package domain

import (
	"testing"
)

func TestNewUser(t *testing.T) {
	tests := []struct {
		name     string
		id       UserID
		email    string
		password string
		wantErr  error
	}{
		{
			name:     "valid user",
			id:       "user-123",
			email:    "user@example.com",
			password: "password123",
			wantErr:  nil,
		},
		{
			name:     "empty email",
			id:       "user-123",
			email:    "",
			password: "password123",
			wantErr:  ErrInvalidEmail,
		},
		{
			name:     "email without @",
			id:       "user-123",
			email:    "not-an-email",
			password: "password123",
			wantErr:  ErrInvalidEmail,
		},
		{
			name:     "email with @ at start",
			id:       "user-123",
			email:    "@example.com",
			password: "password123",
			wantErr:  ErrInvalidEmail,
		},
		{
			name:     "email with @ at end",
			id:       "user-123",
			email:    "user@",
			password: "password123",
			wantErr:  ErrInvalidEmail,
		},
		{
			name:     "email with multiple @",
			id:       "user-123",
			email:    "user@@example.com",
			password: "password123",
			wantErr:  ErrInvalidEmail,
		},
		{
			name:     "short password",
			id:       "user-123",
			email:    "user@example.com",
			password: "short",
			wantErr:  ErrInvalidPassword,
		},
		{
			name:     "empty password",
			id:       "user-123",
			email:    "user@example.com",
			password: "",
			wantErr:  ErrInvalidPassword,
		},
		{
			name:     "minimum valid password",
			id:       "user-123",
			email:    "user@example.com",
			password: "12345678",
			wantErr:  nil,
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			user, err := NewUser(tt.id, tt.email, tt.password)

			if tt.wantErr != nil {
				if err != tt.wantErr {
					t.Errorf("expected error %v, got %v", tt.wantErr, err)
				}
				return
			}

			if err != nil {
				t.Fatalf("unexpected error: %v", err)
			}

			if user.ID != tt.id {
				t.Errorf("expected ID %s, got %s", tt.id, user.ID)
			}

			if user.Email != tt.email {
				t.Errorf("expected email %s, got %s", tt.email, user.Email)
			}

			if user.PasswordHash == "" {
				t.Error("expected password hash to be set")
			}

			if user.PasswordHash == tt.password {
				t.Error("password hash should not equal plaintext password")
			}

			if user.CreatedAt.IsZero() {
				t.Error("expected CreatedAt to be set")
			}

			if user.UpdatedAt.IsZero() {
				t.Error("expected UpdatedAt to be set")
			}
		})
	}
}

func TestUser_CheckPassword(t *testing.T) {
	user, err := NewUser("user-123", "user@example.com", "correctpassword")
	if err != nil {
		t.Fatalf("failed to create user: %v", err)
	}

	tests := []struct {
		name     string
		password string
		want     bool
	}{
		{
			name:     "correct password",
			password: "correctpassword",
			want:     true,
		},
		{
			name:     "wrong password",
			password: "wrongpassword",
			want:     false,
		},
		{
			name:     "empty password",
			password: "",
			want:     false,
		},
		{
			name:     "similar password",
			password: "correctPassword",
			want:     false,
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			got := user.CheckPassword(tt.password)
			if got != tt.want {
				t.Errorf("CheckPassword() = %v, want %v", got, tt.want)
			}
		})
	}
}

func TestUserID(t *testing.T) {
	t.Run("String", func(t *testing.T) {
		id := UserID("user-123")
		if id.String() != "user-123" {
			t.Errorf("String() = %s, want user-123", id.String())
		}
	})

	t.Run("IsZero", func(t *testing.T) {
		var zeroID UserID
		if !zeroID.IsZero() {
			t.Error("expected zero ID to be zero")
		}

		nonZeroID := UserID("user-123")
		if nonZeroID.IsZero() {
			t.Error("expected non-zero ID to not be zero")
		}
	})
}