const std = @import("std");

const GBA = @import("gba").GBA;
const Mode3 = @import("gba").Mode3;
const LCD = @import("gba").LCD;
const OAM = @import("gba").OAM;
const Input = @import("gba").Input;

const SquareSpriteTuple = std.meta.Tuple(&[_]type{ Rainbow, Bebe16, Bebe32, Bebe64 });

// TODO: ZigGBA should support spaces in the ROM Title IIRC
export var gameHeader linksection(".gbaheader") = GBA.Header.setup("2DSPRITE", "PAOD", "00", 0);

// 16x16 4BPP Sprite depicting
// denpa artist Nanahira's pet rabbit: Bebe-chan
const Bebe16 = struct {
    const Self = @This();

    const pal = [8]u32{
        0x00000000, 0x11B32BAF, 0x7FFF3680, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000,
    };

    const tiles = [32]u32{
        0x00000000, 0x00000000, 0x02220000, 0x02222000, 0x22223100, 0x24223310, 0x42233310, 0x32333310,
        0x00000000, 0x00000000, 0x00022200, 0x00232220, 0x01333240, 0x01333324, 0x01333334, 0x00133333,
        0x33333100, 0x13313100, 0x33333510, 0x55555100, 0x55511000, 0x11100000, 0x00000000, 0x00000000,
        0x01553333, 0x05555133, 0x05555513, 0x00555155, 0x00155555, 0x00011111, 0x00000000, 0x00000000,
    };

    fn paletteMode(_: Self) GBA.PaletteMode {
        return .Color16;
    }

    fn size(_: Self) OAM.ObjectSize {
        return .Size16x16;
    }
    fn load(_: Self) void {
        // In Memory, Tile Map is laid out like: 1 2
        //                                       3 4

        const half = Self.tiles.len / 2;

        GBA.memcpy32(GBA.SPRITE_VRAM, &Self.tiles[0], half * @sizeOf(u32)); // Top
        GBA.memcpy32(GBA.SPRITE_VRAM + (half * 0x20), &Self.tiles[half], half * @sizeOf(u32)); // Bottom

        // Palette
        GBA.memcpy32(GBA.OBJ_PALETTE_RAM, &Self.pal, Self.pal.len * @sizeOf(u32));
    }
};

// Bebe-chan but bigger
const Bebe32 = struct {
    const Self = @This();

    const pal = [8]u32{
        0x00000000, 0x11B32BAF, 0x7FFF3680, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000,
    };

    const tiles = [128]u32{
        0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x22000000, 0x22000000,
        0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00222222, 0x00222222, 0x00222222, 0x00222222,
        0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x22220000, 0x22220000, 0x22222200, 0x22222200,
        0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000022, 0x00000022, 0x00002233, 0x00002233,
        0x33110000, 0x33110000, 0x33331100, 0x33331100, 0x33331100, 0x33331100, 0x33331100, 0x33331100,
        0x22222222, 0x22222222, 0x22442222, 0x22442222, 0x44222233, 0x44222233, 0x33223333, 0x33223333,
        0x33224400, 0x33224400, 0x33332244, 0x33332244, 0x33333344, 0x33333344, 0x33333333, 0x33333333,
        0x00113333, 0x00113333, 0x00113333, 0x00113333, 0x00113333, 0x00113333, 0x00001133, 0x00001133,

        0x33110000, 0x33110000, 0x33110000, 0x33110000, 0x33551100, 0x33551100, 0x55110000, 0x55110000,
        0x33333333, 0x33333333, 0x11333311, 0x11333311, 0x33333333, 0x33333333, 0x55555555, 0x55555555,
        0x33333333, 0x33333333, 0x55113333, 0x55113333, 0x55551133, 0x55551133, 0x55115555, 0x55115555,
        0x00115555, 0x00115555, 0x00555555, 0x00555555, 0x00555555, 0x00555555, 0x00005555, 0x00005555,
        0x11000000, 0x11000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000,
        0x55555511, 0x55555511, 0x11111100, 0x11111100, 0x00000000, 0x00000000, 0x00000000, 0x00000000,
        0x55555555, 0x55555555, 0x11111111, 0x11111111, 0x00000000, 0x00000000, 0x00000000, 0x00000000,
        0x00001155, 0x00001155, 0x00000011, 0x00000011, 0x00000000, 0x00000000, 0x00000000, 0x00000000,
    };

    fn paletteMode(_: Self) GBA.PaletteMode {
        return .Color16;
    }

    fn size(_: Self) OAM.ObjectSize {
        return .Size32x32;
    }

    fn load(_: Self) void {
        // In Memory, Tile Map is laid out like: 1  2  3  4
        //                                       5  6  7  8
        //                                       9  10 11 12
        //                                       13 14 15 16

        const quarter = Self.tiles.len / 4;

