#!/usr/bin/env php
<?php
/**
 * .git/hooks/pre-commit
 *
 * This pre-commit hooks will check for PHP errors (lint), and make sure the
 * code is PSR-2 compliant.
 *
 * @author  Reen Lokum http://github.com/reenl
 *
 * The orignal version of this file can be found at:
 * https://github.com/zendframework/zf2/blob/master/README-GIT.md
 *
 * Extended with functionality found at:
 * http://kvz.io/blog/2013/12/29/one-git-commit-hook-to-rule-them-all/
 */

$exit = 0;

// Initial commit
$against = '4b825dc642cb6eb9a060e54bf8d69288fbee4904';
if (run('git rev-parse --verify HEAD > /dev/null')) {
    $against = 'HEAD';
}

// Only run when we're on a branch (to avoid rebase hell)
// http://git-blame.blogspot.nl/2013/06/checking-current-branch-programatically.html
$branch = run('git symbolic-ref --short -q HEAD');
if (!$branch) {
    writeln('Not on any branch');
    exit(0);
}

/*
 * collect all files which have been added, copied or
 * modified and store them in an array called output
 */
$diffLines = array();
exec('git diff-index --cached --full-index --diff-filter=ACM '.$against, $diffLines);

writeln();

// Filter files that don't need a check.
foreach ($diffLines as $line) {
    $partList = preg_split('#\s+#', $line, 6);
    $hash = $partList[3];
    $status = $partList[4];
    $fileName = $partList[5];
    if ('D' === $status) {
        // deleted file; do nothing
        continue;
    }

    $type = strtolower(pathinfo($fileName, PATHINFO_EXTENSION));
    $validator = 'validator_'.$type;
    if (!$type || !function_exists($validator)) {
        $type = run("git cat-file -p ".$hash." | head -n1 | awk -F/ '/^#\!/ {print \$NF}' | sed 's/^env //g'");
        $validator = 'validator_'.$type;
        if (!function_exists($validator)) {
            // No validator
            writeln('  Skipping "'.format($fileName, 'green').'" no validator available.');
            continue;
        }
    }

    write('  Checking "'.format($fileName, 'green').'" with validator '.format($type, 'green').'.');

    $output = '';
    if (!$validator($hash, $fileName, $output)) {
        writeln(PHP_EOL.'X ERROR '.implode(PHP_EOL.'  ', explode(PHP_EOL, $output)).PHP_EOL, 'red');
        $exit = 1;
        continue;
    }
    writeln(' OK', 'green');
}

if ($exit > 0) {
    writeln(PHP_EOL."Please fix the above errors and run 'git add'.", 'gray');
}

exit($exit);

function validator_php($hash, $fileName, &$output)
{
    if (validator_php_syntax($hash, $fileName, $output)) {
        return validator_php_cs($hash, $fileName, $output);
    }

    return false;
}

function validator_php_syntax($hash, $fileName, &$output)
{
    $output = '';
    $exitCode = 0;

    $result = run('git cat-file -p '.escapeshellarg($hash).' | php -l', $output, $exitCode, "purge", "default");
    if ($result) {
        return true;
    }

    $output = 'Syntax Error'.PHP_EOL.$output;

    return false;
}

function validator_php_cs($hash, $fileName, &$output)
{
    // Use .php_cs config if project has one.
    $configFile = '';
    if (file_exists('.php_cs')) {
        $configFile = ' --config-file='.escapeshellarg(realpath('.php_cs'));
    }

    $tmpDir = '/tmp/cs-check/'.$hash;
    $tmp =  $tmpDir.'/'.$fileName;
    run('mkdir -p '.dirname($tmp));
    run('git cat-file -p '.escapeshellarg($hash).' > '.$tmp);

    $return = null;
    run('php-cs-fixer fix --dry-run --diff --verbose --rules=@Symfony'.$configFile.' '.escapeshellarg($tmp), $currentOutput, $return, 'default', 'default');

    run('rm -rf '.escapeshellarg($tmpDir));

    // Check output
    if ($return !== 0) {
        $out = explode(PHP_EOL, $currentOutput);

        $rule = null;
        foreach ($out as $line) {
            if (preg_match('#\s+[0-9]+\)\s#', $line)) {
                $rule = $line;
                break;
            }
        }

        if ($rule !== null && preg_match('#\((.*)\)#', $rule, $matches)) {
            $output = 'Code Style errors'.PHP_EOL.$matches[1];
        } else {
            $output = 'Code Style errors'.PHP_EOL.implode(PHP_EOL, $out).PHP_EOL;
        }

        return false;
    }

    return true;
}

/**
 * Runs like exec with a few changes:
 * - Output is returned as a string.
 * - Output is NOT appended.
 * - STDERR is also added to the output.
 * - STDERR and/or STDOUT can be disabled by passing purge.
 * - Returns the first output line if successful and false when failed.
 * - If no output is generated and the exit status equals 0 then true is returned.
 *
 * @param string $command
 * @param string &$output
 * @param int &$exitCode
 * @param string $stdout
 * @param string $stderr
 *
 * @return boolean
 */
function run($command, &$output = '', &$exitCode = 0, $stdout = 'default', $stderr = 'purge')
{
    $descriptors = array(
        0 => array("pipe", "r"),  // stdin
        1 => array("pipe", "w"),  // stdout
        2 => array("pipe", "w"),   // stderr
    );

    $pipes = array();

    $out = array();
    $process = proc_open($command, $descriptors, $pipes);
    fclose($pipes[0]);
    unset($pipes[0]);

    do {
        $read = $pipes;
        $write  = $except = array();
        if (!stream_select($read, $write, $except, 5)) {
            writeln('Timeout on process: '.$command, 'red');
            break;
        }

        foreach ($read as $pipe) {
            $pipeId = array_search($pipe, $pipes);
            if ($pipeId === false) {
                writeln('Unable to determine where the output came from.', 'red');
            }

            if (feof($pipe)) {
                fclose($pipe);
                if ($pipeId !== false) {
                    unset($pipes[$pipeId]);
                }
                continue;
            }

            $line = fgets($pipe);
            if ($line === false) {
                continue;
            }

            $color = $stderr;
            if ($pipeId == 1) {
                $color = $stdout;
            }

            if ($color != 'purge') {
                $out[] = format(rtrim($line), $color);
            }
        }
    } while (count($pipes) > 0);

    $exitCode = proc_close($process);
    $output = implode(PHP_EOL, $out);

    if ($exitCode == 0) {
        if (!isset($out[0]) || $out[0] == '') {
            return true;
        }

        return $out[0];
    }

    return false;
}

function format($string, $color = 'default')
{
    if ($color == 'default') {
        return $string;
    }

    if ($color == 'purge') {
        return '';
    }

    $colors = array(
        'gray'  => 37,
        'green' => 32,
        'red'   => 31,
    );

    if (!isset($colors[$color])) {
        writeln($color.' is not a valid color.');
        exit(1);
    }

    return chr(0x1B).'['.$colors[$color].'m'.$string.chr(0x1B).'[m';
}

function writeln($write = '', $color = 'default')
{
    write($write.PHP_EOL, $color);
}

function write($write = '', $color = 'default')
{
    echo format($write, $color);
    flush();
}