package proxmox

import (
	"errors"
	"testing"

	"gitea.home.hrajfrisbee.cz/kacerr/egress-proxies-operator/internal/provider"
)

func TestFormatProviderID_roundTrip(t *testing.T) {
	t.Parallel()
	for _, vmid := range []int{100, 150042, 999999999} {
		id := formatProviderID(vmid, "proxy-abcdefghijklmnop")
		gotVMID, gotName, err := parseProviderID(id)
		if err != nil || gotVMID != vmid || gotName != "proxy-abcdefghijklmnop" {
			t.Errorf("parseProviderID(%q) = %d, %q, %v; want %d, proxy-abcdefghijklmnop, nil", id, gotVMID, gotName, err, vmid)
		}
	}
	if got := formatProviderID(150042, "proxy-x"); got != "vms/150042/proxy-x" {
		t.Errorf("formatProviderID() = %q, want vms/150042/proxy-x", got)
	}
}

func TestParseProviderID_malformed(t *testing.T) {
	t.Parallel()
	for _, id := range []string{
		"",
		"vms",
		"vms/150042",
		"vms/150042/",
		"vms//proxy-x",
		"vm/150042/proxy-x",
		"hosts/beelink/domains/proxy-x",
		"vms/150042/proxy-x/extra",
		"vms/abc/proxy-x",
		"vms/0150042/proxy-x",
		"vms/+150042/proxy-x",
		"vms/-5/proxy-x",
		"vms/99/proxy-x",
		"vms/1000000000/proxy-x",
	} {
		t.Run(id, func(t *testing.T) {
			t.Parallel()
			_, _, err := parseProviderID(id)
			if !errors.Is(err, provider.ErrPermanent) {
				t.Errorf("parseProviderID(%q) error = %v, want ErrPermanent", id, err)
			}
		})
	}
}

func TestVMIDFor_deterministicAndInRange(t *testing.T) {
	t.Parallel()
	uids := []string{"3f1c2d7e-8a44-4f1b-9a6c-1d2e3f4a5b6c", "00000000-0000-0000-0000-000000000000", "x"}
	for _, uid := range uids {
		first := vmidFor(uid, 100000, 199999, 0)
		if first < 100000 || first > 199999 {
			t.Errorf("vmidFor(%q) = %d, want within 100000..199999", uid, first)
		}
		if again := vmidFor(uid, 100000, 199999, 0); again != first {
			t.Errorf("vmidFor(%q) = %d then %d, want the same VMID every time", uid, first, again)
		}
	}
	if vmidFor(uids[0], 100000, 199999, 0) == vmidFor(uids[1], 100000, 199999, 0) {
		t.Error("two different UIDs got the same first VMID; the hash does not spread")
	}
}

func TestVMIDFor_probesForwardAndWraps(t *testing.T) {
	t.Parallel()
	const min, max = 500, 509
	uid := "3f1c2d7e-8a44-4f1b-9a6c-1d2e3f4a5b6c"
	start := vmidFor(uid, min, max, 0)
	seen := map[int]bool{}
	for attempt := range 10 {
		got := vmidFor(uid, min, max, attempt)
		want := min + (start-min+attempt)%10
		if got != want {
			t.Errorf("attempt %d: vmidFor = %d, want %d (one step forward, wrapping at max)", attempt, got, want)
		}
		seen[got] = true
	}
	if len(seen) != 10 {
		t.Errorf("10 attempts over a range of 10 visited %d VMIDs, want all 10", len(seen))
	}
	if got := vmidFor(uid, min, max, 10); got != start {
		t.Errorf("attempt 10 = %d, want to wrap back to %d", got, start)
	}
}