<?php
/**
 * ConsoleOptionParser file
 *
 * CakePHP(tm) : Rapid Development Framework (http://cakephp.org)
 * Copyright (c) Cake Software Foundation, Inc. (http://cakefoundation.org)
 *
 * Licensed under The MIT License
 * For full copyright and license information, please see the LICENSE.txt
 * Redistributions of files must retain the above copyright notice.
 *
 * @copyright	  Copyright (c) Cake Software Foundation, Inc. (http://cakefoundation.org)
 * @link		  http://cakephp.org CakePHP(tm) Project
 * @since		  CakePHP(tm) v 2.0
 * @license		  http://www.opensource.org/licenses/mit-license.php MIT License
 */

App::uses('TaskCollection', 'Console');
App::uses('ConsoleOutput', 'Console');
App::uses('ConsoleInput', 'Console');
App::uses('ConsoleInputSubcommand', 'Console');
App::uses('ConsoleInputOption', 'Console');
App::uses('ConsoleInputArgument', 'Console');
App::uses('ConsoleOptionParser', 'Console');
App::uses('HelpFormatter', 'Console');

/**
 * Handles parsing the ARGV in the command line and provides support
 * for GetOpt compatible option definition. Provides a builder pattern implementation
 * for creating shell option parsers.
 *
 * ### Options
 *
 * Named arguments come in two forms, long and short. Long arguments are preceded
 * by two - and give a more verbose option name. i.e. `--version`. Short arguments are
 * preceded by one - and are only one character long. They usually match with a long option,
 * and provide a more terse alternative.
 *
 * ### Using Options
 *
 * Options can be defined with both long and short forms. By using `$parser->addOption()`
 * you can define new options. The name of the option is used as its long form, and you
 * can supply an additional short form, with the `short` option. Short options should
 * only be one letter long. Using more than one letter for a short option will raise an exception.
 *
 * Calling options can be done using syntax similar to most *nix command line tools. Long options
 * cane either include an `=` or leave it out.
 *
 * `cake myshell command --connection default --name=something`
 *
 * Short options can be defined signally or in groups.
 *
 * `cake myshell command -cn`
 *
 * Short options can be combined into groups as seen above. Each letter in a group
 * will be treated as a separate option. The previous example is equivalent to:
 *
 * `cake myshell command -c -n`
 *
 * Short options can also accept values:
 *
 * `cake myshell command -c default`
 *
 * ### Positional arguments
 *
 * If no positional arguments are defined, all of them will be parsed. If you define positional
 * arguments any arguments greater than those defined will cause exceptions. Additionally you can
 * declare arguments as optional, by setting the required param to false.
 *
 * `$parser->addArgument('model', array('required' => false));`
 *
 * ### Providing Help text
 *
 * By providing help text for your positional arguments and named arguments, the ConsoleOptionParser
 * can generate a help display for you. You can view the help for shells by using the `--help` or `-h` switch.
 *
 * @package		  Cake.Console
 */
class ConsoleOptionParser {

/**
 * Description text - displays before options when help is generated
 *
 * @see ConsoleOptionParser::description()
 * @var string
 */
	protected $_description = null;

/**
 * Epilog text - displays after options when help is generated
 *
 * @see ConsoleOptionParser::epilog()
 * @var string
 */
	protected $_epilog = null;

/**
 * Option definitions.
 *
 * @see ConsoleOptionParser::addOption()
 * @var array
 */
	protected $_options = array();

/**
 * Map of short -> long options, generated when using addOption()
 *
 * @var string
 */
	protected $_shortOptions = array();

/**
 * Positional argument definitions.
 *
 * @see ConsoleOptionParser::addArgument()
 * @var array
 */
	protected $_args = array();

/**
 * Subcommands for this Shell.
 *
 * @see ConsoleOptionParser::addSubcommand()
 * @var array
 */
	protected $_subcommands = array();

/**
 * Command name.
 *
 * @var string
 */
	protected $_command = '';

