#[cfg(feature = "sycamore")]
use crate::edit::prelude::*;
use crate::util::PartyError;
#[cfg(feature = "sycamore")]
use crate::view::prelude::*;
#[cfg(feature = "sycamore")]
use lan_party_macros::{web_view_attr, WebEdit, WebView};
use paste::paste;
#[cfg(feature = "openapi")]
use schemars::JsonSchema;
#[cfg(feature = "serde")]
use serde::{Deserialize, Serialize};
use std::{
    collections::{HashMap, HashSet},
    hash::Hash,
};

#[derive(Clone, Debug, PartialEq)]
#[cfg_attr(feature = "openapi", derive(JsonSchema))]
#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
#[cfg_attr(feature = "sycamore", derive(WebEdit, WebView))]
pub enum Ranking<T: Hash + PartialEq + Eq + Clone + Default> {
    /// Ranking of participants by user name or team name (first element is first place, second element is second
    /// place, etc.)
    Ranking(Vec<T>),
    /// Score based ranking of participants/teams
    Scores(HashMap<T, i64>),
}

impl<T: Hash + PartialEq + Eq + Clone + Default> Default for Ranking<T> {
    fn default() -> Self {
        Self::Ranking(Vec::default())
    }
}

impl<T: Hash + PartialEq + Eq + Clone + Default> Ranking<T> {
    pub fn is_valid(&self, participants: &HashSet<T>) -> bool {
        match self {
            Self::Ranking(v) => v.iter().all(|p| participants.contains(p)),
            Self::Scores(m) => m.keys().all(|p| participants.contains(p)),
        }
    }
}

#[derive(Clone, Debug, Default)]
#[cfg_attr(feature = "openapi", derive(JsonSchema))]
#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
pub struct EventOutcome {
    pub points: HashMap<String, i64>,
}

/// # Event
///
/// An event in which participants can win or lose points
#[derive(Clone, Debug, PartialEq)]
#[cfg_attr(feature = "openapi", derive(JsonSchema))]
#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
#[cfg_attr(feature = "sycamore", derive(WebView))]
#[cfg_attr(feature = "sycamore", web_view_attr(title = "name"))]
pub struct Event {
    /// Has this event concluded?
    #[cfg_attr(feature = "serde", serde(default))]
    pub concluded: bool,
    /// Name of the event
    #[cfg_attr(feature = "serde", serde(default))]
    pub name: String,
    /// Description of the event
    #[cfg_attr(feature = "serde", serde(default))]
    pub description: String,
    pub event_type: EventType,
}

impl Event {
    pub fn outcome(&self) -> EventOutcome {
        self.event_type.outcome()
    }

    pub fn conclude(&self) {}

    pub fn apply_update(&mut self, update: EventUpdate) -> Result<(), PartyError> {
        self.event_type.apply_update(update)
    }
}

/// # EventSpec
///
/// A specification of an event
#[derive(Clone, Debug, Default, PartialEq)]
#[cfg_attr(feature = "openapi", derive(JsonSchema))]
#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
#[cfg_attr(feature = "sycamore", derive(WebEdit, WebView))]
pub struct EventSpec {
    /// Name of the event
    pub name: String,
    /// Description of the event
    pub description: String,
    pub event_type: EventTypeSpec,
}

macro_rules! events {
    ($($module:ident => $name:ident),* $(,)?) => {
        paste! {
            /// # EventTypeSpec
            ///
            /// A specification of an event type
            #[derive(Clone, Debug, PartialEq)]
            #[cfg_attr(feature = "openapi", derive(JsonSchema))]
            #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
            #[cfg_attr(feature = "sycamore", derive(WebEdit, WebView))]
            pub enum EventTypeSpec {
                $($name($module::[<$name Spec>]),)*
            }

