,
        }
    }

    pub fn died_to(&self) -> Option<&DiedTo> {
        self.died_to.as_ref()
    }

    pub fn kill(&mut self, died_to: DiedTo) {
        match (&mut self.role, died_to.date_time()) {
            (
                Role::Elder {
                    lost_protection_night: Some(_),
                    ..
                },
                _,
            ) => {}
            (
                Role::Elder {
                    lost_protection_night,
                    ..
                },
                DateTime::Night { number: night },
            ) => {
                *lost_protection_night = lost_protection_night
                    .is_none()
                    .then_some(night)
                    .and_then(NonZeroU8::new);
                return;
            }
            _ => {}
        }
        match &self.died_to {
            Some(_) => {}
            None => self.died_to = Some(died_to),
        }
    }

    pub const fn alive(&self) -> bool {
        self.died_to.is_none()
    }

    pub fn execute(&mut self, day: NonZeroU8) -> Result<()> {
        if self.died_to.is_some() {
            return Err(GameError::CharacterAlreadyDead);
        }
        self.died_to = Some(DiedTo::Execution { day });
        Ok(())
    }

    pub const fn character_id(&self) -> CharacterId {
        self.identity.character_id
    }

    pub const fn player_id(&self) -> PlayerId {
        self.player_id
    }

    pub const fn role_title(&self) -> RoleTitle {
        self.role.title()
    }

    pub const fn gravedigger_dig(&self) -> Option<RoleTitle> {
        match &self.role {
            Role::Shapeshifter {
                shifted_into: Some(_),
            } => None,
            _ => Some(self.role.title()),
        }
    }

    pub const fn alignment(&self) -> Alignment {
        if let Role::Empath { cursed: true } = &self.role {
            return Alignment::Wolves;
        }
        self.role.alignment()
    }

    pub fn elder_reveal(&mut self) {
        if let Role::Elder {
            woken_for_reveal, ..
        } = &mut self.role
        {
            *woken_for_reveal = true
        }
    }

    pub fn role_change(&mut self, new_role: RoleTitle, at: DateTime) -> Result<()> {
        let mut role = new_role.title_to_role_excl_apprentice();
        core::mem::swap(&mut role, &mut self.role);
        self.role_changes.push(RoleChange {
            role,
            new_role,
            changed_on_night: match at {
                DateTime::Day { number: _ } => return Err(GameError::NotNight),
                DateTime::Night { number } => number,
            },
        });

        Ok(())
    }

    pub const fn is_wolf(&self) -> bool {
        self.role.wolf()
    }

    pub const fn is_village(&self) -> bool {
        !self.is_wolf()
    }

    pub const fn known_elder(&self) -> bool {
        matches!(
            self.role,
            Role::Elder {
                woken_for_reveal: true,
                ..
            }
        )
    }

