package billing

import (
	"errors"
	"reflect"
	"testing"
)

func TestIsGrantableFeatureKey(t *testing.T) {
	grantable := []string{
		"stores.hub",
		"settings.api_keys",
		"catalog.products",
		"catalog.products.tab_error",
		"marketing.campaigns.send",
	}
	for _, key := range grantable {
		if !IsGrantableFeatureKey(key) {
			t.Errorf("expected %q to be grantable", key)
		}
	}
	notGrantable := []string{
		"shell.navigation",       // app chrome
		"capability.ai_credits",  // plan metering, not UI access
		"dashboard.overview",     // always-on landing page
		"settings.profile",       // always-on: own password / sign out
		"catalog.not_a_real_key", // unknown
		"",
	}
	for _, key := range notGrantable {
		if IsGrantableFeatureKey(key) {
			t.Errorf("expected %q to NOT be grantable", key)
		}
	}
}

func TestSanitizeMemberPermissions(t *testing.T) {
	t.Run("keeps only denials of grantable keys", func(t *testing.T) {
		got, err := SanitizeMemberPermissions(map[string]bool{
			"stores.hub":        false,
			"settings.api_keys": false,
			"catalog.products":  true, // allow is the default — never stored
		})
		if err != nil {
			t.Fatalf("unexpected error: %v", err)
		}
		want := map[string]bool{"stores.hub": false, "settings.api_keys": false}
		if !reflect.DeepEqual(got, want) {
			t.Fatalf("got %v want %v", got, want)
		}
	})

	t.Run("rejects protected keys instead of silently dropping them", func(t *testing.T) {
		if _, err := SanitizeMemberPermissions(map[string]bool{"shell.navigation": false}); !errors.Is(err, ErrFeatureNotGrantable) {
			t.Fatalf("expected ErrFeatureNotGrantable, got %v", err)
		}
		if _, err := SanitizeMemberPermissions(map[string]bool{"dashboard.overview": false}); !errors.Is(err, ErrFeatureNotGrantable) {
			t.Fatalf("expected ErrFeatureNotGrantable for always-on key, got %v", err)
		}
	})

	t.Run("rejects unknown keys", func(t *testing.T) {
		if _, err := SanitizeMemberPermissions(map[string]bool{"nope.nope": false}); !errors.Is(err, ErrFeatureNotGrantable) {
			t.Fatalf("expected ErrFeatureNotGrantable, got %v", err)
		}
		if _, err := SanitizeMemberPermissions(map[string]bool{"nope.nope": true}); !errors.Is(err, ErrUnknownFeatureKey) {
			t.Fatalf("expected ErrUnknownFeatureKey, got %v", err)
		}
	})
}

func TestMemberDeniesFeature(t *testing.T) {
	perms := map[string]bool{"stores.hub": false, "catalog.products": false}

	if !MemberDeniesFeature(perms, "stores.hub") {
		t.Error("direct denial should apply")
	}
	if !MemberDeniesFeature(perms, "catalog.products.tab_error") {
		t.Error("denying a parent must deny its descendants")
	}
	if MemberDeniesFeature(perms, "catalog.categories") {
		t.Error("sibling keys must stay allowed")
	}
	if MemberDeniesFeature(nil, "stores.hub") {
		t.Error("an empty overlay denies nothing")
	}

	// Protected keys survive even a hand-edited overlay that names them.
	hostile := map[string]bool{"shell.navigation": false, "dashboard.overview": false, "capability.ai_credits": false}
	for key := range hostile {
		if MemberDeniesFeature(hostile, key) {
			t.Errorf("%q must never be deniable", key)
		}
	}
}

func TestApplyMemberPermissions(t *testing.T) {
	features := map[string]bool{
		"stores.hub":                 true,
		"catalog.products":           true,
		"catalog.products.tab_error": true,
		"marketing.campaigns":        false, // already off by plan
		"dashboard.overview":         true,
	}
	perms := map[string]bool{"stores.hub": false, "catalog.products": false, "marketing.campaigns": false}

	got, denied := ApplyMemberPermissions(features, perms)

	for _, key := range []string{"stores.hub", "catalog.products", "catalog.products.tab_error"} {
		if got[key] {
			t.Errorf("expected %q to be denied", key)
		}
	}
	if !got["dashboard.overview"] {
		t.Error("always-on keys must survive the overlay")
	}
	// Already-off plan keys are not reported as member denials — the member did not lose them.
	want := []string{"catalog.products", "catalog.products.tab_error", "stores.hub"}
	if !reflect.DeepEqual(denied, want) {
		t.Fatalf("denied = %v, want %v", denied, want)
	}
	// The input map must not be mutated — it is shared with the company-level cache.
	if !features["stores.hub"] {
		t.Error("ApplyMemberPermissions mutated its input")
	}
}

func TestApplyMemberPermissionsIsNoopWithoutOverlay(t *testing.T) {
	features := map[string]bool{"stores.hub": true}
	got, denied := ApplyMemberPermissions(features, nil)
	if len(denied) != 0 {
		t.Fatalf("expected no denials, got %v", denied)
	}
	if !reflect.DeepEqual(got, features) {
		t.Fatalf("expected the map unchanged, got %v", got)
	}
}

func TestGrantableFeatureKeysExcludeProtectedPrefixes(t *testing.T) {
	keys := GrantableFeatureKeys()
	if len(keys) == 0 {
		t.Fatal("expected a non-empty grantable catalog")
	}
	for _, key := range keys {
		if !IsGrantableFeatureKey(key) {
			t.Errorf("GrantableFeatureKeys returned non-grantable %q", key)
		}
	}
}

func TestGrantableParent(t *testing.T) {
	if got := grantableParent("catalog.products.tab_error"); got != "catalog.products" {
		t.Errorf("got %q, want catalog.products", got)
	}
	// dashboard.overview is always-on, so its children have no grantable parent.
	if got := grantableParent("dashboard.stats"); got != "" {
		t.Errorf("got %q, want empty", got)
	}
	if got := grantableParent("stores.hub"); got != "" {
		t.Errorf("got %q, want empty", got)
	}
}

func TestDecodeMemberPermissionsIsDefensive(t *testing.T) {
	// Garbage must not brick the dashboard — it resolves to "unrestricted".
	if got, _ := decodeMemberPermissions([]byte("not json")); got != nil {
		t.Errorf("expected nil for invalid JSON, got %v", got)
	}
	if got, _ := decodeMemberPermissions([]byte(`{}`)); got != nil {
		t.Errorf("expected nil for an empty overlay, got %v", got)
	}
	// Stale / protected keys are dropped at read time too.
	got, err := decodeMemberPermissions([]byte(`{"stores.hub":false,"shell.navigation":false,"gone.key":false,"feeds.list":true}`))
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
	want := map[string]bool{"stores.hub": false}
	if !reflect.DeepEqual(got, want) {
		t.Fatalf("got %v, want %v", got, want)
	}
}