/*
    Hurry Curry! - a game about cooking
    Copyright 2024 metamuffin
    Copyright 2024 nokoe

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU Affero General Public License as published by
    the Free Software Foundation, version 3 of the License only.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU Affero General Public License for more details.

    You should have received a copy of the GNU Affero General Public License
    along with this program.  If not, see <https://www.gnu.org/licenses/>.

*/
pub mod demands;

use crate::entity::{construct_entity, Entities, EntityDecl};
use anyhow::{anyhow, bail, Result};
use demands::generate_demands;
use hurrycurry_protocol::{
    glam::{IVec2, Vec2},
    Gamedata, ItemIndex, MapMetadata, Recipe, TileIndex,
};
use serde::{Deserialize, Serialize};
use std::{
    collections::{HashMap, HashSet},
    fs::File,
    path::PathBuf,
    str::FromStr,
    sync::{Mutex, RwLock},
};
use tokio::fs::read_to_string;

#[derive(Debug, Deserialize, Serialize, Clone, Copy, Default)]
#[serde(rename_all = "snake_case")]
pub enum Action {
    #[default]
    Never,
    Passive,
    Active,
    Instant,
    Demand,
}

#[derive(Debug, Clone, Deserialize, Serialize)]
pub struct RecipeDecl {
    #[serde(default)]
    tile: Option<String>,
    #[serde(default)]
    inputs: Vec<String>,
    #[serde(default)]
    outputs: Vec<String>,
    #[serde(default)]
    action: Action,
    #[serde(default)]
    warn: bool,
    #[serde(default)]
    revert_duration: Option<f32>,
    #[serde(default)]
    duration: Option<f32>,
    #[serde(default)]
    points: Option<i64>,
}

#[derive(Debug, Clone, Deserialize)]
pub struct InitialMap {
    map: Vec<String>,
    tiles: HashMap<char, String>,
    #[serde(default)]
    items: HashMap<char, String>,
    collider: Vec<String>,
    walkable: Vec<String>,
    chef_spawn: char,
    customer_spawn: char,
    #[serde(default)]
    entities: Vec<EntityDecl>,
    #[serde(default)]
    tile_entities: HashMap<char, EntityDecl>,
    #[serde(default)]
    score_baseline: i64,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct DemandDecl {
    from: String,
    to: Option<String>,
    duration: f32,
    points: i64,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct Demand {
    pub from: ItemIndex,
    pub to: Option<ItemIndex>,
    pub duration: f32,
    pub points: i64,
}

#[derive(Debug,Clone, Default)]
#[rustfmt::skip]
pub struct Serverdata {
    pub demands: Vec<Demand>,
    pub spec: String,
    pub initial_map: HashMap<IVec2, (TileIndex, Option<ItemIndex>)>,
    pub chef_spawn: Vec2,
    pub customer_spawn: Vec2,
    pub score_baseline: i64,
}

#[derive(Debug, Deserialize, Default)]
pub struct DataIndex {
    pub maps: HashMap<String, MapMetadata>,
    pub recipes: HashSet<String>,
}

pub static DATA_DIR: Mutex<Option<PathBuf>> = Mutex::new(None);
fn data_dir() -> PathBuf {
    DATA_DIR
        .lock()
        .unwrap()
        .to_owned()
        .unwrap_or_else(|| PathBuf::from_str("data").unwrap())
}

impl DataIndex {
    pub fn reload(&mut self) -> Result<()> {
        *self = serde_yml::from_reader(File::open(data_dir().join("index.yaml"))?)?;
        Ok(())
    }

    pub async fn read_map(&self, name: &str) -> Result<String> {
        if !self.maps.contains_key(name) {
            bail!("unknown map: {name:?}");
        }
        let path = data_dir().join(format!("maps/{name}.yaml"));
        Ok(read_to_string(path).await?)
    }
    pub async fn read_recipes(&self, name: &str) -> Result<String> {
        if !self.recipes.contains(name) {
            bail!("unknown recipes: {name:?}");
        }
        let path = data_dir().join(format!("recipes/{name}.yaml"));
        Ok(read_to_string(path).await?)
    }

    pub async fn generate(&self, spec: String) -> Result<(Gamedata, Serverdata, Entities)> {
        let (map, recipes) = spec.split_once("-").unwrap_or((spec.as_str(), "default"));

        let map_in = serde_yml::from_str(&self.read_map(map).await?)?;
        let recipes_in = serde_yml::from_str(&self.read_recipes(recipes).await?)?;