            /// # EventUpdate
            ///
            /// An update that can be applied to an event
            #[derive(Clone, Debug)]
            #[cfg_attr(feature = "openapi", derive(JsonSchema))]
            #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
            #[cfg_attr(feature = "sycamore", derive(WebEdit, WebView))]
            pub enum EventUpdate {
                $($name($module::[<$name Update>]),)*
            }

            /// # EventType
            ///
            /// An enumeration of event types
            #[derive(Clone, Debug, PartialEq)]
            #[cfg_attr(feature = "openapi", derive(JsonSchema))]
            #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
            #[cfg_attr(feature = "sycamore", derive(WebEdit, WebView))]
            pub enum EventType {
                $($name($module::$name),)*
            }

            impl EventSpec {
                pub fn create_event(self) -> Result<Event, PartyError> {
                    if self.name.is_empty() {
                        return Err(PartyError::Unknown("invalid name".into()))
                    }

                    let event_type = match self.event_type {
                        $(EventTypeSpec::$name(s) => {
                            EventType::$name($module::$name::from_spec(s))
                        })*
                    };

                    let event = Event {
                        name: self.name,
                        description: self.description,
                        concluded: false,
                        event_type,
                    };

                    Ok(event)
                }
            }

            impl EventType {
                pub fn apply_update(&mut self, update: EventUpdate) -> Result<(), PartyError> {
                    match (self, update) {
                        $((EventType::$name(s), EventUpdate::$name(u)) => {
                            s.apply_update(u)
                        })*
                        _ => Err(PartyError::Unknown("invalid update".into())),
                    }
                }

                pub fn outcome(&self) -> EventOutcome {
                    match self {
                        $(EventType::$name(s) => {
                            s.outcome()
                        })*
                    }
                }
            }
        }
    };
}

pub trait EventTrait {
    type Spec;
    type Update;

    fn from_spec(spec: Self::Spec) -> Self;

    fn apply_update(&mut self, _update: Self::Update) -> Result<(), PartyError> {
        Ok(())
    }

    fn outcome(&self) -> EventOutcome {
        EventOutcome::default()
    }
}

pub mod test {
    use super::*;

    #[derive(Clone, Debug, Default, PartialEq)]
    #[cfg_attr(feature = "openapi", derive(JsonSchema))]
    #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
    #[cfg_attr(feature = "sycamore", derive(WebEdit, WebView))]
    pub struct Test {
        pub num_players: i64,
    }

    #[derive(Clone, Debug, Default, PartialEq)]
    #[cfg_attr(feature = "openapi", derive(JsonSchema))]
    #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
    #[cfg_attr(feature = "sycamore", derive(WebEdit, WebView))]
    pub struct TestSpec {
        pub num_players: i64,
    }

    #[derive(Clone, Debug, Default)]
    #[cfg_attr(feature = "openapi", derive(JsonSchema))]
    #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
    #[cfg_attr(feature = "sycamore", derive(WebEdit, WebView))]
    pub struct TestUpdate {
        pub win_game: bool,
    }

    impl EventTrait for Test {
        type Spec = TestSpec;
        type Update = TestUpdate;

        fn from_spec(spec: TestSpec) -> Self {
            Test {
                num_players: spec.num_players,
            }
        }

        fn apply_update(&mut self, update: TestUpdate) -> Result<(), PartyError> {
            if update.win_game {
                self.num_players += 1;
            }
            Ok(())
        }

        fn outcome(&self) -> EventOutcome {
            let mut points = HashMap::new();
            points.insert("420".into(), self.num_players);
            EventOutcome { points }
        }
    }
}

pub mod team_game {
    use super::{
        free_for_all_game::{FreeForAllGame, FreeForAllGameSpec, FreeForAllGameUpdate},
        *,
    };

    #[derive(Clone, Debug, Default, PartialEq)]
    #[cfg_attr(feature = "openapi", derive(JsonSchema))]
    #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
    #[cfg_attr(feature = "sycamore", derive(WebEdit, WebView))]
    pub struct TeamGame {
        /// Map of teams with a name as key and an array of players as value
        pub teams: HashMap<String, Vec<String>>,

