<?php

$repos = "";

if (!isset($argv[1])) {
    die($argv[0]." REPOS_PATH\n");
}
$repos = $argv[1];

if (!file_exists($repos.'/format')) {
    echo $argv[1].": is not a valid subversion repository.\n";
    die($argv[0]." REPOS_PATH\n");
}

$king = new SVNKing($argv[1]);

$king->determineSubversionKing();
$king->printSubversionKing();


class SVNKing {
    
    public $repos;
    public $delta = array();
    public $total_delta = 0;
    
    public $commitsPerUser = array();
    public $total_commits = 0;
    
    
    public function __construct($repos) {
        $this->repos = $repos;
    }
    
    public function determineSubversionKing() {
        $this_month     = date('n');      
        $youngest       = $this->getYoungestRevision();
        $youngest_date  = $this->getRevisionDate($youngest);
        $youngest_month = date('n', $youngest_date);
         
        $revision       = $youngest;
        $revision_month = $youngest_month;
        
        while ($revision_month == $youngest_month) {            
            $revision--;
            $revision_date  = $this->getRevisionDate($revision);
            $revision_month = date('n', $revision_date);
            
            if ($revision_month < $youngest_month) {
                break;
            }

            $author = $this->getRevisionAuthor($revision);
            // echo "$author $revision ".date("d.m.Y H:i:s", $revision_date)."\n";
            if (trim($author) == "") {
                $author = "Unknown";
            }
            if (!isset($this->delta[$author])) {
                $this->delta[$author] = 0;
            }
            if (!isset($this->commitsPerUser[$author])) {
                $this->commitsPerUser[$author] = 0; 
            }
            $delta = $this->getRevisionLineDelta($revision);
            $this->delta[$author] += $delta;
            $this->commitsPerUser[$author]++;
            
            $this->total_delta += $delta;
            $this->total_commits++;
        }
    }
    
    public function printSubversionKing() {
        arsort($this->delta);
        arsort($this->commitsPerUser);
        
        $i = 1;
        echo "Repository: ". $this->repos."\n";
        echo "Total number of commits: ".$this->total_commits."\n";
        echo "Total line delta in the repository: " . $this->total_delta."\n";
        echo "--- Most productive users for ".date("m/Y")." ---\n";
        
        foreach ($this->delta as $user => $lines) {
            $percent = round( ($lines / $this->total_delta ) * 100, 2);
            echo str_pad($i,      4);
            echo str_pad($user,  20);
            echo str_pad($lines, 10);
            echo str_pad(sprintf("%05s%%", $percent), 10);
            echo "\n";
            $i++;
        }
        $i = 1;
        echo "--- Most active commiters for ".date("m/Y")." ---\n";        
        foreach ($this->commitsPerUser as $user => $commits) {
            $percent = round( ($commits / $this->total_commits ) * 100, 2);
            echo str_pad($i,        4);
            echo str_pad($user,    20);
            echo str_pad($commits, 10);
            echo str_pad(sprintf("%02d%%", $percent), 10);
            echo "\n";
            $i++;
        }
        echo "-----------------------------------------\n";
    }
    
    public function getYoungestRevision() {
        $repos = $this->repos;
        $revision = trim(`svnlook youngest $repos`);
        return $revision;
    }
    
    public function getRevisionDate($revision) {
        $repos = $this->repos;
        $date = trim(`svnlook date -r $revision $repos`);
        
        $iso = substr($date, 0, strpos($date, "(")-1 ); 
        
        $timestamp = strtotime($iso);
        if (!$timestamp) {
            throw new Exception("Could not parse revision date.");
        }
        return $timestamp;
    }
    
    public function getRevisionAuthor($revision) {
        $repos = $this->repos;
        return trim(`svnlook author -r $revision $repos`);
    }

    public function getRevisionLineDelta($revision) {
        $modified = 0;
        $repos = $this->repos;
        $diff = `svnlook diff -r $revision $repos`;
        $lines = explode("\n", $diff);
        foreach ($lines as $line) {
            if (substr($line, 0, 1) == '+') {
                $modified++;
            }
            if (substr($line, 0, 1) == '-') {
                $modified--;
            }
        }
        return $modified;
    }
}