refactor: extract common filter logic into shared runtime

cmd/runtime.go

@@ -0,0 +1,201 @@
+package cmd
+
+import (
+	"fmt"
+	"snitch/internal/collector"
+	"snitch/internal/color"
+	"strconv"
+	"strings"
+
+	"github.com/spf13/cobra"
+)
+
+// Runtime holds the shared state for all commands.
+// it handles common filter logic, fetching, and filtering connections.
+type Runtime struct {
+	// filter options built from flags and args
+	Filters collector.FilterOptions
+
+	// filtered connections ready for rendering
+	Connections []collector.Connection
+
+	// common settings
+	ColorMode string
+	Numeric   bool
+}
+
+// shared filter flags - used by all commands
+var (
+	filterTCP    bool
+	filterUDP    bool
+	filterListen bool
+	filterEstab  bool
+	filterIPv4   bool
+	filterIPv6   bool
+)
+
+// BuildFilters constructs FilterOptions from command args and shortcut flags.
+func BuildFilters(args []string) (collector.FilterOptions, error) {
+	filters, err := ParseFilterArgs(args)
+	if err != nil {
+		return filters, err
+	}
+
+	// apply ipv4/ipv6 flags
+	filters.IPv4 = filterIPv4
+	filters.IPv6 = filterIPv6
+
+	// apply protocol shortcut flags
+	if filterTCP && !filterUDP {
+		filters.Proto = "tcp"
+	} else if filterUDP && !filterTCP {
+		filters.Proto = "udp"
+	}
+
+	// apply state shortcut flags
+	if filterListen && !filterEstab {
+		filters.State = "LISTEN"
+	} else if filterEstab && !filterListen {
+		filters.State = "ESTABLISHED"
+	}
+
+	return filters, nil
+}
+
+// FetchConnections gets connections from the collector and applies filters.
+func FetchConnections(filters collector.FilterOptions) ([]collector.Connection, error) {
+	connections, err := collector.GetConnections()
+	if err != nil {
+		return nil, err
+	}
+
+	return collector.FilterConnections(connections, filters), nil
+}
+
+// NewRuntime creates a runtime with fetched and filtered connections.
+func NewRuntime(args []string, colorMode string, numeric bool) (*Runtime, error) {
+	color.Init(colorMode)
+
+	filters, err := BuildFilters(args)
+	if err != nil {
+		return nil, fmt.Errorf("failed to parse filters: %w", err)
+	}
+
+	connections, err := FetchConnections(filters)
+	if err != nil {
+		return nil, fmt.Errorf("failed to fetch connections: %w", err)
+	}
+
+	return &Runtime{
+		Filters:     filters,
+		Connections: connections,
+		ColorMode:   colorMode,
+		Numeric:     numeric,
+	}, nil
+}
+
+// SortConnections sorts the runtime's connections in place.
+func (r *Runtime) SortConnections(opts collector.SortOptions) {
+	collector.SortConnections(r.Connections, opts)
+}
+
+// ParseFilterArgs parses key=value filter arguments.
+// exported for testing.
+func ParseFilterArgs(args []string) (collector.FilterOptions, error) {
+	filters := collector.FilterOptions{}
+	for _, arg := range args {
+		parts := strings.SplitN(arg, "=", 2)
+		if len(parts) != 2 {
+			return filters, fmt.Errorf("invalid filter format: %s (expected key=value)", arg)
+		}
+		key, value := parts[0], parts[1]
+		if err := applyFilter(&filters, key, value); err != nil {
+			return filters, err
+		}
+	}
+	return filters, nil
+}
+
+// applyFilter applies a single key=value filter to FilterOptions.
+func applyFilter(filters *collector.FilterOptions, key, value string) error {
+	switch strings.ToLower(key) {
+	case "proto":
+		filters.Proto = value
+	case "state":
+		filters.State = value
+	case "pid":
+		pid, err := strconv.Atoi(value)
+		if err != nil {
+			return fmt.Errorf("invalid pid value: %s", value)
+		}
+		filters.Pid = pid
+	case "proc":
+		filters.Proc = value
+	case "lport":
+		port, err := strconv.Atoi(value)
+		if err != nil {
+			return fmt.Errorf("invalid lport value: %s", value)
+		}
+		filters.Lport = port
+	case "rport":
+		port, err := strconv.Atoi(value)
+		if err != nil {
+			return fmt.Errorf("invalid rport value: %s", value)
+		}
+		filters.Rport = port
+	case "user":
+		uid, err := strconv.Atoi(value)
+		if err == nil {
+			filters.UID = uid
+		} else {
+			filters.User = value
+		}
+	case "laddr":
+		filters.Laddr = value
+	case "raddr":
+		filters.Raddr = value
+	case "contains":
+		filters.Contains = value
+	case "if", "interface":
+		filters.Interface = value
+	case "mark":
+		filters.Mark = value
+	case "namespace":
+		filters.Namespace = value
+	case "inode":
+		inode, err := strconv.ParseInt(value, 10, 64)
+		if err != nil {
+			return fmt.Errorf("invalid inode value: %s", value)
+		}
+		filters.Inode = inode
+	case "since":
+		since, sinceRel, err := collector.ParseTimeFilter(value)
+		if err != nil {
+			return fmt.Errorf("invalid since value: %s", value)
+		}
+		filters.Since = since
+		filters.SinceRel = sinceRel
+	default:
+		return fmt.Errorf("unknown filter key: %s", key)
+	}
+	return nil
+}
+
+// FilterFlagsHelp returns the help text for common filter flags.
+const FilterFlagsHelp = `
+Filters are specified in key=value format. For example:
+  snitch ls proto=tcp state=established
+
+Available filters:
+  proto, state, pid, proc, lport, rport, user, laddr, raddr, contains, if, mark, namespace, inode, since`
+
+// addFilterFlags adds the common filter flags to a command.
+func addFilterFlags(cmd *cobra.Command) {
+	cmd.Flags().BoolVarP(&filterTCP, "tcp", "t", false, "Show only TCP connections")
+	cmd.Flags().BoolVarP(&filterUDP, "udp", "u", false, "Show only UDP connections")
+	cmd.Flags().BoolVarP(&filterListen, "listen", "l", false, "Show only listening sockets")
+	cmd.Flags().BoolVarP(&filterEstab, "established", "e", false, "Show only established connections")
+	cmd.Flags().BoolVarP(&filterIPv4, "ipv4", "4", false, "Only show IPv4 connections")
+	cmd.Flags().BoolVarP(&filterIPv6, "ipv6", "6", false, "Only show IPv6 connections")
+}
+