Refactoring modules

modules/utils/view_selector.go

@@ -0,0 +1,107 @@
+package utils
+
+import (
+	"fmt"
+
+	"regexp"
+	"strings"
+
+	"github.com/bettercap/bettercap/session"
+
+	"github.com/evilsocket/islazy/tui"
+)
+
+type ViewSelector struct {
+	owner *session.SessionModule
+
+	Filter     string
+	filterName string
+	filterPrev string
+	Expression *regexp.Regexp
+
+	SortField  string
+	Sort       string
+	SortSymbol string
+	sortFields map[string]bool
+	sortName   string
+	sortParser string
+	sortParse  *regexp.Regexp
+
+	Limit     int
+	limitName string
+}
+
+func ViewSelectorFor(m *session.SessionModule, prefix string, sortFields []string, defExpression string) *ViewSelector {
+	parser := "(" + strings.Join(sortFields, "|") + ") (desc|asc)"
+	s := &ViewSelector{
+		owner:      m,
+		filterName: prefix + ".filter",
+		sortName:   prefix + ".sort",
+		sortParser: parser,
+		sortParse:  regexp.MustCompile(parser),
+		limitName:  prefix + ".limit",
+	}
+
+	m.AddParam(session.NewStringParameter(s.filterName, "", "", "Defines a regular expression filter for "+prefix))
+	m.AddParam(session.NewStringParameter(
+		s.sortName,
+		defExpression,
+		s.sortParser,
+		"Defines sorting field ("+strings.Join(sortFields, ", ")+") and direction (asc or desc) for "+prefix))
+
+	m.AddParam(session.NewIntParameter(s.limitName, "0", "Defines limit for "+prefix))
+
+	s.parseSorting()
+
+	return s
+}
+
+func (s *ViewSelector) parseFilter() (err error) {
+	if err, s.Filter = s.owner.StringParam(s.filterName); err != nil {
+		return
+	}
+
+	if s.Filter != "" {
+		if s.Filter != s.filterPrev {
+			if s.Expression, err = regexp.Compile(s.Filter); err != nil {
+				return
+			}
+		}
+	} else {
+		s.Expression = nil
+	}
+	s.filterPrev = s.Filter
+	return
+}
+
+func (s *ViewSelector) parseSorting() (err error) {
+	expr := ""
+	if err, expr = s.owner.StringParam(s.sortName); err != nil {
+		return
+	}
+
+	tokens := s.sortParse.FindAllStringSubmatch(expr, -1)
+	if tokens == nil {
+		return fmt.Errorf("expression '%s' doesn't parse", expr)
+	}
+
+	s.SortField = tokens[0][1]
+	s.Sort = tokens[0][2]
+	s.SortSymbol = tui.Blue("▾")
+	if s.Sort == "asc" {
+		s.SortSymbol = tui.Blue("▴")
+	}
+
+	return
+}
+
+func (s *ViewSelector) Update() (err error) {
+	if err = s.parseFilter(); err != nil {
+		return
+	} else if err = s.parseSorting(); err != nil {
+		return
+	} else if err, s.Limit = s.owner.IntParam(s.limitName); err != nil {
+		return
+	}
+	return
+}