        #[cfg_attr(feature = "serde", serde(flatten))]
        pub ffa_game: FreeForAllGame,
    }

    #[derive(Clone, Debug, PartialEq, Default)]
    #[cfg_attr(feature = "openapi", derive(JsonSchema))]
    #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
    #[cfg_attr(feature = "sycamore", derive(WebEdit, WebView))]
    pub struct TeamGameSpec {
        /// Map of teams with a name as key and an array of players as value
        pub teams: HashMap<String, Vec<String>>,

        /// Rewards for winning the game (first element for first place, second element for second
        /// place, etc.)
        #[cfg_attr(
            feature = "openapi",
            schemars(example = "super::free_for_all_game::example_win_rewards")
        )]
        pub win_rewards: Vec<i64>,
        /// Rewards for losing the game (first element for last place, second element for second to
        /// last place, etc.)
        #[cfg_attr(
            feature = "openapi",
            schemars(example = "super::free_for_all_game::example_lose_rewards")
        )]
        pub lose_rewards: Vec<i64>,
    }

    #[derive(Clone, Debug, Default)]
    #[cfg_attr(feature = "openapi", derive(JsonSchema))]
    #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
    #[cfg_attr(feature = "sycamore", derive(WebEdit, WebView))]
    pub struct TeamGameUpdateSetTeam {
        pub team: String,
        pub members: Vec<String>,
    }

    #[derive(Clone, Debug, Default, PartialEq, Eq, Hash)]
    #[cfg_attr(feature = "openapi", derive(JsonSchema))]
    #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
    #[cfg_attr(feature = "sycamore", derive(WebEdit, WebView))]
    pub struct Team {
        name: String,
    }

    #[derive(Clone, Debug)]
    #[cfg_attr(feature = "openapi", derive(JsonSchema))]
    #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
    #[cfg_attr(feature = "serde", serde(untagged))]
    #[cfg_attr(feature = "sycamore", derive(WebEdit, WebView))]
    pub enum TeamGameUpdate {
        /// Add or replace a team with the given name and array of members
        SetTeam(TeamGameUpdateSetTeam),
        /// Remove team with given name
        RemoveTeam(String),
        /// Replace the current ranking with the given ranking
        SetRanking(Ranking<String>),
        /// If the current ranking is of type `Scores`, apply the given score deltas
        ScoreDelta(HashMap<String, i64>),
        /// Set rewards for winning the game
        SetWinRewards(Vec<i64>),
        /// Set rewards for losing the game
        SetLoseRewards(Vec<i64>),
    }

    impl Default for TeamGameUpdate {
        fn default() -> Self {
            TeamGameUpdate::SetTeam(TeamGameUpdateSetTeam::default())
        }
    }

    impl EventTrait for TeamGame {
        type Spec = TeamGameSpec;
        type Update = TeamGameUpdate;

        fn from_spec(spec: TeamGameSpec) -> Self {
            let ffa_game_spec = FreeForAllGameSpec {
                participants: spec.teams.keys().cloned().collect(),
                win_rewards: spec.win_rewards,
                lose_rewards: spec.lose_rewards,
            };

            TeamGame {
                teams: spec.teams,
                ffa_game: FreeForAllGame::from_spec(ffa_game_spec),
            }
        }