/**
 * Construct an OptionParser so you can define its behavior
 *
 * @param string $command The command name this parser is for. The command name is used for generating help.
 * @param bool $defaultOptions Whether you want the verbose and quiet options set. Setting
 *	this to false will prevent the addition of `--verbose` & `--quiet` options.
 */
	public function __construct($command = null, $defaultOptions = true) {
		$this->command($command);

		$this->addOption('help', array(
			'short' => 'h',
			'help' => __d('cake_console', 'Display this help.'),
			'boolean' => true
		));

		if ($defaultOptions) {
			$this->addOption('verbose', array(
				'short' => 'v',
				'help' => __d('cake_console', 'Enable verbose output.'),
				'boolean' => true
			))->addOption('quiet', array(
				'short' => 'q',
				'help' => __d('cake_console', 'Enable quiet output.'),
				'boolean' => true
			));
		}
	}

/**
 * Static factory method for creating new OptionParsers so you can chain methods off of them.
 *
 * @param string $command The command name this parser is for. The command name is used for generating help.
 * @param bool $defaultOptions Whether you want the verbose and quiet options set.
 * @return ConsoleOptionParser
 */
	public static function create($command, $defaultOptions = true) {
		return new ConsoleOptionParser($command, $defaultOptions);
	}

/**
 * Build a parser from an array. Uses an array like
 *
 * ```
 * $spec = array(
 *		'description' => 'text',
 *		'epilog' => 'text',
 *		'arguments' => array(
 *			// list of arguments compatible with addArguments.
 *		),
 *		'options' => array(
 *			// list of options compatible with addOptions
 *		),
 *		'subcommands' => array(
 *			// list of subcommands to add.
 *		)
 * );
 * ```
 *
 * @param array $spec The spec to build the OptionParser with.
 * @return ConsoleOptionParser
 */
	public static function buildFromArray($spec) {
		$parser = new ConsoleOptionParser($spec['command']);
		if (!empty($spec['arguments'])) {
			$parser->addArguments($spec['arguments']);
		}
		if (!empty($spec['options'])) {
			$parser->addOptions($spec['options']);
		}
		if (!empty($spec['subcommands'])) {
			$parser->addSubcommands($spec['subcommands']);
		}
		if (!empty($spec['description'])) {
			$parser->description($spec['description']);
		}
		if (!empty($spec['epilog'])) {
			$parser->epilog($spec['epilog']);
		}
		return $parser;
	}

/**
 * Get or set the command name for shell/task.
 *
 * @param string $text The text to set, or null if you want to read
 * @return string|$this If reading, the value of the command. If setting $this will be returned.
 */
	public function command($text = null) {
		if ($text !== null) {
			$this->_command = Inflector::underscore($text);
			return $this;
		}
		return $this->_command;
	}

/**
 * Get or set the description text for shell/task.
 *
 * @param string|array $text The text to set, or null if you want to read. If an array the
 *	 text will be imploded with "\n"
 * @return string|$this If reading, the value of the description. If setting $this will be returned.
 */
	public function description($text = null) {
		if ($text !== null) {
			if (is_array($text)) {
				$text = implode("\n", $text);
			}
			$this->_description = $text;
			return $this;
		}
		return $this->_description;
	}

/**
 * Get or set an epilog to the parser. The epilog is added to the end of
 * the options and arguments listing when help is generated.
 *
 * @param string|array $text Text when setting or null when reading. If an array the text will be imploded with "\n"
 * @return string|$this If reading, the value of the epilog. If setting $this will be returned.
 */
	public function epilog($text = null) {
		if ($text !== null) {
			if (is_array($text)) {
				$text = implode("\n", $text);
			}
			$this->_epilog = $text;
			return $this;
		}
		return $this->_epilog;
	}