        GBA.memcpy32(GBA.SPRITE_VRAM, &Self.tiles[0], quarter * @sizeOf(u32));
        GBA.memcpy32(GBA.SPRITE_VRAM + (quarter * 0x10), &Self.tiles[quarter], quarter * @sizeOf(u32));
        GBA.memcpy32(GBA.SPRITE_VRAM + (quarter * 0x20), &Self.tiles[quarter * 2], quarter * @sizeOf(u32));
        GBA.memcpy32(GBA.SPRITE_VRAM + (quarter * 0x30), &Self.tiles[quarter * 3], quarter * @sizeOf(u32));

        // Palette
        GBA.memcpy32(GBA.OBJ_PALETTE_RAM, &Self.pal, Self.pal.len * @sizeOf(u32));
    }
};

// The Biggest Bebe-chan yet
const Bebe64 = struct {
    const Self = @This();

    const pal = [8]u32{
        0x00000000, 0x11B32BAF, 0x7FFF3680, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000,
    };

    const tiles = [512]u32{
        0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000,
        0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000,
        0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000,
        0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000,
        0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000,
        0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000,
        0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000,
        0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000,

        0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000,
        0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x22220000, 0x22220000, 0x22220000, 0x22220000,
        0x22222222, 0x22222222, 0x22222222, 0x22222222, 0x22222222, 0x22222222, 0x22222222, 0x22222222,
        0x00002222, 0x00002222, 0x00002222, 0x00002222, 0x00002222, 0x00002222, 0x00002222, 0x00002222,
        0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x22220000, 0x22220000, 0x22220000, 0x22220000,
        0x22222222, 0x22222222, 0x22222222, 0x22222222, 0x22222222, 0x22222222, 0x22222222, 0x22222222,
        0x00002222, 0x00002222, 0x00002222, 0x00002222, 0x22223333, 0x22223333, 0x22223333, 0x22223333,
        0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000,

        0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x11110000, 0x11110000, 0x11110000, 0x11110000,
        0x33331111, 0x33331111, 0x33331111, 0x33331111, 0x33333333, 0x33333333, 0x33333333, 0x33333333,
        0x22222222, 0x22222222, 0x22222222, 0x22222222, 0x22222222, 0x22222222, 0x22222222, 0x22222222,
        0x22222222, 0x22222222, 0x22222222, 0x22222222, 0x22224444, 0x22224444, 0x22224444, 0x22224444,
        0x44440000, 0x44440000, 0x44440000, 0x44440000, 0x22224444, 0x22224444, 0x22224444, 0x22224444,
        0x33332222, 0x33332222, 0x33332222, 0x33332222, 0x33333333, 0x33333333, 0x33333333, 0x33333333,
        0x33333333, 0x33333333, 0x33333333, 0x33333333, 0x33333333, 0x33333333, 0x33333333, 0x33333333,
        0x00001111, 0x00001111, 0x00001111, 0x00001111, 0x00001111, 0x00001111, 0x00001111, 0x00001111,

        0x11110000, 0x11110000, 0x11110000, 0x11110000, 0x11110000, 0x11110000, 0x11110000, 0x11110000,
        0x33333333, 0x33333333, 0x33333333, 0x33333333, 0x33333333, 0x33333333, 0x33333333, 0x33333333,
        0x22223333, 0x22223333, 0x22223333, 0x22223333, 0x33333333, 0x33333333, 0x33333333, 0x33333333,
        0x44442222, 0x44442222, 0x44442222, 0x44442222, 0x33332222, 0x33332222, 0x33332222, 0x33332222,
        0x33334444, 0x33334444, 0x33334444, 0x33334444, 0x33333333, 0x33333333, 0x33333333, 0x33333333,
        0x33333333, 0x33333333, 0x33333333, 0x33333333, 0x33333333, 0x33333333, 0x33333333, 0x33333333,
        0x33333333, 0x33333333, 0x33333333, 0x33333333, 0x11113333, 0x11113333, 0x11113333, 0x11113333,
        0x00001111, 0x00001111, 0x00001111, 0x00001111, 0x00000000, 0x00000000, 0x00000000, 0x00000000,