        fn apply_update(&mut self, update: Self::Update) -> Result<(), PartyError> {
            match update {
                TeamGameUpdate::SetRanking(x) => self
                    .ffa_game
                    .apply_update(FreeForAllGameUpdate::SetRanking(x)),
                TeamGameUpdate::ScoreDelta(x) => self
                    .ffa_game
                    .apply_update(FreeForAllGameUpdate::ScoreDelta(x)),
                TeamGameUpdate::SetWinRewards(x) => self
                    .ffa_game
                    .apply_update(FreeForAllGameUpdate::SetWinRewards(x)),
                TeamGameUpdate::SetLoseRewards(x) => self
                    .ffa_game
                    .apply_update(FreeForAllGameUpdate::SetLoseRewards(x)),
                TeamGameUpdate::SetTeam(u) => {
                    self.ffa_game
                        .apply_update(FreeForAllGameUpdate::AddParticipant(u.team.clone()))?;
                    self.teams.insert(u.team, u.members);
                    Ok(())
                }
                TeamGameUpdate::RemoveTeam(team) => {
                    self.ffa_game
                        .apply_update(FreeForAllGameUpdate::RemoveParticipant(team.clone()))?;
                    self.teams.remove(&team);
                    Ok(())
                }
            }
        }

        fn outcome(&self) -> EventOutcome {
            let ffa_outcome = self.ffa_game.outcome();

            let mut points = HashMap::new();

            for (team, reward) in ffa_outcome.points.iter() {
                if let Some(team) = self.teams.get(team) {
                    for player in team {
                        let score = points.get(player).unwrap_or(&0);
                        points.insert(player.clone(), score + reward);
                    }
                }
            }

            EventOutcome { points }
        }
    }
}

pub mod free_for_all_game {
    use std::collections::HashSet;

    use super::*;

    #[derive(Clone, Debug, Default, PartialEq, Eq, Hash)]
    #[cfg_attr(feature = "openapi", derive(JsonSchema))]
    #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
    #[cfg_attr(feature = "sycamore", derive(WebEdit, WebView))]
    pub struct User {
        name: String,
    }

    #[derive(Clone, Debug, Default, PartialEq)]
    #[cfg_attr(feature = "openapi", derive(JsonSchema))]
    #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
    #[cfg_attr(feature = "sycamore", derive(WebEdit, WebView))]
    pub struct FreeForAllGame {
        /// Ranking of participants by user name or team name (first element is first place, second element is second
        /// place, etc.)
        pub ranking: Option<Ranking<String>>,

        /// Specification of the game
        #[cfg_attr(feature = "serde", serde(flatten))]
        pub spec: FreeForAllGameSpec,
    }

    pub fn example_win_rewards() -> Vec<i64> {
        vec![10, 7, 5, 3, 2, 1]
    }

    pub fn example_lose_rewards() -> Vec<i64> {
        vec![-3, -2, -1]
    }

    #[derive(Clone, Debug, PartialEq, Default)]
    #[cfg_attr(feature = "openapi", derive(JsonSchema))]
    #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
    #[cfg_attr(feature = "sycamore", derive(WebEdit, WebView))]
    pub struct FreeForAllGameSpec {
        /// Array of user ids that participate in the game
        pub participants: HashSet<String>,

        /// Rewards for winning the game (first element for first place, second element for second
        /// place, etc.)
        #[cfg_attr(feature = "schemars", schemars(example = "example_win_rewards"))]
        pub win_rewards: Vec<i64>,
        /// Rewards for losing the game (first element for last place, second element for second to
        /// last place, etc.)
        #[cfg_attr(feature = "schemars", schemars(example = "example_lose_rewards"))]
        pub lose_rewards: Vec<i64>,
    }

    #[derive(Clone, Debug)]
    #[cfg_attr(feature = "openapi", derive(JsonSchema))]
    #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
    #[cfg_attr(feature = "serde", serde(untagged))]
    #[cfg_attr(feature = "sycamore", derive(WebEdit, WebView))]
    pub enum FreeForAllGameUpdate {
        /// Replace the current ranking with the given ranking
        SetRanking(Ranking<String>),
        /// If the current ranking is of type `Scores`, apply the given score deltas
        ScoreDelta(HashMap<String, i64>),
        /// Set rewards for winning the game
        SetWinRewards(Vec<i64>),
        /// Set rewards for losing the game
        SetLoseRewards(Vec<i64>),
        /// Set list of participants participating in the game
        SetParticipants(HashSet<String>),
        /// Add participant by name
        AddParticipant(String),
        /// Remove participant by name
        RemoveParticipant(String),
    }