/**
 * Add an option to the option parser. Options allow you to define optional or required
 * parameters for your console application. Options are defined by the parameters they use.
 *
 * ### Options
 *
 * - `short` - The single letter variant for this option, leave undefined for none.
 * - `help` - Help text for this option. Used when generating help for the option.
 * - `default` - The default value for this option. Defaults are added into the parsed params when the
 *	  attached option is not provided or has no value. Using default and boolean together will not work.
 *	  are added into the parsed parameters when the option is undefined. Defaults to null.
 * - `boolean` - The option uses no value, its just a boolean switch. Defaults to false.
 *	  If an option is defined as boolean, it will always be added to the parsed params. If no present
 *	  it will be false, if present it will be true.
 * - `choices` A list of valid choices for this option. If left empty all values are valid..
 *	 An exception will be raised when parse() encounters an invalid value.
 *
 * @param ConsoleInputOption|string $name The long name you want to the value to be parsed out as when options are parsed.
 *	 Will also accept an instance of ConsoleInputOption
 * @param array $options An array of parameters that define the behavior of the option
 * @return $this
 */
	public function addOption($name, $options = array()) {
		if (is_object($name) && $name instanceof ConsoleInputOption) {
			$option = $name;
			$name = $option->name();
		} else {
			$defaults = array(
				'name' => $name,
				'short' => null,
				'help' => '',
				'default' => null,
				'boolean' => false,
				'choices' => array()
			);
			$options += $defaults;
			$option = new ConsoleInputOption($options);
		}
		$this->_options[$name] = $option;
		if ($option->short() !== null) {
			$this->_shortOptions[$option->short()] = $name;
		}
		return $this;
	}

/**
 * Add a positional argument to the option parser.
 *
 * ### Params
 *
 * - `help` The help text to display for this argument.
 * - `required` Whether this parameter is required.
 * - `index` The index for the arg, if left undefined the argument will be put
 *	 onto the end of the arguments. If you define the same index twice the first
 *	 option will be overwritten.
 * - `choices` A list of valid choices for this argument. If left empty all values are valid..
 *	 An exception will be raised when parse() encounters an invalid value.
 *
 * @param ConsoleInputArgument|string $name The name of the argument. Will also accept an instance of ConsoleInputArgument
 * @param array $params Parameters for the argument, see above.
 * @return $this
 */
	public function addArgument($name, $params = array()) {
		if (is_object($name) && $name instanceof ConsoleInputArgument) {
			$arg = $name;
			$index = count($this->_args);
		} else {
			$defaults = array(
				'name' => $name,
				'help' => '',
				'index' => count($this->_args),
				'required' => false,
				'choices' => array()
			);
			$options = $params + $defaults;
			$index = $options['index'];
			unset($options['index']);
			$arg = new ConsoleInputArgument($options);
		}
		$this->_args[$index] = $arg;
		ksort($this->_args);
		return $this;
	}

/**
 * Add multiple arguments at once. Take an array of argument definitions.
 * The keys are used as the argument names, and the values as params for the argument.
 *
 * @param array $args Array of arguments to add.
 * @see ConsoleOptionParser::addArgument()
 * @return $this
 */
	public function addArguments(array $args) {
		foreach ($args as $name => $params) {
			$this->addArgument($name, $params);
		}
		return $this;
	}

/**
 * Add multiple options at once. Takes an array of option definitions.
 * The keys are used as option names, and the values as params for the option.
 *
 * @param array $options Array of options to add.
 * @see ConsoleOptionParser::addOption()
 * @return $this
 */
	public function addOptions(array $options) {
		foreach ($options as $name => $params) {
			$this->addOption($name, $params);
		}
		return $this;
	}

