<?php

namespace NoccyLabs\Shell;

class Context
{
    protected $name;

    protected $commands = [];

    protected $commandInfo = [];

    protected $data = [];

    protected $parent;

    protected $shell;

    public function __construct($name=null, array $data=[])
    {
        $this->name = $name;
        $this->data = $data;
        $this->configure();
    }

    public function getContextInfo()
    {
        return null;
    }

    public function setShell(Shell $shell)
    {
        $this->shell = $shell;
    }

    public function getShell()
    {
        return $this->shell;
    }

    public function setParent(Context $parent=null)
    {
        $this->parent = $parent;
    }

    public function getParent()
    {
        return $this->parent;
    }

    public function getRoot()
    {
        if (!$this->parent) {
            return $this;
        }
        $node = $this;
        while ($parent = $node->getParent()) {
            $node = $parent;
        }
        return $parent;
    }

    protected function configure()
    {
        // Override this to do setup stuff
        $this->findCommands();
    }

    protected function findCommands()
    {
        $refl = new \ReflectionClass(get_called_class());
        foreach ($refl->getMethods() as $method) {
            $docblock = $method->getDocComment();
            $lines = array_map(function ($line) {
                return trim($line, "*/ \t");
            }, explode("\n", $docblock));
            $info = [];
            foreach ($lines as $line) {
                if (preg_match("/^@(command|help|args|global)\\s*(.*)$/", $line, $match)) {
                    list($void,$key,$value) = $match;
                    $info[$key] = $value; 
                }
                if (count($info)>0) {
                    $cmdName = array_key_exists("command",$info)?$info["command"]:$method->getName();
                    $this->addCommand($cmdName, [$this, $method->getName()], $info);
                }
            }
        }
    }

    public function addCommand($command, callable $handler, array $info=[])
    {
        $this->commands[$command] = $handler;
        $this->commandInfo[$command] = $info;
        ksort($this->commands);
    }

    public function setCommandHelp($command, $help)
    {
        if (!array_key_exists($command, $this->commandInfo)) {
            return;
        }
        $this->commandInfo[$command]['help'] = $help;
    }

    public function addCommands(array $commands)
    {
        foreach ($commands as $command=>$handler) {
            // Make it easier to connect commands direct to local functions
            if (is_string($handler) && is_callable([$this,$handler])) {
                $handler = [ $this,$handler ];
            }
            // Add the command to the command list
            $this->addCommand($command, $handler);
        }
    }

    public function hasCommand($command)
    {
        return array_key_exists($command, $this->commands);
    }

    public function getCommand($command)
    {
        return $this->commands[$command];
    }

    public function getCommandHelp()
    {
        $ret = [];
        foreach ($this->commands as $command=>$handler) {
            $info = $this->commandInfo[$command];
            $args = array_key_exists("args",$info)?$info['args']:"";
            $help = array_key_exists("help",$info)?$info['help']:"";
            $ret[trim("{$command} {$args}")] = $help;
        }
        return $ret;
    }

    public function isCommandGlobal($command)
    {
        if (strpos($command," ")!==false) {
            list($command, $void) = explode(" ",$command,2);
        }
        $info = $this->commandInfo[$command];
        return array_key_exists('global', $info);
    }

    /**
     * Catch-all handler for commands not defined in context, globally or builtin.
     * Override this function and return true if the command is handled ok.
     *
     * @param string $command The command to execute
     * @param string[] $args The arguments to the command
     * @return bool True if the command was handled
     */
    public function execute($command, ...$args)
    {
        return false;
    }

    /**
     * Get the name of the context
     *
     */
    public function getName()
    {
        return $this->name;
    }

    public function __get($key)
    {
        if (!array_key_exists($key,$this->data)) {
            return false;
        }
        return $this->data[$key];
    }

    public function __set($key,$value)
    {
        $this->data[$key] = $value;
    }

    public function __isset($key)
    {
        return array_key_exists($key);
    }

    public function __unset($key)
    {
        unset($this->data[$key]);
    }

    public function getData()
    {
        return $this->data;
    }

}