    pub fn night_action_prompts(&self, village: &Village) -> Result<Box<[ActionPrompt]>> {
        if !self.alive() || !self.role.wakes(village) {
            return Ok(Box::new([]));
        }
        let night = match village.date_time() {
            DateTime::Day { number: _ } => return Err(GameError::NotNight),
            DateTime::Night { number } => number,
        };
        Ok(Box::new([match &self.role {
            Role::Empath { cursed: true }
            | Role::Diseased
            | Role::Weightlifter
            | Role::BlackKnight { .. }
            | Role::Shapeshifter {
                shifted_into: Some(_),
            }
            | Role::AlphaWolf { killed: Some(_) }
            | Role::Militia { targeted: Some(_) }
            | Role::Scapegoat { redeemed: false }
            | Role::Elder {
                woken_for_reveal: true,
                ..
            }
            | Role::Villager => return Ok(Box::new([])),
            Role::Scapegoat { redeemed: true } => {
                let mut dead = village.dead_characters();
                dead.shuffle(&mut rand::rng());
                if let Some(pr) = dead
                    .into_iter()
                    .find_map(|d| (d.is_village() && d.is_power_role()).then_some(d.role_title()))
                {
                    ActionPrompt::RoleChange {
                        character_id: self.identity(),
                        new_role: pr,
                    }
                } else {
                    return Ok(Box::new([]));
                }
            }
            Role::Seer => ActionPrompt::Seer {
                character_id: self.identity(),
                living_players: village.living_players_excluding(self.character_id()),
                marked: None,
            },
            Role::Arcanist => ActionPrompt::Arcanist {
                character_id: self.identity(),
                living_players: village.living_players_excluding(self.character_id()),
                marked: (None, None),
            },
            Role::Protector {
                last_protected: Some(last_protected),
            } => ActionPrompt::Protector {
                character_id: self.identity(),
                targets: village.living_players_excluding(*last_protected),
                marked: None,
            },
            Role::Protector {
                last_protected: None,
            } => ActionPrompt::Protector {
                character_id: self.identity(),
                targets: village.living_players_excluding(self.character_id()),
                marked: None,
            },
            Role::Apprentice(role) => {
                let current_night = match village.date_time() {
                    DateTime::Day { number: _ } => return Ok(Box::new([])),
                    DateTime::Night { number } => number,
                };
                return Ok(village
                    .characters()
                    .into_iter()
                    .filter(|c| c.role_title() == *role)
                    .filter_map(|char| char.died_to)
                    .any(|died_to| match died_to.date_time() {
                        DateTime::Day { number } => number.get() + 1 >= current_night,
                        DateTime::Night { number } => number + 1 >= current_night,
                    })
                    .then(|| ActionPrompt::RoleChange {
                        character_id: self.identity(),
                        new_role: *role,
                    })
                    .into_iter()
                    .collect());
            }
            Role::Elder {
                knows_on_night,
                woken_for_reveal: false,
                ..
            } => {
                let current_night = match village.date_time() {
                    DateTime::Day { number: _ } => return Ok(Box::new([])),
                    DateTime::Night { number } => number,
                };
                return Ok((current_night >= knows_on_night.get())
                    .then_some({
                        ActionPrompt::ElderReveal {
                            character_id: self.identity(),
                        }
                    })
                    .into_iter()
                    .collect());
            }
            Role::Militia { targeted: None } => ActionPrompt::Militia {
                character_id: self.identity(),
                living_players: village.living_players_excluding(self.character_id()),
                marked: None,
            },
            Role::Werewolf => ActionPrompt::WolfPackKill {
                living_villagers: village.living_players(),
                marked: None,
            },
            Role::AlphaWolf { killed: None } => ActionPrompt::AlphaWolf {
                character_id: self.identity(),
                living_villagers: village.living_players_excluding(self.character_id()),
                marked: None,
            },
            Role::DireWolf => ActionPrompt::DireWolf {
                character_id: self.identity(),
                living_players: village.living_players(),
                marked: None,
            },
            Role::Shapeshifter { shifted_into: None } => ActionPrompt::Shapeshifter {
                character_id: self.identity(),
            },
            Role::Gravedigger => {
                let dead = village.dead_targets();
                if dead.is_empty() {
                    return Ok(Box::new([]));
                }
                ActionPrompt::Gravedigger {
                    character_id: self.identity(),
                    dead_players: village.dead_targets(),
                    marked: None,
                }
            }
            Role::Hunter { target } => ActionPrompt::Hunter {
                character_id: self.identity(),
                current_target: target.as_ref().and_then(|t| village.target_by_id(*t).ok()),
                living_players: village.living_players_excluding(self.character_id()),
                marked: None,
            },
            Role::MapleWolf { last_kill_on_night } => ActionPrompt::MapleWolf {
                character_id: self.identity(),
                kill_or_die: last_kill_on_night + MAPLE_WOLF_ABSTAIN_LIMIT.get() == night,
                living_players: village.living_players_excluding(self.character_id()),
                marked: None,
            },
            Role::Guardian {
                last_protected: Some(PreviousGuardianAction::Guard(prev_target)),
            } => ActionPrompt::Guardian {
                character_id: self.identity(),
                previous: Some(PreviousGuardianAction::Guard(prev_target.clone())),
                living_players: village.living_players_excluding(prev_target.character_id),
                marked: None,
            },
            Role::Guardian {
                last_protected: Some(PreviousGuardianAction::Protect(prev_target)),
            } => ActionPrompt::Guardian {
                character_id: self.identity(),
                previous: Some(PreviousGuardianAction::Protect(prev_target.clone())),
                living_players: village.living_players(),
                marked: None,
            },
            Role::Guardian {
                last_protected: None,
            } => ActionPrompt::Guardian {
                character_id: self.identity(),
                previous: None,
                living_players: village.living_players(),
                marked: None,
            },
            Role::Adjudicator => ActionPrompt::Adjudicator {
                character_id: self.identity(),
                living_players: village.living_players_excluding(self.character_id()),
                marked: None,
            },
            Role::PowerSeer => ActionPrompt::PowerSeer {
                character_id: self.identity(),
                living_players: village.living_players_excluding(self.character_id()),
                marked: None,
            },
            Role::Mortician => ActionPrompt::Mortician {
                character_id: self.identity(),
                dead_players: village.dead_targets(),
                marked: None,
            },
            Role::Beholder => ActionPrompt::Beholder {
                character_id: self.identity(),
                living_players: village.living_players_excluding(self.character_id()),
                marked: None,
            },
            Role::MasonLeader {
                recruits_available,
                recruits,
            } => {
                return Ok(recruits
                    .is_empty()
                    .not()
                    .then_some(ActionPrompt::MasonsWake {
                        character_id: self.identity(),
                        masons: recruits
                            .iter()
                            .map(|r| village.character_by_id(*r).map(|c| c.identity()))
                            .collect::<Result<Box<[CharacterIdentity]>>>()?,
                    })
                    .into_iter()
                    .chain(
                        NonZeroU8::new(*recruits_available).map(|recruits_available| {
                            ActionPrompt::MasonLeaderRecruit {
                                character_id: self.identity(),
                                recruits_left: recruits_available,
                                potential_recruits: village
                                    .living_players_excluding(self.character_id())
                                    .into_iter()
                                    .filter(|c| !recruits.contains(&c.character_id))
                                    .collect(),
                                marked: None,
                            }
                        }),
                    )
                    .collect());
            }
            Role::Empath { cursed: false } => ActionPrompt::Empath {
                character_id: self.identity(),
                living_players: village.living_players_excluding(self.character_id()),
                marked: None,
            },
            Role::Vindicator => {
                let last_day = match village.date_time() {
                    DateTime::Day { .. } => {
                        log::error!(
                            "vindicator trying to get a prompt during the day? village state: {village:?}"
                        );
                        return Ok(Box::new([]));
                    }
                    DateTime::Night { number } => {
                        if number == 0 {
                            return Ok(Box::new([]));
                        }
                        NonZeroU8::new(number).unwrap()
                    }
                };
                return Ok(village
                    .executions_on_day(last_day)
                    .iter()
                    .any(|c| c.is_village())
                    .then(|| ActionPrompt::Vindicator {
                        character_id: self.identity(),
                        living_players: village.living_players_excluding(self.character_id()),
                        marked: None,
                    })
                    .into_iter()
                    .collect());
            }
            Role::PyreMaster { .. } => ActionPrompt::PyreMaster {
                character_id: self.identity(),
                living_players: village.living_players_excluding(self.character_id()),
                marked: None,
            },
        }]))
    }

