// Copyright (c) 2019-2020 Alexander Medvednikov. All rights reserved.
// Use of this source code is governed by an MIT license
// that can be found in the LICENSE file.
module gg

import gx
import os
import sokol
import sokol.sapp
import sokol.sgl
import sokol.gfx
import gg.ft

type FNvoidptr1 fn(voidptr)
type FNvoidptr2 fn(voidptr,voidptr)
type FNFail fn(string,voidptr)

pub struct Config {
pub:
	width         int
	height        int
	use_ortho     bool
	retina        bool
	resizable     bool
	user_data     voidptr
	font_size     int
	create_window bool
	// window_user_ptr voidptr
	window_title  string
	borderless_window bool
	always_on_top bool
	scale         f32  = 1.0
	bg_color      gx.Color
	init_fn       FNvoidptr1 = voidptr(0)
	frame_fn      FNvoidptr1 = voidptr(0)
	event_fn      FNvoidptr2 = voidptr(0)
	cleanup_fn    FNvoidptr1 = voidptr(0)
	fail_fn       FNFail = voidptr(0)
	wait_events   bool // set this to true for UIs, to save power
	font_path string
}

pub struct GG {
	scale      f32 = 1.0// retina = 2 , normal = 1
pub mut:
	width      int
	height     int
	clear_pass C.sg_pass_action
	window     C.sapp_desc
	config     Config
}

pub struct Size { pub: width int height int }

fn gg_init_sokol_window(user_data voidptr) {
	mut g := &GG(user_data)
	desc := C.sg_desc{
		mtl_device: sapp.metal_get_device()
		mtl_renderpass_descriptor_cb: sapp.metal_get_renderpass_descriptor
		mtl_drawable_cb: sapp.metal_get_drawable
		d3d11_device: sapp.d3d11_get_device()
		d3d11_device_context: sapp.d3d11_get_device_context()
		d3d11_render_target_view_cb: sapp.d3d11_get_render_target_view
		d3d11_depth_stencil_view_cb: sapp.d3d11_get_depth_stencil_view
	}
	gfx.setup(&desc)
	sgl_desc := C.sgl_desc_t{}
	sgl.setup(&sgl_desc)
	if g.config.init_fn != voidptr(0) {
		g.config.init_fn( g.config.user_data )
	}
}

fn gg_frame_fn(user_data voidptr) {
	mut g := &GG(user_data)
	if g.config.frame_fn != voidptr(0) {
		g.config.frame_fn( g.config.user_data )
	}
}

fn gg_event_fn(e &C.sapp_event, user_data voidptr){
	mut g := &GG(user_data)
	if g.config.event_fn != voidptr(0) {
		g.config.event_fn(e, g.config.user_data)
	}
}

fn gg_cleanup_fn(user_data voidptr){
	mut g := &GG(user_data)
	if g.config.cleanup_fn != voidptr(0) {
		g.config.cleanup_fn(g.config.user_data)
	}
}

fn gg_fail_fn(msg charptr, user_data voidptr){
	mut g := &GG(user_data)
	vmsg := tos3(msg)
	if g.config.fail_fn != voidptr(0) {
		g.config.fail_fn(vmsg, g.config.user_data)
	}else{
		eprintln('gg error: $vmsg')
	}
}

//

pub fn new_context(cfg Config) &GG {
	mut g := &GG{
		width: cfg.width
		height: cfg.height
		clear_pass: gfx.create_clear_pass( f32(cfg.bg_color.r) / 255.0, f32(cfg.bg_color.g) / 255.0,
f32(cfg.bg_color.b) / 255.0, 1.0)
		scale: cfg.scale //sapp.dpi_scale()// cfg.scale
		config: cfg
	}

	//C.printf('new_context() %p\n', cfg.user_data)
	window := C.sapp_desc{
		user_data: g
		init_userdata_cb: gg_init_sokol_window
		frame_userdata_cb: gg_frame_fn
		event_userdata_cb: gg_event_fn
		fail_userdata_cb: gg_fail_fn
		cleanup_userdata_cb: gg_cleanup_fn
		window_title: cfg.window_title.str
		html5_canvas_name: cfg.window_title.str
		width: cfg.width
		height: cfg.height
		high_dpi: cfg.scale > 1
	}
	//b := sapp.high_dpi()
	//println('scale=$g.scale high_dpi=$b')
	if cfg.use_ortho {}
	else {}
	g.window = window
	return g
}

pub fn (gg &GG) run() {
	sapp.run(&gg.window)
}

pub fn (ctx &GG) draw_rect(x, y, w, h f32, c gx.Color) {
	sgl.c4b(c.r, c.g, c.b, 128)
	sgl.begin_quads()
	sgl.v2f(x * ctx.scale, y * ctx.scale)
	sgl.v2f((x + w) * ctx.scale, y * ctx.scale)
	sgl.v2f((x + w) * ctx.scale, (y + h) * ctx.scale)
	sgl.v2f(x * ctx.scale, (y + h) * ctx.scale)
	sgl.end()
}

pub fn (gg &GG) draw_empty_rect(x, y, w, h f32, c gx.Color) {
	sgl.c4b(c.r, c.g, c.b, 128)
	sgl.begin_line_strip()
	sgl.v2f(x, y)
	sgl.v2f(x + w, y)
	sgl.v2f(x + w, y + h)
	sgl.v2f(x, y + h)
	sgl.v2f(x, y)
	sgl.end()
}

pub fn create_image(file string) u32 {
	// println('gg create image "$file"')
	if !os.exists(file) {
		println('gg create image no such file "$file"')
		return u32(0)
	}
	// img := stbi.load(file)
	// img.free()
	return 0 // texture
}

pub fn create_image_from_memory(buf byteptr) u32 {
	// texture := gl.gen_texture()
	// img := stbi.load_from_memory(buf)
	// img.free()
	return 0 // texture
}

pub fn (gg &GG) begin() {
	sgl.defaults()
	sgl.matrix_mode_projection()
	sgl.ortho(0.0, f32(sapp.width()), f32(sapp.height()), 0.0, -1.0, 1.0)
}

pub fn (gg &GG) end() {
	gfx.begin_default_pass(gg.clear_pass, sapp.width(), sapp.height())
	sgl.draw()
	gfx.end_pass()
	gfx.commit()
	if gg.config.wait_events {
		//println('gg: waiting')
		wait_events()
	}
}

pub fn (ctx &GG) draw_line(x, y, x2, y2 f32, color gx.Color) {}

fn C.WaitMessage()

pub fn wait_events() {
	unsafe {
		$if macos  {
		# NSEvent *event = [NSApp nextEventMatchingMask:NSEventMaskAny
		# untilDate:[NSDate distantFuture]
		# inMode:NSDefaultRunLoopMode
		# dequeue:YES];
		# [NSApp sendEvent:event];
		}
		$if windows {
			C.WaitMessage()
		}
	}
}