<?php

namespace base\common\service\scheme;

use think\facade\Db;
use think\facade\Config;
use think\helper\Str;

class DbToSchemeService
{
    protected string $module = 'admin';
    protected string $connection;

    public function __construct()
    {
        $this->connection = Config::get('database.default', 'mysql');
    }

    public function generate(string $tableName, string $className = null): string
    {
        $prefix = Config::get('database.connections.' . $this->connection . '.prefix', '');
        $fullTableName = $tableName;
        // 如果表名不包含前缀，且配置了前缀，则添加
        if ($prefix && !str_starts_with($tableName, $prefix)) {
             $fullTableName = $prefix . $tableName;
        }
        
        // 尝试获取表信息
        try {
            // 获取列信息，TP通用方法
            $columns = Db::connect($this->connection)->getFields($fullTableName);
        } catch (\Exception $e) {
            // 尝试直接使用tableName
            $fullTableName = $tableName;
            $columns = Db::connect($this->connection)->getFields($fullTableName);
        }

        // 获取表注释
        $tableComment = $this->getTableComment($fullTableName);

        // 获取索引信息
        $indices = $this->getTableIndices($fullTableName);

        // 生成类名
        if (empty($className)) {
            // 去除前缀
            $shortName = $tableName;
            if ($prefix && str_starts_with($tableName, $prefix)) {
                $shortName = substr($tableName, strlen($prefix));
            }
            $className = Str::studly($shortName);
        }

        // 构建类内容
        return $this->buildClass($className, $fullTableName, $tableComment, $columns, $indices);
    }

    protected function getTableComment($tableName): string
    {
        $type = strtolower((string)Config::get('database.connections.' . $this->connection . '.type', ''));
        if ($type !== 'mysql') {
            return '';
        }

        try {
            $escaped = addcslashes($tableName, "\\_%");
            $rows = Db::connect($this->connection)->query("SHOW TABLE STATUS LIKE '$escaped'");
            if (!empty($rows)) {
                return isset($rows[0]['Comment']) ? (string)$rows[0]['Comment'] : '';
            }
        } catch (\Exception $e) {
        }

        try {
            $rows = Db::connect($this->connection)->query("SHOW CREATE TABLE `$tableName`");
            if (!empty($rows)) {
                $create = $rows[0]['Create Table'] ?? '';
                if ($create !== '' && preg_match("/COMMENT='(.*?)'/s", $create, $matches)) {
                    return stripcslashes($matches[1]);
                }
            }
        } catch (\Exception $e) {
        }

        return '';
    }

    protected function getTableIndices($tableName): array
    {
        try {
            // SHOW KEYS FROM table
            $keys = Db::connect($this->connection)->query("SHOW KEYS FROM `$tableName`");
            $indices = [];
            foreach ($keys as $key) {
                $name = $key['Key_name'];
                if ($name === 'PRIMARY') continue; // 主键在 Field 中处理
                
                if (!isset($indices[$name])) {
                    $indices[$name] = [
                        'name' => $name,
                        'columns' => [],
                        'type' => $key['Non_unique'] == 0 ? 'UNIQUE' : ($key['Index_type'] == 'FULLTEXT' ? 'FULLTEXT' : 'NORMAL')
                    ];
                }
                $indices[$name]['columns'][] = $key['Column_name'];
            }
            return array_values($indices);
        } catch (\Exception $e) {
            return [];
        }
    }

    protected function buildClass($className, $tableName, $tableComment, $columns, $indices): string
    {
        $fieldsCode = [];
        
        foreach ($columns as $field) {
            $fieldName = $field['name'];
            $type = $field['type']; // varchar(255)
            $comment = $field['comment'] ?? '';
            $default = $field['default'] ?? null;
            $notNull = $field['notnull'] ?? false;
            $primary = $field['primary'] ?? false;
            $autoinc = $field['autoinc'] ?? false;

            // 解析类型和长度
            preg_match('/(\w+)(?:\((\d+)(?:,(\d+))?\))?/', $type, $matches);
            $dbType = $matches[1] ?? 'varchar';
            $length = isset($matches[2]) ? (int)$matches[2] : null;
            $precision = isset($matches[2]) ? (int)$matches[2] : 0; // For decimal
            $scale = isset($matches[3]) ? (int)$matches[3] : 0;

            // 解析 Ulthon 组件语法
            $componentAttr = '';
            $cleanComment = $comment;
            
