pub fn main() !void {
    var gpa = std.heap.GeneralPurposeAllocator(.{}){};
    defer _ = gpa.deinit();
    const allocator = gpa.allocator();

    raylib.SetConfigFlags(raylib.FLAG_VSYNC_HINT); // | raylib.FLAG_WINDOW_RESIZABLE);
    raylib.InitWindow(@intFromFloat(screen_width), @intFromFloat(screen_height), "ReX");
    defer raylib.CloseWindow();

    raylib.SetWindowMinSize(480, 272);
    raylib.SetWindowMaxSize(1920, 1080);
    scales.recalculate();

    global_font = raylib.LoadFontEx("font/SCE-PS3-RD-R-LATIN.TTF", 32, 0, 250);
    raylib.SetTextureFilter(global_font.texture, raylib.TEXTURE_FILTER_BILINEAR);

    var background = Background.init();
    var column = Column.init(
        allocator,
        raylib.LoadTextureFromImage(raylib.GenImageChecked(64, 64, 8, 8, raylib.BLACK, raylib.WHITE)),
        "Game",
    );
    defer column.deinit();

    var item1 = Item.init(
        raylib.LoadTexture("menu/game/CometCrash/ICON0.PNG"),
        "Comet Crash",
        "3/1/2025  23:11",
    );
    var item2 = Item.init(
        raylib.LoadTexture("menu/game/LBP1/ICON0.PNG"),
        "LittleBigPlanet",
        "3/1/2025  23:15",
    );
    var item3 = Item.init(
        raylib.LoadTexture("menu/game/LBP2/ICON0.PNG"),
        "LittleBigPlanet 2",
        "3/1/2025  23:26",
    );
    var item4 = Item.init(
        raylib.LoadTexture("menu/game/LBP3/ICON0.PNG"),
        "LittleBigPlanet 3",
        "3/1/2025  23:48",
    );
    try column.appendItem(&item1);
    try column.appendItem(&item2);
    try column.appendItem(&item3);
    try column.appendItem(&item4);

    raylib.SetTargetFPS(120);
    while (!raylib.WindowShouldClose()) {
        if (raylib.IsWindowResized()) {
            screen_width = @floatFromInt(raylib.GetScreenWidth());
            screen_height = @floatFromInt(raylib.GetScreenHeight());
            scales.recalculate();
        }
        if (raylib.IsKeyPressed('D')) debug_draw = !debug_draw;
        if (raylib.IsKeyPressed('Z')) item1.setLarge(!item1.large);
        if (raylib.IsKeyPressed('S')) raylib.TakeScreenshot("screenshot.png");

        column.updatePositions();

        raylib.BeginDrawing();
        defer raylib.EndDrawing();

        background.draw();
        column.draw();

        raylib.DrawFPS(1, 1);

        const debug_text = try std.fmt.allocPrint(allocator,
            \\screen size = {d}x{d}
            \\selected = {d}
        , .{
            screen_width,
            screen_height,
            column.selected,
        });
        defer allocator.free(debug_text);
        raylib.DrawText(@ptrCast(debug_text), 80, 2, 8, raylib.GREEN);
    }
}

var debug_draw = true;

var global_font: raylib.Font = undefined;

var screen_width: f32 = 480;
var screen_height: f32 = 272;

var scales: Scales = undefined;

/// Cached scaling and positioning values for dynamic window resizing.
pub const Scales = struct {
    item_icon_small_width: f32,
    item_icon_small_height: f32,
    item_icon_large_width: f32,
    item_icon_large_height: f32,
    item_title_font_size: f32,
    item_subtitle_font_size: f32,

    column_icon_scale: f32,
    column_title_font_size: f32,
    column_position_center: raylib.Vector2,
    column_position_spacing: f32,
    column_item_spacing: f32,
    column_item_start: f32,

