package main

import (
	"os"
	"path/filepath"
	"testing"
	"time"
)

// postgres's own part of the moved path (issue 849): the shared driving of it is proven in the SDK's harness package.

// Where the file is not there, postgres takes the grant directory, as before; where it is, the helper.
func TestTheGrantPathIsTakenWhereTheConsumersFileIsAbsent(t *testing.T) {
	dir := t.TempDir()
	at := filepath.Join(dir, "consumers.json")
	env := func(k string) string {
		if k == "MESH_CONSUMERS_FILE" {
			return at
		}
		return ""
	}
	if got := handedConsumersFile(env, os.Stat); got != "" {
		t.Fatalf("took %q for a file that is not there", got)
	}
	if got := handedConsumersFile(func(string) string { return "" }, os.Stat); got != "" {
		t.Fatalf("took %q with no environment", got)
	}
	if err := os.WriteFile(at, []byte("[]"), 0o600); err != nil {
		t.Fatal(err)
	}
	if got := handedConsumersFile(env, os.Stat); got != at {
		t.Fatalf("took %q, want %q", got, at)
	}
}

// The grant path restarts itself when the consumers file is first filled.
func TestTheGrantPathLeavesWhenTheConsumersFileIsFilled(t *testing.T) {
	at := filepath.Join(t.TempDir(), "consumers.json")
	done := make(chan struct{})
	go exitWhenFilled(at, os.Stat, time.Millisecond, func() { close(done) })
	select {
	case <-done:
		t.Fatal("left before the file was there")
	case <-time.After(20 * time.Millisecond):
	}
	if err := os.WriteFile(at, []byte("[]"), 0o600); err != nil {
		t.Fatal(err)
	}
	select {
	case <-done:
	case <-time.After(2 * time.Second):
		t.Fatal("did not leave when the file was filled")
	}
}