feat: add info command for JSON host details

Adds a jq-friendly `sshm info` subcommand with host completion and documentation, and makes home directory resolution testable for backup path tests.

cmd/info.go

@@ -0,0 +1,199 @@
+package cmd
+
+import (
+	"encoding/json"
+	"io"
+	"os"
+	"strconv"
+	"strings"
+
+	"github.com/Gu1llaum-3/sshm/internal/config"
+
+	"github.com/spf13/cobra"
+)
+
+type infoResponse struct {
+	Schema   string      `json:"schema"`
+	OK       bool        `json:"ok"`
+	Hostname string      `json:"hostname"`
+	Result   *infoResult `json:"result"`
+	Error    *infoError  `json:"error"`
+}
+
+type infoResult struct {
+	CanonicalName string      `json:"canonical_name"`
+	Target        infoTarget  `json:"target"`
+	IdentityFile  *string     `json:"identity_file"`
+	ProxyJump     *string     `json:"proxy_jump"`
+	ProxyCommand  *string     `json:"proxy_command"`
+	Options       *string     `json:"options"`
+	Tags          []string    `json:"tags"`
+	RemoteCommand *string     `json:"remote_command"`
+	RequestTTY    *string     `json:"request_tty"`
+	Source        *infoSource `json:"source"`
+}
+
+type infoTarget struct {
+	Host     string  `json:"host"`
+	Hostname *string `json:"hostname"`
+	User     *string `json:"user"`
+	Port     *int    `json:"port"`
+}
+
+type infoSource struct {
+	File string `json:"file"`
+	Line int    `json:"line"`
+}
+
+type infoError struct {
+	Code    string          `json:"code"`
+	Message string          `json:"message"`
+	Details json.RawMessage `json:"details"`
+}
+
+func maybeString(v string) *string {
+	trimmed := strings.TrimSpace(v)
+	if trimmed == "" {
+		return nil
+	}
+	return &trimmed
+}
+
+func maybePort(v string) (*int, error) {
+	trimmed := strings.TrimSpace(v)
+	if trimmed == "" {
+		return nil, nil
+	}
+	port, err := strconv.Atoi(trimmed)
+	if err != nil {
+		return nil, err
+	}
+	return &port, nil
+}
+
+func writeInfoJSON(out io.Writer, pretty bool, resp infoResponse) {
+	var b []byte
+	var err error
+	if pretty {
+		b, err = json.MarshalIndent(resp, "", "  ")
+	} else {
+		b, err = json.Marshal(resp)
+	}
+	if err != nil {
+		_, _ = io.WriteString(out, `{"schema":"sshm.info.v1","ok":false,"hostname":"","result":null,"error":{"code":"INTERNAL","message":"failed to marshal JSON","details":null}}\n`)
+		return
+	}
+	_, _ = out.Write(append(b, '\n'))
+}
+
+func runInfo(out io.Writer, hostnameArg string, cfgFile string, pretty bool) int {
+	resp := infoResponse{
+		Schema:   "sshm.info.v1",
+		OK:       false,
+		Hostname: hostnameArg,
+		Result:   nil,
+		Error:    nil,
+	}
+
+	var host *config.SSHHost
+	var err error
+	if cfgFile != "" {
+		host, err = config.GetSSHHostFromFile(hostnameArg, cfgFile)
+	} else {
+		host, err = config.GetSSHHost(hostnameArg)
+	}
+	if err != nil {
+		code := 1
+		errCode := "CONFIG_ERROR"
+		msg := err.Error()
+		if strings.Contains(msg, "not found") {
+			code = 2
+			errCode = "NOT_FOUND"
+		}
+
+		resp.Error = &infoError{Code: errCode, Message: msg, Details: nil}
+		writeInfoJSON(out, pretty, resp)
+		return code
+	}
+
+	port, portErr := maybePort(host.Port)
+	if portErr != nil {
+		resp.Error = &infoError{Code: "CONFIG_ERROR", Message: "invalid port in host configuration", Details: nil}
+		writeInfoJSON(out, pretty, resp)
+		return 1
+	}
+
+	res := infoResult{
+		CanonicalName: host.Name,
+		Target: infoTarget{
+			Host:     hostnameArg,
+			Hostname: maybeString(host.Hostname),
+			User:     maybeString(host.User),
+			Port:     port,
+		},
+		IdentityFile:  maybeString(host.Identity),
+		ProxyJump:     maybeString(host.ProxyJump),
+		ProxyCommand:  maybeString(host.ProxyCommand),
+		Options:       maybeString(host.Options),
+		Tags:          host.Tags,
+		RemoteCommand: maybeString(host.RemoteCommand),
+		RequestTTY:    maybeString(host.RequestTTY),
+		Source: &infoSource{
+			File: host.SourceFile,
+			Line: host.LineNumber,
+		},
+	}
+
+	resp.OK = true
+	resp.Result = &res
+	writeInfoJSON(out, pretty, resp)
+	return 0
+}
+
+var infoPretty bool
+
+var infoCmd = &cobra.Command{
+	Use:           "info <hostname>",
+	Short:         "Print machine-readable information about a host",
+	Long:          "Print machine-readable information (JSON) about a configured SSH host.",
+	Args:          cobra.ExactArgs(1),
+	SilenceUsage:  true,
+	SilenceErrors: true,
+	ValidArgsFunction: func(cmd *cobra.Command, args []string, toComplete string) ([]string, cobra.ShellCompDirective) {
+		if len(args) != 0 {
+			return nil, cobra.ShellCompDirectiveNoFileComp
+		}
+
+		var hosts []config.SSHHost
+		var err error
+		if configFile != "" {
+			hosts, err = config.ParseSSHConfigFile(configFile)
+		} else {
+			hosts, err = config.ParseSSHConfig()
+		}
+		if err != nil {
+			return nil, cobra.ShellCompDirectiveError
+		}
+
+		var completions []string
+		toCompleteLower := strings.ToLower(toComplete)
+		for _, host := range hosts {
+			if strings.HasPrefix(strings.ToLower(host.Name), toCompleteLower) {
+				completions = append(completions, host.Name)
+			}
+		}
+		return completions, cobra.ShellCompDirectiveNoFileComp
+	},
+	RunE: func(cmd *cobra.Command, args []string) error {
+		exitCode := runInfo(cmd.OutOrStdout(), args[0], configFile, infoPretty)
+		if exitCode != 0 {
+			os.Exit(exitCode)
+		}
+		return nil
+	},
+}
+
+func init() {
+	infoCmd.Flags().BoolVar(&infoPretty, "pretty", false, "Pretty-print JSON output")
+	RootCmd.AddCommand(infoCmd)
+}