Fix -pm <value> parsing and add comma-separated multi-fact -F (#14)

Two related query-ergonomics fixes surfaced while using the tool interactively.

## 1. `-pm <value>` failed with `unknown command "k8s"`

pflag does not attach a space-separated value to a string flag (`-m`) grouped with a bool flag (`-p`), so `k8s` was left as a stray positional. Only `-pm=k8s` or the un-grouped `-p -m k8s` worked.

- Allow one positional argument (`cobra.MaximumNArgs(1)`) and fall back to it for the match value when `-m` is empty (`matchValue()`). `-pm/-im/-ipm <value>` and a bare `-p <value>` now all work; `-m` still wins when both are given.

## 2. `-F a,b` (multiple facts) returned `{}`

`-jF ipaddress,enc_role` queried a single fact literally named `ipaddress,enc_role`.

- Split `-F` on commas (`splitFactNames`) and match any of them via an `or` over `["=","name",<n>]` clauses (`nameFilter`); a single name keeps the plain `=` form.
- Key JSON output by each result's real fact name so all requested facts appear under the host.

Both paths have unit tests; verified live: `node-lookup -R -pm externaldns | node-lookup -jF ipaddress,enc_role` returns both facts per host. AGENTS.md updated.

Reviewed-on: #14
Co-authored-by: Ben Vincent <ben@unkin.net>
Co-committed-by: Ben Vincent <ben@unkin.net>

main.go

@@ -110,6 +110,31 @@ type fact struct {
 	Value    json.RawMessage `json:"value"`
 }
 
+// splitFactNames splits a comma-separated -F value into trimmed, non-empty
+// names, so `-F ipaddress,enc_role` queries both facts.
+func splitFactNames(factName string) []string {
+	var names []string
+	for _, n := range strings.Split(factName, ",") {
+		if n = strings.TrimSpace(n); n != "" {
+			names = append(names, n)
+		}
+	}
+	return names
+}
+
+// nameFilter returns a PQL filter matching any of the given fact names: a plain
+// equality for one name, an "or" over per-name equalities for several.
+func nameFilter(names []string) []interface{} {
+	if len(names) == 1 {
+		return []interface{}{"=", "name", names[0]}
+	}
+	or := []interface{}{"or"}
+	for _, n := range names {
+		or = append(or, []interface{}{"=", "name", n})
+	}
+	return or
+}
+
 func buildQuery(node, factName, match, roleFact string, showRole, partial, inverse bool) string {
 	type filter = []interface{}
 	var filters []filter
@@ -117,8 +142,8 @@ func buildQuery(node, factName, match, roleFact string, showRole, partial, inver
 	if node != "" {
 		filters = append(filters, filter{"=", "certname", node})
 	}
-	if factName != "" {
-		filters = append(filters, filter{"=", "name", factName})
+	if names := splitFactNames(factName); len(names) > 0 {
+		filters = append(filters, nameFilter(names))
 	} else if showRole {
 		filters = append(filters, filter{"=", "name", roleFact})
 	}
@@ -236,6 +261,46 @@ func stdinReader(f *os.File) (*bufio.Reader, bool) {
 	return r, true
 }
 
+// matchValue resolves the value to match against. The -m/--match flag wins; if
+// it is empty, the (optional) positional argument is used instead. The
+// positional fallback exists so combined shorthands like `-pm k8s` work — pflag
+// leaves the space-separated `k8s` as a positional rather than attaching it to
+// the grouped -m flag.
+func matchValue(flagMatch string, args []string) string {
+	if flagMatch != "" {
+		return flagMatch
+	}
+	if len(args) > 0 {
+		return args[0]
+	}
+	return ""
+}
+
+// factsByHost groups collected facts into {certname: {factname: value}}. Each
+// value is keyed by the fact's real name, so multiple -F facts each appear
+// under the host; it falls back to the -F string, the role fact (with -R), or
+// "value" only when a result carries no name. Shared by the -j and -A outputs.
+func factsByHost(collected []fact, factName, roleFact string, showRole bool) map[string]map[string]interface{} {
+	out := map[string]map[string]interface{}{}
+	for _, f := range collected {
+		if _, ok := out[f.Certname]; !ok {
+			out[f.Certname] = map[string]interface{}{}
+		}
+		key := f.Name
+		if key == "" {
+			if key = factName; key == "" {
+				if showRole {
+					key = roleFact
+				} else {
+					key = "value"
+				}
+			}
+		}
+		out[f.Certname][key] = valueAny(f.Value)
+	}
+	return out
+}
+
 func allFactsForNode(puppetDBURL, node string) ([]fact, error) {
 	query, _ := json.Marshal([]interface{}{"=", "certname", node})
 	return queryPuppetDB(puppetDBURL, string(query))
@@ -306,25 +371,10 @@ func run(cfg config, nodeName, factName, match string, showRole, partial, invers
 
