use super::{Entity, EntityContext};
use crate::{trm, TrError};
use anyhow::Result;
use hurrycurry_protocol::{
    glam::IVec2, ItemIndex, Message, PacketC, PlayerID, Recipe, RecipeIndex, TileIndex,
};
use log::{debug, warn};

pub struct Tutorial {
    pub player: PlayerID,
    target: ItemIndex,

    next_update_due: f32,
    had_aquired_target: bool,

    current_hint: Option<(Option<IVec2>, Message)>,
    delete_timer: f32,
}

impl Tutorial {
    pub fn new(player: PlayerID, item: ItemIndex) -> Self {
        Self {
            player,
            next_update_due: 0.,
            target: item,
            current_hint: None,
            delete_timer: 1.5,
            had_aquired_target: false,
        }
    }
}

impl Entity for Tutorial {
    fn finished(&self) -> bool {
        self.delete_timer <= 0.
    }
    fn destructor(&mut self, c: EntityContext<'_>) {
        if let Some((position, _)) = self.current_hint {
            c.packet_out.push_back(PacketC::ServerHint {
                position,
                player: self.player,
                message: None,
            });
        }
        c.packet_out.push_back(PacketC::TutorialEnded {
            player: self.player,
            item: self.target,
            success: false,
        });
    }
    fn tick(&mut self, c: EntityContext<'_>) -> Result<()> {
        const TARGET_DT: f32 = 0.2;
        self.next_update_due -= c.dt;
        if self.next_update_due > 0. {
            return Ok(());
        }
        self.next_update_due += TARGET_DT;

        let mut hint = StepContext {
            ent: &c,
            had_aquired_target: &mut self.had_aquired_target,
            player: self.player,
            recursion_abort: 0,
        }
        .fulfil_demand(self.target)
        .err();
        if hint.is_none() {
            self.delete_timer -= TARGET_DT;
            if self.delete_timer <= 0. {
                hint = None;
                c.packet_out.push_back(PacketC::TutorialEnded {
                    item: self.target,
                    player: self.player,
                    success: true,
                });
            } else {
                hint = Some((None, trm!("s.tutorial.finished")));
            }
        }

        if hint != self.current_hint {
            if let Some((position, _)) = self.current_hint.take() {
                c.packet_out.push_back(PacketC::ServerHint {
                    position,
                    player: self.player,
                    message: None,
                });
            }
            if let Some((position, message)) = hint.clone() {
                c.packet_out.push_back(PacketC::ServerHint {
                    player: self.player,
                    position,
                    message: Some(message),
                });
            }
            self.current_hint = hint;
        }

        Ok(())
    }
    fn interact(
        &mut self,
        _c: EntityContext<'_>,
        _pos: Option<IVec2>,
        _player: PlayerID,
    ) -> Result<bool, TrError> {
        Ok(false)
    }
}

struct StepContext<'a> {
    ent: &'a EntityContext<'a>,
    had_aquired_target: &'a mut bool,
    recursion_abort: usize,
    player: PlayerID,
}

