package test

import (
	"RenewCMS/internal/domain/role"
	"errors"
	"go/ast"
	"go/parser"
	"go/token"
	"path/filepath"
	"reflect"
	"slices"
	"strconv"
	"strings"
	"testing"
)

func TestGrantSetScopeFor(t *testing.T) {
	longKey := strings.Repeat("a", 101)
	cases := []struct {
		grants  []string
		key     string
		typeKey string
		want    role.Scope
	}{
		{[]string{"content.update=all"}, "content.update", "", role.ScopeAll},
		{[]string{"content.update=all"}, "content.update", "blog", role.ScopeAll},
		{[]string{"content.update=all", "content.update:blog=own"}, "content.update", "blog", role.ScopeOwn},
		{[]string{"content.update=all", "content.update:blog=own"}, "content.update", "news", role.ScopeAll},
		{[]string{"content.update=all", "content.update:blog=none"}, "content.update", "blog", role.ScopeNone},
		{[]string{"content.update=own", "content.update:blog=all"}, "content.update", "blog", role.ScopeAll},
		{[]string{"content.update:blog=all"}, "content.update", "blog", role.ScopeAll},
		{[]string{"content.update:blog=all"}, "content.update", "news", role.ScopeNone},
		{[]string{"content.update:blog=all"}, "content.update", "", role.ScopeNone},
		{[]string{"content.create=all", "content.create:blog=none"}, "content.create", "blog", role.ScopeNone},
		{[]string{"content.create=all", "content.create:blog=all"}, "content.create", "blog", role.ScopeAll},
		{[]string{"content.read=all"}, "content.read", "Bad Key", role.ScopeNone},
		{[]string{"content.read=all"}, "content.read", longKey, role.ScopeNone},
		{[]string{"schema.view=all"}, "schema.view", "blog", role.ScopeNone},
		{[]string{"schema.view=all"}, "schema.view", "", role.ScopeAll},
		{[]string{"content.explode=all"}, "content.explode", "", role.ScopeNone},
		{nil, "content.read", "", role.ScopeNone},
	}
	for _, c := range cases {
		name := strings.Join(c.grants, ", ") + " | " + c.key + " | " + c.typeKey
		if len(name) > 90 {
			name = name[:90]
		}
		t.Run(name, func(t *testing.T) {
			if got := unlockedGrantSet(c.grants...).ScopeFor(c.key, c.typeKey); got != c.want {
				t.Errorf("expected %s, got %s", c.want, got)
			}
		})
	}

	t.Run("a zero GrantSet resolves everything to none", func(t *testing.T) {
		var empty role.GrantSet
		if empty.ScopeFor("content.read", "") != role.ScopeNone || empty.ScopeFor("content.read", "blog") != role.ScopeNone || empty.Holds("content.read") || empty.HoldsAll("content.read") || empty.HoldsFor("content.read", "blog") {
			t.Error("a zero set must hold nothing")
		}
	})

	t.Run("HoldsFor is true for own and all of the typed scope only", func(t *testing.T) {
		set := unlockedGrantSet("content.update=all", "content.update:blog=own", "content.update:news=none")
		if !set.HoldsFor("content.update", "blog") || !set.HoldsFor("content.update", "other") || set.HoldsFor("content.update", "news") {
			t.Errorf("unexpected HoldsFor results")
		}
	})
}

func TestGrantSetPermits(t *testing.T) {
	cases := []struct {
		scope     role.Scope
		caller    uint32
		createdBy uint32
		want      bool
	}{
		{role.ScopeAll, 9, 21, true},
		{role.ScopeAll, 9, 0, true},
		{role.ScopeOwn, 21, 21, true},
		{role.ScopeOwn, 9, 21, false},
		{role.ScopeOwn, 21, 0, false},
		{role.ScopeOwn, 0, 0, false},
		{role.ScopeNone, 21, 21, false},
	}
	for _, c := range cases {
		name := string(c.scope) + " caller " + strconv.Itoa(int(c.caller)) + " created_by " + strconv.Itoa(int(c.createdBy))
		t.Run(name, func(t *testing.T) {
			set := unlockedGrantSet("content.update:blog=" + string(c.scope))
			if got := set.Permits("content.update", "blog", c.caller, c.createdBy); got != c.want {
				t.Errorf("expected %v, got %v", c.want, got)
			}
		})
	}

