use rand::RngExt;

use crate::sim::{cell::Cell, materials::MaterialId, sim::UpdateCtx};

trait FireCellView {
    fn get_ticks_lived(self) -> u16;
    fn set_ticks_lived(&mut self, ticks: u16) -> ();
    fn is_flammable(self) -> bool;
}

impl FireCellView for Cell {
    fn get_ticks_lived(self) -> u16 {
        self.data
    }
    fn set_ticks_lived(&mut self, ticks: u16) -> () {
        self.data = ticks;
    }
    // this could be a property of the material def, I think it's better here for now
    fn is_flammable(self) -> bool {
        [MaterialId::Wood].contains(&self.material)
    }
}

// TODO optimize number of rng calls?
#[inline]
pub fn sim_update(ctx: &mut UpdateCtx) {
    let ticks_lived = ctx.cell.get_ticks_lived();
    // 2 seconds
    if ticks_lived > 240 {
        // we have a chance to live longer--roughly 50% chance of living an extra second
        if ctx.rng.random_range(0.0..1.0) > 0.995 {
            // kill ourselves, with a chance to turn into ash
            if ctx.rng.random_range(0.0..1.0) > 0.8 {
                // TODO ash material
                ctx.set_cell(0, 0, Cell::from_material(MaterialId::Sand));
            } else {
                ctx.set_cell(0, 0, Cell::void());
            }
            return;
        }
    }

    // at an average of 4 times per lifespan, try to spread
    // 1/60 * 240 = 4
    if ctx.rng.random_range(0.0..1.0) > (59.0 / 60.0) {
        let (dx, dy) = (ctx.rng.random_range(-1..=1), ctx.rng.random_range(-1..=1));
        if let Some(target) = ctx.get_cell(dx, dy)
            && target.is_flammable()
        {
            ctx.set_cell(dx, dy, Cell::from_material(MaterialId::Fire));
        }
    }

    // 8 times in our lifespan, emit smoke
    if ticks_lived % 30 == 0 {
        if let Some(target) = ctx.get_cell(0, -1)
            && target.material == MaterialId::Void
        {
            for (dx, dy) in [
                (0, -1),
                (1 - ctx.seqno_parity as i32 * 2, 0),
                (-1 + ctx.seqno_parity as i32 * 2, 0),
                (0, 1),
            ] {
                if let Some(target) = ctx.get_cell(dx, dy)
                    && target.material == MaterialId::Void
                {
                    ctx.set_cell(dx, dy, Cell::from_material(MaterialId::Smoke));
                    break;
                }
            }
        }
    }

    ctx.cell.set_ticks_lived(ticks_lived + 1);
    ctx.set_cell(0, 0, *ctx.cell);
}