        0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000,
        0x33331111, 0x33331111, 0x33331111, 0x33331111, 0x33331111, 0x33331111, 0x33331111, 0x33331111,
        0x33333333, 0x33333333, 0x33333333, 0x33333333, 0x33331111, 0x33331111, 0x33331111, 0x33331111,
        0x33333333, 0x33333333, 0x33333333, 0x33333333, 0x11113333, 0x11113333, 0x11113333, 0x11113333,
        0x33333333, 0x33333333, 0x33333333, 0x33333333, 0x33333333, 0x33333333, 0x33333333, 0x33333333,
        0x33333333, 0x33333333, 0x33333333, 0x33333333, 0x55551111, 0x55551111, 0x55551111, 0x55551111,
        0x55555555, 0x55555555, 0x55555555, 0x55555555, 0x55555555, 0x55555555, 0x55555555, 0x55555555,
        0x00001111, 0x00001111, 0x00001111, 0x00001111, 0x00005555, 0x00005555, 0x00005555, 0x00005555,

        0x11110000, 0x11110000, 0x11110000, 0x11110000, 0x00000000, 0x00000000, 0x00000000, 0x00000000,
        0x33335555, 0x33335555, 0x33335555, 0x33335555, 0x55551111, 0x55551111, 0x55551111, 0x55551111,
        0x33333333, 0x33333333, 0x33333333, 0x33333333, 0x55555555, 0x55555555, 0x55555555, 0x55555555,
        0x33333333, 0x33333333, 0x33333333, 0x33333333, 0x55555555, 0x55555555, 0x55555555, 0x55555555,
        0x11113333, 0x11113333, 0x11113333, 0x11113333, 0x55555555, 0x55555555, 0x55555555, 0x55555555,
        0x55555555, 0x55555555, 0x55555555, 0x55555555, 0x55551111, 0x55551111, 0x55551111, 0x55551111,
        0x55555555, 0x55555555, 0x55555555, 0x55555555, 0x55555555, 0x55555555, 0x55555555, 0x55555555,
        0x00005555, 0x00005555, 0x00005555, 0x00005555, 0x00000000, 0x00000000, 0x00000000, 0x00000000,

        0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000,
        0x11110000, 0x11110000, 0x11110000, 0x11110000, 0x00000000, 0x00000000, 0x00000000, 0x00000000,
        0x55551111, 0x55551111, 0x55551111, 0x55551111, 0x11110000, 0x11110000, 0x11110000, 0x11110000,
        0x55555555, 0x55555555, 0x55555555, 0x55555555, 0x11111111, 0x11111111, 0x11111111, 0x11111111,
        0x55555555, 0x55555555, 0x55555555, 0x55555555, 0x11111111, 0x11111111, 0x11111111, 0x11111111,
        0x55555555, 0x55555555, 0x55555555, 0x55555555, 0x11111111, 0x11111111, 0x11111111, 0x11111111,
        0x11115555, 0x11115555, 0x11115555, 0x11115555, 0x00001111, 0x00001111, 0x00001111, 0x00001111,
        0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000,

        0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000,
        0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000,
        0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000,
        0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000,
        0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000,
        0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000,
        0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000,
        0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000,
    };

    fn paletteMode(_: Self) GBA.PaletteMode {
        return .Color16;
    }

    fn size(_: Self) OAM.ObjectSize {
        return .Size64x64;
    }

    fn load(_: Self) void {
        // In Memory, Tile Map is laid out like: 1  2  3  4  5  6  7  8
        //                                       9  10 11 12 13 14 15 16
        //                                       17 18 19 20 21 22 23 24
        //                                       25 26 27 28 29 30 31 32

        const eighth = Self.tiles.len / 8;