    /// Recalculate scales after screen resize.
    pub fn recalculate(self: *Scales) void {
        self.item_icon_small_width = 67;
        self.item_icon_small_height = 48;
        self.item_icon_large_width = 67;
        self.item_icon_large_height = 48;
        self.item_title_font_size = 18;
        self.item_subtitle_font_size = 12;

        self.column_icon_scale = 0.75;
        self.column_title_font_size = 13;
        self.column_position_center = .{
            .x = std.math.lerp(0.0, screen_width, 0.18),
            .y = std.math.lerp(0.0, screen_height, 0.15),
        };
        self.column_position_spacing = 64;
        self.column_item_spacing = 16;
        self.column_item_start = 117.8;
    }
};

pub const Column = struct {
    icon: raylib.Texture2D,
    title: []const u8,

    items: std.ArrayList(*Item),
    selected: usize = 0,
    start_y: f32 = undefined,

    pub fn init(allocator: Allocator, icon: raylib.Texture2D, title: []const u8) Column {
        raylib.SetTextureFilter(icon, raylib.TEXTURE_FILTER_BILINEAR);
        return .{
            .icon = icon,
            .title = title,
            .items = .init(allocator),
        };
    }

    pub fn deinit(self: *Column) void {
        self.items.deinit();
    }

    pub fn draw(self: *Column) void {
        var icon = Image{
            .texture = self.icon,
            .box = .{
                .x = scales.column_position_center.x,
                .y = scales.column_position_center.y,
                .w = 67,
                .h = 48,
            },
        };

        var title = Text{
            .string = self.title,
            .font_size = scales.column_title_font_size,
            .font_spacing = 1,
            .box = .{
                .x = icon.box.x - 8,
                .y = icon.box.y + icon.box.h + 6,
                .w = icon.box.w + 16,
                .h = scales.column_title_font_size,
            },
            .align_h = .center,
        };

        // self.start_y = scales.column_position_center.y + icon.box.h + title.box.h + scales.column_item_spacing;
        for (self.items.items) |item| item.draw();

        icon.draw();
        title.draw();
    }

    pub fn appendItem(self: *Column, item: *Item) !void {
        try self.items.append(item);
        self.refresh();
    }

    pub fn insertItem(self: *Column, idx: usize, item: *Item) !void {
        try self.items.insert(idx, item);
        self.refresh();
    }

    pub fn removeItem(self: *Column, idx: usize) void {
        _ = try self.items.orderedRemove(idx);
        self.refresh();
    }

    fn updatePositions(self: *Column) void {
        const up = raylib.IsKeyPressed(raylib.KEY_UP) or raylib.IsKeyPressedRepeat(raylib.KEY_UP);
        const down = raylib.IsKeyPressed(raylib.KEY_DOWN) or raylib.IsKeyPressedRepeat(raylib.KEY_DOWN);
        if (up and self.selected > 0) self.selected -= 1;
        if (down and self.selected < self.items.items.len - 1) self.selected += 1;

        if (up or down) self.refresh();
    }

    fn refresh(self: *Column) void {
        var y = scales.column_item_start;
        for (self.items.items[self.selected..]) |item| {
            item.setPosition(.{ .x = scales.column_position_center.x, .y = y });
            y += scales.item_icon_small_height + scales.column_item_spacing;
        }
    }
};

pub const Item = struct {
    position: raylib.Vector2 = .{ .x = 0, .y = 0 },
    // icon_scale: f32,
    // start_scale: f32,
    time: f32 = 0.0,
    start_position: raylib.Vector2 = .{ .x = 0, .y = 0 },

    icon: raylib.Texture2D,
    title: []const u8,
    subtitle: []const u8,
    large: bool = false,

    pub fn init(texture: raylib.Texture2D, title: []const u8, subtitle: []const u8) Item {
        raylib.SetTextureFilter(texture, raylib.TEXTURE_FILTER_BILINEAR);
        return .{
            .icon = texture,
            .title = title,
            .subtitle = subtitle,
            // .icon_scale = scales.item_icon_small_scale,
            // .start_scale = scales.item_icon_small_scale,
        };
    }

    pub fn draw(self: *Item) void {
        self.time += raylib.GetFrameTime();
        // self.icon_scale = std.math.lerp(
        //     self.start_scale,
        //     if (self.large) scales.item_icon_large_scale else scales.item_icon_small_scale,
        //     easeOutExpo(self.time / 0.333),
        // );
        const position = raylib.Vector2Lerp(
            self.start_position,
            self.position,
            easeOutExpo(self.time / 0.333),
        );

