roguelike-game/src/saveload_system.rs

//! Serializes / Deserializes game data for saving and loading
use std::fs::{self, File};
use std::path::Path;

use ::bracket_lib::prelude::*;
use ::specs::error::NoError;
use ::specs::prelude::*;
use ::specs::saveload::{
    DeserializeComponents, MarkedBuilder, SerializeComponents, SimpleMarker, SimpleMarkerAllocator,
};

use crate::components::*;
use crate::map::{Map, MasterDungeonMap};
use crate::spatial;

macro_rules! serialize_individually {
    ($ecs:expr, $ser:expr, $data:expr, $( $type:ty),*,) => {
        $(
            SerializeComponents::<NoError, SimpleMarker<SerializeMe>>::serialize(
                &( $ecs.read_storage::<$type>(), ),
                &$data.0,
                &$data.1,
                &mut $ser,
            )
            .unwrap();
        )*
    };
}

#[cfg(target_arch = "wasm32")]
pub fn save_game(_ecs: &mut World) {}

/// Saves the game data to a file
#[cfg(not(target_arch = "wasm32"))]
pub fn save_game(ecs: &mut World) {
    // Create helper
    let mapcopy = ecs.get_mut::<Map>().unwrap().clone();
    let dungeon_master = ecs.get_mut::<MasterDungeonMap>().unwrap().clone();
    let savehelper = ecs
        .create_entity()
        .with(SerializationHelper { map: mapcopy })
        .marked::<SimpleMarker<SerializeMe>>()
        .build();
    let savehelper2 = ecs
        .create_entity()
        .with(DMSerializationHelper {
            map: dungeon_master,
            log: crate::gamelog::clone_log(),
            events: crate::gamelog::clone_events(),
        })
        .marked::<SimpleMarker<SerializeMe>>()
        .build();

    // Actually serialize
    {
        let data = (
            ecs.entities(),
            ecs.read_storage::<SimpleMarker<SerializeMe>>(),
        );

        let writer = File::create("./savegame.json").unwrap();
        let mut serializer = ::serde_json::Serializer::new(writer);
        serialize_individually!(
            ecs,
            serializer,
            data,
            AlwaysTargetsSelf,
            ApplyMove,
            ApplyTeleport,
            AreaOfEffect,
            AttributeBonus,
            Attributes,
            BlocksTile,
            BlocksVisibility,
            Chasing,
            Confusion,
            Consumable,
            CursedItem,
            DamageOverTime,
            DMSerializationHelper,
            Door,
            Duration,
            EntityMoved,
            EntryTrigger,
            EquipmentChanged,
            Equippable,
            Equipped,
            Faction,
            Hidden,
            HungerClock,
            IdentifiedItem,
            InBackpack,
            InflictsDamage,
            Initiative,
            Item,
            KnownSpells,
            LightSource,
            LootTable,
            MagicItem,
            MagicMapper,
            MoveMode,
            MyTurn,
            Name,
            NaturalAttackDefense,
            ObfuscatedName,
            OnDeath,
            OtherLevelPosition,
            ParticleLifetime,
            Player,
            Pools,
            Position,
            ProvidesFood,
            ProvidesHealing,
            ProvidesIdentification,
            ProvidesMana,
            ProvidesRemoveCurse,
            Quips,
            Ranged,
            Renderable,
            SerializationHelper,
            SingleActivation,
            Skills,
            Slow,
            SpawnParticleBurst,
            SpawnParticleLine,
            SpecialAbilities,
            SpellTemplate,
            StatusEffect,
            Target,
            TeachesSpell,
            TeleportTo,
            TileSize,
            TownPortal,
            Vendor,
            Viewshed,
            WantsToApproach,
            WantsToCastSpell,
            WantsToDropItem,
            WantsToFlee,
            WantsToMelee,
            WantsToPickupItem,
            WantsToRemoveItem,
            WantsToShoot,
            WantsToUseItem,
            Weapon,
            Wearable,
        );
    }

    // Clean up
    ecs.delete_entity(savehelper)
        .expect("Failed to clean up savehelper component");
    ecs.delete_entity(savehelper2)
        .expect("Failed to clean up savehelper2 component");
}

/// Does the save game exist?
pub fn does_save_exist() -> bool {
    Path::new("./savegame.json").exists()
}

macro_rules! deserialize_individually {
    ($ecs:expr, $de:expr, $data:expr, $( $type:ty),*,) => {
        $(
            DeserializeComponents::<NoError, _>::deserialize(
                &mut ( &mut $ecs.write_storage::<$type>(), ),
                &$data.0, // entities
                &mut $data.1, // marker
                &mut $data.2, // allocater
                &mut $de,
            )
            .unwrap();
        )*
    };
}