        GBA.memcpy32(GBA.SPRITE_VRAM, &Self.tiles[0], eighth * @sizeOf(u32));
        GBA.memcpy32(GBA.SPRITE_VRAM + (eighth * 0x8), &Self.tiles[eighth], eighth * @sizeOf(u32));
        GBA.memcpy32(GBA.SPRITE_VRAM + (eighth * 0x10), &Self.tiles[eighth * 2], eighth * @sizeOf(u32));
        GBA.memcpy32(GBA.SPRITE_VRAM + (eighth * 0x18), &Self.tiles[eighth * 3], eighth * @sizeOf(u32));
        GBA.memcpy32(GBA.SPRITE_VRAM + (eighth * 0x20), &Self.tiles[eighth * 4], eighth * @sizeOf(u32));
        GBA.memcpy32(GBA.SPRITE_VRAM + (eighth * 0x28), &Self.tiles[eighth * 5], eighth * @sizeOf(u32));
        GBA.memcpy32(GBA.SPRITE_VRAM + (eighth * 0x30), &Self.tiles[eighth * 6], eighth * @sizeOf(u32));
        GBA.memcpy32(GBA.SPRITE_VRAM + (eighth * 0x38), &Self.tiles[eighth * 7], eighth * @sizeOf(u32));

        // Palette
        GBA.memcpy32(GBA.OBJ_PALETTE_RAM, &Self.pal, Self.pal.len * @sizeOf(u32));
    }
};

// 8x8 4bpp Sprite depicting a Rainbow
// (it's more of a gradiant, I don't know english, whatever.)
// source: Laziness? I can't draw, especially within the confines of 8x8 pixels
const Rainbow = struct {
    const Self = @This();

    const pal = [8]u32{
        0x001F0000, 0x03FF01FF, 0x03E003EF, 0x7FE03FE0, 0x00007DE0, 0x00000000, 0x00000000, 0x00000000,
    };

    const tiles = [8]u32{
        0x11111111, 0x22222222, 0x33333333, 0x44444444, 0x55555555, 0x66666666, 0x77777777, 0x88888888,
    };

    inline fn paletteMode(_: Self) GBA.PaletteMode {
        return .Color16;
    }

    inline fn size(_: Self) OAM.ObjectSize {
        return .Size8x8;
    }

    inline fn load(_: Self) void {
        // 8x8 Sprites don't differ in any meaningful way between 1D and 2D mapping

        // Copy Tile Mapping
        GBA.memcpy32(GBA.SPRITE_VRAM, &Self.tiles, Self.tiles.len * @sizeOf(u32));

        // Copy Palette
        GBA.memcpy32(GBA.OBJ_PALETTE_RAM, &Self.pal, Self.pal.len * @sizeOf(u32));
    }
};

const square_sprites = withoutThisMethodZigComplains();

fn withoutThisMethodZigComplains() SquareSpriteTuple {
    return .{ Rainbow{}, Bebe16{}, Bebe32{}, Bebe64{} };
}

pub fn main() noreturn {
    LCD.setupDisplayControl(.{
        .mode = .Mode0, // No Affine BGs
        .objectLayer = .Show, // Enable Sprites
        .objVramCharacterMapping = .TwoDimension, // 2D Sprite Mapping
    });

    OAM.init();

    square_sprites[0].load(); // Copy Mapping to VRAM and Palette to PALRAM

    var sprite: *OAM.Attribute = OAM.allocate();
    sprite.paletteMode = square_sprites[0].paletteMode();
    sprite.palette = 0;
    sprite.tileIndex = 0;
    sprite.setSize(square_sprites[0].size());

    var x: i32 = 96;
    var y: i32 = 32;

    var i: i32 = 0;

    while (true) {
        LCD.naiveVSync();
        Input.readInput();

        const shoulder = Input.getShoulderJustPressed();
        if (shoulder != 0) {
            i = (i + shoulder) & 0b11;

            // Index must be comptime known unfortunately
            // so we need this ugly switch statement
            switch (i) {
                0 => {
                    square_sprites[0].load();
                    sprite.setSize(square_sprites[0].size());
                },
                1 => {
                    square_sprites[1].load();
                    sprite.setSize(square_sprites[1].size());
                },
                2 => {
                    square_sprites[2].load();
                    sprite.setSize(square_sprites[2].size());
                },
                3 => {
                    square_sprites[3].load();
                    sprite.setSize(square_sprites[3].size());
                },
                else => unreachable,
            }
        }

        x += Input.getHorizontal() * 2;
        y += Input.getVertical() * 2;

        sprite.setPosition(x, y);

        OAM.update(1);
    }
}