        var icon = Image{
            .texture = self.icon,
            .box = .{
                .x = position.x - scales.item_icon_small_width / 2.0 + 67.0 / 2.0,
                .y = position.y,
                .w = scales.item_icon_small_width,
                .h = scales.item_icon_small_height,
            },
        };

        var title = Text{
            .string = self.title,
            .box = .{
                .x = icon.box.x + 8 + icon.box.w,
                .y = icon.box.y,
                .w = 300,
                .h = icon.box.h / 2.0 - 2,
            },
            .font_size = scales.item_title_font_size,
            .font_spacing = 1,
            .align_v = .right,
        };

        var subtitle = Text{
            .string = self.subtitle,
            .box = .{
                .x = icon.box.x + 8 + icon.box.w,
                .y = icon.box.y + icon.box.h / 2.0 + 1,
                .w = 200,
                .h = icon.box.h / 2.0 - 2,
            },
            .font_size = scales.item_subtitle_font_size,
            .font_spacing = 1,
            .align_v = .left,
        };

        icon.draw();
        title.draw();
        subtitle.draw();
    }

    pub fn setLarge(self: *Item, large: bool) void {
        self.large = large;
        // self.time = 0;
        // self.start_scale = self.icon_scale;
    }

    pub fn setPosition(self: *Item, position: raylib.Vector2) void {
        self.start_position = self.position;
        self.position = position;
        self.time = 0;
    }

    fn easeOutExpo(x: f32) f32 {
        return 1.0 - std.math.pow(f32, 2, -10 * std.math.clamp(x, 0.0, 1.0));
    }
};

/// Draws the dynamic gradient background.
// TODO shift based on time of day
// TODO image wallpaper
// TODO slideshow wallpaper
// TODO animated image wallpaper
pub const Background = struct {
    top_left: Color,
    top_right: Color,
    bottom_right: Color,
    bottom_left: Color,

    pub fn init() Background {
        var self: Background = undefined;
        self.setColors(NIGHT_08);
        return self;
    }

    pub fn setColors(self: *Background, colors: [4]Color) void {
        self.top_left = colors[0];
        self.bottom_right = colors[1];
        self.top_right = colors[2];
        self.bottom_left = colors[3];
    }

    pub fn draw(self: *Background) void {
        raylib.DrawRectangleGradientEx(
            .{
                .x = 0,
                .y = 0,
                .width = screen_width,
                .height = screen_height,
            },
            self.top_left.toRaylib(),
            self.bottom_left.toRaylib(),
            self.top_right.toRaylib(),
            self.bottom_right.toRaylib(),
        );
    }

    pub const Color = struct {
        r: f32,
        g: f32,
        b: f32,

        fn toRaylib(self: Color) raylib.Color {
            return .{
                .r = @intFromFloat(self.r * 255.0),
                .g = @intFromFloat(self.g * 255.0),
                .b = @intFromFloat(self.b * 255.0),
                .a = 255,
            };
        }
    };

    pub const DAY_06 = [4]Color{
        .{ .r = 0.408, .g = 0.333, .b = 0.643 },
        .{ .r = 0.518, .g = 0.365, .b = 0.855 },
        .{ .r = 0.761, .g = 0.510, .b = 0.851 },
        .{ .r = 0.569, .g = 0.325, .b = 0.620 },
    };

    pub const DAY_08 = [4]Color{
        .{ .r = 0.243, .g = 0.608, .b = 0.831 },
        .{ .r = 0.039, .g = 0.690, .b = 0.878 },
        .{ .r = 0.016, .g = 0.306, .b = 0.694 },
        .{ .r = 0.000, .g = 0.027, .b = 0.310 },
    };

    pub const NIGHT_08 = [4]Color{
        .{ .r = 0.000, .g = 0.145, .b = 0.349 },
        .{ .r = 0.000, .g = 0.008, .b = 0.106 },
        .{ .r = 0.251, .g = 0.494, .b = 0.576 },
        .{ .r = 0.008, .g = 0.537, .b = 0.612 },
    };
};

pub const BoundingBox = struct {
    x: f32 = 0,
    y: f32 = 0,
    w: f32,
    h: f32,
};