/**
 * Append a subcommand to the subcommand list.
 * Subcommands are usually methods on your Shell, but can also be used to document Tasks.
 *
 * ### Options
 *
 * - `help` - Help text for the subcommand.
 * - `parser` - A ConsoleOptionParser for the subcommand. This allows you to create method
 *	  specific option parsers. When help is generated for a subcommand, if a parser is present
 *	  it will be used.
 *
 * @param ConsoleInputSubcommand|string $name Name of the subcommand. Will also accept an instance of ConsoleInputSubcommand
 * @param array $options Array of params, see above.
 * @return $this
 */
	public function addSubcommand($name, $options = array()) {
		if (is_object($name) && $name instanceof ConsoleInputSubcommand) {
			$command = $name;
			$name = $command->name();
		} else {
			$defaults = array(
				'name' => $name,
				'help' => '',
				'parser' => null
			);
			$options += $defaults;
			$command = new ConsoleInputSubcommand($options);
		}
		$this->_subcommands[$name] = $command;
		return $this;
	}

/**
 * Remove a subcommand from the option parser.
 *
 * @param string $name The subcommand name to remove.
 * @return $this
 */
	public function removeSubcommand($name) {
		unset($this->_subcommands[$name]);
		return $this;
	}

/**
 * Add multiple subcommands at once.
 *
 * @param array $commands Array of subcommands.
 * @return $this
 */
	public function addSubcommands(array $commands) {
		foreach ($commands as $name => $params) {
			$this->addSubcommand($name, $params);
		}
		return $this;
	}

/**
 * Gets the arguments defined in the parser.
 *
 * @return array Array of argument descriptions
 */
	public function arguments() {
		return $this->_args;
	}

/**
 * Get the defined options in the parser.
 *
 * @return array
 */
	public function options() {
		return $this->_options;
	}

/**
 * Get the array of defined subcommands
 *
 * @return array
 */
	public function subcommands() {
		return $this->_subcommands;
	}

/**
 * Parse the argv array into a set of params and args. If $command is not null
 * and $command is equal to a subcommand that has a parser, that parser will be used
 * to parse the $argv
 *
 * @param array $argv Array of args (argv) to parse.
 * @param string $command The subcommand to use. If this parameter is a subcommand, that has a parser,
 *	  That parser will be used to parse $argv instead.
 * @return Array array($params, $args)
 * @throws ConsoleException When an invalid parameter is encountered.
 */
	public function parse($argv, $command = null) {
		if (isset($this->_subcommands[$command]) && $this->_subcommands[$command]->parser()) {
			return $this->_subcommands[$command]->parser()->parse($argv);
		}
		$params = $args = array();
		$this->_tokens = $argv;
		while (($token = array_shift($this->_tokens)) !== null) {
			if (substr($token, 0, 2) === '--') {
				$params = $this->_parseLongOption($token, $params);
			} elseif (substr($token, 0, 1) === '-') {
				$params = $this->_parseShortOption($token, $params);
			} else {
				$args = $this->_parseArg($token, $args);
			}
		}
		foreach ($this->_args as $i => $arg) {
			if ($arg->isRequired() && !isset($args[$i]) && empty($params['help'])) {
				throw new ConsoleException(
					__d('cake_console', 'Missing required arguments. %s is required.', $arg->name())
				);
			}
		}
		foreach ($this->_options as $option) {
			$name = $option->name();
			$isBoolean = $option->isBoolean();
			$default = $option->defaultValue();

			if ($default !== null && !isset($params[$name]) && !$isBoolean) {
				$params[$name] = $default;
			}
			if ($isBoolean && !isset($params[$name])) {
				$params[$name] = false;
			}
		}
		return array($params, $args);
	}

/**
 * Gets formatted help for this parser object.
 * Generates help text based on the description, options, arguments, subcommands and epilog
 * in the parser.
 *
 * @param string $subcommand If present and a valid subcommand that has a linked parser.
 *	  That subcommands help will be shown instead.
 * @param string $format Define the output format, can be text or xml
 * @param int $width The width to format user content to. Defaults to 72
 * @return string Generated help.
 */
	public function help($subcommand = null, $format = 'text', $width = 72) {
		if (isset($this->_subcommands[$subcommand]) &&
			$this->_subcommands[$subcommand]->parser() instanceof self
		) {
			$subparser = $this->_subcommands[$subcommand]->parser();
			$subparser->command($this->command() . ' ' . $subparser->command());
			return $subparser->help(null, $format, $width);
		}
		$formatter = new HelpFormatter($this);
		if ($format === 'text' || $format === true) {
			return $formatter->text($width);
		} elseif ($format === 'xml') {
			return $formatter->xml();
		}
	}

