From f56dbede20fc43a1d1625573ca3d35a2f4d1a37f Mon Sep 17 00:00:00 2001
From: rsteube <rsteube@users.noreply.github.com>
Date: Tue, 20 Feb 2024 21:33:39 +0100
Subject: [PATCH] bash: more completion locations

---
 pkg/bridges/bash.go | 91 +++++++++++++++++++++++++++++++++++++++++----
 1 file changed, 83 insertions(+), 8 deletions(-)

diff --git a/pkg/bridges/bash.go b/pkg/bridges/bash.go
index 037a9be..1e832b7 100644
--- a/pkg/bridges/bash.go
+++ b/pkg/bridges/bash.go
@@ -1,6 +1,7 @@
 package bridges
 
 import (
+	"fmt"
 	"os"
 	"runtime"
 	"strings"
@@ -19,14 +20,7 @@ func Bash() []string {
 
 	return cache("bash", func() ([]string, error) {
 		unique := make(map[string]bool)
-		for _, location := range []string{
-			"/data/data/com.termux/files/etc/bash_completion.d",                 // termux
-			"/data/data/com.termux/files/usr/share/bash-completion/completions", // termux
-			"/etc/bash_completion.d",                                            // linux
-			"/usr/local/etc/bash_completion.d",                                  // osx
-			"/usr/local/share/bash-completion/completions",                      // osx
-			"/usr/share/bash-completion/completions",                            // linux
-		} {
+		for _, location := range bashCompletionLocations() {
 			entries, err := os.ReadDir(location)
 			if err != nil {
 				carapace.LOG.Println(err.Error())
@@ -47,3 +41,84 @@ func Bash() []string {
 		return completers, nil
 	})
 }
+
+// bashCompletionLocations return folders containing bash completion scripts
+//
+//	https://github.com/scop/bash-completion/blob/7864377cacb7858893a475e69c9c7461c2727e02/bash_completion#L3159C5-L3194C61
+func bashCompletionLocations() []string {
+	locations := []string{
+		// TODO fix order
+		"/data/data/com.termux/files/etc/bash_completion.d", // termux
+		"/etc/bash_completion.d",                            // linux
+		"/usr/local/etc/bash_completion.d",                  // osx
+	}
+
+	// # Lookup order:
+	// # 1) From BASH_COMPLETION_USER_DIR (e.g. ~/.local/share/bash-completion):
+	// # User installed completions.
+	// if [[ ${BASH_COMPLETION_USER_DIR-} ]]; then
+	//     _comp_split -F : paths "$BASH_COMPLETION_USER_DIR" &&
+	//         dirs+=("${paths[@]/%//completions}")
+	// else
+	//     dirs=("${XDG_DATA_HOME:-$HOME/.local/share}/bash-completion/completions")
+	// fi
+	if userDirs, ok := os.LookupEnv("BASH_COMPLETION_USER_DIR"); ok {
+		for userDir := range strings.Split(userDirs, string(os.PathListSeparator)) {
+			locations = append(locations, fmt.Sprintf("%v/completions", userDir))
+		}
+	} else {
+		if dataHome, ok := os.LookupEnv("XDG_DATA_HOME"); ok {
+			locations = append(locations, fmt.Sprintf("%v/.local/share/bash-completion/completions", dataHome))
+		} else if home, err := os.UserHomeDir(); err == nil {
+			locations = append(locations, fmt.Sprintf("%v/.local/share/bash-completion/completions", home))
+		}
+	}
+
+	// # 2) From the location of bash_completion: Completions relative to the main
+	// # script. This is primarily for run-in-place-from-git-clone setups, where
+	// # we want to prefer in-tree completions over ones possibly coming with a
+	// # system installed bash-completion. (Due to usual install layouts, this
+	// # often hits the correct completions in system installations, too.)
+	// if [[ $BASH_SOURCE == */* ]]; then
+	//     dirs+=("${BASH_SOURCE%/*}/completions")
+	// else
+	//     dirs+=(./completions)
+	// fi
+	if sourceDir, ok := os.LookupEnv("BASH_SOURCE"); ok {
+		locations = append(locations, fmt.Sprintf("%v/completions", sourceDir))
+	} else {
+		locations = append(locations, "./completions")
+	}
+
+	// # 3) From bin directories extracted from the specified path to the command,
+	// # the real path to the command, and $PATH
+	// paths=()
+	// [[ $cmd == /* ]] && paths+=("${cmd%/*}")
+	// _comp_realcommand "$cmd" && paths+=("${REPLY%/*}")
+	// _comp_split -aF : paths "$PATH"
+	// for dir in "${paths[@]%/}"; do
+	//     [[ $dir == ?*/@(bin|sbin) ]] &&
+	//         dirs+=("${dir%/*}/share/bash-completion/completions")
+	// done
+	for _, pathDir := range strings.Split(os.Getenv("$PATH"), string(os.PathListSeparator)) {
+		locations = append(locations, fmt.Sprintf("%v/share/bash-completion/completions", pathDir))
+	}
+
+	// # 4) From XDG_DATA_DIRS or system dirs (e.g. /usr/share, /usr/local/share):
+	// # Completions in the system data dirs.
+	// _comp_split -F : paths "${XDG_DATA_DIRS:-/usr/local/share:/usr/share}" &&
+	//     dirs+=("${paths[@]/%//bash-completion/completions}")
+	if dataDirs, ok := os.LookupEnv("XDG_DATA_DIRS"); ok {
+		for _, dataDir := range strings.Split(dataDirs, string(os.PathListSeparator)) {
+			locations = append(locations, fmt.Sprintf("%v/bash-completion/completions", dataDir))
+		}
+	} else {
+		locations = append(locations,
+			"/data/data/com.termux/files/usr/share/bash-completion/completions", // termux
+			"/usr/local/share/bash-completion/completions",                      // osx
+			"/usr/share/bash-completion/completions",                            // linux
+		)
+	}
+
+	return locations
+}