/// A texture within a bounding box. Positions and scales based on configurable parameters.
/// Will not crop texture if using `Mode.original`.
pub const Image = struct {
    box: BoundingBox,
    texture: raylib.Texture2D,

    mode: Mode = .fit,
    align_w: Align = .center,
    align_h: Align = .center,

    pub fn draw(self: *Image) void {
        const width: f32 = @floatFromInt(self.texture.width);
        const height: f32 = @floatFromInt(self.texture.height);
        const width_scale: f32 = if (width == 0) 0.0 else self.box.w / width;
        const height_scale: f32 = if (height == 0) 0.0 else self.box.h / height;
        const scale = switch (self.mode) {
            .original => 1.0,
            .fit => @min(width_scale, height_scale),
            .fill => @max(width_scale, height_scale),
        };
        const position = raylib.Vector2{
            .x = switch (self.align_w) {
                .left => 0,
                .center => self.box.x + self.box.w / 2.0 - (width * scale) / 2.0,
                .right => self.box.x + self.box.w - width * scale,
            },
            .y = switch (self.align_h) {
                .left => 0,
                .center => self.box.y + self.box.h / 2.0 - (height * scale) / 2.0,
                .right => self.box.y + self.box.h - height * scale,
            },
        };
        if (debug_draw)
            raylib.DrawRectangleLines(
                @intFromFloat(self.box.x),
                @intFromFloat(self.box.y),
                @intFromFloat(self.box.w),
                @intFromFloat(self.box.h),
                raylib.MAROON,
            )
        else
            raylib.DrawTextureEx(self.texture, position, 0, scale, raylib.WHITE);
    }

    pub const Mode = enum { original, fit, fill };
    pub const Align = enum { left, center, right };
};

/// Draws a string inside a bounding box.
// TODO ellipsize text
// TODO clip text and scroll
pub const Text = struct {
    box: BoundingBox,
    string: []const u8,
    font_size: f32,
    font_spacing: f32,

    align_h: Align = .left,
    align_v: Align = .left,

    pub fn draw(self: *Text) void {
        const size = raylib.MeasureTextEx(
            global_font,
            @ptrCast(self.string),
            self.font_size,
            self.font_spacing,
        );
        if (debug_draw)
            raylib.DrawRectangleLines(
                @intFromFloat(self.box.x),
                @intFromFloat(self.box.y),
                @intFromFloat(self.box.w),
                @intFromFloat(self.box.h),
                raylib.GREEN,
            )
        else
            raylib.DrawTextEx(
                global_font,
                @ptrCast(self.string),
                .{
                    .x = switch (self.align_h) {
                        .left => self.box.x,
                        .center => self.box.x + self.box.w / 2.0 - size.x / 2.0,
                        .right => self.box.x + self.box.w - size.x,
                    },
                    .y = switch (self.align_v) {
                        .left => self.box.y,
                        .center => self.box.y + self.box.h / 2.0 - size.y / 2.0,
                        .right => self.box.y + self.box.h - size.y,
                    },
                },
                self.font_size,
                self.font_spacing,
                raylib.WHITE,
            );
    }

    pub const Align = enum { left, center, right };
};

/// Create ortho camera looking down at the XY plane, with a fovy of 1 for UV-like positioning.
fn createCamera() raylib.Camera3D {
    var camera = raylib.Camera3D{};

    camera.position.x = 0;
    camera.position.y = 10;
    camera.position.z = 0;

    // camera pointing down, oriented correctly
    // TODO this works but looks weird. do better.
    camera.target.x = 0;
    camera.target.y = 0;
    camera.target.z = -0.000000000000001;

    camera.up.x = 0;
    camera.up.y = 1;
    camera.up.z = 0;

    camera.fovy = 1;
    camera.projection = raylib.CAMERA_ORTHOGRAPHIC;

    return camera;
}

const std = @import("std");
const Allocator = std.mem.Allocator;

const c = @import("c.zig");
const raylib = c.raylib;