    #[cfg(test)]
    pub const fn role(&self) -> &Role {
        &self.role
    }

    pub const fn killer(&self) -> bool {
        if let Role::Empath { cursed: true } = &self.role {
            return true;
        }
        self.role.killer()
    }

    pub const fn powerful(&self) -> bool {
        if let Role::Empath { cursed: true } = &self.role {
            return true;
        }
        self.role.powerful()
    }

    pub const fn hunter<'a>(&'a self) -> Result<Hunter<'a>> {
        match &self.role {
            Role::Hunter { target } => Ok(Hunter(target)),
            _ => Err(GameError::InvalidRole {
                expected: RoleTitle::Hunter,
                got: self.role_title(),
            }),
        }
    }

    pub const fn hunter_mut<'a>(&'a mut self) -> Result<HunterMut<'a>> {
        let title = self.role.title();
        match &mut self.role {
            Role::Hunter { target } => Ok(HunterMut(target)),
            _ => Err(GameError::InvalidRole {
                expected: RoleTitle::Hunter,
                got: title,
            }),
        }
    }

    pub const fn shapeshifter<'a>(&'a self) -> Result<Shapeshifter<'a>> {
        match &self.role {
            Role::Shapeshifter { shifted_into } => Ok(Shapeshifter(shifted_into)),
            _ => Err(GameError::InvalidRole {
                expected: RoleTitle::Shapeshifter,
                got: self.role_title(),
            }),
        }
    }

    pub const fn shapeshifter_mut<'a>(&'a mut self) -> Result<ShapeshifterMut<'a>> {
        let title = self.role.title();
        match &mut self.role {
            Role::Shapeshifter { shifted_into } => Ok(ShapeshifterMut(shifted_into)),
            _ => Err(GameError::InvalidRole {
                expected: RoleTitle::Shapeshifter,
                got: title,
            }),
        }
    }

