// vtest build: macos && !sanitized_job?
import os
import stbi

@[direct_array_access]
fn png_has_non_black_pixels(path string) !bool {
    img := stbi.load(path)!
    defer {
        img.free()
    }
    for i in 0 .. img.width * img.height {
        unsafe {
            if img.data[i * 4] != 0 || img.data[i * 4 + 1] != 0 || img.data[i * 4 + 2] != 0 {
                return true
            }
        }
    }
    return false
}

fn test_streaming_r8_zero_buffer_stays_black_on_gl_backend() {
    vexe := @VEXE
    vroot := os.dir(vexe)
    sample_path := os.join_path(vroot, 'vlib/gg/testdata/streaming_r8_zero_buffer_issue_10989.vv')
    temp_dir := os.join_path(os.temp_dir(), 'v_gg_issue_10989_${os.getpid()}')
    os.mkdir_all(temp_dir) or { panic(err) }
    defer {
        os.rmdir_all(temp_dir) or {}
    }
    exe_path := os.join_path(temp_dir, 'issue10989_repro')
    // Force the GL backend so this exercises the packed texture upload path from issue #10989.
    compile_cmd := '${os.quoted_path(vexe)} -d gg_record -d darwin_sokol_glcore33 -o ${os.quoted_path(exe_path)} ${os.quoted_path(sample_path)}'
    compile_res := os.execute(compile_cmd)
    assert compile_res.exit_code == 0, compile_res.output
    run_cmd := 'VGG_STOP_AT_FRAME=2 VGG_SCREENSHOT_FRAMES=2 VGG_SCREENSHOT_FOLDER=${os.quoted_path(temp_dir)} ${os.quoted_path(exe_path)}'
    run_res := os.execute(run_cmd)
    if run_res.exit_code != 0 {
        if run_res.output.contains('glpixelformat') || run_res.exit_code == 134 {
            // OpenGL context creation failed (e.g. headless CI runners without GPU).
            // Skip the test rather than failing.
            eprintln('skipping: GL context creation failed on this system')
            return
        }
        assert run_res.exit_code == 0, run_res.output
    }
    screenshot_path := os.join_path(temp_dir, 'issue10989_repro_2.png')
    assert os.exists(screenshot_path)
    assert png_has_non_black_pixels(screenshot_path)! == false
}