You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: lighting_system.rs
    path of file: ./repos/rustrogueliketutorial/chapter-71-logging/src
    
    the code of the file until where you have to start completion: use specs::prelude::*;
use super::{Viewshed, Position, Map, LightSource};
use rltk::RGB;

pub struct LightingSystem {}

impl<'a> System<'a> for LightingSystem {
    #[allow(clippy::type_complexity)]
    type SystemData = ( WriteExpect<'a, Map>,
                        ReadStorage<'a, Viewshed>,
                        ReadStorage<'a, Position>,
                        ReadStorage<'a, LightSource>);

    fn run(&mut self, data : Self::SystemData) {
        let (mut map, viewshed, positions, lighting) = data;

        if map.outdoors {
            return;
        }

        let black = RGB::from_f32(0.0, 0.0, 0.0);
        for l in map.light.iter_mut() {
            *l = black;
        }

        for (viewshed, pos, light) in (&viewshed, &positions, &lighting).join() {
            let light_point = rltk::Point::new(pos.x
    
    fn run(&mut self, data : Self::SystemData) {
        let (mut map, viewshed, positions, lighting) = data;

        if map.outdoors {
            return;
        }

        let black = RGB::from_f32(0.0, 0.0, 0.0);
        for l in map.light.iter_mut() {
            *l = black;
        }

        for (viewshed, pos, light) in (&viewshed, &positions, &lighting).join() {
            let light_point = rltk::Point::new(pos.x, pos.y);
            let range_f = light.range as f32;
            for t in viewshed.visible_tiles.iter() {
                if t.x > 0 && t.x < map.width && t.y > 0 && t.y < map.height {
                    let idx = map.xy_idx(t.x, t.y);
                    let distance = rltk::DistanceAlg::Pythagoras.distance2d(light_point, *t);
                    let intensity = (range_f - distance) / range_f;

                    map.light[idx] = map.light[idx] + (light.color * intensity);
                }
            }
        }
    }