	t.Run("a typed scope replaces the wildcard for Permits", func(t *testing.T) {
		set := unlockedGrantSet("content.update=all", "content.update:blog=own")
		if set.Permits("content.update", "blog", 9, 21) || !set.Permits("content.update", "news", 9, 21) {
			t.Errorf("unexpected Permits results")
		}
	})
}

func TestRoleGrantSetNormalisation(t *testing.T) {
	duplicates := []struct {
		rows    []string
		key     string
		typeKey string
		want    role.Scope
	}{
		{[]string{"content.update=own", "content.update=all"}, "content.update", "", role.ScopeOwn},
		{[]string{"content.update=all", "content.update=own"}, "content.update", "", role.ScopeOwn},
		{[]string{"content.update:blog=all", "content.update:blog=own"}, "content.update", "blog", role.ScopeOwn},
		{[]string{"content.update=all", "content.update:blog=own"}, "content.update", "blog", role.ScopeOwn},
		{[]string{"content.read=all", "content.read=none"}, "content.read", "", role.ScopeNone},
	}
	for _, c := range duplicates {
		t.Run("duplicates resolve to the most restrictive: "+strings.Join(c.rows, ", "), func(t *testing.T) {
			forward := unlockedGrantSet(c.rows...)
			reversed := slices.Clone(c.rows)
			slices.Reverse(reversed)
			backward := unlockedGrantSet(reversed...)
			if forward.ScopeFor(c.key, c.typeKey) != c.want || backward.ScopeFor(c.key, c.typeKey) != c.want {
				t.Errorf("expected %s both ways, got %s and %s", c.want, forward.ScopeFor(c.key, c.typeKey), backward.ScopeFor(c.key, c.typeKey))
			}
		})
	}

	t.Run("a toggle key stored at own is none", func(t *testing.T) {
		if got := unlockedGrantSet("schema.view=own").ScopeFor("schema.view", ""); got != role.ScopeNone {
			t.Errorf("expected none, got %s", got)
		}
	})
	t.Run("an unknown scope string is none", func(t *testing.T) {
		if got := unlockedGrantSet("content.read=everything").ScopeFor("content.read", ""); got != role.ScopeNone {
			t.Errorf("expected none, got %s", got)
		}
	})
	t.Run("a typed key on a non-content key or with an invalid type key is dropped", func(t *testing.T) {
		set := unlockedGrantSet("schema.view:blog=all", "content.read:Bad Key=all", "content.read=all")
		if set.ScopeFor("schema.view", "blog") != role.ScopeNone || set.ScopeFor("content.read", "Bad Key") != role.ScopeNone || set.ScopeFor("content.read", "x") != role.ScopeAll {
			t.Errorf("unexpected scopes")
		}
	})
}

func TestRoleGrantSetOwnerOnlyKeys(t *testing.T) {
	ownerOnly := []string{"settings.delete_site", "roles.edit_owner_only", "system.apply_updates", "system.edit_retention", "system.transfer_ownership"}

	t.Run("owner-only keys are dropped on a role that is not locked", func(t *testing.T) {
		for _, key := range ownerOnly {
			set := role.Role{Locked: false, Grants: grantRows(key + "=all")}.GrantSet()
			if set.ScopeFor(key, "") != role.ScopeNone || set.Holds(key) || set.HoldsAll(key) {
				t.Errorf("%s must not be effective on an unlocked role", key)
			}
		}
	})
	t.Run("owner-only keys are kept on a locked role", func(t *testing.T) {
		for _, key := range ownerOnly {
			set := role.Role{Locked: true, Grants: grantRows(key + "=all")}.GrantSet()
			if set.ScopeFor(key, "") != role.ScopeAll {
				t.Errorf("%s must be effective on a locked role", key)
			}
		}
	})
	t.Run("the built-in roles keep their catalogue", func(t *testing.T) {
		builtIns := role.BuiltInRoles()
		owner, admin := builtIns[0].GrantSet(), builtIns[1].GrantSet()
		for _, permission := range role.Catalogue() {
			if owner.ScopeFor(permission.Key, "") != role.ScopeAll {
				t.Errorf("Owner lacks %s", permission.Key)
			}
			if permission.OwnerOnly && admin.ScopeFor(permission.Key, "") != role.ScopeNone {
				t.Errorf("Admin holds %s", permission.Key)
			}
		}
	})
}

