<?php

header('Content-Type: application/json; charset=UTF-8');

error_reporting(E_ALL);
ini_set('display_errors', 1);

require_once('../../includes/common.php');

$debug_info = [];
$debug_info['current_dir'] = __DIR__;
$debug_info['current_file'] = __FILE__;
$debug_info['require_path'] = '../../includes/common.php';
$debug_info['file_exists'] = file_exists('../../includes/common.php') ? 'yes' : 'no';
$debug_info['parent_dir'] = dirname(__DIR__);
$debug_info['DB_isset'] = isset($DB) ? 'yes' : 'no';
if (isset($DB)) {
    $debug_info['DB_methods'] = get_class_methods($DB);
}

if (isset($_GET['api'])) {
    $api = $_GET['api'];
    
    if ($api === 'captcha') {
        session_start();
        $num1 = mt_rand(1, 10);
        $num2 = mt_rand(1, 10);
        $answer = $num1 + $num2;
        $captcha_key = 'captcha_' . session_id();
        $_SESSION[$captcha_key] = (string)$answer;
        
        echo json_encode([
            'ok' => true,
            'num1' => $num1,
            'num2' => $num2
        ], JSON_UNESCAPED_UNICODE);
        exit;
    }
    
    if ($api === 'categories') {
        try {
            $categories = [];
            $debug_info['DB_findAll_exists'] = method_exists($DB, 'findAll') ? 'yes' : 'no';
            
            if ($DB && method_exists($DB, 'findAll')) {
                $categories = $DB->findAll('category', '*', null, 'sid asc');
                $debug_info['categories_count'] = count($categories);
            }
            
            if (empty($categories)) {
                $categories = [
                    ['catename' => '唐诗'],
                    ['catename' => '宋词'],
                    ['catename' => '元曲'],
                    ['catename' => '诗词句'],
                    ['catename' => '现代诗']
                ];
                $debug_info['used_fallback'] = 'yes';
            }
            
            echo json_encode([
                'ok' => true,
                'categories' => $categories,
                'debug' => $debug_info
            ], JSON_UNESCAPED_UNICODE);
        } catch (Exception $e) {
            $debug_info['exception'] = $e->getMessage();
            echo json_encode([
                'ok' => true,
                'categories' => [
                    ['catename' => '唐诗'],
                    ['catename' => '宋词'],
                    ['catename' => '元曲'],
                    ['catename' => '诗词句'],
                    ['catename' => '现代诗']
                ],
                'debug' => $debug_info
            ], JSON_UNESCAPED_UNICODE);
        }
        exit;
    }
    
    if ($api === 'check-name') {
        if (!isset($_POST['name'])) {
            echo json_encode(['ok' => false, 'error' => '缺少name参数']);
            exit;
        }
        
        try {
            $name = trim($_POST['name']);
            $exists = false;
            $similar_count = 0;
            $max_similarity = 0;
            $threshold = isset($_POST['threshold']) ? intval($_POST['threshold']) : 80;
            $threshold = max(0, min(100, $threshold));
            
            if ($DB && method_exists($DB, 'findAll')) {
                $tables_to_check = ['site', 'apply'];
                
                foreach ($tables_to_check as $table) {
                    $all_records = $DB->findAll($table, 'name');
                    
                    if ($all_records) {
                        foreach ($all_records as $record) {
                            $db_name = trim($record['name']);
                            
                            if ($db_name === $name) {
                                $exists = true;
                                $max_similarity = 100;
                                $similar_count = 1;
                                break 2;
                            }
                            
                            $similarity = calculateSimilarity($name, $db_name);
                            if ($similarity >= $threshold) {
                                $similar_count++;
                                if ($similarity > $max_similarity) {
                                    $max_similarity = $similarity;
                                }
                            }
                        }
                    }
                }
            }
            
            if ($max_similarity >= $threshold) {
                $exists = true;
            }
            
            echo json_encode([
                'ok' => true,
                'exists' => $exists,
                'similar_count' => $similar_count,
                'max_similarity' => $max_similarity,
                'threshold' => $threshold
            ], JSON_UNESCAPED_UNICODE);
        } catch (Exception $e) {
            echo json_encode([
                'ok' => true,
                'exists' => false,
                'similar_count' => 0,
                'max_similarity' => 0,
                'threshold' => 80
            ], JSON_UNESCAPED_UNICODE);
        }
        exit;
    }
    
    if ($api === 'submit') {
        $submit_debug = [];
        
        session_start();
        $client_ip = $_SERVER['REMOTE_ADDR'] ?? 'unknown';
        $rate_limit_key = 'submit_rate_' . $client_ip;
        
        if (!isset($_SESSION[$rate_limit_key])) {
            $_SESSION[$rate_limit_key] = [];
        }
        
        $current_time = time();
        $_SESSION[$rate_limit_key] = array_filter($_SESSION[$rate_limit_key], function($time) use ($current_time) {
            return ($current_time - $time) < 60;
        });
        
        if (count($_SESSION[$rate_limit_key]) >= 3) {
            echo json_encode(['ok' => false, 'error' => '提交过于频繁，请稍后再试']);
            exit;
        }
        
