//! Runs the full server simulation headless, the same way singleplayer does:
//! client events are triggered locally and handled by the server observers.

use std::time::Duration;

use bevy::{prelude::*, state::app::StatesPlugin, time::TimeUpdateStrategy};
use bevy_replicon::prelude::*;
use game_core::{CorePlugin, components::*, grid::Dir, protocol::*};
use game_server::{GameServerPlugin, ServerSettings};

#[derive(Resource, Default)]
struct Log(Vec<String>);

fn app() -> App {
    let mut app = App::new();
    app.add_plugins((
        MinimalPlugins,
        StatesPlugin,
        RepliconPlugins,
        CorePlugin,
        GameServerPlugin {
            settings: ServerSettings::default(),
        },
    ))
    .insert_resource(TimeUpdateStrategy::ManualDuration(Duration::from_millis(
        50,
    )))
    .init_resource::<Log>()
    .add_observer(|ev: On<GameLog>, mut log: ResMut<Log>| log.0.push(ev.text.clone()));
    // Normally done by `App::run`; replicon builds its message systems in `finish`.
    app.finish();
    app.cleanup();
    app.update();
    app
}

fn send(app: &mut App, ev: impl Event) {
    app.world_mut().client_trigger(ev);
    // Resent locally in PostUpdate, triggered on the server in the next PreUpdate.
    app.update();
    app.update();
}

fn take_log(app: &mut App) -> Vec<String> {
    // Server events also go through a local resend before the client observer sees them.
    app.update();
    std::mem::take(&mut app.world_mut().resource_mut::<Log>().0)
}

fn count(app: &App, me: Entity, item: &str) -> u32 {
    app.world().get::<Inventory>(me).unwrap().count(item)
}

#[test]
fn login_move_and_interact() {
    let mut app = app();

    // The map defines buildings and items.
    let mut buildings = app.world_mut().query::<&Building>();
    assert_eq!(buildings.iter(app.world()).count(), 18);

    send(
        &mut app,
        Login {
            name: "Tester".into(),
        },
    );
    let me = app
        .world_mut()
        .query_filtered::<Entity, With<Character>>()
        .single(app.world())
        .expect("one character");
    let start = *app.world().get::<GridPos>(me).unwrap();
    let log = take_log(&mut app);
    assert!(log.iter().any(|t| t.contains("Tester")), "{log:?}");
    assert_eq!(count(&app, me, "apple"), 2);

    // A second login with the same name is rejected.
    send(
        &mut app,
        Login {
            name: "Tester".into(),
        },
    );
    let mut characters = app.world_mut().query::<&Character>();
    assert_eq!(characters.iter(app.world()).count(), 1);

    // Walk east one tile.
    send(&mut app, SetMoveDir(Some(Dir::East)));
    send(&mut app, SetMoveDir(None));
    for _ in 0..5 {
        app.update();
    }
    let pos = *app.world().get::<GridPos>(me).unwrap();
    assert_eq!(pos, GridPos::new(start.x + 1, start.y), "start {start:?}");

    // Eat an apple through the Rune script.
    app.world_mut().get_mut::<Vitals>(me).unwrap().nutrition = 50.0;
    send(&mut app, UseItem { slot: 0 });
    let vitals = app.world().get::<Vitals>(me).unwrap();
    assert!(vitals.nutrition > 50.0, "{vitals:?}");
    assert_eq!(count(&app, me, "apple"), 1);
    assert!(take_log(&mut app).iter().any(|t| t.contains("Delicious")));

    // Build a table next to us.
    let target = GridPos::new(pos.x, pos.y + 1);
    let data = app.world().resource::<game_core::GameData>().clone();
    app.world_mut()
        .get_mut::<Inventory>(me)
        .unwrap()
        .add("plank", 2, &data);
    send(
        &mut app,
        Construct {
            building: "table".into(),
            target,
        },
    );
    let log = take_log(&mut app);
    let mut q = app.world_mut().query::<(&Building, &GridPos)>();
    assert!(
        q.iter(app.world())
            .any(|(b, p)| b.proto == "table" && *p == target),
        "{log:?}"
    );
    assert_eq!(count(&app, me, "plank"), 0);

    // Doors toggle via script.
    let door_pos = GridPos::new(pos.x + 1, pos.y + 1);
    app.world_mut().spawn((
        Building {
            proto: "door".into(),
        },
        door_pos,
        BuildingState {
            solid: true,
            ..default()
        },
    ));
    send(&mut app, Interact { target: door_pos });
    let mut q = app
        .world_mut()
        .query::<(&Building, &GridPos, &BuildingState)>();
    let (_, _, state) = q
        .iter(app.world())
        .find(|(b, p, _)| b.proto == "door" && **p == door_pos)
        .unwrap();
    assert!(!state.solid);
    assert_eq!(state.variant.as_deref(), Some("open"));

    // Deconstruction refunds the materials.
    send(&mut app, Deconstruct { target });
    let mut q = app.world_mut().query::<(&Building, &GridPos)>();
    assert!(!q.iter(app.world()).any(|(_, p)| *p == target));
    assert_eq!(count(&app, me, "plank"), 2);

    // Drop and pick up again.
    let slot = app
        .world()
        .get::<Inventory>(me)
        .unwrap()
        .slots
        .iter()
        .position(|s| s.item == "plank")
        .unwrap();
    send(&mut app, DropItem { slot });
    assert_eq!(count(&app, me, "plank"), 0);
    send(&mut app, PickUp { target: pos });
    assert_eq!(count(&app, me, "plank"), 2);

    // Crafting without a station fails with a reason.
    take_log(&mut app);
    send(
        &mut app,
        Craft {
            recipe: "smelt_iron".into(),
        },
    );
    let log = take_log(&mut app);
    assert!(log.iter().any(|t| t.contains("furnace")), "{log:?}");
}