/**
 * Parse the value for a long option out of $this->_tokens. Will handle
 * options with an `=` in them.
 *
 * @param string $option The option to parse.
 * @param array $params The params to append the parsed value into
 * @return array Params with $option added in.
 */
	protected function _parseLongOption($option, $params) {
		$name = substr($option, 2);
		if (strpos($name, '=') !== false) {
			list($name, $value) = explode('=', $name, 2);
			array_unshift($this->_tokens, $value);
		}
		return $this->_parseOption($name, $params);
	}

/**
 * Parse the value for a short option out of $this->_tokens
 * If the $option is a combination of multiple shortcuts like -otf
 * they will be shifted onto the token stack and parsed individually.
 *
 * @param string $option The option to parse.
 * @param array $params The params to append the parsed value into
 * @return array Params with $option added in.
 * @throws ConsoleException When unknown short options are encountered.
 */
	protected function _parseShortOption($option, $params) {
		$key = substr($option, 1);
		if (strlen($key) > 1) {
			$flags = str_split($key);
			$key = $flags[0];
			for ($i = 1, $len = count($flags); $i < $len; $i++) {
				array_unshift($this->_tokens, '-' . $flags[$i]);
			}
		}
		if (!isset($this->_shortOptions[$key])) {
			throw new ConsoleException(__d('cake_console', 'Unknown short option `%s`', $key));
		}
		$name = $this->_shortOptions[$key];
		return $this->_parseOption($name, $params);
	}

/**
 * Parse an option by its name index.
 *
 * @param string $name The name to parse.
 * @param array $params The params to append the parsed value into
 * @return array Params with $option added in.
 * @throws ConsoleException
 */
	protected function _parseOption($name, $params) {
		if (!isset($this->_options[$name])) {
			throw new ConsoleException(__d('cake_console', 'Unknown option `%s`', $name));
		}
		$option = $this->_options[$name];
		$isBoolean = $option->isBoolean();
		$nextValue = $this->_nextToken();
		$emptyNextValue = (empty($nextValue) && $nextValue !== '0');
		if (!$isBoolean && !$emptyNextValue && !$this->_optionExists($nextValue)) {
			array_shift($this->_tokens);
			$value = $nextValue;
		} elseif ($isBoolean) {
			$value = true;
		} else {
			$value = $option->defaultValue();
		}
		if ($option->validChoice($value)) {
			$params[$name] = $value;
			return $params;
		}
		return array();
	}

/**
 * Check to see if $name has an option (short/long) defined for it.
 *
 * @param string $name The name of the option.
 * @return bool
 */
	protected function _optionExists($name) {
		if (substr($name, 0, 2) === '--') {
			return isset($this->_options[substr($name, 2)]);
		}
		if ($name{0} === '-' && $name{1} !== '-') {
			return isset($this->_shortOptions[$name{1}]);
		}
		return false;
	}

/**
 * Parse an argument, and ensure that the argument doesn't exceed the number of arguments
 * and that the argument is a valid choice.
 *
 * @param string $argument The argument to append
 * @param array $args The array of parsed args to append to.
 * @return array Args
 * @throws ConsoleException
 */
	protected function _parseArg($argument, $args) {
		if (empty($this->_args)) {
			$args[] = $argument;
			return $args;
		}
		$next = count($args);
		if (!isset($this->_args[$next])) {
			throw new ConsoleException(__d('cake_console', 'Too many arguments.'));
		}

		if ($this->_args[$next]->validChoice($argument)) {
			$args[] = $argument;
			return $args;
		}
	}

/**
 * Find the next token in the argv set.
 *
 * @return string next token or ''
 */
	protected function _nextToken() {
		return isset($this->_tokens[0]) ? $this->_tokens[0] : '';
	}

}
