Intercept the completion script inside bal shell script

resources/bin/bal

@@ -30,11 +30,29 @@ elif test -d "$CURRENT_PATH/../dependencies/jdk8u202-b08-jre"; then
   JAVA_COMMAND="$CURRENT_PATH/../dependencies/jdk8u202-b08-jre/bin/java"
 fi
 
+if [ "$1" == "completion" ]
+then
+    if [ "$2" == "bash" ]
+    then
+      printf "#!/usr/bin/env bash\n\n"
+      cat $CURRENT_PATH/../scripts/bal_completion.bash
+    else
+      printf "#!/usr/bin/env bash\n\n"
+      printf "autoload -U +X bashcompinit && bashcompinit\n"
+      printf "autoload -U +X compinit && compinit\n\n"
+      cat $CURRENT_PATH/../scripts/bal_completion.bash
+    fi
+    if [ $? -ne '0' ]; then
+      echo "Failed to generate the completion script"
+      EXIT_CODE=$?
+    fi
+    exit 0
+fi
+
 RUN_COMMAND=false
 RUN_BALLERINA=true
 
-if [ "$1" == "dist" ] || [ "$2" == "dist" ] || [ "$1" == "update" ]|| [ "$2" == "update" ] || \
-[ "$1" == "completion" ] || [ "$2" == "completion" ]
+if [ "$1" == "dist" ] || [ "$2" == "dist" ] || [ "$1" == "update" ]|| [ "$2" == "update" ]
 then
     RUN_COMMAND=true
     RUN_BALLERINA=false

resources/scripts/bal_completion.bash

@@ -0,0 +1,49 @@
+# Get the file path based on OS type
+if [[ "$OSTYPE" == "linux-gnu"* ]]; then
+    dists_path=/usr/lib/ballerina/distributions
+elif [[ "$OSTYPE" == "darwin"* ]]; then
+    dists_path=/Library/Ballerina/distributions
+fi
+
+_bal_completions()
+{
+    balCommands="-v --version add build clean dist doc format help new pull push run test update version"
+    dist="list pull remove update use"
+
+    # Get current ballerina version
+    if test -f "$HOME/.ballerina/ballerina-version"; then
+        bal_version=$(cat $HOME/.ballerina/ballerina-version)
+    else
+        bal_version=$(cat $dists_path/ballerina-version)
+    fi
+
+    file_path=$dists_path/$bal_version/resources/command-completion/command-completion.csv
+
+    if test -f "$file_path"; then
+        # Read the optional flags from command-completion file
+        while IFS=, read -r cmdname flags
+        do
+            if [[ "${COMP_WORDS[1]}" = "$cmdname" ]]; then
+                flags_arr="$flags"
+            elif [[ "$cmdname" == "bal" ]]; then
+                balCommands="$flags"
+            fi
+        done < <(tail -n +2 $file_path)
+    fi
+
+    if [[ "$COMP_CWORD" == "1" ]]; then
+        COMPREPLY=($(compgen -W "$balCommands -h --help" -- "${COMP_WORDS[$COMP_CWORD]}"))
+        return
+    else
+        if [[ ("${COMP_WORDS[1]}" = "dist") ]]; then
+            COMPREPLY=($(compgen -W "$dist -h --help" "${COMP_WORDS[$COMP_CWORD]}"))
+            return
+        elif [[ "${COMP_WORDS[$COMP_CWORD]}" =~ ^\-.* ]] && [ -f "$file_path" ]; then
+            # If last word has - we will suggest flags.
+            COMPREPLY=($(compgen -W "${flags_arr[@]} -h --help" -- "${COMP_WORDS[$COMP_CWORD]}"))
+            return
+        fi
+    fi
+}
+
+complete -o bashdefault -o default -F _bal_completions bal

