<?php

function visitor_ideas_dir(): string {
    return getenv('WEBSITE_IDEAS_WRITE_DIR') ?: sys_get_temp_dir() . '/website-ideas';
}

function visitor_ideas_file(): string {
    return visitor_ideas_dir() . '/ideas.jsonl';
}

function visitor_ideas_rate_file(): string {
    return visitor_ideas_dir() . '/rate.json';
}

function visitor_ideas_ensure_dir(): bool {
    $dir = visitor_ideas_dir();
    return is_dir($dir) || mkdir($dir, 0750, true);
}

function visitor_idea_clean(string $value, int $maxLength): string {
    $value = preg_replace('/<\s*(script|style)\b[^>]*>.*?<\s*\/\s*\1\s*>/is', '', $value) ?? $value;
    $value = strip_tags($value);
    $value = str_replace(["\r\n", "\r"], "\n", $value);
    $value = preg_replace('/[\x00-\x08\x0B\x0C\x0E-\x1F\x7F]/u', '', $value) ?? '';
    $value = preg_replace('/[ \t]+/u', ' ', $value) ?? $value;
    $value = preg_replace("/\n{3,}/", "\n\n", $value) ?? $value;
    $value = trim($value);
    if (strlen($value) > $maxLength) {
        $value = substr($value, 0, $maxLength);
    }
    return $value;
}

function visitor_ideas_recently_submitted(int $seconds = 45): bool {
    if (!visitor_ideas_ensure_dir()) {
        return true;
    }

    $file = visitor_ideas_rate_file();
    $key = hash('sha256', $_SERVER['REMOTE_ADDR'] ?? 'unknown');
    $now = time();
    $handle = fopen($file, 'c+');
    if (!$handle) {
        return true;
    }

    flock($handle, LOCK_EX);
    $raw = stream_get_contents($handle);
    $rates = json_decode($raw ?: '{}', true);
    if (!is_array($rates)) {
        $rates = [];
    }

    foreach ($rates as $rateKey => $timestamp) {
        if (!is_int($timestamp) && !ctype_digit((string) $timestamp)) {
            unset($rates[$rateKey]);
            continue;
        }
        if ($now - (int) $timestamp > 86400) {
            unset($rates[$rateKey]);
        }
    }

    $last = (int) ($rates[$key] ?? 0);
    $blocked = $now - $last < $seconds;
    if (!$blocked) {
        $rates[$key] = $now;
        rewind($handle);
        ftruncate($handle, 0);
        fwrite($handle, json_encode($rates, JSON_UNESCAPED_SLASHES));
    }
    fflush($handle);
    flock($handle, LOCK_UN);
    fclose($handle);

    return $blocked;
}

function visitor_ideas_append(string $name, string $idea): bool {
    if (!visitor_ideas_ensure_dir()) {
        return false;
    }

    $entry = [
        'name' => $name !== '' ? $name : 'Anonymous visitor',
        'idea' => $idea,
        'created_at' => gmdate('c'),
    ];

    return file_put_contents(
        visitor_ideas_file(),
        json_encode($entry, JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES) . "\n",
        FILE_APPEND | LOCK_EX
    ) !== false;
}

function visitor_ideas_read(int $limit = 6): array {
    $file = visitor_ideas_file();
    if (!is_readable($file)) {
        return [];
    }

    $lines = file($file, FILE_IGNORE_NEW_LINES | FILE_SKIP_EMPTY_LINES);
    if (!$lines) {
        return [];
    }

    $ideas = [];
    foreach (array_reverse($lines) as $line) {
        $entry = json_decode($line, true);
        if (!is_array($entry) || !isset($entry['idea'], $entry['name'], $entry['created_at'])) {
            continue;
        }
        $ideas[] = [
            'name' => visitor_idea_clean((string) $entry['name'], 80),
            'idea' => visitor_idea_clean((string) $entry['idea'], 600),
            'created_at' => visitor_idea_clean((string) $entry['created_at'], 40),
        ];
        if (count($ideas) >= $limit) {
            break;
        }
    }

    return $ideas;
}