Rework user flag to use new-style filters

Also
- validates user input (according to core app `User#login` Regexp).
- supports lists of users (separated by a comma).

cmd/list/time_entries.go

@@ -2,11 +2,16 @@ package list
 
 import (
 	"github.com/opf/openproject-cli/components/printer"
+	"github.com/opf/openproject-cli/components/requests"
+	"github.com/opf/openproject-cli/components/resources"
 	"github.com/opf/openproject-cli/components/resources/time_entries"
+	"github.com/opf/openproject-cli/components/resources/time_entries/filters"
 	"github.com/spf13/cobra"
 )
 
-var user string
+var activeTimeEntryFilters = map[string]resources.Filter{
+	"user": filters.NewUserFilter(),
+}
 
 var timeEntriesCmd = &cobra.Command{
 	Use:   "timeentries",
@@ -16,19 +21,30 @@ var timeEntriesCmd = &cobra.Command{
 }
 
 func listTimeEntries(_ *cobra.Command, _ []string) {
-	if all, err := time_entries.All(timeEntriesFilterOptions()); err == nil {
+	query, err := buildTimeEntriesQuery()
+	if err != nil {
+		printer.ErrorText(err.Error())
+		return
+	}
+
+	if all, err := time_entries.All(query); err == nil {
 		printer.TimeEntryList(all)
 	} else {
 		printer.Error(err)
 	}
 }
 
-func timeEntriesFilterOptions() *map[time_entries.FilterOption]string {
-	options := make(map[time_entries.FilterOption]string)
+func buildTimeEntriesQuery() (requests.Query, error) {
+	var q requests.Query
+
+	for _, filter := range activeTimeEntryFilters {
+		err := filter.ValidateInput()
+		if err != nil {
+			return requests.NewEmptyQuery(), err
+		}
 
-	if len(user) > 0 {
-		options[time_entries.User] = user
+		q = q.Merge(filter.Query())
 	}
 
-	return &options
+	return q, nil
 }

cmd/list/time_entries_flags.go

@@ -1,11 +1,13 @@
 package list
 
 func initTimeEntriesFlags() {
-	timeEntriesCmd.Flags().StringVarP(
-		&user,
-		"user",
-		"u",
-		"me",
-		"User the time entry tracks expenditures for (can be name, ID or 'me')",
-	)
+	for _, filter := range activeTimeEntryFilters {
+		timeEntriesCmd.Flags().StringVarP(
+			filter.ValuePointer(),
+			filter.Name(),
+			filter.ShortHand(),
+			filter.DefaultValue(),
+			filter.Usage(),
+		)
+	}
 }

components/resources/time_entries/filters/user.go

@@ -0,0 +1,64 @@
+package filters
+
+import (
+	"fmt"
+	"regexp"
+	"strings"
+
+	"github.com/opf/openproject-cli/components/errors"
+	"github.com/opf/openproject-cli/components/printer"
+	"github.com/opf/openproject-cli/components/requests"
+)
+
+const validValueRegexp = `^([\pL0-9_\-@.+ ]+|[0-9]+|me)(,([\pL0-9_\-@.+ ]+|[0-9]+|me))*$`
+
+type UserFilter struct {
+	value string
+}
+
+func (f *UserFilter) ValuePointer() *string {
+	return &f.value
+}
+
+func (f *UserFilter) Value() string {
+	return f.value
+}
+
+func (f *UserFilter) Name() string {
+	return "user"
+}
+
+func (f *UserFilter) ShortHand() string {
+	return "u"
+}
+
+func (f *UserFilter) Usage() string {
+	return `User the time entry tracks expenditures for (can be name, ID or 'me')`
+}
+
+func (f *UserFilter) ValidateInput() error {
+	matched, _ := regexp.Match(validValueRegexp, []byte(f.value))
+	if !matched {
+		return errors.Custom(fmt.Sprintf("Invalid user value %s.", printer.Yellow(f.value)))
+	}
+
+	return nil
+}
+
+func (f *UserFilter) DefaultValue() string {
+	return "me"
+}
+
+func (f *UserFilter) Query() requests.Query {
+	return requests.NewQuery(nil, []requests.Filter{
+		{
+			Operator: "=",
+			Name:     "user",
+			Values:   strings.Split(f.value, ","),
+		},
+	})
+}
+
+func NewUserFilter() *UserFilter {
+	return &UserFilter{}
+}

components/resources/time_entries/functions.go

@@ -8,17 +8,7 @@ import (
 	"github.com/opf/openproject-cli/models"
 )
 
-func All(filterOptions *map[FilterOption]string) ([]*models.TimeEntry, error) {
-	var filters []requests.Filter
-
-	for updateOpt, value := range *filterOptions {
-		if updateOpt == User {
-			filters = append(filters, UserFilter(value))
-		}
-	}
-
-	query := requests.NewPaginatedQuery(-1, filters)
-
+func All(query requests.Query) ([]*models.TimeEntry, error) {
 	response, err := requests.Get(paths.TimeEntries(), &query)
 	if err != nil {
 		return nil, err