const std = @import("std");
const builtin = @import("builtin");
const mem = std.mem;
const fmt = std.fmt;
const fs = std.fs;
const io = std.io;

const Allocator = mem.Allocator;
const Thread = std.Thread;

const input = @import("input.zig");
const gui = @import("ui.zig");

var allocator: Allocator = undefined;

pub const Pixel = packed struct {
    r: u8 = 0,
    g: u8 = 0,
    b: u8 = 0,
    _a: u8 = undefined,
};
var pixel_buffer: *const []Pixel = undefined;

pub const Action = enum {
    primary,
    text_cursor_left,
    text_cursor_right,
};

// DEBUG
var img: gui.Image = undefined;
var font: gui.Font = undefined;

pub fn init() !void {
    allocator = @import("root").allocator;

    img = try .fromPath("assets/img/test_image.png", allocator);
    //font = try .fromPath("assets/font/OpendyslexicRegular.otf", allocator, .{.font_height = 128});
    font = try .fromPath("assets/font/OpenSans-VariableFont_wdth,wght.ttf", allocator, .{.font_height = 256});

    try input.bindPointerButton(.primary, .left);
    try input.bindKey(.text_cursor_left, .arrow_left);
    try input.bindKey(.text_cursor_right, .arrow_right);

    try gui.globalInit(allocator);
    ui = try gui.Context.init(.{.allocator = allocator});
    errdefer ui.deinit();

    user_input = try ui.textBufferFromString("samplwwwawwwwwwwwwwwwwwwwwwwwwwwwwwwww");
}

pub fn deinit() void {
    font.deinit();
    img.deinit();

    user_input.deinit();
    ui.deinit();
    gui.globalDeinit();
}

var window_size: @Vector(2, u32) = undefined;
var fwindow_size: @Vector(2, f32) = undefined;
pub fn setWindowSize(ws: @Vector(2, c_uint)) void {
    window_size = @intCast(ws);
    fwindow_size = @floatFromInt(window_size);
    pixel_buffer = @ptrCast(@import("root").pixels);
}

var ui: gui.Context = undefined;
var user_input: gui.TextBuffer = undefined;
var dbg_poss = [3]gui.V2{.{0.1, 0.1}, .{0.2, 0.2}, .{0.3, 0.3}};
var dbg_colors = [3]gui.Color{.hex(0xFFFF0000), .hex(0xFF00FF00), .hex(0xFF0000FF)};
var time: f32 = 0;
pub fn loop(dt: f32) !bool {
    // TODO styles or something. TBD once we have some real world tests
    ui.frameStart();
    //std.debug.print("{d}\n", .{gui.mouse_delta});
    //if (@reduce(.And, gui.mouse_delta == @Vector(2, f32){0, 0})) return false;
    time += dt;
    try ui.textFmt("{d:.1} FPS", .{1/dt}, .{.pos = .{0, 0}, .size = .{1, 1}}, .{.font = &font, .scale = 0.1});
    //std.debug.print("{d:.1}\n", .{1/dt});

    //const pos = gui.V2{-1+time*0.1,-1+time*0.1};
    //const color = gui.Color.float(1,1,0,0.5);
    //try ui.rectangle(.{.pos = pos, .size = .{1,1}}, .{.color = color});
    try ui.rectangle(.{.pos = .{0,0}, .size = .{1,1}}, .{.color = .float(1,1,1,1), .image = img});

    //try ui.areaBegin(.{.rect = .{.pos = .{time * 0.0, 0.0}, .size = .{0.9-0.0*time, 0.9}}, .children_offset = .{time * 0.0, -time * 0.1}});
    //for (0..1) |i| {
    //    try ui.textField(&user_input, @import("root").utf8_of_keys_pressed, .{.pos = .{0, 0.1 + 0.1 * @as(f32, @floatFromInt(i)) / 3}, .size = .{1, 1}}, .{
    //        .text_options = .{.font = &font, .scale = 0.05},
    //        .cursor_to_hovered_glpyh_if = input.ended(.primary),
    //        .cursor_move_left = input.ended(.text_cursor_left),
    //        .cursor_move_right = input.ended(.text_cursor_right),
    //    });
    //}
    //try ui.rectangle(.{.pos = .{time * 0.0, 0}, .size = .{1,1}}, .{
    //    .color = .hex(0xffff0000),
    //});
    //try ui.rectangle(ui._current_area.rect, .{.color = .hex(0xff00ff00), .apply_area_transformations = false, .clip_to_area = true});
    //try ui.areaEnd();

    //for (&dbg_poss, &dbg_colors) |*dbg_pos, dbg_color| {
    //    var rect_drag: ?gui.V2 = null;
    //    try ui.rectangle(.{.pos = dbg_pos.*, .size = .{1, 0.2}}, .{
    //        .color = dbg_color,
    //        .drag = &rect_drag,
    //        .begin_drag_if_hover_and = input.started(.primary),
    //        .end_drag_if = input.ended(.primary),
    //    });
    //    if (rect_drag) |drag| {
    //        dbg_pos.* += drag;
    //        dbg_pos[0] = @max(dbg_pos[0], 0);
    //        dbg_pos[1] = @max(dbg_pos[1], 0);
    //    }
    //}

    gui.clear(@ptrCast(pixel_buffer.*));
    try ui.draw(.{
        .pixels = @ptrCast(pixel_buffer.*),
        .bytes_per_pixel = @sizeOf(Pixel),
        .pixels_per_row = window_size[0],
    });
    return true;
}