func TestValidateGrantsRows(t *testing.T) {
	cases := []struct {
		rows []string
		want error
	}{
		{[]string{"content.update=all", "content.update=own"}, role.ErrDuplicateGrant},
		{[]string{"content.update:blog=all", "content.update:blog=own"}, role.ErrDuplicateGrant},
		{[]string{"content.update=all", "content.update:blog=own"}, nil},
		{[]string{"content.update:blog=none"}, nil},
		{[]string{"content.update=none"}, role.ErrInvalidScope},
		{[]string{"content.create:blog=none"}, nil},
		{[]string{"content.create:blog=own"}, role.ErrInvalidScope},
		{[]string{"content.update:Bad Key=all"}, role.ErrUnknownPermission},
		{[]string{"schema.view:blog=all"}, role.ErrUnknownPermission},
		{[]string{"settings.delete_site=all"}, role.ErrOwnerOnlyGrant},
	}
	for _, c := range cases {
		t.Run(strings.Join(c.rows, ", "), func(t *testing.T) {
			err := role.ValidateGrants(false, grantRows(c.rows...))
			if c.want == nil && err != nil || c.want != nil && !errors.Is(err, c.want) {
				t.Errorf("expected %v, got %v", c.want, err)
			}
		})
	}
}

func TestRoleHasNoParallelDecisionHelpers(t *testing.T) {
	roleType := reflect.TypeOf(role.Role{})
	for _, name := range []string{"Allows", "AllowsFor", "scopeOf"} {
		if _, present := roleType.MethodByName(name); present {
			t.Errorf("Role must not have %s", name)
		}
	}
	for _, source := range roleDomainSources(t) {
		if strings.Contains(source.text, "func NewGrantSet") || strings.Contains(source.text, "scopeOf(") {
			t.Errorf("%s still holds a parallel implementation", source.path)
		}
	}
}

type goSource struct {
	path string
	text string
}

func roleDomainSources(t *testing.T) []goSource {
	t.Helper()
	files, err := filepath.Glob("../internal/domain/role/*.go")
	if err != nil || len(files) == 0 {
		t.Fatalf("no role domain files: %v", err)
	}
	sources := []goSource{}
	for _, file := range files {
		sources = append(sources, goSource{path: file, text: readTestFile(t, file)})
	}
	return sources
}

func TestRoleKeyConstantsMatchTheCatalogue(t *testing.T) {
	file, err := parser.ParseFile(token.NewFileSet(), "../internal/domain/role/roleKeys.go", nil, 0)
	if err != nil {
		t.Fatal(err)
	}
	constants := map[string]string{}
	ast.Inspect(file, func(node ast.Node) bool {
		spec, ok := node.(*ast.ValueSpec)
		if !ok {
			return true
		}
		for index, name := range spec.Names {
			literal, isLiteral := spec.Values[index].(*ast.BasicLit)
			if !isLiteral || !name.IsExported() {
				continue
			}
			value, _ := strconv.Unquote(literal.Value)
			constants[name.Name] = value
		}
		return true
	})

	catalogueKeys := map[string]bool{}
	for _, permission := range role.Catalogue() {
		catalogueKeys[permission.Key] = true
	}
	constantValues := map[string]bool{}
	for name, value := range constants {
		constantValues[value] = true
		if !catalogueKeys[value] {
			t.Errorf("constant %s = %q is not a catalogue key", name, value)
		}
		if want := constantNameOf(value); name != want {
			t.Errorf("constant for %q is named %s, want %s", value, name, want)
		}
	}
	for key := range catalogueKeys {
		if !constantValues[key] {
			t.Errorf("catalogue key %q has no constant", key)
		}
	}
	if len(constants) != len(catalogueKeys) {
		t.Errorf("expected %d constants, got %d", len(catalogueKeys), len(constants))
	}
}

func constantNameOf(key string) string {
	group, action, _ := strings.Cut(key, ".")
	words := append([]string{group}, strings.Split(action, "_")...)
	name := "Key"
	for _, word := range words {
		if word == "apikeys" {
			name += "APIKeys"
			continue
		}
		name += strings.ToUpper(word[:1]) + word[1:]
	}
	return name
}