    impl Default for FreeForAllGameUpdate {
        fn default() -> Self {
            Self::AddParticipant(String::new())
        }
    }

    impl EventTrait for FreeForAllGame {
        type Spec = FreeForAllGameSpec;
        type Update = FreeForAllGameUpdate;

        fn from_spec(spec: Self::Spec) -> Self {
            FreeForAllGame {
                ranking: None,
                spec,
            }
        }

        fn apply_update(&mut self, update: Self::Update) -> Result<(), PartyError> {
            match update {
                FreeForAllGameUpdate::SetRanking(r) => {
                    if !r.is_valid(&self.spec.participants) {
                        return Err(PartyError::Unknown("invalid ranking, all participants mentioned in ranking must be participating".into()));
                    }
                    self.ranking = Some(r)
                }
                FreeForAllGameUpdate::ScoreDelta(d) => match &mut self.ranking {
                    Some(Ranking::Ranking(_)) | None => {
                        return Err(PartyError::Unknown("cannot apply score delta".into()))
                    }
                    Some(Ranking::Scores(s)) => {
                        for (participant, delta) in d.iter() {
                            if let Some(value) = s.get(participant) {
                                s.insert(participant.clone(), value + delta);
                            }
                        }
                    }
                },
                FreeForAllGameUpdate::AddParticipant(name) => {
                    self.spec.participants.insert(name);
                }
                FreeForAllGameUpdate::RemoveParticipant(name) => {
                    self.spec.participants.remove(&name);

                    if !self
                        .ranking
                        .as_ref()
                        .map(|r| r.is_valid(&self.spec.participants))
                        .unwrap_or(true)
                    {
                        self.spec.participants.insert(name);
                        return Err(PartyError::Unknown("cannot remove participant, all participants mentioned in ranking must be participating".into()));
                    }
                }
                FreeForAllGameUpdate::SetParticipants(participants) => {
                    if !self
                        .ranking
                        .as_ref()
                        .map(|r| r.is_valid(&participants))
                        .unwrap_or(true)
                    {
                        return Err(PartyError::Unknown("invalid list of participants, all participants mentioned in ranking must be participating".into()));
                    }
                    self.spec.participants = participants;
                }
                FreeForAllGameUpdate::SetWinRewards(rewards) => {
                    self.spec.win_rewards = rewards;
                }
                FreeForAllGameUpdate::SetLoseRewards(rewards) => {
                    self.spec.lose_rewards = rewards;
                }
            }
            Ok(())
        }

        fn outcome(&self) -> EventOutcome {
            let ranking = match &self.ranking {
                Some(Ranking::Ranking(r)) => r.clone(),
                Some(Ranking::Scores(s)) => {
                    let mut results: Vec<(_, _)> = s.iter().collect();
                    results.sort_by(|a, b| b.1.cmp(a.1));
                    results.into_iter().map(|(k, _)| k.clone()).collect()
                }
                None => return EventOutcome::default(),
            };

            let mut points = HashMap::new();

            for (participant, reward) in ranking.iter().zip(self.spec.win_rewards.iter()) {
                let score = points.get(participant).unwrap_or(&0);
                points.insert(participant.clone(), score + reward);
            }

            for (participant, reward) in ranking.iter().rev().zip(self.spec.lose_rewards.iter()) {
                let score = points.get(participant).unwrap_or(&0);
                points.insert(participant.clone(), score + reward);
            }

            EventOutcome { points }
        }
    }
}

events!(test => Test, team_game => TeamGame, free_for_all_game => FreeForAllGame);

impl Default for EventTypeSpec {
    fn default() -> Self {
        Self::Test(test::TestSpec::default())
    }
}

impl Default for EventUpdate {
    fn default() -> Self {
        Self::Test(test::TestUpdate::default())
    }
}