elvish: revise the ssh integration

The previous implementation wasn't quite working. This revision reworks
it in a few ways:

- Fix various syntax issues
- Redirect the `ssh` command to our 'ssh-integration' function
- Locate the `ghostty` binary using $GHOSTTY_BIN_DIR
- Use os:temp-dir to create our temporary directory

Also, consistently use 2-space indents, which is the Elvish standard.

.editorconfig

@@ -1,6 +1,6 @@
 root = true
 
-[*.{sh,bash}]
+[*.{sh,bash,elv}]
 indent_size = 2
 indent_style = space
 

src/shell-integration/elvish/lib/ghostty-integration.elv

@@ -38,6 +38,9 @@
 {
   use str
 
+  # List of enabled shell integration features
+  var features = [(str:split ',' $E:GHOSTTY_SHELL_FEATURES)]
+
   # helper used by `mark-*` functions
   fn set-prompt-state {|new| set-env __ghostty_prompt_state $new }
 
@@ -98,93 +101,81 @@
     (external sudo) $@args
   }
 
-  # SSH Integration
-  use str
+  fn ssh-integration {|@args|
+    var ssh-term = "xterm-256color"
+    var ssh-opts = []
 
-  if (str:contains $E:GHOSTTY_SHELL_FEATURES ssh-) {
-      fn ssh {|@args|
-          var ssh-term = "xterm-256color"
-          var ssh-opts = []
+    # Configure environment variables for remote session
+    if (has-value $features ssh-env) {
+      set ssh-opts = (conj $ssh-opts ^
+        -o "SetEnv COLORTERM=truecolor" ^
+        -o "SendEnv TERM_PROGRAM TERM_PROGRAM_VERSION")
+    }
 
