Install the new shell completion logic

Add a new make target (completion) to generate the shell
completion scripts. This will generate the scripts for bash,
zsh and fish for both podman and podman-remote with `podman completion`.
The scripts are put into the completions directory and can be
installed system wide with `sudo make install.completions`.

This commit replaces the current handwritten scripts for bash and zsh.

The `validate.completion` target has been adjusted to make sure nobody
edits these scripts directly.

Signed-off-by: Paul Holzinger <paul.holzinger@web.de>

1 files changed, 182 insertions, 0 deletions

diff --git a/completions/fish/podman-remote.fish b/completions/fish/podman-remote.fish
new file mode 100644
index 000000000..e0216844d
--- /dev/null
+++ b/completions/fish/podman-remote.fish
@@ -0,0 +1,182 @@
+# fish completion for podman-remote                        -*- shell-script -*-
+
+function __podman_remote_debug
+    set file "$BASH_COMP_DEBUG_FILE"
+    if test -n "$file"
+        echo "$argv" >> $file
+    end
+end
+
+function __podman_remote_perform_completion
+    __podman_remote_debug "Starting __podman_remote_perform_completion"
+
+    set args (string split -- " " (commandline -c))
+    set lastArg "$args[-1]"
+
+    __podman_remote_debug "args: $args"
+    __podman_remote_debug "last arg: $lastArg"
+
+    set emptyArg ""
+    if test -z "$lastArg"
+        __podman_remote_debug "Setting emptyArg"
+        set emptyArg \"\"
+    end
+    __podman_remote_debug "emptyArg: $emptyArg"
+
+    if not type -q "$args[1]"
+        # This can happen when "complete --do-complete podman-remote" is called when running this script.
+        __podman_remote_debug "Cannot find $args[1]. No completions."
+        return
+    end
+
+    set requestComp "$args[1] __complete $args[2..-1] $emptyArg"
+    __podman_remote_debug "Calling $requestComp"
+
+    set results (eval $requestComp 2> /dev/null)
+    set comps $results[1..-2]
+    set directiveLine $results[-1]
+
+    # For Fish, when completing a flag with an = (e.g., <program> -n=<TAB>)
+    # completions must be prefixed with the flag
+    set flagPrefix (string match -r -- '-.*=' "$lastArg")
+
+    __podman_remote_debug "Comps: $comps"
+    __podman_remote_debug "DirectiveLine: $directiveLine"
+    __podman_remote_debug "flagPrefix: $flagPrefix"
+
+    for comp in $comps
+        printf "%s%s\n" "$flagPrefix" "$comp"
+    end
+
+    printf "%s\n" "$directiveLine"
+end
+
+# This function does two things:
+# - Obtain the completions and store them in the global __podman_remote_comp_results
+# - Return false if file completion should be performed
+function __podman_remote_prepare_completions
+    __podman_remote_debug ""
+    __podman_remote_debug "========= starting completion logic =========="
+
+    # Start fresh
+    set --erase __podman_remote_comp_results
+
+    set results (__podman_remote_perform_completion)
+    __podman_remote_debug "Completion results: $results"
+
+    if test -z "$results"
+        __podman_remote_debug "No completion, probably due to a failure"
+        # Might as well do file completion, in case it helps
+        return 1
+    end
+
+    set directive (string sub --start 2 $results[-1])
+    set --global __podman_remote_comp_results $results[1..-2]
+
+    __podman_remote_debug "Completions are: $__podman_remote_comp_results"
+    __podman_remote_debug "Directive is: $directive"
+
+    set shellCompDirectiveError 1
+    set shellCompDirectiveNoSpace 2
+    set shellCompDirectiveNoFileComp 4
+    set shellCompDirectiveFilterFileExt 8
+    set shellCompDirectiveFilterDirs 16
+    set shellCompDirectiveLegacyCustomComp 32
+    set shellCompDirectiveLegacyCustomArgsComp 64
+
+    if test -z "$directive"
+        set directive 0
+    end
+
+    set compErr (math (math --scale 0 $directive / $shellCompDirectiveError) % 2)
+    if test $compErr -eq 1
+        __podman_remote_debug "Received error directive: aborting."
+        # Might as well do file completion, in case it helps
+        return 1
+    end
+
+    set legacyCustom (math (math --scale 0 $directive / $shellCompDirectiveLegacyCustomComp) % 2)
