package test

import (
	"RenewCMS/internal/domain/role"
	"RenewCMS/internal/domain/user"
	"RenewCMS/internal/infrastructure/useCases"
	"errors"
	"testing"
)

func missingKeyOf(t *testing.T, err error) string {
	t.Helper()
	var missing role.MissingPermissionError
	if !errors.As(err, &missing) {
		t.Fatalf("expected a MissingPermissionError, got %v", err)
	}
	return missing.Key
}

func TestCheckPermissionUseCase(t *testing.T) {
	newCheck := func() (*useCases.CheckPermissionUseCase, *mockRoleRepo) {
		roles := newSeededMockRoleRepo()
		return useCases.NewCheckPermissionUseCase(roles), roles
	}
	owner := user.User{ID: 3, RoleID: ownerRoleID}
	admin := user.User{ID: 5, RoleID: adminRoleID}
	writer := user.User{ID: 9, RoleID: writerRoleID}

	t.Run("Require passes for held keys and refuses the others", func(t *testing.T) {
		check, _ := newCheck()
		cases := []struct {
			name    string
			account user.User
			key     string
			allowed bool
		}{
			{"owner holds an owner-only key", owner, "system.apply_updates", true},
			{"admin lacks an owner-only key", admin, "system.apply_updates", false},
			{"admin holds users.invite", admin, "users.invite", true},
			{"writer lacks users.invite", writer, "users.invite", false},
			{"writer holds schema.view", writer, "schema.view", true},
			{"writer holds a scoped key at own", writer, "activity.view", true},
			{"an unknown key is refused", owner, "no.such_key", false},
		}
		for _, c := range cases {
			t.Run(c.name, func(t *testing.T) {
				_, err := check.Require(c.account, c.key)
				if c.allowed && err != nil {
					t.Fatalf("expected pass, got %v", err)
				}
				if !c.allowed {
					if !errors.Is(err, role.ErrMissingPermission) || missingKeyOf(t, err) != c.key {
						t.Fatalf("expected missing permission for %s, got %v", c.key, err)
					}
				}
			})
		}
	})

	t.Run("RequireAll refuses a scoped key held only at own", func(t *testing.T) {
		check, _ := newCheck()
		if _, err := check.RequireAll(writer, "activity.view"); !errors.Is(err, role.ErrMissingPermission) {
			t.Fatalf("expected refusal, got %v", err)
		}
		if _, err := check.RequireAll(admin, "activity.view"); err != nil {
			t.Fatalf("expected admin to pass, got %v", err)
		}
	})

	t.Run("Require returns the resolved grants", func(t *testing.T) {
		check, _ := newCheck()
		grants, err := check.Require(writer, "authors.view")
		if err != nil {
			t.Fatal(err)
		}
		if grants.ScopeFor("authors.edit", "") != role.ScopeOwn || grants.ScopeFor("users.view", "") != role.ScopeNone {
			t.Errorf("unexpected grants %v", grants)
		}
	})

	t.Run("A custom role is judged by its grants only, owner-only keys excluded", func(t *testing.T) {
		check, roles := newCheck()
		custom, _ := roles.Create(role.Role{Name: "Hand made", Version: 1, Grants: []role.Grant{{Key: "system.apply_updates", Scope: role.ScopeAll}}})
		account := user.User{ID: 20, RoleID: custom.ID}
		if _, err := check.Require(account, "system.apply_updates"); !errors.Is(err, role.ErrMissingPermission) {
			t.Errorf("expected the hand-placed owner-only key to be ignored on an unlocked role, got %v", err)
		}
		if _, err := check.Require(account, "schema.view"); !errors.Is(err, role.ErrMissingPermission) {
			t.Errorf("expected no implied keys, got %v", err)
		}
	})

	t.Run("An unresolvable role is refused as a missing permission", func(t *testing.T) {
		check, _ := newCheck()
		for name, account := range map[string]user.User{
			"unknown role_id":         {ID: 13, RoleID: 99},
			"empty legacy and no id":  {ID: 14, Role: ""},
			"editor legacy and no id": {ID: 15, Role: "editor"},
			"legacy owner string ignored when role_id names Writer": {ID: 16, Role: user.RoleOwner, RoleID: writerRoleID},
		} {
			_, err := check.Require(account, "users.invite")
			if !errors.Is(err, role.ErrMissingPermission) || missingKeyOf(t, err) != "users.invite" {
				t.Errorf("%s: got %v", name, err)
			}
		}
	})

	t.Run("The legacy string resolves only owner and admin when there is no role_id", func(t *testing.T) {
		check, _ := newCheck()
		if _, err := check.Require(user.User{ID: 17, Role: user.RoleOwner}, "system.apply_updates"); err != nil {
			t.Errorf("legacy owner: %v", err)
		}
		if _, err := check.Require(user.User{ID: 18, Role: user.RoleAdmin}, "system.apply_updates"); !errors.Is(err, role.ErrMissingPermission) {
			t.Errorf("legacy admin should lack owner-only keys, got %v", err)
		}
	})

	t.Run("A repository failure is not a missing permission", func(t *testing.T) {
		check, roles := newCheck()
		roles.fail.failNext("Get")
		_, err := check.Require(owner, "users.view")
		if err == nil || errors.Is(err, role.ErrMissingPermission) {
			t.Fatalf("expected a plain failure, got %v", err)
		}
	})

	t.Run("Grant changes apply to the next call with no cache", func(t *testing.T) {
		check, roles := newCheck()
		if _, err := check.Require(writer, "settings.view"); !errors.Is(err, role.ErrMissingPermission) {
			t.Fatalf("expected refusal first, got %v", err)
		}
		stored := roles.roles[writerRoleID]
		stored.Grants = append(stored.Grants, role.Grant{Key: "settings.view", Scope: role.ScopeAll})
		roles.roles[writerRoleID] = stored
		if _, err := check.Require(writer, "settings.view"); err != nil {
			t.Fatalf("expected pass after the edit, got %v", err)
		}
	})
}

func TestGrantSet(t *testing.T) {
	t.Run("an absent key is none and a nil set holds nothing", func(t *testing.T) {
		var empty role.GrantSet
		if empty.ScopeFor("users.view", "") != role.ScopeNone || empty.Holds("users.view") || empty.HoldsAll("users.view") {
			t.Error("a nil set must hold nothing")
		}
	})
	t.Run("Holds is true for own and all, HoldsAll only for all", func(t *testing.T) {
		set := unlockedGrantSet("content.update=own", "content.delete=all", "content.read=none")
		if !set.Holds("content.update") || set.HoldsAll("content.update") || !set.Holds("content.delete") || !set.HoldsAll("content.delete") || set.Holds("content.read") {
			t.Errorf("unexpected %v", set)
		}
	})
	t.Run("MissingPermissionError matches the sentinel and carries the key", func(t *testing.T) {
		err := error(role.MissingPermissionError{Key: "users.invite"})
		if !errors.Is(err, role.ErrMissingPermission) || missingKeyOf(t, err) != "users.invite" {
			t.Errorf("unexpected %v", err)
		}
	})
}

var (
	activityViewAllGrants = unlockedGrantSet(role.KeyActivityView + "=all")
	activityViewOwnGrants = unlockedGrantSet(role.KeyActivityView + "=own")
	authorsEditOwnGrants  = unlockedGrantSet(role.KeyAuthorsEdit + "=own")
	authorsEditAllGrants  = unlockedGrantSet(role.KeyAuthorsEdit + "=all")
)