#!/usr/bin/env python3
"""
多关键词搜索MCP服务器
支持关键词数组匹配，按匹配数量排序输出
参考json_reader_server.py的实现方式
"""

import json
import os
import sys
import asyncio
import re
from typing import Any, Dict, List, Optional, Union


def validate_file_path(file_path: str, allowed_dir: str) -> str:
    """验证文件路径是否在允许的目录内"""
    # 转换为绝对路径
    if not os.path.isabs(file_path):
        file_path = os.path.abspath(file_path)
    
    allowed_dir = os.path.abspath(allowed_dir)
    
    # 检查路径是否在允许的目录内
    if not file_path.startswith(allowed_dir):
        raise ValueError(f"访问被拒绝: 路径 {file_path} 不在允许的目录 {allowed_dir} 内")
    
    # 检查路径遍历攻击
    if ".." in file_path:
        raise ValueError(f"访问被拒绝: 检测到路径遍历攻击尝试")
    
    return file_path


def get_allowed_directory():
    """获取允许访问的目录"""
    # 从环境变量读取项目数据目录
    project_dir = os.getenv("PROJECT_DATA_DIR", "./projects")
    return os.path.abspath(project_dir)


def is_regex_pattern(pattern: str) -> bool:
    """检测字符串是否为正则表达式模式"""
    # 检查 /pattern/ 格式
    if pattern.startswith('/') and pattern.endswith('/') and len(pattern) > 2:
        return True
    
    # 检查 r"pattern" 或 r'pattern' 格式
    if pattern.startswith(('r"', "r'")) and pattern.endswith(('"', "'")) and len(pattern) > 3:
        return True
    
    # 检查是否包含正则特殊字符
    regex_chars = {'*', '+', '?', '|', '(', ')', '[', ']', '{', '}', '^', '$', '\\', '.'}
    return any(char in pattern for char in regex_chars)


def compile_pattern(pattern: str) -> Union[re.Pattern, str, None]:
    """编译正则表达式模式，如果不是正则则返回原字符串"""
    if not is_regex_pattern(pattern):
        return pattern
    
    try:
        # 处理 /pattern/ 格式
        if pattern.startswith('/') and pattern.endswith('/'):
            regex_body = pattern[1:-1]
            return re.compile(regex_body)
        
        # 处理 r"pattern" 或 r'pattern' 格式
        if pattern.startswith(('r"', "r'")) and pattern.endswith(('"', "'")):
            regex_body = pattern[2:-1]
            return re.compile(regex_body)
        
        # 直接编译包含正则字符的字符串
        return re.compile(pattern)
    except re.error as e:
        # 如果编译失败，返回None表示无效的正则
        print(f"警告: 正则表达式 '{pattern}' 编译失败: {e}")
        return None


def multi_keyword_search(keywords: List[str], file_paths: List[str], 
                        limit: int = 10, case_sensitive: bool = False) -> Dict[str, Any]:
    """执行多关键词和正则表达式搜索"""
    if not keywords:
        return {
            "content": [
                {
                    "type": "text",
                    "text": "错误：关键词列表不能为空"
                }
            ]
        }
    
    if not file_paths:
        return {
            "content": [
                {
                    "type": "text", 
                    "text": "错误：文件路径列表不能为空"
                }
            ]
        }
    
    # 预处理和验证关键词中的正则表达式
    valid_keywords = []
    regex_errors = []
    
    for keyword in keywords:
        compiled = compile_pattern(keyword)
        if compiled is None:
            regex_errors.append(keyword)
        else:
            valid_keywords.append(keyword)
    
    if regex_errors:
        error_msg = f"警告: 以下正则表达式编译失败，将被忽略: {', '.join(regex_errors)}"
        print(error_msg)
    
    # 处理项目目录限制
    project_data_dir = get_allowed_directory()
    
    # 验证文件路径
    valid_paths = []
    for file_path in file_paths:
        try:
            # 解析相对路径
            if not os.path.isabs(file_path):
                # 移除 projects/ 前缀（如果存在）
                clean_path = file_path
                if clean_path.startswith('projects/'):
                    clean_path = clean_path[9:]  # 移除 'projects/' 前缀
                elif clean_path.startswith('./projects/'):
                    clean_path = clean_path[11:]  # 移除 './projects/' 前缀
                