resources/scripts/install

@@ -43,6 +43,17 @@ if [ $? -ne '0' ]; then
   exit $?
 fi
 
+\cp $CURRENT_PATH/ballerina-command-@version@/scripts/bal_completion.bash $CURRENT_PATH/../scripts
+
+if [ $? -ne '0' ]; then
+  echo "error occurred while copying completion script file."
+  # remove already copied jar.
+  if [ -f "$CURRENT_PATH/../lib/ballerina-command-@[email protected]" ]; then
+        rm -rf $CURRENT_PATH/../lib/ballerina-command-@[email protected]
+  fi
+  exit $?
+fi
+
 echo "Updating environment variables"
 if [ -f "/usr/lib/ballerina/bin/ballerina" ] 
 then

src/main/java/org/ballerinalang/command/BallerinaCliCommands.java

@@ -33,7 +33,4 @@ public class BallerinaCliCommands {
     public static final String USE = "use";
     public static final String REMOVE = "remove";
     public static final String VERSION = "version";
-    public static final String COMPLETION = "completion";
-    public static final String BASH = "bash";
-    public static final String ZSH = "zsh";
 }

src/main/java/org/ballerinalang/command/Main.java

@@ -17,9 +17,7 @@
 package org.ballerinalang.command;
 
 import org.ballerinalang.command.cmd.BCommand;
-import org.ballerinalang.command.cmd.BashCommand;
 import org.ballerinalang.command.cmd.BuildCommand;
-import org.ballerinalang.command.cmd.CompletionCommand;
 import org.ballerinalang.command.cmd.DefaultCommand;
 import org.ballerinalang.command.cmd.DistributionCommand;
 import org.ballerinalang.command.cmd.HelpCommand;
@@ -30,7 +28,6 @@
 import org.ballerinalang.command.cmd.UpdateToolCommand;
 import org.ballerinalang.command.cmd.UseCommand;
 import org.ballerinalang.command.cmd.VersionCommand;
-import org.ballerinalang.command.cmd.ZshCommand;
 import org.ballerinalang.command.exceptions.CommandException;
 import org.ballerinalang.command.util.ErrorUtil;
 import picocli.CommandLine;
@@ -74,18 +71,6 @@ private static Optional<BCommand> getInvokedCmd(String... args) {
             CommandLine distCmdParser = new CommandLine(distCmd);
             distCmd.setParentCmdParser(distCmdParser);
 
-            CompletionCommand completionCmd = new CompletionCommand(outStream);
-            CommandLine completionCmdParser = new CommandLine(completionCmd);
-            completionCmd.setParentCmdParser(completionCmdParser);
-
-            BashCommand bashCmd = new BashCommand(outStream);
-            completionCmdParser.addSubcommand(BallerinaCliCommands.BASH, bashCmd);
-            bashCmd.setParentCmdParser(completionCmdParser);
-
-            ZshCommand zshCmd = new ZshCommand(outStream);
-            completionCmdParser.addSubcommand(BallerinaCliCommands.ZSH, zshCmd);
-            zshCmd.setParentCmdParser(completionCmdParser);
-
             ListCommand listCmd = new ListCommand(outStream);
             distCmdParser.addSubcommand(BallerinaCliCommands.LIST, listCmd);
             listCmd.setParentCmdParser(distCmdParser);
@@ -113,11 +98,7 @@ private static Optional<BCommand> getInvokedCmd(String... args) {
             distCmdParser.setCommandName("dist");
             distCmdParser.setPosixClusteredShortOptionsAllowed(false);
 
-            completionCmdParser.setCommandName("completion");
-            completionCmdParser.setPosixClusteredShortOptionsAllowed(false);
-
             cmdParser.addSubcommand(BallerinaCliCommands.DIST, distCmdParser);
-            cmdParser.addSubcommand(BallerinaCliCommands.COMPLETION, completionCmdParser);
 
             UpdateToolCommand updateToolCommand = new UpdateToolCommand(outStream);
             cmdParser.addSubcommand(BallerinaCliCommands.UPDATE, updateToolCommand);