Add remove and update completions based on required packages

Resolves #4

Author: stecman

README.md

@@ -16,6 +16,7 @@ This is an experimental hack to add [Symfony BASH auto complete](https://github.
     # so  for this hack to work, we are always running the completion command in ~/.composer
     function _composercomplete {
         export COMP_LINE COMP_POINT COMP_WORDBREAKS;
+        local -x COMPOSER_CWD=`pwd`
         local RESULT STATUS
 
         # Honour the COMPOSER_HOME variable if set
@@ -59,6 +60,7 @@ This is an experimental hack to add [Symfony BASH auto complete](https://github.
         fi
 
         local RESULT STATUS
+        local -x COMPOSER_CWD=`pwd`
         RESULT=("${(@f)$( cd $composer_dir && composer _completion )}")
         STATUS=$?;
 

src/ComposerCompletionCommand.php

@@ -7,6 +7,12 @@
 
 class ComposerCompletionCommand extends CompletionCommand
 {
+    /**
+     * Whether or not composer is being run using the global command
+     * @var boolean
+     */
+    protected $isGlobal = false;
+
     protected function runCompletion()
     {
         $context = $this->handler->getContext();
@@ -24,6 +30,22 @@ protected function runCompletion()
             $context->setCommandLine(
                 preg_replace_callback('/( global| g)( |$)/', $replace, $context->getCommandLine(), 1)
             );
+
+            $this->isGlobal = true;
+        }
+
+        // Complete for composer.json in current directory
+        if ($this->isGlobal) {
+            $composerFile = getcwd() . '/composer.json';
+        } else {
+            $workingDir = getenv('COMPOSER_CWD');
+            $composerFile = $workingDir . '/composer.json';
+        }
+
+        if (file_exists($composerFile)) {
+            $this->addProjectLocalCompletions(
+                json_decode(file_get_contents($composerFile), true)
+            );
         }
 
         // Complete for `help` command's `command` argument
@@ -47,4 +69,41 @@ function() use ($application) {
 
         return $this->handler->runCompletion();
     }
+
+    /**
+     * Setup completions that require a composer.json file to work
+     * @param array $config - parsed composer.json
+     */
+    protected function addProjectLocalCompletions($config)
+    {
+        $packages = $this->getRequiredPackages($config);
+
+        $completeRequiredPackages = function() use ($packages) {
+            return $packages;
+        };
+
+        // Complete for `remove` and `update` commands `packages` argument
+        $this->handler->addHandler(new Completion('remove', 'packages', Completion::TYPE_ARGUMENT, $completeRequiredPackages));
+        $this->handler->addHandler(new Completion('update', 'packages', Completion::TYPE_ARGUMENT, $completeRequiredPackages));
+    }
+
+    /**
+     * Get a list of package names that are required in a composer.json config
+     * @param  array $config
+     * @return array
+     */
+    protected function getRequiredPackages($config)
+    {
+        $packages = array();
+
+        if (isset($config['require'])) {
+            $packages = array_merge($packages, array_keys($config['require']));
+        }
+
+        if (isset($config['require-dev'])) {
+            $packages = array_merge($packages, array_keys($config['require-dev']));
+        }
+
+        return $packages;
+    }
 }