impl<'a> StepContext<'a> {
    fn is_hand_item(&self, item: ItemIndex) -> bool {
        self.ent
            .game
            .players
            .get(&self.player)
            .map_or(false, |p| p.item.as_ref().map_or(false, |i| i.kind == item))
    }
    pub fn find_demand(&self, item: ItemIndex) -> Option<IVec2> {
        self.ent
            .game
            .players
            .iter()
            .find_map(|(_, pl)| match &pl.communicate_persist {
                Some((Message::Item(i), _)) if *i == item => Some(pl.movement.position.as_ivec2()),
                _ => None,
            })
    }
    fn find_recipe_with_output(&self, item: ItemIndex) -> Option<RecipeIndex> {
        self.ent
            .game
            .data
            .recipes
            .iter()
            .enumerate()
            .find(|(_, r)| r.outputs().contains(&item))
            .map(|(i, _)| RecipeIndex(i))
    }
    fn find_item_on_map(&self, item: ItemIndex) -> Option<IVec2> {
        self.ent
            .game
            .tiles
            .iter()
            .find(|(_, t)| t.item.as_ref().map_or(false, |t| t.kind == item))
            .map(|(p, _)| *p)
    }
    fn find_tile(&self, tile: TileIndex) -> Option<IVec2> {
        self.ent
            .game
            .tiles
            .iter()
            .find(|(_, t)| t.kind == tile)
            .map(|(p, _)| *p)
    }
    fn aquire_placed_item(&mut self, item: ItemIndex) -> Result<IVec2, (Option<IVec2>, Message)> {
        debug!(
            "aquire placed item {:?}",
            self.ent.game.data.item_names[item.0]
        );
        if let Some(pos) = self.find_item_on_map(item) {
            return Ok(pos);
        }
        self.aquire_item(item)?;
        Err((None, trm!("s.tutorial.put_away")))
    }
    fn fulfil_demand(&mut self, item: ItemIndex) -> Result<(), (Option<IVec2>, Message)> {
        if !*self.had_aquired_target {
            self.aquire_item(item)?;
            *self.had_aquired_target = true;
        }
        if let Some(pos) = self.find_demand(item) {
            Err((Some(pos), trm!("s.tutorial.serve")))
        } else {
            Ok(())
        }
    }
    fn aquire_item(&mut self, item: ItemIndex) -> Result<(), (Option<IVec2>, Message)> {
        debug!("aquire item {:?}", self.ent.game.data.item_names[item.0]);
        self.recursion_abort += 1;
        if self.recursion_abort > 32 {
            warn!("too much recursion");
            return Err((None, trm!("s.tutorial.error")));
        }
        if self.is_hand_item(item) {
            return Ok(());
        }
        if let Some(pos) = self.find_item_on_map(item) {
            return Err((Some(pos), trm!("s.tutorial.pickup")));
        }
        if let Some(recipe) = self.find_recipe_with_output(item) {
            let r = &self.ent.game.data.recipes[recipe.0];
            match r {
                Recipe::Instant {
                    tile: Some(tile),
                    inputs: [None, None],
                    ..
                } => {
                    if let Some(pos) = self.find_tile(*tile) {
                        return Err((Some(pos), trm!("s.tutorial.take", i = item)));
                    }
                }
                Recipe::Instant {
                    tile: None,
                    inputs: [Some(a), Some(b)],
                    ..
                } => {
                    let apos = self.aquire_placed_item(*a)?;
                    self.aquire_item(*b)?;
                    return Err((Some(apos), trm!("s.tutorial.interact")));
                }
                Recipe::Instant {
                    tile: None,
                    inputs: [Some(input), None],
                    ..
                } => {
                    self.aquire_item(*input)?;
                    return Err((None, trm!("s.tutorial.interact_empty")));
                }
                Recipe::Active {
                    tile: Some(tile),
                    input,
                    speed,
                    ..
                } => {
                    if let Some(pos) = self.find_tile(*tile) {
                        if let Some(item) = &self.ent.game.tiles.get(&pos).unwrap().item {
                            if item.kind == *input {
                                return Err((Some(pos), trm!("s.tutorial.hold_interact")));
                            }
                        }
                        self.aquire_item(*input)?;
                        return Err((
                            Some(pos),
                            trm!("s.tutorial.active", s = format!("{:.01}", 1. / speed)),
                        ));
                    }
                }
                Recipe::Passive {
                    tile: Some(tile),
                    input,
                    ..
                } => {
                    if let Some(pos) = self.find_tile(*tile) {
                        if let Some(item) = &self.ent.game.tiles.get(&pos).unwrap().item {
                            if item.kind == *input {
                                return Err((Some(pos), trm!("s.tutorial.wait_finish")));
                            }
                        }
                        self.aquire_item(*input)?;
                        return Err((Some(pos), trm!("s.tutorial.put_on", t = *tile)));
                    }
                }
                Recipe::Passive {
                    tile: None, input, ..
                } => {
                    let pos = self.aquire_placed_item(*input)?;
                    return Err((Some(pos), trm!("s.tutorial.wait_finish")));
                }
                _ => warn!("recipe too hard {r:?}"),
            }
        }
        warn!(
            "stuck at making item {:?}",
            self.ent.game.data.item_names[item.0]
        );
        Err((None, trm!("s.tutorial.error")))
    }
}