                # 尝试在项目目录中查找文件
                full_path = os.path.join(project_data_dir, clean_path.lstrip('./'))
                if os.path.exists(full_path):
                    valid_paths.append(full_path)
                else:
                    # 如果直接路径不存在，尝试递归查找
                    found = find_file_in_project(clean_path, project_data_dir)
                    if found:
                        valid_paths.append(found)
            else:
                if file_path.startswith(project_data_dir) and os.path.exists(file_path):
                    valid_paths.append(file_path)
        except Exception as e:
            continue
    
    if not valid_paths:
        return {
            "content": [
                {
                    "type": "text",
                    "text": f"错误：在项目目录 {project_data_dir} 中未找到指定文件"
                }
            ]
        }
    
    # 收集所有匹配结果
    all_results = []
    
    for file_path in valid_paths:
        try:
            results = search_keywords_in_file(file_path, valid_keywords, case_sensitive)
            all_results.extend(results)
        except Exception as e:
            continue
    
    # 按匹配数量排序（降序）
    all_results.sort(key=lambda x: x['match_count'], reverse=True)
    
    # 限制结果数量
    limited_results = all_results[:limit]
    
    # 格式化输出
    if not limited_results:
        return {
            "content": [
                {
                    "type": "text",
                    "text": "未找到匹配的结果"
                }
            ]
        }
    
    # 增强格式化输出，显示匹配类型和详细信息
    formatted_lines = []
    for result in limited_results:
        line_prefix = f"{result['line_number']}:match_count({result['match_count']}):"
        
        # 构建匹配详情
        match_details = []
        for pattern in result['matched_patterns']:
            if pattern['type'] == 'regex':
                match_details.append(f"[regex:{pattern['original']}={pattern['match']}]")
            else:
                match_details.append(f"[keyword:{pattern['match']}]")
        
        match_info = " ".join(match_details) if match_details else ""
        formatted_line = f"{line_prefix}{match_info}:{result['content']}" if match_info else f"{line_prefix}{result['content']}"
        formatted_lines.append(formatted_line)
    
    formatted_output = "\n".join(formatted_lines)
    
    return {
        "content": [
            {
                "type": "text",
                "text": formatted_output
            }
        ]
    }


def search_keywords_in_file(file_path: str, keywords: List[str], 
                          case_sensitive: bool) -> List[Dict[str, Any]]:
    """搜索单个文件中的关键词和正则表达式"""
    results = []
    
    try:
        with open(file_path, 'r', encoding='utf-8', errors='ignore') as f:
            lines = f.readlines()
    except Exception as e:
        return results
    
    # 预处理所有模式
    processed_patterns = []
    for keyword in keywords:
        compiled = compile_pattern(keyword)
        if compiled is not None:  # 跳过无效的正则表达式
            processed_patterns.append({
                'original': keyword,
                'pattern': compiled,
                'is_regex': isinstance(compiled, re.Pattern)
            })
    
    for line_number, line in enumerate(lines, 1):
        line_content = line.rstrip('\n\r')
        search_line = line_content if case_sensitive else line_content.lower()
        
        # 统计匹配的模式数量
        matched_patterns = []
        for pattern_info in processed_patterns:
            pattern = pattern_info['pattern']
            is_regex = pattern_info['is_regex']
            
            match_found = False
            match_details = None
            
            if is_regex:
                # 正则表达式匹配
                if case_sensitive:
                    match = pattern.search(line_content)
                else:
                    # 对于不区分大小写的正则，需要重新编译
                    if isinstance(pattern, re.Pattern):
                        # 创建不区分大小写的版本
                        flags = pattern.flags | re.IGNORECASE
                        case_insensitive_pattern = re.compile(pattern.pattern, flags)
                        match = case_insensitive_pattern.search(line_content)
                    else:
                        match = pattern.search(search_line)
                
                if match:
                    match_found = True
                    match_details = match.group(0)
            else:
                # 普通字符串匹配
                search_keyword = pattern if case_sensitive else pattern.lower()
                if search_keyword in search_line:
                    match_found = True
                    match_details = pattern
            
            if match_found:
                matched_patterns.append({
                    'original': pattern_info['original'],
                    'type': 'regex' if is_regex else 'keyword',
                    'match': match_details
                })
        
        match_count = len(matched_patterns)
        
        if match_count > 0:
            results.append({
                'line_number': line_number,
                'content': line_content,
                'match_count': match_count,
                'matched_patterns': matched_patterns,
                'file_path': file_path
            })
    
    return results


def find_file_in_project(filename: str, project_dir: str) -> Optional[str]:
    """在项目目录中递归查找文件"""
    for root, dirs, files in os.walk(project_dir):
        if filename in files:
            return os.path.join(root, filename)
    return None


