use super::*;
use crate::{
    site2::{gen::PrimitiveTransform, util::Dir},
    Land,
};
use common::terrain::BlockKind;
use rand::prelude::*;
use vek::*;

/// Represents glider ring data generated by the `generate()` method
pub struct GliderRing {
    /// Location of center of ring post
    center: Vec2<i32>,
    /// Represents the direction the ring is facing
    direction: Dir,
    /// The numeral on the ring sign
    number: usize,
    /// Starting altitude
    base: i32,
    /// The thickness of the ring from the inner to outer radius
    ring_thickness: i32,
    /// The height above the base altitude where the ring starts
    ring_height: i32,
    /// The inner radius of the ring
    ring_radius: i32,
}

impl GliderRing {
    pub fn generate(
        land: &Land,
        _rng: &mut impl Rng,
        _site: &Site,
        wpos: &Vec2<i32>,
        number: usize,
        direction: Dir,
    ) -> Self {
        Self {
            center: *wpos,
            direction,
            number,
            base: land.get_alt_approx(*wpos) as i32 + 1,
            ring_thickness: 4,
            ring_height: 35,
            ring_radius: 16,
        }
    }
}

impl Structure for GliderRing {
    #[cfg(feature = "use-dyn-lib")]
    const UPDATE_FN: &'static [u8] = b"render_glider_ring\0";

    #[cfg_attr(feature = "be-dyn-lib", export_name = "render_glider_ring")]
    fn render_inner(&self, _site: &Site, _land: &Land, painter: &Painter) {
        let rotate_turns = match self.direction {
            Dir::X => 0,
            Dir::Y => 1,
            Dir::NegX => 2,
            Dir::NegY => 3,
        };
        let rotation_center = Vec3::new(self.center.x, self.center.y, self.base);

        let red = Fill::Brick(BlockKind::Wood, Rgb::new(200, 0, 0), 24);
        let green = Fill::Brick(BlockKind::Wood, Rgb::new(0, 200, 0), 24);
        let white = Fill::Brick(BlockKind::GlowingRock, Rgb::new(200, 200, 200), 24);
        let black = Fill::Brick(BlockKind::Wood, Rgb::new(0, 0, 0), 24);
        let wood = Fill::Brick(BlockKind::Wood, Rgb::new(55, 25, 8), 24);

        let ring_base = self.base + self.ring_height;
        let ring_diameter = self.ring_radius * 2;
        let ring_top = ring_base + ring_diameter;

