module main

import gg
import gx
import os


struct App {
mut:
    ctx    &gg.Context = unsafe { nil }
    img  gg.Image
    file_name string
}

const (
    win_width = 800
    win_height = 600
)

fn main() {
    println(os.args.len)

    if os.args.len < 1  {
        println("Usage: imgview <filename>.png/.jpg/.jpeg")
        return
    }
    else {
        mut file_name := os.args[1]

        mut app := &App{
            ctx: 0,
            file_name: file_name
        }

        app.ctx = gg.new_context(
            bg_color: gx.white
            width: win_width
            height: win_height
            create_window: true
            window_title: "imgview - ${file_name}"
            frame_fn: frame
            user_data: app
            init_fn: init
        )

        app.ctx.run()

    }
}

fn init(mut app &App) {

    app.img = app.ctx.create_image(os.resource_abs_path(app.file_name))

}

fn (app &App) draw() {

    app.ctx.draw_image(0, 0, app.img.width, app.img.height, app.img)

}

fn frame(app &App) {
    app.ctx.begin()
    app.draw()
    app.ctx.end()
}