 	switch {
 	case jsonMode:
-		hostFactMap := map[string]map[string]interface{}{}
-		for _, f := range collected {
-			if _, ok := hostFactMap[f.Certname]; !ok {
-				hostFactMap[f.Certname] = map[string]interface{}{}
-			}
-			key := factName
-			if key == "" {
-				if showRole {
-					key = cfg.RoleFact
-				} else {
-					key = "value"
-				}
-			}
-			hostFactMap[f.Certname][key] = valueAny(f.Value)
-		}
 		enc := json.NewEncoder(os.Stdout)
 		enc.SetIndent("", "  ")
 		enc.SetEscapeHTML(false)
-		_ = enc.Encode(hostFactMap)
+		_ = enc.Encode(factsByHost(collected, factName, cfg.RoleFact, showRole))
 
 	case count:
 		values := stdinLines
@@ -334,10 +384,11 @@ func run(cfg config, nodeName, factName, match string, showRole, partial, invers
 		fmt.Println(strings.Join(countResults(values), "\n"))
 
 	case ansible:
+		// Attach each host's queried fact(s) as inventory host vars, e.g.
+		// `-F ipaddress,enc_role -A` yields hosts with ipaddress + enc_role set.
 		hosts := map[string]interface{}{}
-		for _, line := range returnData {
-			host := strings.Fields(line)[0]
-			hosts[host] = map[string]interface{}{}
+		for host, vars := range factsByHost(collected, factName, cfg.RoleFact, showRole) {
+			hosts[host] = vars
 		}
 		inventory := map[string]interface{}{
 			"all": map[string]interface{}{"hosts": hosts},
@@ -389,8 +440,14 @@ func main() {
 	)
 
 	rootCmd := &cobra.Command{
-		Use:   appName,
+		Use:   appName + " [value]",
 		Short: "Query PuppetDB for nodes.",
+		// Accept an optional positional match value in addition to -m. This makes
+		// combined shorthands like `-pm k8s` work: pflag does not attach a
+		// space-separated value to a string flag grouped with a bool flag (only
+		// `-pm=k8s` or `-p -m k8s` do), so `k8s` arrives here as a positional
+		// argument instead. Falling back to it keeps the ergonomic form working.
+		Args: cobra.MaximumNArgs(1),
 		PersistentPreRunE: func(cmd *cobra.Command, args []string) error {
 			if cmd.Flags().Changed("url") {
 				cfg.PuppetDBURL = puppetDBURL
@@ -398,14 +455,14 @@ func main() {
 			return nil
 		},
 		RunE: func(cmd *cobra.Command, args []string) error {
-			return run(cfg, nodeName, factName, match, showRole, partial, inverse, nodeOnly, valueOnly, count, ansible, jsonMode, allFacts)
+			return run(cfg, nodeName, factName, matchValue(match, args), showRole, partial, inverse, nodeOnly, valueOnly, count, ansible, jsonMode, allFacts)
 		},
 		SilenceUsage: true,
 	}
 
 	f := rootCmd.Flags()
 	f.StringVarP(&nodeName, "node", "n", "", "Node name")
-	f.StringVarP(&factName, "fact", "F", "", "Fact name")
+	f.StringVarP(&factName, "fact", "F", "", "Fact name (comma-separated for several, e.g. -F ipaddress,enc_role)")
 	f.BoolVarP(&showRole, "role", "R", false, "Show role fact ("+defaultRoleFact+" by default)")
 	f.StringVarP(&match, "match", "m", "", "Value to match (use with -p and/or -i)")
 	f.BoolVarP(&partial, "partial", "p", false, "Partial/regex match modifier (combine with -m)")