        Ok(build_data(
            self.maps.clone(),
            spec.clone(),
            map.to_string(),
            map_in,
            recipes_in,
        )?)
    }
}

pub fn build_data(
    maps: HashMap<String, MapMetadata>,
    spec: String,
    map_name: String,
    map_in: InitialMap,
    recipes_in: Vec<RecipeDecl>,
) -> Result<(Gamedata, Serverdata, Entities)> {
    let reg = ItemTileRegistry::default();
    let mut recipes = Vec::new();
    let mut entities = Vec::new();
    let mut raw_demands = Vec::new();

    for mut r in recipes_in {
        let r2 = r.clone();
        let mut inputs = r.inputs.into_iter().map(|i| reg.register_item(i));
        let mut outputs = r.outputs.into_iter().map(|o| reg.register_item(o));
        let tile = r.tile.map(|t| reg.register_tile(t));
        match r.action {
            Action::Never => {}
            Action::Passive => recipes.push(Recipe::Passive {
                duration: r.duration.ok_or(anyhow!("duration for passive missing"))?,
                warn: r.warn,
                tile,
                revert_duration: r.revert_duration,
                input: inputs
                    .next()
                    .ok_or(anyhow!("passive recipe without input"))?,
                output: outputs.next(),
            }),
            Action::Active => recipes.push(Recipe::Active {
                duration: r.duration.ok_or(anyhow!("duration for active missing"))?,
                tile,
                input: inputs
                    .next()
                    .ok_or(anyhow!("active recipe without input"))?,
                outputs: [outputs.next(), outputs.next()],
            }),
            Action::Instant => {
                recipes.push(Recipe::Instant {
                    points: r.points.take().unwrap_or(0),
                    tile,
                    inputs: [inputs.next(), inputs.next()],
                    outputs: [outputs.next(), outputs.next()],
                });
            }
            Action::Demand => raw_demands.push((
                inputs.next().ok_or(anyhow!("demand needs inputs"))?,
                outputs.next(),
                r.duration.unwrap_or(10.),
            )),
        }
        assert_eq!(inputs.next(), None, "{r2:?} inputs left over");
        assert_eq!(outputs.next(), None, "{r2:?} outputs left over");
        assert_eq!(r.points, None, "points specified where not possible")
    }

    // TODO
    // for d in demands_in {
    //     demands.push(Demand {
    //         from: reg.register_item(d.from),
    //         to: d.to.map(|to| reg.register_item(to)),
    //         duration: d.duration,
    //         points: d.points,
    //     })
    // }

    let mut chef_spawn = Vec2::new(0., 0.);
    let mut customer_spawn = Vec2::new(0., 0.);
    let mut initial_map = HashMap::new();
    let mut tiles_used = HashSet::new();
    let mut items_used = HashSet::new();
    for (y, line) in map_in.map.iter().enumerate() {
        for (x, tile) in line.chars().enumerate() {
            if tile == ' ' {
                continue; // space is empty space
            }
            let pos = IVec2::new(x as i32, y as i32);
            if tile == map_in.chef_spawn {
                chef_spawn = pos.as_vec2() + Vec2::splat(0.5);
            }
            if tile == map_in.customer_spawn {
                customer_spawn = pos.as_vec2() + Vec2::splat(0.5);
            }
            let tilename = map_in
                .tiles
                .get(&tile)
                .ok_or(anyhow!("tile {tile} is undefined"))?
                .clone();

            let itemname = map_in.items.get(&tile).cloned();
            let tile = reg.register_tile(tilename);
            let item = itemname.map(|i| reg.register_item(i));
            tiles_used.insert(tile);
            if let Some(i) = item {
                items_used.insert(i);
            };
            initial_map.insert(pos, (tile, item));
        }
    }

    for (y, line) in map_in.map.iter().enumerate() {
        for (x, tile) in line.trim().chars().enumerate() {
            let pos = IVec2::new(x as i32, y as i32);
            if let Some(ent) = map_in.tile_entities.get(&tile) {
                entities.push(construct_entity(Some(pos), ent, &reg)?);
            }
        }
    }

    entities.extend(
        map_in
            .entities
            .iter()
            .map(|decl| construct_entity(None, decl, &reg))
            .try_collect::<Vec<_>>()?,
    );

    let demands = generate_demands(&tiles_used, &items_used, &raw_demands, &recipes);

    let item_names = reg.items.into_inner().unwrap();
    let tile_names = reg.tiles.into_inner().unwrap();
    let tile_collide = tile_names
        .iter()
        .map(|i| !map_in.walkable.contains(i))
        .collect();
    let tile_interact = tile_names
        .iter()
        .map(|i| !map_in.collider.contains(i) && !map_in.walkable.contains(i))
        .collect();

    Ok((
        Gamedata {
            current_map: map_name,
            maps,
            tile_collide,
            tile_interact,
            recipes,
            item_names,
            tile_names,
        },
        Serverdata {
            spec,
            demands,
            initial_map,
            chef_spawn,
            customer_spawn,
            score_baseline: map_in.score_baseline,
        },
        entities,
    ))
}

#[derive(Default)]
pub struct ItemTileRegistry {
    tiles: RwLock<Vec<String>>,
    items: RwLock<Vec<String>>,
}

impl ItemTileRegistry {
    pub fn register_tile(&self, name: String) -> TileIndex {
        TileIndex(Self::register(&self.tiles, name))
    }
    pub fn register_item(&self, name: String) -> ItemIndex {
        ItemIndex(Self::register(&self.items, name))
    }
    fn register(db: &RwLock<Vec<String>>, name: String) -> usize {
        let mut db = db.write().unwrap();
        if let Some(index) = db.iter().position(|e| e == &name) {
            index
        } else {
            let index = db.len();
            db.push(name);
            index
        }
    }
}