<?php

namespace Kaliop\eZMigrationBundle\Core\Executor;

use Kaliop\eZMigrationBundle\API\Value\MigrationStep;
use Kaliop\eZMigrationBundle\Core\ReferenceResolver\PrefixBasedResolverInterface;

class FileExecutor extends AbstractExecutor
{
    use IgnorableStepExecutorTrait;

    protected $supportedStepTypes = array('file');
    protected $supportedActions = array('load', 'save', 'copy', 'move', 'delete', 'append', 'prepend', 'exists');

    /** @var PrefixBasedResolverInterface $referenceResolver */
    protected $referenceResolver;

    public function __construct(PrefixBasedResolverInterface $referenceResolver)
    {
        $this->referenceResolver = $referenceResolver;
    }

    /**
     * @param MigrationStep $step
     * @return mixed
     * @throws \Exception
     */
    public function execute(MigrationStep $step)
    {
        parent::execute($step);

        if (!isset($step->dsl['mode'])) {
            throw new \Exception("Invalid step definition: missing 'mode'");
        }

        $action = $step->dsl['mode'];

        if (!in_array($action, $this->supportedActions)) {
            throw new \Exception("Invalid step definition: value '$action' is not allowed for 'mode'");
        }

        $this->skipStepIfNeeded($step);

        return $this->$action($step->dsl, $step->context);
    }

    /**
     * @param array $dsl
     * @param array $context
     * @return string
     * @throws \Exception
     */
    protected function load($dsl, $context)
    {
        if (!isset($dsl['file'])) {
            throw new \Exception("Can not load file: name missing");
        }
        $fileName = $this->referenceResolver->resolveReference($dsl['file']);
        if (!file_exists($fileName)) {
            throw new \Exception("Can not load '$fileName': file missing");
        }

        $this->setReferences($fileName, $dsl);

        return file_get_contents($fileName);
    }

    /**
     * @param array $dsl
     * @param array $context
     * @return string
     * @throws \Exception
     */
    protected function exists($dsl, $context)
    {
        if (!isset($dsl['file'])) {
            throw new \Exception("Can not check for existence of file: name missing");
        }
        $fileName = $this->referenceResolver->resolveReference($dsl['file']);

        $exists = file_exists($fileName);

        if (array_key_exists('references', $dsl)) {
            foreach ($dsl['references'] as $reference) {
                switch ($reference['attribute']) {
                    case 'exists':
                        $overwrite = false;
                        if (isset($reference['overwrite'])) {
                            $overwrite = $reference['overwrite'];
                        }
                        $this->referenceResolver->addReference($reference['identifier'], $exists, $overwrite);
                        break;
                }
            }
        }

        return $exists;
    }

    /**
     * @param array $dsl
     * @param array $context
     * @return int
     * @throws \Exception
     */
    protected function save($dsl, $context)
    {
        if (!isset($dsl['file']) || (!isset($dsl['body']) && !isset($dsl['template']))) {
            throw new \Exception("Can not save file: name or body or template missing");
        }

        if (is_string($dsl['body'])) {
            $contents = $this->resolveReferencesInText($dsl['body']);
        } elseif (is_string($dsl['template'])) {
            $contents = $this->resolveReferencesInText(file_get_contents($this->resolveReferences($dsl['template'])));
        } else {
            throw new \Exception("Can not save file: either body or template tag must be a string");
        }

        $fileName = $this->referenceResolver->resolveReference($dsl['file']);

        $overwrite = isset($dsl['overwrite']) ? $overwrite = $dsl['overwrite'] : false;
        if (!$overwrite && file_exists($fileName)) {
            throw new \Exception("Can not save file '$fileName: file already exists");
        }

        $return = file_put_contents($fileName, $contents);

        $this->setReferences($fileName, $dsl);

        return $return;
    }

    /**
     * @param array $dsl
     * @param array $context
     * @return int
     * @throws \Exception
     */
    protected function append($dsl, $context)
    {
        if (!isset($dsl['file']) || (!isset($dsl['body']) && !isset($dsl['template']))) {
            throw new \Exception("Can not append to file: name or body or template missing");
        }

        if (is_string($dsl['body'])) {
            $contents = $this->resolveReferencesInText($dsl['body']);
        } elseif (is_string($dsl['template'])) {
            $contents = $this->resolveReferencesInText(file_get_contents($this->resolveReferences($dsl['template'])));
        } else {
            throw new \Exception("Can not append to file: either body or template tag must be a string");
        }

        $fileName = $this->referenceResolver->resolveReference($dsl['file']);

        $return = file_put_contents($fileName, $contents, FILE_APPEND);

        $this->setReferences($fileName, $dsl);

        return $return;
    }

    /**
     * @param array $dsl
     * @param array $context
     * @return int
     * @throws \Exception
     */
    protected function prepend($dsl, $context)
    {
        if (!isset($dsl['file']) || (!isset($dsl['body']) && !isset($dsl['template']))) {
            throw new \Exception("Can not prepend to file: name or body or template missing");
        }

        if (is_string($dsl['body'])) {
            $contents = $this->resolveReferencesInText($dsl['body']);
        } elseif (is_string($dsl['template'])) {
            $contents = $this->resolveReferencesInText(file_get_contents($this->resolveReferences($dsl['template'])));
        } else {
            throw new \Exception("Can not append to file: either body or template tag must be a string");
        }