        // Base
        let base = painter.aabb(Aabb {
            min: Vec2::new(self.center.x - 1, self.center.y - 2).with_z(self.base - 30),
            max: Vec2::new(self.center.x + 2, self.center.y + 2)
                .with_z(self.base + self.ring_height + 1),
        });
        // Ring
        let green_ring = painter.horizontal_cylinder(
            Aabb {
                min: Vec2::new(self.center.x - 1, self.center.y - self.ring_radius)
                    .with_z(ring_base),
                max: Vec2::new(self.center.x, self.center.y + self.ring_radius).with_z(ring_top),
            },
            Dir::X,
        );
        let red_ring = painter.horizontal_cylinder(
            Aabb {
                min: Vec2::new(self.center.x, self.center.y - self.ring_radius).with_z(ring_base),
                max: Vec2::new(self.center.x + 2, self.center.y + self.ring_radius)
                    .with_z(ring_top),
            },
            Dir::X,
        );
        let front_white_ring = painter.horizontal_cylinder(
            Aabb {
                min: Vec2::new(
                    self.center.x - 1,
                    self.center.y - self.ring_radius + self.ring_thickness - 1,
                )
                .with_z(ring_base + self.ring_thickness - 1),
                max: Vec2::new(
                    self.center.x,
                    self.center.y + self.ring_radius - self.ring_thickness + 1,
                )
                .with_z(ring_top - self.ring_thickness + 1),
            },
            Dir::X,
        );
        let back_white_ring = painter.horizontal_cylinder(
            Aabb {
                min: Vec2::new(
                    self.center.x + 1,
                    self.center.y - self.ring_radius + self.ring_thickness - 1,
                )
                .with_z(ring_base + self.ring_thickness - 1),
                max: Vec2::new(
                    self.center.x + 2,
                    self.center.y + self.ring_radius - self.ring_thickness + 1,
                )
                .with_z(ring_top - self.ring_thickness + 1),
            },
            Dir::X,
        );
        let mut black_fills = Vec::new();
        for y in self.center.y - self.ring_radius + self.ring_thickness - 1
            ..=self.center.y + self.ring_radius - self.ring_thickness + 1
        {
            if y % 4 == 0 {
                let stripe = painter
                    .aabb(Aabb {
                        min: Vec2::new(self.center.x - 1, y + 1).with_z(ring_base),
                        max: Vec2::new(self.center.x, y + 3).with_z(ring_top),
                    })
                    .intersect(front_white_ring);
                black_fills.push(stripe);
            }
        }
        for z in ring_base + self.ring_thickness + 3..=ring_top - self.ring_thickness - 9 {
            if z % 4 == 0 {
                let stripe = painter
                    .aabb(Aabb {
                        min: Vec2::new(
                            self.center.x - 1,
                            self.center.y - self.ring_radius + self.ring_thickness - 1,
                        )
                        .with_z(z + 1),
                        max: Vec2::new(
                            self.center.x,
                            self.center.y + self.ring_radius - self.ring_thickness + 1,
                        )
                        .with_z(z + 3),
                    })
                    .intersect(front_white_ring);
                black_fills.push(stripe);
            }
        }
        let ring_clear = painter.horizontal_cylinder(
            Aabb {
                min: Vec2::new(
                    self.center.x - 5,
                    self.center.y - self.ring_radius + self.ring_thickness,
                )
                .with_z(ring_base + self.ring_thickness),
                max: Vec2::new(
                    self.center.x + 6,
                    self.center.y + self.ring_radius - self.ring_thickness,
                )
                .with_z(ring_top - self.ring_thickness),
            },
            Dir::X,
        );
        // Sign
        let sign_base = ring_top - self.ring_thickness - 1;
        let sign_height = 7;
        let sign = painter.aabb(Aabb {
            min: Vec2::new(self.center.x - 1, self.center.y - 3).with_z(sign_base),
            max: Vec2::new(self.center.x + 1, self.center.y + 3).with_z(sign_base + sign_height),
        });
        // Sign number
        let numeral_origin = Vec3::new(self.center.x, self.center.y - 2, sign_base + 1);
        // need to rotate the numeral 180 degrees as the ring direction is the direction
        // of travel. The "positive" direction is towards the back of the ring
        let numeral = painter
            .numeral(numeral_origin, self.number)
            .rotate_z_90_about(2, rotation_center);

        let wood_fills = [base];
        let red_fills = [red_ring];
        let green_fills = [green_ring];
        let white_fills = [front_white_ring, back_white_ring];
        let sign_fills = [numeral];
        let black_sign_fills = [sign];
        let clear_fills = [ring_clear];

        let fills = [
            (&wood_fills as &[_], Some(wood)),
            (&red_fills, Some(red)),
            (&green_fills, Some(green)),
            (&white_fills, Some(white.clone())),
            (&black_fills, Some(black.clone())),
            (&clear_fills, None),
            (&black_sign_fills, Some(black)),
            (&sign_fills, Some(white)),
        ];
        for (primitives, fill_color_maybe) in fills {
            for prim in primitives {
                if let Some(fill_color) = &fill_color_maybe {
                    prim.rotate_z_90_about(rotate_turns, rotation_center)
                        .fill(fill_color.clone());
                } else {
                    prim.rotate_z_90_about(rotate_turns, rotation_center)
                        .clear();
                }
            }
        }
    }
}