@[has_globals]
module main

import time
import v.debug

__global counter = HookCounter{}

struct HookCounter {
pub mut:
    after  int
    before int
}

@[heap]
struct Profiler {
mut:
    fn_map map[string]time.StopWatch
}

fn (mut p Profiler) trace_after(fn_name string) {
    counter.after++
    println('>>> called after ${fn_name} - ${p.fn_map[fn_name].elapsed()}')
}

fn (mut p Profiler) trace_before(fn_name string) {
    p.fn_map[fn_name] = time.new_stopwatch()
    println('>>> called before ${fn_name}')
    counter.before++
}

fn test_call() {
    println('${@FN} got called')
    time.sleep(100)
}

fn hook_before(fn_name string) {
    counter.before++
}

fn hook_after(fn_name string) {
    counter.after++
}

fn test_main() {
    counter = HookCounter{}
    mut myprofiler := Profiler{}
    hook1 := debug.add_after_call(myprofiler.trace_after)
    hook2 := debug.add_before_call(myprofiler.trace_before)
    hook3 := debug.add_before_call(hook_before)
    hook4 := debug.add_after_call(hook_after)
    test_call()
    debug.remove_after_call(hook1)
    debug.remove_before_call(hook2)
    debug.remove_before_call(hook3)
    debug.remove_after_call(hook4)
    test_call()
    $if trace ? {
        assert counter.before == 4
        assert counter.after == 4
    } $else {
        assert counter.before == 0
        assert counter.after == 0
    }
}