<?php
/**
 * This file is part of escpos-php: PHP receipt printer library for use with
 * ESC/POS-compatible thermal and impact printers.
 *
 * Copyright (c) 2014-16 Michael Billington < michael.billington@gmail.com >,
 * incorporating modifications by others. See CONTRIBUTORS.md for a full list.
 *
 * This software is distributed under the terms of the MIT license. See LICENSE.md
 * for details.
 */
namespace Mike42\Escpos;

use Mike42\Escpos\CodePage;
use \InvalidArgumentException;

/**
 * Store compatibility information about one printer.
 */
class CapabilityProfile
{

    /**
     *
     * @var string $codePageCacheKey
     *  Hash of the code page data structure, to identify it for caching.
     */
    protected $codePageCacheKey;

    /**
     *
     * @var array $codePages
     *  Associtive array of CodePage objects, indicating which encodings the printer supports.
     */
    protected $codePages;

    /**
     *
     * @var array $colors
     *  Not used.
     */
    protected $colors;

    /**
     *
     * @var array $features
     *  Feature values.
     */
    protected $features;

    /**
     *
     * @var array $fonts
     *  Not used
     */
    protected $fonts;

    /**
     *
     * @var array $media
     *  Not used
     */
    protected $media;

    /**
     *
     * @var string $name
     *  Name of the profile, including model number.
     */
    protected $name;

    /**
     *
     * @var string $notes
     *  Notes on the profile, null if not set.
     */
    protected $notes;

    /**
     *
     * @var string $profileId
     *  ID of the profile.
     */
    protected $profileId;

    
    /**
     * @var string $vendor
     *  Name of manufacturer.
     */
    protected $vendor;
    
    /**
     *
     * @var array $encodings
     *  Data structure containing encodings loaded from disk, null if not loaded yet.
     */
    protected static $encodings = null;

    /**
     *
     * @var array $profiles
     *  Data structure containing profiles loaded from disk, null if not loaded yet.
     */
    protected static $profiles = null;

    /**
     * Construct new CapabilityProfile.
     * The encoding data must be loaded from disk before calling.
     *
     * @param unknown $profileId
     *            ID of the profile
     * @param array $profileData
     *            Profile data from disk.
     */
    protected function __construct($profileId, array $profileData)
    {
        // Basic primitive fields
        $this->profileId = $profileId;
        $this->name = $profileData['name'];
        $this->notes = $profileData['notes'];
        $this->vendor = $profileData['vendor'];
        // More complex fields that are not currently loaded into custom objects
        $this->features = $profileData['features'];
        $this->colors = $profileData['colors'];
        $this->fonts = $profileData['fonts'];
        $this->media = $profileData['media'];
        // More complex fields that are loaded into custom objects
        $this->codePages = array();
        $this->codePageCacheKey = md5(json_encode($profileData['codePages']));
        foreach ($profileData['codePages'] as $k => $v) {
            $this->codePages[$k] = new CodePage($v, self::$encodings[$v]);
        }
    }

    /**
     *
     * @return string Hash of the code page data structure, to identify it for caching.
     */
    public function getCodePageCacheKey()
    {
        return $this->codePageCacheKey;
    }

    /**
     *
     * @return array Associtive array of CodePage objects, indicating which encodings the printer supports.
     */
    public function getCodePages()
    {
        return $this->codePages;
    }

    /**
     *
     * @param string $featureName
     *            Name of the feature to retrieve.
     * @throws \InvalidArgumentException Where the feature does not exist.
     *         The exception will contain suggestions for the closest-named features.
     * @return mixed feature value.
     */
    public function getFeature($featureName)
    {
        if (isset($this->features[$featureName])) {
            return $this->features[$featureName];
        }
        $suggestionsArr = $this->suggestFeatureName($featureName);
        $suggestionsStr = implode(", ", $suggestionsArr);
        $str = "The feature '$featureName' does not exist. Try one that does exist, such as $suggestionsStr";
        throw new \InvalidArgumentException($str);
    }

    /**
     *
     * @return string ID of the profile.
     */
    public function getId()
    {
        return $this->profileId;
    }

    /**
     *
     * @return string Name of the printer.
     */
    public function getName()
    {
        return $this->name;
    }

