feat: add library access methods to User model

Signed-off-by: Deluan <deluan@navidrome.org>

model/user.go

@@ -1,6 +1,8 @@
 package model
 
-import "time"
+import (
+	"time"
+)
 
 type User struct {
 	ID           string     `structs:"id" json:"id"`
@@ -25,6 +27,45 @@ type User struct {
 	CurrentPassword string `structs:"current_password,omitempty" json:"currentPassword,omitempty"`
 }
 
+func (u User) HasLibraryAccess(libraryID int) bool {
+	if u.IsAdmin {
+		return true // Admin users have access to all libraries
+	}
+	for _, lib := range u.Libraries {
+		if lib.ID == libraryID {
+			return true
+		}
+	}
+	return false
+}
+
+// AccessibleLibraryIDs returns a slice of library IDs that the user has access to
+func (u User) AccessibleLibraryIDs() []int {
+	if len(u.Libraries) == 0 {
+		return nil
+	}
+
+	ids := make([]int, len(u.Libraries))
+	for i, lib := range u.Libraries {
+		ids[i] = lib.ID
+	}
+	return ids
+}
+
+func (u User) FilteredLibraries(libraryIds []int) Libraries {
+	libMap := make(map[int]Library, len(u.Libraries))
+	for _, lib := range u.Libraries {
+		libMap[lib.ID] = lib
+	}
+	var filtered Libraries
+	for _, id := range libraryIds {
+		if lib, ok := libMap[id]; ok {
+			filtered = append(filtered, lib)
+		}
+	}
+	return filtered
+}
+
 type Users []User
 
 type UserRepository interface {

model/user_test.go

@@ -0,0 +1,152 @@
+package model_test
+
+import (
+	"github.com/navidrome/navidrome/model"
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+)
+
+var _ = Describe("User", func() {
+	var user model.User
+	var libraries model.Libraries
+
+	BeforeEach(func() {
+		libraries = model.Libraries{
+			{ID: 1, Name: "Rock Library", Path: "/music/rock"},
+			{ID: 2, Name: "Jazz Library", Path: "/music/jazz"},
+			{ID: 3, Name: "Classical Library", Path: "/music/classical"},
+		}
+
+		user = model.User{
+			ID:        "user1",
+			UserName:  "testuser",
+			Name:      "Test User",
+			Email:     "test@example.com",
+			IsAdmin:   false,
+			Libraries: libraries,
+		}
+	})
+
+	Describe("HasLibraryAccess", func() {
+		Context("when user is admin", func() {
+			BeforeEach(func() {
+				user.IsAdmin = true
+			})
+
+			It("returns true for any library ID", func() {
+				Expect(user.HasLibraryAccess(1)).To(BeTrue())
+				Expect(user.HasLibraryAccess(99)).To(BeTrue())
+				Expect(user.HasLibraryAccess(-1)).To(BeTrue())
+			})
+
+			It("returns true even when user has no libraries assigned", func() {
+				user.Libraries = nil
+				Expect(user.HasLibraryAccess(1)).To(BeTrue())
+			})
+		})
+
+		Context("when user is not admin", func() {
+			BeforeEach(func() {
+				user.IsAdmin = false
+			})
+
+			It("returns true for libraries the user has access to", func() {
+				Expect(user.HasLibraryAccess(1)).To(BeTrue())
+				Expect(user.HasLibraryAccess(2)).To(BeTrue())
+				Expect(user.HasLibraryAccess(3)).To(BeTrue())
+			})
+
+			It("returns false for libraries the user does not have access to", func() {
+				Expect(user.HasLibraryAccess(4)).To(BeFalse())
+				Expect(user.HasLibraryAccess(99)).To(BeFalse())
+				Expect(user.HasLibraryAccess(-1)).To(BeFalse())
+				Expect(user.HasLibraryAccess(0)).To(BeFalse())
+			})
+
+			It("returns false when user has no libraries assigned", func() {
+				user.Libraries = nil
+				Expect(user.HasLibraryAccess(1)).To(BeFalse())
+			})
+
+			It("handles duplicate library IDs correctly", func() {
+				user.Libraries = model.Libraries{
+					{ID: 1, Name: "Library 1", Path: "/music1"},
+					{ID: 1, Name: "Library 1 Duplicate", Path: "/music1-dup"},
+					{ID: 2, Name: "Library 2", Path: "/music2"},
+				}
+				Expect(user.HasLibraryAccess(1)).To(BeTrue())
+				Expect(user.HasLibraryAccess(2)).To(BeTrue())
+				Expect(user.HasLibraryAccess(3)).To(BeFalse())
+			})
+		})
+	})
+
+	Describe("FilteredLibraries", func() {
+		It("returns only libraries that match the filter", func() {
+			filtered := user.FilteredLibraries([]int{1, 3})
+			expected := model.Libraries{
+				{ID: 1, Name: "Rock Library", Path: "/music/rock"},
+				{ID: 3, Name: "Classical Library", Path: "/music/classical"},
+			}
+			Expect(filtered).To(Equal(expected))
+		})
+
+		It("returns single library when filter contains one matching ID", func() {
+			filtered := user.FilteredLibraries([]int{2})
+			expected := model.Libraries{
+				{ID: 2, Name: "Jazz Library", Path: "/music/jazz"},
+			}
+			Expect(filtered).To(Equal(expected))
+		})
+
+		It("returns nil slice when filter has no matching IDs", func() {
+			filtered := user.FilteredLibraries([]int{99, 100})
+			Expect(filtered).To(BeNil())
+		})
+
+		It("returns nil slice when filter is empty", func() {
+			filtered := user.FilteredLibraries([]int{})
+			Expect(filtered).To(BeNil())
+		})
+
+		It("returns nil slice when filter is nil", func() {
+			filtered := user.FilteredLibraries(nil)
+			Expect(filtered).To(BeNil())
+		})
+
+		It("returns nil slice when user has no libraries", func() {
+			user.Libraries = nil
+			filtered := user.FilteredLibraries([]int{1, 2, 3})
+			Expect(filtered).To(BeNil())
+		})
+
+		It("returns nil slice when user has empty libraries", func() {
+			user.Libraries = model.Libraries{}
+			filtered := user.FilteredLibraries([]int{1, 2, 3})
+			Expect(filtered).To(BeNil())
+		})
+
+		It("handles partial matches correctly", func() {
+			filtered := user.FilteredLibraries([]int{1, 99, 2, 100})
+			expected := model.Libraries{
+				{ID: 1, Name: "Rock Library", Path: "/music/rock"},
+				{ID: 2, Name: "Jazz Library", Path: "/music/jazz"},
+			}
+			Expect(filtered).To(Equal(expected))
+		})
+	})
+
+	Describe("AccessibleLibraryIDs", func() {
+		It("returns all library IDs when user has libraries", func() {
+			ids := user.AccessibleLibraryIDs()
+			expected := []int{1, 2, 3}
+			Expect(ids).To(Equal(expected))
+		})
+
+		It("returns nil when user has no libraries", func() {
+			user.Libraries = nil
+			ids := user.AccessibleLibraryIDs()
+			Expect(ids).To(BeNil())
+		})
+	})
+})