        $img = isset($_POST['img']) ? trim($_POST['img']) : '';
        $isFlutter = strpos($img, 'Flutter') !== false;
        
        $required = ['name', 'catename', 'url', 'keywords', 'introduce'];
        if (!$isFlutter) {
            $required[] = 'captcha';
        }
        
        foreach ($required as $field) {
            if (!isset($_POST[$field]) || empty(trim($_POST[$field]))) {
                echo json_encode(['ok' => false, 'error' => "缺少必填字段：{$field}"]);
                exit;
            }
        }
        
        if (!$isFlutter) {
            $captcha = trim($_POST['captcha']);
            $captcha_key = 'captcha_' . session_id();
            if (!isset($_SESSION[$captcha_key]) || $_SESSION[$captcha_key] != $captcha) {
                echo json_encode(['ok' => false, 'error' => '验证码错误，请重新输入']);
                exit;
            }
            unset($_SESSION[$captcha_key]);
        }
        
        try {
            $name = trim($_POST['name']);
            $threshold = isset($_POST['threshold']) ? intval($_POST['threshold']) : 80;
            $threshold = max(0, min(100, $threshold));
            
            $similar_exists = false;
            if ($DB && method_exists($DB, 'findAll')) {
                $tables_to_check = ['site', 'apply'];
                
                foreach ($tables_to_check as $table) {
                    $all_records = $DB->findAll($table, 'name');
                    
                    if ($all_records) {
                        foreach ($all_records as $record) {
                            $db_name = trim($record['name']);
                            
                            if ($db_name === $name) {
                                $similar_exists = true;
                                break 2;
                            }
                            
                            $similarity = calculateSimilarity($name, $db_name);
                            if ($similarity >= $threshold) {
                                $similar_exists = true;
                                break 2;
                            }
                        }
                    }
                }
            }
            
            if ($similar_exists) {
                echo json_encode(['ok' => false, 'error' => '该诗词已存在！']);
                exit;
            }
            $catename = trim($_POST['catename']);
            $url = trim($_POST['url']);
            $keywords = trim($_POST['keywords']);
            $introduce = trim($_POST['introduce']);
            $img = isset($_POST['img']) ? trim($_POST['img']) : 'default';
            
            $submit_debug['input_data'] = [
                'name' => $name,
                'catename' => $catename,
                'url' => $url,
                'keywords' => $keywords,
                'introduce' => $introduce,
                'img' => $img
            ];
            
            $data = [
                'name' => $name,
                'img' => $img,
                'catename' => $catename,
                'url' => $url,
                'keywords' => $keywords,
                'introduce' => $introduce,
                'reject' => 0,
                'create_time' => date('Y-m-d H:i:s'),
                'update_time' => date('Y-m-d H:i:s')
            ];
            
            $submit_debug['insert_data'] = $data;
            $submit_debug['DB_insert_exists'] = method_exists($DB, 'insert') ? 'yes' : 'no';
            
            $result = false;
            $db_error = '';
            if ($DB && method_exists($DB, 'insert')) {
                $result = $DB->insert('apply', $data);
                $submit_debug['insert_result'] = $result;
                if (method_exists($DB, 'error')) {
                    $db_error = $DB->error();
                    $submit_debug['db_error'] = $db_error;
                }
                if (method_exists($DB, 'lastInsertId')) {
                    $submit_debug['last_insert_id'] = $DB->lastInsertId();
                }
            }
            
            if ($result) {
                $_SESSION[$rate_limit_key][] = $current_time;
                
                echo json_encode([
                    'ok' => true,
                    'message' => '✅ 提交成功！等待审核',
                    'debug' => $submit_debug
                ], JSON_UNESCAPED_UNICODE);
            } else {
                echo json_encode([
                    'ok' => false,
                    'error' => '❌ 数据库写入失败：无法插入数据',
                    'debug' => $submit_debug
                ], JSON_UNESCAPED_UNICODE);
            }
        } catch (Exception $e) {
            $submit_debug['exception'] = $e->getMessage();
            $submit_debug['trace'] = $e->getTraceAsString();
            echo json_encode([
                'ok' => false,
                'error' => $e->getMessage(),
                'debug' => $submit_debug
            ], JSON_UNESCAPED_UNICODE);
        }
        exit;
    }
}

function calculateSimilarity($str1, $str2) {
    $str1 = preg_replace('/[^\p{L}\p{N}\s]/u', '', $str1);
    $str2 = preg_replace('/[^\p{L}\p{N}\s]/u', '', $str2);
    $str1 = preg_replace('/\s+/', '', $str1);
    $str2 = preg_replace('/\s+/', '', $str2);
    
    $len1 = mb_strlen($str1, 'UTF-8');
    $len2 = mb_strlen($str2, 'UTF-8');
    
    if ($len1 === 0 || $len2 === 0) {
        return 0;
    }
    
    $maxLen = max($len1, $len2);
    $distance = levenshtein($str1, $str2);
    
    if ($distance === 0) {
        return 100;
    }
    
    $similarity = round((1 - $distance / $maxLen) * 100, 2);
    return max(0, min(100, $similarity));
}

echo json_encode(['ok' => false, 'error' => '无效的API请求']);