<?php
// Validation, and sanitize

function validate_register_id($s) {
	$s = mbtrim($s);
	$len = mb_strlen(mbtrim($s));
	if ($len < 3) { return ['ID は必須、3文字以上。']; }
	if ($len > 12) { return ['ID は 12文字以内。']; }
	if (!preg_match('/^[a-zA-Z0-9]+$/', $s)) { return ['ID は半角英數のみ。']; }
	return [];
}

function validate_register_username($s) {
	$len = mb_strlen(mbtrim($s));
	if ($len < 1) { return ['名前は必須。']; }
	if ($len > 50) { return ['名前は 50文字以内。']; }
	return [];
}

function sanitize_register_username($s) {
	// Escape fake trip (◆embcMFBoog -> ◇embcMFBoog)
	return str_replace('◆', '◇', sanitize_oneline($s));
}

function validate_register_password($s, $confirm) {
	if (mb_strlen($s) <= 0) { return ['パスワードは必須。']; }
	if ($s !== $confirm) { return ['パスワードが確認用と不一致。']; }
	return [];
}

function validate_bio($s) {
	if (mb_strlen($s) > 1000) { return ['自己紹介は 1000 文字以内。']; }
	return [];
}

function sanitize_bio($s) {
	return sanitize_multiline($s);
}

function validate_post_id($s) {
	if ((string)(int)$s !== $s || $s < 0) { return ['投稿 ID が不正。']; }
	return [];
}

function validate_post_title($s) {
	$len = mb_strlen(mbtrim($s));
	if ($len > 50) { return ['件名は 50 文字以内。']; }
	return [];
}

function sanitize_post_title($s) {
	return sanitize_oneline($s);
}

function validate_post_body($s) {
	$len = mb_strlen(mbtrim($s));
	if ($len <= 0) { return ['本文は必須。']; }
	if ($len > 5000) { return ['本文は 500 文字以内。']; }
	return [];
}

function sanitize_post_body($s) {
	return sanitize_multiline($s);
}

// Common

// See: https://www.php.net/manual/ja/regexp.reference.unicode.php

function sanitize_multiline($s) {
	$s = preg_replace('/[^\p{L}\{M}\p{N}\p{P}\p{Sc}\p{S}\p{Z}\012\015\040-\176]/u', '', $s);
	$s = mbtrim($s);
	return $s;
}

function sanitize_oneline($s) {
	// Newlines will be removed
	$s = preg_replace('/[^\p{L}\{M}\p{N}\p{P}\p{Sc}\p{S}\p{Z}\040-\176]/u', '', $s);
	$s = mbtrim($s);
	return $s;
}