use space_crush_common::{
    components::{Fleet, MeetingPoint, Position},
    misc::LogResult,
};
use specs::{prelude::*, ReadExpect, ReadStorage, System, World};

use crate::{
    misc::{HorizontalAlign, Text, TextManager, VerticalAlign},
    resources::{Camera, GameState},
    Error,
};

pub struct Fleets {
    text: Text,
}

#[derive(SystemData)]
pub struct FleetData<'a> {
    game_state: ReadExpect<'a, GameState>,
    camera: ReadExpect<'a, Camera>,
    positions: ReadStorage<'a, Position>,
    meeting_points: ReadStorage<'a, MeetingPoint>,
    fleets: ReadStorage<'a, Fleet>,
}

impl Fleets {
    pub fn new(manager: &TextManager) -> Result<Self, Error> {
        let cache = manager.create_cache()?;
        let text = cache
            .new_text()
            .scale(20.0)
            .font("resources/fonts/DroidSansMono.ttf")
            .color(0.7, 0.7, 0.7, 1.0)
            .vert_align(VerticalAlign::Center)
            .horz_align(HorizontalAlign::Center)
            .text("")
            .build()?;

        Ok(Self { text })
    }
}

impl<'a> System<'a> for Fleets {
    type SystemData = FleetData<'a>;

    fn run(&mut self, data: Self::SystemData) {
        let FleetData {
            game_state,
            camera,
            positions,
            meeting_points,
            fleets,
        } = data;

        let player_index = game_state.player_index();

        gl::enable(gl::BLEND);

        for (position, meeting_point) in (&positions, &meeting_points).join() {
            let fleet_id = match meeting_point.fleet(player_index) {
                Some(fleet_id) => fleet_id,
                None => continue,
            };
            let fleet = fleets.get(fleet_id).unwrap();

            gl::blend_func(gl::SRC_ALPHA, gl::ONE_MINUS_SRC_ALPHA);
            gl::blend_equation(gl::FUNC_SUBTRACT);
            self.text
                .update(
                    0,
                    format!(
                        "F:{}\nB:{}\nT:{}",
                        fleet.count().fighter,
                        fleet.count().bomber,
                        fleet.count().transporter
                    ),
                )
                .panic("Unable to update text")
                .render_offset(&camera.world_to_window(*position.get()));
        }

        gl::blend_equation(gl::FUNC_ADD);
        gl::disable(gl::BLEND);
    }
}