    /**
     *
     * @return boolean True if Barcode B command is supported, false otherwise
     */
    public function getSupportsBarcodeB()
    {
        return $this->getFeature('barcodeB') === true;
    }

    /**
     *
     * @return boolean True if Bit Image Raster command is supported, false otherwise
     */
    public function getSupportsBitImageRaster()
    {
        return $this->getFeature('bitImageRaster') === true;
    }

    /**
     *
     * @return boolean True if Graphics command is supported, false otherwise
     */
    public function getSupportsGraphics()
    {
        return $this->getFeature('graphics') === true;
    }

    /**
     *
     * @return boolean True if PDF417 code command is supported, false otherwise
     */
    public function getSupportsPdf417Code()
    {
        // TODO submit 'pdf417Code' as a new feature to be tracked in upstream profiles
        return $this->getFeature('qrCode') === true;
    }

    /**
     *
     * @return boolean True if QR code command is supported, false otherwise
     */
    public function getSupportsQrCode()
    {
        return $this->getFeature('qrCode') === true;
    }

    /**
     *
     * @return boolean True if Star mode commands are supported, false otherwise
     */
    public function getSupportsStarCommands()
    {
        return $this->getFeature('starCommands') === true;
    }

    /**
     *
     * @return string Vendor of this printer.
     */
    public function getVendor()
    {
        return $this->vendor;
    }

    /**
     *
     * @param string $featureName
     *            Feature that does not exist
     * @return array Three most similar feature names that do exist.
     */
    protected function suggestFeatureName($featureName)
    {
        return self::suggestNearest($featureName, array_keys($this->features), 3);
    }

    /**
     *
     * @return array Names of all profiles that exist.
     */
    public static function getProfileNames()
    {
        self::loadCapabilitiesDataFile();
        return array_keys(self::$profiles);
    }

    /**
     * Retrieve the CapabilityProfile with the given ID.
     *
     * @param string $profileName
     *            The ID of the profile to load.
     * @throws InvalidArgumentException Where the ID does not exist. Some similarly-named profiles will be suggested in the Exception text.
     * @return CapabilityProfile The CapabilityProfile that was requested.
     */
    public static function load($profileName)
    {
        self::loadCapabilitiesDataFile();
        if (! isset(self::$profiles[$profileName])) {
            $suggestionsArray = self::suggestProfileName($profileName);
            $suggestionsStr = implode(", ", $suggestionsArray);
            throw new InvalidArgumentException("The CapabilityProfile '$profileName' does not exist. Try one that does exist, such as $suggestionsStr.");
        }
        return new CapabilityProfile($profileName, self::$profiles[$profileName]);
    }

    /**
     * Ensure that the capabilities.json data file has been loaded.
     */
    protected static function loadCapabilitiesDataFile()
    {
        if (self::$profiles === null) {
            $filename = dirname(__FILE__) . "/resources/capabilities.json";
            $capabilitiesData = json_decode(file_get_contents($filename), true);
            self::$profiles = $capabilitiesData['profiles'];
            self::$encodings = $capabilitiesData['encodings'];
        }
    }

    /**
     * Return choices with smallest edit distance to an invalid input.
     *
     * @param string $input
     *            Input that is not a valid choice
     * @param array $choices
     *            Array of valid choices.
     * @param int $num
     *            Number of suggestions to return
     */
    public static function suggestNearest($input, array $choices, $num)
    {
        $distances = array_fill_keys($choices, PHP_INT_MAX);
        foreach ($distances as $word => $_) {
            $distances[$word] = levenshtein($input, $word);
        }
        asort($distances);
        return array_slice(array_keys($distances), 0, min($num, count($choices)));
    }

    /**
     *
     * @param string $profileName
     *            profile name that does not exist
     * @return array Three similar profile names that do exist, plus 'simple' and 'default' for good measure.
     */
    protected static function suggestProfileName($profileName)
    {
        $suggestions = self::suggestNearest($profileName, array_keys(self::$profiles), 3);
        $alwaysSuggest = array(
            'simple',
            'default'
        );
        foreach ($alwaysSuggest as $item) {
            if (array_search($item, $suggestions) === false) {
                array_push($suggestions, $item);
            }
        }
        return $suggestions;
    }
}