/// Loads the game data from a file
pub fn load_game(ecs: &mut World) {
    {
        // Delete everything
        let mut to_delete = Vec::new();
        for e in ecs.entities().join() {
            to_delete.push(e);
        }

        for del in to_delete.iter() {
            ecs.delete_entity(*del).expect("Failed to delete entity");
        }
    }

    let data = fs::read_to_string("./savegame.json").unwrap();
    let mut de = ::serde_json::Deserializer::from_str(&data);

    {
        let mut d = (
            &mut ecs.entities(),
            &mut ecs.write_storage::<SimpleMarker<SerializeMe>>(),
            &mut ecs.write_resource::<SimpleMarkerAllocator<SerializeMe>>(),
        );

        deserialize_individually!(
            ecs,
            de,
            d,
            AlwaysTargetsSelf,
            ApplyMove,
            ApplyTeleport,
            AreaOfEffect,
            AttributeBonus,
            Attributes,
            BlocksTile,
            BlocksVisibility,
            Chasing,
            Confusion,
            Consumable,
            CursedItem,
            DamageOverTime,
            DMSerializationHelper,
            Door,
            Duration,
            EntityMoved,
            EntryTrigger,
            EquipmentChanged,
            Equippable,
            Equipped,
            Faction,
            Hidden,
            HungerClock,
            IdentifiedItem,
            InBackpack,
            InflictsDamage,
            Initiative,
            Item,
            KnownSpells,
            LightSource,
            LootTable,
            MagicItem,
            MagicMapper,
            MoveMode,
            MyTurn,
            Name,
            NaturalAttackDefense,
            ObfuscatedName,
            OnDeath,
            OtherLevelPosition,
            ParticleLifetime,
            Player,
            Pools,
            Position,
            ProvidesFood,
            ProvidesHealing,
            ProvidesIdentification,
            ProvidesMana,
            ProvidesRemoveCurse,
            Quips,
            Ranged,
            Renderable,
            SerializationHelper,
            SingleActivation,
            Skills,
            Slow,
            SpawnParticleBurst,
            SpawnParticleLine,
            SpecialAbilities,
            SpellTemplate,
            StatusEffect,
            Target,
            TeachesSpell,
            TeleportTo,
            TileSize,
            TownPortal,
            Vendor,
            Viewshed,
            WantsToApproach,
            WantsToCastSpell,
            WantsToDropItem,
            WantsToFlee,
            WantsToMelee,
            WantsToPickupItem,
            WantsToRemoveItem,
            WantsToShoot,
            WantsToUseItem,
            Weapon,
            Wearable,
        );
    }

    let mut deleteme: Option<Entity> = None;
    let mut deleteme2: Option<Entity> = None;
    {
        let entities = ecs.entities();
        let helper = ecs.read_storage::<SerializationHelper>();
        let helper2 = ecs.read_storage::<DMSerializationHelper>();
        let player = ecs.read_storage::<Player>();
        let position = ecs.read_storage::<Position>();

        for (e, h) in (&entities, &helper).join() {
            let mut worldmap = ecs.write_resource::<Map>();
            *worldmap = h.map.clone();
            spatial::set_size((worldmap.height * worldmap.width) as usize);
            deleteme = Some(e);
        }
        for (e, h) in (&entities, &helper2).join() {
            let mut dungeon_master = ecs.write_resource::<MasterDungeonMap>();
            *dungeon_master = h.map.clone();
            deleteme2 = Some(e);
            crate::gamelog::restore_log(&mut h.log.clone());
            crate::gamelog::load_events(h.events.clone());
        }

        for (e, _p, pos) in (&entities, &player, &position).join() {
            let mut ppos = ecs.write_resource::<Point>();
            *ppos = Point::from(*pos);

            let mut player_resource = ecs.write_resource::<Entity>();
            *player_resource = e;
        }
    }

    ecs.delete_entity(deleteme.unwrap())
        .expect("Unable to delete helper entity");
    ecs.delete_entity(deleteme2.unwrap())
        .expect("Unable to delete helper2 entity");
}

/// Deletes the save file, if it exists
pub fn delete_save() {
    if Path::new("./savegame.json").exists() {
        std::fs::remove_file("./savegame.json").expect("Failed to delete save file.");
    }
}