Rewrite the zsh completion script

share/zsh/_tsm

@@ -1,7 +1,9 @@
 #compdef tsm
 #autoload
 
-_tsm_commands=(
+local context state line curcontext="$curcontext" ret=1
+local -a cmds
+cmds=(
   'list:List saved sessions'
   'show:Show details about a session'
   'save:Save the current session'
@@ -16,9 +18,30 @@ _tsm_commands=(
   'help:Show usage information'
 )
 
-_arguments '*:: :->command'
+_arguments -C \
+  '1:tsm command:->subcommand' \
+  '*:: :->args' \
+  && ret=0
 
-if (( CURRENT == 1 )); then
-  _describe -t commands "tsm commands" _tsm_commands
-  return
-fi
+case $state in
+  subcommand)
+    _describe -t commands 'tsm commands' cmds && ret=0
+    ;;
+esac
+
+case "$line[1]" in
+  show|remove|rename|copy|duplicate|restore|resume)
+    local -a session_files
+    session_files=("${TSM_SESSIONS_DIR}"/*.txt(.NOmf:gu+r::t:r))
+
+    _values 'Sessions' $session_files && ret=0
+    ;;
+  help)
+    _describe -t commands 'tsm commands' cmds && ret=0
+    ;;
+  list|quit|version)
+    _message -e 'no more arguments' && ret=1
+    ;;
+esac
+
+return ret