    pub const fn mason_leader<'a>(&'a self) -> Result<MasonLeader<'a>> {
        match &self.role {
            Role::MasonLeader {
                recruits_available,
                recruits,
            } => Ok(MasonLeader(recruits_available, recruits)),
            _ => Err(GameError::InvalidRole {
                expected: RoleTitle::MasonLeader,
                got: self.role_title(),
            }),
        }
    }

    pub const fn mason_leader_mut<'a>(&'a mut self) -> Result<MasonLeaderMut<'a>> {
        let title = self.role.title();
        match &mut self.role {
            Role::MasonLeader {
                recruits_available,
                recruits,
            } => Ok(MasonLeaderMut(recruits_available, recruits)),
            _ => Err(GameError::InvalidRole {
                expected: RoleTitle::MasonLeader,
                got: title,
            }),
        }
    }

    pub const fn scapegoat<'a>(&'a self) -> Result<Scapegoat<'a>> {
        match &self.role {
            Role::Scapegoat { redeemed } => Ok(Scapegoat(redeemed)),
            _ => Err(GameError::InvalidRole {
                expected: RoleTitle::Scapegoat,
                got: self.role_title(),
            }),
        }
    }

    pub const fn scapegoat_mut<'a>(&'a mut self) -> Result<ScapegoatMut<'a>> {
        let title = self.role.title();
        match &mut self.role {
            Role::Scapegoat { redeemed } => Ok(ScapegoatMut(redeemed)),
            _ => Err(GameError::InvalidRole {
                expected: RoleTitle::Scapegoat,
                got: title,
            }),
        }
    }

    pub const fn empath<'a>(&'a self) -> Result<Empath<'a>> {
        match &self.role {
            Role::Empath { cursed } => Ok(Empath(cursed)),
            _ => Err(GameError::InvalidRole {
                expected: RoleTitle::Empath,
                got: self.role_title(),
            }),
        }
    }

    pub const fn empath_mut<'a>(&'a mut self) -> Result<EmpathMut<'a>> {
        let title = self.role.title();
        match &mut self.role {
            Role::Empath { cursed } => Ok(EmpathMut(cursed)),
            _ => Err(GameError::InvalidRole {
                expected: RoleTitle::Empath,
                got: title,
            }),
        }
    }

    pub const fn initial_shown_role(&self) -> RoleTitle {
        self.role.initial_shown_role()
    }
}

macro_rules! decl_ref_and_mut {
	($($name:ident, $name_mut:ident: $contains:ty;)*) => {
		$(
			pub struct $name<'a>(&'a $contains);
			impl core::ops::Deref for $name<'_> {
				type Target = $contains;

				fn deref(&self) -> &Self::Target {
					self.0
				}
			}
			pub struct $name_mut<'a>(&'a mut $contains);
			impl core::ops::Deref for $name_mut<'_> {
				type Target = $contains;

				fn deref(&self) -> &Self::Target {
					self.0
				}
			}
			impl core::ops::DerefMut for $name_mut<'_> {
				fn deref_mut(&mut self) -> &mut Self::Target {
					self.0
				}
			}
		)*
	};
}

decl_ref_and_mut!(
    Hunter, HunterMut: Option<CharacterId>;
    Shapeshifter, ShapeshifterMut: Option<CharacterId>;
    Scapegoat, ScapegoatMut: bool;
    Empath, EmpathMut: bool;
);

pub struct MasonLeader<'a>(&'a u8, &'a [CharacterId]);
impl MasonLeader<'_> {
    pub const fn remaining_recruits(&self) -> u8 {
        *self.0
    }

    pub const fn recruits(&self) -> usize {
        self.1.len()
    }
}

pub struct MasonLeaderMut<'a>(&'a mut u8, &'a mut Box<[CharacterId]>);
impl MasonLeaderMut<'_> {
    pub const fn remaining_recruits(&self) -> u8 {
        *self.0
    }

    pub fn recruit(self, target: CharacterId) {
        let mut recruits = self.1.to_vec();
        recruits.push(target);
        *self.1 = recruits.into_boxed_slice();
        if let Some(new) = self.0.checked_sub(1) {
            *self.0 = new;
        }
    }
}