async def handle_request(request: Dict[str, Any]) -> Dict[str, Any]:
    """Handle MCP request"""
    try:
        method = request.get("method")
        params = request.get("params", {})
        request_id = request.get("id")
        
        if method == "initialize":
            return {
                "jsonrpc": "2.0",
                "id": request_id,
                "result": {
                    "protocolVersion": "2024-11-05",
                    "capabilities": {
                        "tools": {}
                    },
                    "serverInfo": {
                        "name": "multi-keyword-search",
                        "version": "1.0.0"
                    }
                }
            }
        
        elif method == "ping":
            return {
                "jsonrpc": "2.0",
                "id": request_id,
                "result": {
                    "pong": True
                }
            }
        
        elif method == "tools/list":
            return {
                "jsonrpc": "2.0",
                "id": request_id,
                "result": {
                    "tools": [
                        {
                            "name": "multi_keyword_search",
                            "description": "智能关键词和正则表达式混合搜索工具，返回按匹配数量排序的结果。支持普通关键词和正则表达式混合使用。正则表达式支持格式：/pattern/、r\"pattern\"或包含正则特殊字符的字符串。结果格式：[行号]:[匹配数量]:[匹配信息]:[行的原始内容]",
                            "inputSchema": {
                                "type": "object",
                                "properties": {
                                    "keywords": {
                                        "type": "array",
                                        "items": {"type": "string"},
                                        "description": "要搜索的关键词和正则表达式数组。支持：1)普通关键词 2)/pattern/格式正则 3)r\"pattern\"格式正则 4)包含正则特殊字符的字符串"
                                    },
                                    "file_paths": {
                                        "type": "array", 
                                        "items": {"type": "string"},
                                        "description": "要搜索的文件路径列表"
                                    },
                                    "limit": {
                                        "type": "integer",
                                        "description": "返回结果的最大数量，默认10",
                                        "default": 10
                                    },
                                    "case_sensitive": {
                                        "type": "boolean",
                                        "description": "是否区分大小写，默认false",
                                        "default": False
                                    }
                                },
                                "required": ["keywords", "file_paths"]
                            }
                        }
                    ]
                }
            }
        
        elif method == "tools/call":
            tool_name = params.get("name")
            arguments = params.get("arguments", {})
            
            if tool_name == "multi_keyword_search":
                keywords = arguments.get("keywords", [])
                file_paths = arguments.get("file_paths", [])
                limit = arguments.get("limit", 10)
                case_sensitive = arguments.get("case_sensitive", False)
                
                result = multi_keyword_search(keywords, file_paths, limit, case_sensitive)
                
                return {
                    "jsonrpc": "2.0",
                    "id": request_id,
                    "result": result
                }
            
            else:
                return {
                    "jsonrpc": "2.0",
                    "id": request_id,
                    "error": {
                        "code": -32601,
                        "message": f"Unknown tool: {tool_name}"
                    }
                }
        
        else:
            return {
                "jsonrpc": "2.0",
                "id": request_id,
                "error": {
                    "code": -32601,
                    "message": f"Unknown method: {method}"
                }
            }
    
    except Exception as e:
        return {
            "jsonrpc": "2.0",
            "id": request.get("id"),
            "error": {
                "code": -32603,
                "message": f"Internal error: {str(e)}"
            }
        }


async def main():
    """Main entry point."""
    try:
        while True:
            # Read from stdin
            line = await asyncio.get_event_loop().run_in_executor(None, sys.stdin.readline)
            if not line:
                break
            
            line = line.strip()
            if not line:
                continue
            
            try:
                request = json.loads(line)
                response = await handle_request(request)
                
                # Write to stdout
                sys.stdout.write(json.dumps(response) + "\n")
                sys.stdout.flush()
            
            except json.JSONDecodeError:
                error_response = {
                    "jsonrpc": "2.0",
                    "error": {
                        "code": -32700,
                        "message": "Parse error"
                    }
                }
                sys.stdout.write(json.dumps(error_response) + "\n")
                sys.stdout.flush()
            
            except Exception as e:
                error_response = {
                    "jsonrpc": "2.0",
                    "error": {
                        "code": -32603,
                        "message": f"Internal error: {str(e)}"
                    }
                }
                sys.stdout.write(json.dumps(error_response) + "\n")
                sys.stdout.flush()
    
    except KeyboardInterrupt:
        pass


if __name__ == "__main__":
    asyncio.run(main())