        $fileName = $this->referenceResolver->resolveReference($dsl['file']);

        if (file_exists($fileName)) {
            $contents .= file_get_contents($fileName);
        }

        $return = file_put_contents($fileName, $contents);

        $this->setReferences($fileName, $dsl);

        return $return;
    }

    /**
     * @param array $dsl
     * @param array $context
     * @return true
     * @throws \Exception
     */
    protected function copy($dsl, $context)
    {
        if (!isset($dsl['from']) || !isset($dsl['to'])) {
            throw new \Exception("Can not copy file: from or to missing");
        }

        $fileName = $this->referenceResolver->resolveReference($dsl['from']);
        if (!file_exists($fileName)) {
            throw new \Exception("Can not copy file '$fileName': file missing");
        }

        $this->setReferences($fileName, $dsl);

        $to = $this->referenceResolver->resolveReference($dsl['to']);
        $overwrite = isset($dsl['overwrite']) ? $overwrite = $dsl['overwrite'] : false;
        if (!$overwrite && file_exists($to)) {
            throw new \Exception("Can not copy file to '$to: file already exists");
        }

        if (!copy($fileName, $to)) {
            throw new \Exception("Can not copy file '$fileName' to '$to': operation failed");
        }

        return true;
    }

    /**
     * @param array $dsl
     * @param array $context
     * @return true
     * @throws \Exception
     */
    protected function move($dsl, $context)
    {
        if (!isset($dsl['from']) || !isset($dsl['to'])) {
            throw new \Exception("Can not move file: from or to missing");
        }

        $fileName = $this->referenceResolver->resolveReference($dsl['from']);
        if (!file_exists($fileName)) {
            throw new \Exception("Can not move file '$fileName': file missing");
        }

        $this->setReferences($fileName, $dsl);

        $to = $this->referenceResolver->resolveReference($dsl['to']);
        $overwrite = isset($dsl['overwrite']) ? $overwrite = $dsl['overwrite'] : false;
        if (!$overwrite && file_exists($to)) {
            throw new \Exception("Can not move to '$to': file already exists");
        }

        if (!rename($fileName, $to)) {
            throw new \Exception("Can not move file '$fileName': operation failed");
        }

        return true;
    }

    /**
     * @param array $dsl
     * @param array $context
     * @return true
     * @throws \Exception
     */
    protected function delete($dsl, $context)
    {
        if (!isset($dsl['file'])) {
            throw new \Exception("Can not delete file: name missing");
        }

        $fileName = $this->referenceResolver->resolveReference($dsl['file']);
        if (!file_exists($fileName)) {
            throw new \Exception("Can not move delete '$fileName': file missing");
        }

        $this->setReferences($fileName, $dsl);

        if (!unlink($fileName)) {
            throw new \Exception("Can not delete file '$fileName': operation failed");
        }

        return true;
    }

    protected function setReferences($fileName, $dsl)
    {
        if (!array_key_exists('references', $dsl)) {
            return false;
        }

        clearstatcache(true, $fileName);
        $stats = stat($fileName);

        if (!$stats) {
            throw new \Exception("Can not set references for file '$fileName': stat failed");
        }

        foreach ($dsl['references'] as $reference) {
            switch ($reference['attribute']) {
                case 'body':
                    $value = file_get_contents($fileName);
                    break;
                case 'size':
                    $value = $stats[7];
                    break;
                case 'uid':
                    $value = $stats[4];
                    break;
                case 'gid':
                    $value = $stats[5];
                    break;
                case 'atime':
                    $value = $stats[8];
                    break;
                case 'mtime':
                    $value = $stats[9];
                    break;
                case 'ctime':
                    $value = $stats[10];
                    break;
                default:
                    throw new \InvalidArgumentException('File executor does not support setting references for attribute ' . $reference['attribute']);
            }

            $overwrite = false;
            if (isset($reference['overwrite'])) {
                $overwrite = $reference['overwrite'];
            }
            $this->referenceResolver->addReference($reference['identifier'], $value, $overwrite);
        }

        return true;
    }

    /**
     * Replaces any references inside a string
     *
     * @param string $text
     * @return string
     */
    protected function resolveReferencesInText($text)
    {
        // we need to alter the regexp we get from the resolver, as it will be used to match parts of text, not the whole string
        $regexp = substr($this->referenceResolver->getRegexp(), 1, -1);
        // NB: here we assume that all regexp resolvers give us a regexp with a very specific format...
        $regexp = '/\[' . preg_replace(array('/^\^/'), array('', ''), $regexp) . '[^]]+\]/';

        $count = preg_match_all($regexp, $text, $matches);
        // $matches[0][] will have the matched full string eg.: [reference:example_reference]
        if ($count) {
            foreach ($matches[0] as $referenceIdentifier) {
                $reference = $this->referenceResolver->getReferenceValue(substr($referenceIdentifier, 1, -1));
                $text = str_replace($referenceIdentifier, $reference, $text);
            }
        }

        return $text;
    }
}