-          # Configure environment variables for remote session
-          if (str:contains $E:GHOSTTY_SHELL_FEATURES ssh-env) {
-              set ssh-opts = (conj $ssh-opts 
-                  -o "SetEnv COLORTERM=truecolor"
-                  -o "SendEnv TERM_PROGRAM TERM_PROGRAM_VERSION"
-              )
+    if (has-value $features ssh-terminfo) {
+      var ssh-user = ""
+      var ssh-hostname = ""
+
+      # Parse ssh config
+      for line [((external ssh) -G $@args)] {
+        var parts = [(str:fields $line)]
+        if (> (count $parts) 1) {
+          var ssh-key = $parts[0]
+          var ssh-value = $parts[1]
+          if (eq $ssh-key user) {
+            set ssh-user = $ssh-value
+          } elif (eq $ssh-key hostname) {
+            set ssh-hostname = $ssh-value
           }
-
-          # Install terminfo on remote host if needed
-          if (str:contains $E:GHOSTTY_SHELL_FEATURES ssh-terminfo) {
-              var ssh-user = ""
-              var ssh-hostname = ""
-
-              # Parse ssh config
-              var ssh-config = (external ssh -G $@args 2>/dev/null | slurp)
-              for line (str:split "\n" $ssh-config) {
-                  var parts = (str:split " " $line)
-                  if (> (count $parts) 1) {
-                      var ssh-key = $parts[0]
-                      var ssh-value = $parts[1]
-                      if (eq $ssh-key user) {
-                          set ssh-user = $ssh-value
-                      } elif (eq $ssh-key hostname) {
-                          set ssh-hostname = $ssh-value
-                      }
-                      if (and (not-eq $ssh-user "") (not-eq $ssh-hostname "")) {
-                          break
-                      }
-                  }
-              }
-
-              if (not-eq $ssh-hostname "") {
-                  var ssh-target = $ssh-user"@"$ssh-hostname
-
-                  # Check if terminfo is already cached
-                  if (and (has-external ghostty) (bool ?(external ghostty +ssh-cache --host=$ssh-target >/dev/null 2>&1))) {
-                      set ssh-term = "xterm-ghostty"
-                  } elif (has-external infocmp) {
-                      var ssh-terminfo = (external infocmp -0 -x xterm-ghostty 2>/dev/null | slurp)
-
-                      if (not-eq $ssh-terminfo "") {
-                          echo "Setting up xterm-ghostty terminfo on "$ssh-hostname"..." >&2
-
-                          var ssh-cpath-dir = ""
-                          try {
-                              set ssh-cpath-dir = (external mktemp -d "/tmp/ghostty-ssh-"$ssh-user".XXXXXX" 2>/dev/null | slurp)
-                          } catch {
-                              set ssh-cpath-dir = "/tmp/ghostty-ssh-"$ssh-user"."(randint 10000 99999)
-                          }
-                          var ssh-cpath = $ssh-cpath-dir"/socket"
-
-                          if (bool ?(echo $ssh-terminfo | external ssh $@ssh-opts -o ControlMaster=yes -o ControlPath=$ssh-cpath -o ControlPersist=60s $@args '
-                                  infocmp xterm-ghostty >/dev/null 2>&1 && exit 0
-                                  command -v tic >/dev/null 2>&1 || exit 1
-                                  mkdir -p ~/.terminfo 2>/dev/null && tic -x - 2>/dev/null && exit 0
-                                  exit 1
-                              ' 2>/dev/null)) {
-                              set ssh-term = "xterm-ghostty"
-                              set ssh-opts = (conj $ssh-opts -o ControlPath=$ssh-cpath)
-
-                              # Cache successful installation
-                              if (has-external ghostty) {
-                                  external ghostty +ssh-cache --add=$ssh-target >/dev/null 2>&1
-                              }
-                          } else {
-                              echo "Warning: Failed to install terminfo." >&2
-                          }
-                      } else {
-                          echo "Warning: Could not generate terminfo data." >&2
-                      }
-                  } else {
-                      echo "Warning: ghostty command not available for cache management." >&2
-                  }
-              }
+          if (and (not-eq $ssh-user "") (not-eq $ssh-hostname "")) {
+            break
           }
-
-          # Execute SSH with TERM environment variable
-          external E:TERM=$ssh-term ssh $@ssh-opts $@args
+        }
       }
+
+      if (not-eq $ssh-hostname "") {
+        var ghostty = $E:GHOSTTY_BIN_DIR/"ghostty"
+        var ssh-target = $ssh-user"@"$ssh-hostname
+
+        # Check if terminfo is already cached
+        if (bool ?($ghostty +ssh-cache --host=$ssh-target)) {
+          set ssh-term = "xterm-ghostty"
+        } elif (has-external infocmp) {
+          var ssh-terminfo = ((external infocmp) -0 -x xterm-ghostty 2>/dev/null | slurp)
+
+          if (not-eq $ssh-terminfo "") {
+            echo "Setting up xterm-ghostty terminfo on "$ssh-hostname"..." >&2
+
+            use os
+            var ssh-cpath-dir = (os:temp-dir "ghostty-ssh-"$ssh-user".*")
+            var ssh-cpath = $ssh-cpath-dir"/socket"
+
+            if (bool ?(echo $ssh-terminfo | (external ssh) $@ssh-opts -o ControlMaster=yes -o ControlPath=$ssh-cpath -o ControlPersist=60s $@args '
+                  infocmp xterm-ghostty >/dev/null 2>&1 && exit 0
+                  command -v tic >/dev/null 2>&1 || exit 1
+                  mkdir -p ~/.terminfo 2>/dev/null && tic -x - 2>/dev/null && exit 0
+                  exit 1
+                ' 2>/dev/null)) {
+              set ssh-term = "xterm-ghostty"
+              set ssh-opts = (conj $ssh-opts -o ControlPath=$ssh-cpath)
+
+              # Cache successful installation
+              $ghostty +ssh-cache --add=$ssh-target >/dev/null
+            } else {
+              echo "Warning: Failed to install terminfo." >&2
+            }
+          } else {
+            echo "Warning: Could not generate terminfo data." >&2
+          }
+        } else {
+          echo "Warning: ghostty command not available for cache management." >&2
+        }
+      }
+    }
+
+    with [E:TERM = $ssh-term] {
+      (external ssh) $@ssh-opts $@args
+    }
   }
 
   defer {
@@ -196,8 +187,6 @@
   set edit:after-readline  = (conj $edit:after-readline $mark-output-start~)
   set edit:after-command   = (conj $edit:after-command $mark-output-end~)
 
-  var features = [(str:split ',' $E:GHOSTTY_SHELL_FEATURES)]
-
   if (has-value $features title) {
     set after-chdir = (conj $after-chdir {|_| report-pwd })
   }
@@ -210,4 +199,7 @@
   if (and (has-value $features sudo) (not-eq "" $E:TERMINFO) (has-external sudo)) {
     edit:add-var sudo~ $sudo-with-terminfo~
   }
+  if (and (str:contains $E:GHOSTTY_SHELL_FEATURES ssh-) (has-external ssh)) {
+    edit:add-var ssh~ $ssh-integration~
+  }
 }