// modules
mod tile;

// namespacing
use crate::{util::*, MainState, Result};
use ggez::{
    graphics::{self, DrawParam},
    Context,
};
use mint::{Point2, Vector2, Vector3};
use std::{collections::HashMap, path::PathBuf};
use tile::*;

/// represent a whole rendered world
pub struct World {
    width: isize,
    depth: isize,
    height: isize,
    data: HashMap<Vector3<isize>, Tile>,
    builder: TileBuilder,
    offset: Point2<f32>,
    zoom: Vector2<f32>,
}

impl World {
    /// create a new world instance
    pub fn new(
        ctx: &mut Context,
        tile_config: PathBuf,
        width: isize,
        depth: isize,
        height: isize,
    ) -> Result<World> {
        let builder = TileBuilder::new(ctx, tile_config)?;
        let mut data: HashMap<Vector3<isize>, Tile> = HashMap::new();
        let offset: Point2<f32> = [350.0f32, 100.0f32].into();
        let zoom: Vector2<f32> = [1.0f32, 1.0f32].into();

        for x in 0..width {
            for y in 0..depth {
                for z in 0..height {
                    data.insert([x, y, z].into(), builder.build("nothing".to_owned())?);
                }
            }
        }

        Ok(World {
            width,
            height,
            depth,
            data,
            builder: builder,
            offset,
            zoom,
        })
    }

    /// renders the world to the window
    pub fn render(&self, ctx: &mut Context) -> Result<()> {
        for x in 0..self.width {
            for y in 0..self.depth {
                for z in 0..self.height {
                    let tile = self.data.get(&[x, y, z].into()).unwrap();
                    let iso_coord: IsometricVector2 = Point2::from([x as f32, y as f32]).into();
                    let scale = [self.zoom.x, self.zoom.y];
                    let dest = [
                        iso_coord.x() * (self.builder.tile_width() / 2.0) * scale[0]
                            + self.offset.x,
                        iso_coord.y() * (self.builder.tile_height() / 2.0) * scale[1]
                            + self.offset.y,
                    ];

                    let param = DrawParam::default()
                        .dest(Point2::from_slice(&dest))
                        .scale(Point2::from_slice(&scale));

                    graphics::draw(ctx, tile.texture(), param)?;
                }
            }
        }

        Ok(())
    }
}

/// action struct for wrapping offsetting input
#[derive(Debug)]
pub struct OffsetAction(Vector2<f32>);

impl OffsetAction {
    /// construct a new offset action
    pub fn new(offset: Vector2<f32>) -> OffsetAction {
        OffsetAction(offset)
    }
}

impl crate::Action for OffsetAction {
    fn execute(&self, _ctx: &mut Context, state: &mut MainState) -> Result<()> {
        state.world.offset.x =
            self.0.x * (state.world.builder.tile_width() / 2.0) + state.world.offset.x;
        state.world.offset.y =
            self.0.y * (state.world.builder.tile_height() / 2.0) + state.world.offset.y;
        Ok(())
    }

    fn undo(&self, _ctx: &mut Context, state: &mut MainState) -> Result<()> {
        state.world.offset.x = state.world.offset.x - self.0.x;
        state.world.offset.y = state.world.offset.y - self.0.y;
        Ok(())
    }
}

/// action struct for wrapping zoom input
#[derive(Debug)]
pub struct ZoomAction(Vector2<f32>);

impl ZoomAction {
    /// construct a new scale action
    pub fn new(scale: Vector2<f32>) -> ZoomAction {
        ZoomAction(scale)
    }
}

impl crate::Action for ZoomAction {
    fn execute(&self, _ctx: &mut Context, state: &mut MainState) -> Result<()> {
        state.world.zoom.x = self.0.x + state.world.zoom.x;
        state.world.zoom.y = self.0.y + state.world.zoom.y;
        Ok(())
    }

    fn undo(&self, _ctx: &mut Context, state: &mut MainState) -> Result<()> {
        state.world.zoom.x = state.world.zoom.x - self.0.x;
        state.world.zoom.y = state.world.zoom.y - self.0.y;
        Ok(())
    }
}