#!/usr/bin/env php
<?php

	$wd = getcwd();

	$git_dir = shell_exec('git rev-parse --show-toplevel');

	if(!$git_dir) {
		fprintf(STDERR, "Not inside a git path");
		exit(1);
	}

	$git_wd = substr($wd, strlen($git_dir));

	[$arguments, $flags] = parse_arguments(array_slice($argv, 1));

	$branches = [];

	if(count($arguments) == 1)
	{
		$branches['HEAD'] = hash_branch('HEAD', $flags);
	}

	foreach($arguments as $branch_name)
	{
		if(!isset($branches[$branch_name]))
		{
			$branches[$branch_name] = hash_branch($branch_name, $flags);
		}
	}

	$patch_index = [];
	foreach($branches as $branch_name => $branch_commits)
	{
		foreach($branch_commits as $commit)
		{
			if(empty($commit['patch_hash'])) continue;
			$patch_index[$commit['patch_hash']][$commit['commit_hash']] = $commit['branches'];
		}
	}

	$branch_compare_count = count($branches);

	foreach($patch_index as $patch_hash => $patch_commits)
	{
		$patch_branches = [];
		foreach($patch_commits as $commit_branches)
		{
			foreach($commit_branches as $branch_name)
			{
				$patch_branches[$branch_name] = $branch_name;
			}
		}

		$patch_branch_count = count($patch_branches);
		$first_commit = array_keys($patch_commits)[0];
		$first_branch = $patch_commits[$first_commit][0];
		$short_commit = substr($first_commit, 0, 7);

		if($patch_branch_count == $branch_compare_count)
		{
			if(count($patch_commits) > 1)
			{
				echo "{$short_commit} (ALL:cherry) {$branches[$first_branch][$first_commit]['title']}\n";

			}
			else
			{
				echo "{$short_commit} (ALL:same) {$branches[$first_branch][$first_commit]['title']}\n";
			}
		}
		else
		{
			echo "{$short_commit} (" . implode(', ', $patch_branches) . ") {$branches[$first_branch][$first_commit]['title']}\n";
		}
	}

	exit(0);

	function hash_branch($branch_name, $flags)
	{
		static $hashes = [];

		$cmd = 'git log --format="format:%H %s" ';
		if(!empty($flags['-c']))
		{
			$cmd .= ' -' . ((int) $flags['-c'][0]) . ' ';
		}
		if($branch_name)
		{
			$cmd .= escapeshellarg($branch_name);
		}

		$error = 0;
		$output = [];
		exec($cmd, $output, $error);
		if($error)
		{
			return FALSE;
		}

		$branch_hases = [];

		foreach($output as $row)
		{
			[$commit_hash, $commit_title] = explode(' ', $row, 2);

			if(!isset($hashes[$commit_hash]))
			{
				$hashes[$commit_hash] = load_commit($commit_hash, $commit_title, $flags);
			}

			$hashes[$commit_hash]['branches'][] = $branch_name;
			$branch_hases[$commit_hash] = &$hashes[$commit_hash];
		}

		return $branch_hases;
	}

	function load_commit($commit_hash, $commit_title, $flags)
	{
		$commit = ['commit_hash' => $commit_hash, 'title' => $commit_title, 'patch_hash' => NULL, 'branches' => []];
		$cmd = 'git show --format=format:%H ' . escapeshellarg($commit_hash);
		$error = 0;
		$output = [];
		exec($cmd, $output, $error);
		if($error)
		{
			return FALSE;
		}

		$compare_commit_hash = trim(array_shift($output));

		if($compare_commit_hash != $commit_hash)
		{
			return FALSE;
		}

		$hash_data = array();
		$include_file = TRUE;
		foreach($output as $row)
		{
			if(substr($row, 0, 5) == 'diff ')
			{
				if($flags AND isset($flags['-x']))
				{
					$match = FALSE;
					$row_parts = explode(' ', $row, 3);
					foreach($flags['-x'] as $path)
					{
						$path = trim($path);
						if(substr($path, 0, 1) == '/')
						{
							$path = substr($path, 1);
						}
						if(substr($path, -1) == '*')
						{
							$path = substr($path, 0, -1);
						}
						else if(substr($path, -1) != '/')
						{
							$path .= ' ';
						}
						if($row_parts[1] == '--git')
						{
							if(substr($row, 0, 13 + strlen($path)) == "diff --git a/{$path}")
							{
								$match = TRUE;
								break;
							}
						}
						else if($row_parts[1] == '--cc')
						{
							if(substr($row, 0, 10 + strlen($path)) == "diff --cc {$path}")
							{
								$match = TRUE;
								break;
							}
						}
					}
					if($match)
					{
						$include_file = FALSE;
						continue;
					}
				}

				$include_file = TRUE;
				$hash_data[] = $row;
				continue;
			}

			if(!$include_file)
			{
				continue;
			}

			if(substr($row, 0, 6) == 'index ')
			{
				continue;
			}

			if(substr($row, 0, 3) == '@@ ')
			{
				$hash_data[] = '@@';
				continue;
			}

			$hash_data[] = $row;
		}

		if($hash_data)
		{
			$commit['patch_hash'] = sha1(implode(PHP_EOL, $hash_data));
		}

		return $commit;
	}

	function parse_arguments($raw_arguments)
	{
		$arguments = array();
		$flags = array();

		while($raw_arguments)
		{
			$current_arguemnt = array_shift($raw_arguments);
			if(substr($current_arguemnt, 0, 1) != '-')
			{
				$arguments[] = $current_arguemnt;
				continue;
			}

			if($current_arguemnt == '--')
			{
				while($current_arguemnt = array_shift($raw_arguments))
				{
					$arguments[] = $current_arguemnt;
				}
				break;
			}

			$next_argument = array_shift($raw_arguments);
			$flags[$current_arguemnt][] = $next_argument;
		}

		return array($arguments, $flags);
	}