const std = @import("std");
const glfw = @import("glfw");
const assert = std.debug.assert;
const ig = @import("imgui");
const ig_impl_glfw = @import("imgui_impl_glfw.zig");

const ProfileMark = @import("../common/profiler.zig").ProfileMark;

// TODO memory
var gpa = std.heap.GeneralPurposeAllocator(.{}){};
const allocator = gpa.allocator();

pub fn init(window: *glfw.Window) !void {
    ig.CHECKVERSION();

    // TODO
    //ig.SetAllocatorFunctions(igAlloc, igFree);

    _ = ig.CreateContext();
    errdefer ig.DestroyContext();

    if (!ig_impl_glfw.InitForVulkan(window, false)) {
        return error.ImGuiFailedToInitialize;
    }

    ig.StyleColorsDark();
    _ = window;
}

pub fn deinit() void {
    ig_impl_glfw.Shutdown();
    ig.DestroyContext();
}

const pm_beginframe = ProfileMark.init("ui.beginFrame");
pub fn beginFrame() void {
    pm_beginframe.begin();
    defer pm_beginframe.end();

    ig_impl_glfw.NewFrame();
    ig.NewFrame();
}

const pm_endframe = ProfileMark.init("ui.endFrame");
pub fn endFrame() void {
    pm_endframe.begin();
    defer pm_endframe.end();

    ig.EndFrame();
}

// TODO
//fn igAlloc(sz: usize, user_data: ?*anyopaque) callconv(.C) ?*anyopaque {
//    _ = user_data;
//    const mem = allocator.alloc(u8, sz) catch return null;
//    return @ptrCast(*anyopaque, mem);
//}
//
//fn igFree(ptr: ?*anyopaque, user_data: ?*anyopaque) callconv(.C) void {
//    _ = user_data;
//    if (ptr) |p| allocator.free(@ptrCast([*]u8, p));
//}