            // 匹配 {type} (options)
            // 改进：允许 options 中含有冒号，且 key:value 之间可能有空格，或者没有括号
            // 例子：{radio} (0:禁用,1:启用) 或 {image} 或 {relation} (table:mall_cate,relationBindSelect:title)
            if (preg_match('/\{(.*?)\}\s*(\((.*?)\))?/', $comment, $cmatch)) {
                $compType = $cmatch[1];
                $compOptionsStr = $cmatch[3] ?? '';
                $cleanComment = trim(str_replace($cmatch[0], '', $comment));
                
                // 解析选项 (1:A, 2:B) 或 (table:mall_cate,relationBindSelect:title)
                $optionsCode = '[]';
                if ($compOptionsStr) {
                    $options = [];
                    // 简单的 explode 可能有问题，如果值里面有逗号。但目前假设选项格式比较简单。
                    $parts = explode(',', $compOptionsStr);
                    foreach ($parts as $p) {
                        // 尝试分割 key:value
                        $kv = explode(':', trim($p), 2); // Limit to 2 parts
                        if (count($kv) >= 2) {
                            $k = trim($kv[0]);
                            $v = trim($kv[1]);
                            $options[$k] = $v;
                        } else {
                            $options[] = trim($p);
                        }
                    }
                    $optionsCode = $this->exportArray($options);
                }
                
                $componentAttr = "\n    #[Component(type: '$compType', options: $optionsCode)]";
            }

            // 如果是整型且未指定长度，默认11 (兼容旧习俗)
            if (str_contains($dbType, 'int') && !$length) {
                $length = 11;
            }

            // 构建 Field 注解参数
            $fieldParams = [];

            // type (default: varchar)
            if ($dbType !== 'varchar') {
                $fieldParams[] = "type: '$dbType'";
            }

            // length (default: null)
            if ($length !== null) {
                $fieldParams[] = "length: $length";
            }

            // precision (default: 0)
            if ($precision !== 0) {
                $fieldParams[] = "precision: $precision";
            }

            // scale (default: 0)
            if ($scale !== 0) {
                $fieldParams[] = "scale: $scale";
            }

            // nullable (default: true)
            if ($notNull) {
                $fieldParams[] = "nullable: false";
            }

            // default (default: null)
            if (!is_null($default)) {
                $defaultVal = is_string($default) ? "'$default'" : $default;
                $fieldParams[] = "default: $defaultVal";
            }

            // comment (default: '')
            if ($cleanComment !== '') {
                $fieldParams[] = "comment: '$cleanComment'";
            }

            // unsigned (default: false)
            if (str_contains($type, 'unsigned')) {
                $fieldParams[] = "unsigned: true";
            }

            // autoIncrement (default: false)
            if ($autoinc) {
                $fieldParams[] = "autoIncrement: true";
            }

            // primary (default: false)
            if ($primary) {
                $fieldParams[] = "primary: true";
            }

            $fieldAttrStr = implode(', ', $fieldParams);

            $fieldsCode[] = <<<PHP
    #[Field($fieldAttrStr)]$componentAttr
    public \$$fieldName;
PHP;
        }

        $fieldsBody = implode("\n\n", $fieldsCode);
        
        // 构建 Index 注解
        $indexAttrs = '';
        foreach ($indices as $idx) {
            $cols = $this->exportArray($idx['columns']);
            $indexAttrs .= "\n#[Index(columns: $cols, name: '{$idx['name']}', type: '{$idx['type']}')]";
        }

        return <<<PHP
<?php

namespace app\\{$this->module}\scheme;

use app\common\scheme\BaseScheme;
use app\common\scheme\attribute\Table;
use app\common\scheme\attribute\Field;
use app\common\scheme\attribute\Component;
use app\common\scheme\attribute\Index;

#[Table(name: '$tableName', comment: '$tableComment')]$indexAttrs
class $className extends BaseScheme
{
$fieldsBody
}
PHP;
    }

    protected function exportArray(array $array): string
    {
        // 简易数组导出
        $items = [];
        // 判断是否是关联数组
        $isAssoc = array_keys($array) !== range(0, count($array) - 1);
        
        foreach ($array as $k => $v) {
            $val = is_string($v) ? "'$v'" : $v;
            if ($isAssoc) {
                $key = is_int($k) ? $k : "'$k'";
                $items[] = "$key => $val";
            } else {
                $items[] = $val;
            }
        }
        return '[' . implode(', ', $items) . ']';
    }
}