package api

import "testing"

// What a car's page shows — which tabs, which rows of the Information tab, and
// the order those rows are laid out in — is stored on the car as key lists, so
// the validation has to keep them to keys the page actually renders.
// Information itself stays out of the hideable tabs: a car with no tabs left
// would be a dead end.

func TestNormalizeHiddenTabs(t *testing.T) {
	got, err := normalizeKeys([]string{" fuel ", "parts", "fuel", ""}, hideableCarTabs, "tab")
	if err != nil {
		t.Fatalf("normalizeKeys: %v", err)
	}
	want := []string{"fuel", "parts"} // trimmed, blanks dropped, deduped
	assertKeys(t, got, want)

	// Clearing the list is how a car goes back to showing everything.
	if empty, err := normalizeKeys(nil, hideableCarTabs, "tab"); err != nil || len(empty) != 0 {
		t.Errorf("normalizeKeys(nil) = %v, %v; want empty and no error", empty, err)
	}

	// Information is the car itself; hiding it would leave a page with no tabs.
	if _, err := normalizeKeys([]string{"info"}, hideableCarTabs, "tab"); err == nil {
		t.Error("normalizeKeys allowed hiding the info tab, want an error")
	}
	// A key from a stale or wrong client is an error, not something to drop
	// quietly while the tab stays visible.
	if _, err := normalizeKeys([]string{"fuel", "nonsense"}, hideableCarTabs, "tab"); err == nil {
		t.Error("normalizeKeys accepted an unknown tab, want an error")
	}

	// The hideable set is the contract the web app's HIDEABLE_TABS mirrors:
	// every tab the car page renders beside Information.
	for _, key := range []string{"provider", "services", "technical", "maintenance", "fuel", "documents", "parts", "reminders"} {
		if !hideableCarTabs[key] {
			t.Errorf("tab %q should be hideable", key)
		}
	}
	if len(hideableCarTabs) != 8 {
		t.Errorf("hideableCarTabs has %d entries, want the 8 tabs beside Information", len(hideableCarTabs))
	}
}

func TestNormalizeHiddenFields(t *testing.T) {
	got, err := normalizeKeys([]string{"vin", " differentialOil ", "vin"}, hideableCarFields, "field")
	if err != nil {
		t.Fatalf("normalizeKeys: %v", err)
	}
	assertKeys(t, got, []string{"vin", "differentialOil"})

	if _, err := normalizeKeys([]string{"oilSpec", "nonsense"}, hideableCarFields, "field"); err == nil {
		t.Error("normalizeKeys accepted an unknown field, want an error")
	}
	// A tab key is not a field key — the two sets are validated separately.
	if _, err := normalizeKeys([]string{"fuel"}, hideableCarFields, "field"); err == nil {
		t.Error("normalizeKeys accepted a tab key as a field, want an error")
	}

	// Every Information row the web app renders must be hideable; unlike the
	// tabs there is no row the page has to keep.
	for _, key := range []string{
		"oilSpec", "transmissionOil", "differentialOil", "brakeFluid", "coolant",
		"odometer", "serviceInterval", "nextDue", "registrationPlate",
		"registrationCountry", "vin", "fuelType", "buildDate", "firstRegistration",
	} {
		if !hideableCarFields[key] {
			t.Errorf("field %q should be hideable", key)
		}
	}
	if len(hideableCarFields) != 14 {
		t.Errorf("hideableCarFields has %d entries, want the 14 Information rows", len(hideableCarFields))
	}
}

// The arrangement of the Information rows shares the field key set — every row
// can be moved — but not the meaning: here the order of the list is the point,
// so it has to survive validation exactly as it was sent.
func TestNormalizeFieldOrder(t *testing.T) {
	got, err := normalizeKeys([]string{"vin", "odometer", "oilSpec"}, hideableCarFields, "field")
	if err != nil {
		t.Fatalf("normalizeKeys: %v", err)
	}
	assertKeys(t, got, []string{"vin", "odometer", "oilSpec"})

	// A key repeated by a client that lost track keeps its first position; a
	// second entry for the same row would put it in two places at once.
	got, err = normalizeKeys([]string{"vin", "odometer", "vin"}, hideableCarFields, "field")
	if err != nil {
		t.Fatalf("normalizeKeys: %v", err)
	}
	assertKeys(t, got, []string{"vin", "odometer"})

	// A partial arrangement is fine — the rows it leaves out follow the arranged
	// ones — but an invented row is still an error.
	if _, err := normalizeKeys([]string{"vin", "nonsense"}, hideableCarFields, "field"); err == nil {
		t.Error("normalizeKeys accepted an unknown field in an arrangement, want an error")
	}
}

func assertKeys(t *testing.T, got, want []string) {
	t.Helper()
	if len(got) != len(want) {
		t.Fatalf("keys = %v, want %v", got, want)
	}
	for i := range got {
		if got[i] != want[i] {
			t.Fatalf("keys = %v, want %v", got, want)
		}
	}
}