package outpost

import (
	"strings"
	"testing"
	"time"
)

func TestNewID(t *testing.T) {
	const n = 1000

	ids := make([]string, n)
	for i := range ids {
		id, err := newID()
		if err != nil {
			t.Fatalf("newID: %v", err)
		}
		ids[i] = id
	}

	t.Run("unique", func(t *testing.T) {
		seen := make(map[string]bool, len(ids))
		for _, id := range ids {
			if seen[id] {
				t.Fatalf("duplicate id %q", id)
			}
			seen[id] = true
		}
	})

	t.Run("26 Crockford characters", func(t *testing.T) {
		for _, id := range ids {
			if len(id) != 26 {
				t.Fatalf("len(%q) = %d, want 26", id, len(id))
			}
			for _, r := range id {
				if !strings.ContainsRune(crockford, r) {
					t.Fatalf("id %q contains %q, which is not Crockford", id, r)
				}
			}
		}
	})

	t.Run("timestamp decodes to now", func(t *testing.T) {
		for _, id := range ids {
			raw, err := idEncoding.DecodeString(id)
			if err != nil {
				t.Fatalf("decode %q: %v", id, err)
			}
			var ms int64
			for j := 0; j < 6; j++ {
				ms = ms<<8 | int64(raw[j])
			}
			if d := time.Since(time.UnixMilli(ms)); d < -time.Second || d > time.Minute {
				t.Fatalf("timestamp of %q is %s from now", id, d)
			}
		}
	})
}