+    set legacyCustomArgs (math (math --scale 0 $directive / $shellCompDirectiveLegacyCustomArgsComp) % 2)
+    if test $legacyCustom -eq 1; or test $legacyCustomArgs -eq 1
+        __podman_remote_debug "Legacy bash custom completion not applicable to fish"
+        # Do full file completion instead
+        set --global __podman_remote_comp_do_file_comp 1
+        return 1
+    end
+
+    set filefilter (math (math --scale 0 $directive / $shellCompDirectiveFilterFileExt) % 2)
+    set dirfilter (math (math --scale 0 $directive / $shellCompDirectiveFilterDirs) % 2)
+    if test $filefilter -eq 1; or test $dirfilter -eq 1
+        __podman_remote_debug "File extension filtering or directory filtering not supported"
+        # Do full file completion instead
+        return 1
+    end
+
+    set nospace (math (math --scale 0 $directive / $shellCompDirectiveNoSpace) % 2)
+    set nofiles (math (math --scale 0 $directive / $shellCompDirectiveNoFileComp) % 2)
+
+    __podman_remote_debug "nospace: $nospace, nofiles: $nofiles"
+
+    # If we want to prevent a space, or if file completion is NOT disabled,
+    # we need to count the number of valid completions.
+    # To do so, we will filter on prefix as the completions we have received
+    # may not already be filtered so as to allow fish to match on different
+    # criteria than prefix.
+    if test $nospace -ne 0; or test $nofiles -eq 0
+        set prefix (commandline -t)
+        __podman_remote_debug "prefix: $prefix"
+
+        set completions
+        for comp in $__podman_remote_comp_results
+            if test (string match -e -r "^$prefix" "$comp")
+                set -a completions $comp
+            end
+        end
+        set --global __podman_remote_comp_results $completions
+        __podman_remote_debug "Filtered completions are: $__podman_remote_comp_results"
+
+        # Important not to quote the variable for count to work
+        set numComps (count $__podman_remote_comp_results)
+        __podman_remote_debug "numComps: $numComps"
+
+        if test $numComps -eq 1; and test $nospace -ne 0
+            # To support the "nospace" directive we trick the shell
+            # by outputting an extra, longer completion.
+            # We must first split on \t to get rid of the descriptions because
+            # the extra character we add to the fake second completion must be
+            # before the description.  We don't need descriptions anyway since
+            # there is only a single real completion which the shell will expand
+            # immediately.
+            __podman_remote_debug "Adding second completion to perform nospace directive"
+            set split (string split --max 1 \t $__podman_remote_comp_results[1])
+            set --global __podman_remote_comp_results $split[1] $split[1].
+            __podman_remote_debug "Completions are now: $__podman_remote_comp_results"
+        end
+
+        if test $numComps -eq 0; and test $nofiles -eq 0
+            # To be consistent with bash and zsh, we only trigger file
+            # completion when there are no other completions
+            __podman_remote_debug "Requesting file completion"
+            return 1
+        end
+    end
+
+    return 0
+end
+
+# Since Fish completions are only loaded once the user triggers them, we trigger them ourselves
+# so we can properly delete any completions provided by another script.
+# The space after the the program name is essential to trigger completion for the program
+# and not completion of the program name itself.
+complete --do-complete "podman-remote " > /dev/null 2>&1
+# Using '> /dev/null 2>&1' since '&>' is not supported in older versions of fish.
+
+# Remove any pre-existing completions for the program since we will be handling all of them.
+complete -c podman-remote -e
+
+# The call to __podman_remote_prepare_completions will setup __podman_remote_comp_results
+# which provides the program's completion choices.
+complete -c podman-remote -n '__podman_remote_prepare_completions' -f -a '$__podman_remote_comp_results'
+
+
+# This file is generated with "podman-remote completion"; see: podman-completion(1)