import base64
import re
import os
import email
from email import policy
from datetime import datetime, timedelta
import psutil
import time

from flask import jsonify, request, current_app
from sqlalchemy import or_, func, desc

from . import api_bp
from ..models import Email, Domain, Mailbox, get_session
from ..services import get_mail_store

# 调试接口 - 检查邮件接收状态
@api_bp.route('/debug_email', methods=['GET'])
def debug_email():
    """
    调试接口：检查某个邮箱的邮件状态并提供详细信息
    
    查询参数:
    - email: 邮箱地址 (例如: newsadd1test@nosqli.com)
    """
    try:
        # 获取查询参数
        email_address = request.args.get('email')
        
        # 验证邮箱地址是否有效
        if not email_address or '@' not in email_address:
            return jsonify({
                'success': False,
                'error': '无效的邮箱地址',
                'message': '请提供有效的邮箱地址，格式为user@domain.com'
            }), 400
        
        # 解析邮箱地址
        username, domain_name = email_address.split('@', 1)
        
        result = {
            'email_address': email_address,
            'username': username,
            'domain': domain_name,
            'system_info': {},
            'logs': [],
            'files': []
        }
        
        # 查询数据库
        db = get_session()
        try:
            # 查找域名
            domain = db.query(Domain).filter_by(name=domain_name).first()
            
            if domain:
                result['system_info']['domain'] = {
                    'id': domain.id,
                    'name': domain.name,
                    'active': domain.active,
                    'created_at': str(domain.created_at) if hasattr(domain, 'created_at') else None
                }
                
                # 查找邮箱
                mailbox = db.query(Mailbox).filter_by(
                    domain_id=domain.id,
                    address=username
                ).first()
                
                if mailbox:
                    result['system_info']['mailbox'] = {
                        'id': mailbox.id,
                        'address': mailbox.address,
                        'full_address': f"{mailbox.address}@{domain_name}",
                        'created_at': str(mailbox.created_at) if hasattr(mailbox, 'created_at') else None
                    }
                    
                    # 获取邮件
                    emails = db.query(Email).filter_by(mailbox_id=mailbox.id).all()
                    
                    result['system_info']['emails_count'] = len(emails)
                    result['system_info']['emails'] = []
                    
                    for email_obj in emails:
                        email_info = {
                            'id': email_obj.id,
                            'subject': email_obj.subject,
                            'sender': email_obj.sender,
                            'received_at': str(email_obj.received_at),
                            'verification_code': email_obj.verification_code if hasattr(email_obj, 'verification_code') else None
                        }
                        result['system_info']['emails'].append(email_info)
                else:
                    result['system_info']['mailbox'] = "未找到邮箱记录"
            else:
                result['system_info']['domain'] = "未找到域名记录"
            
            # 查找文件
            email_data_dir = current_app.config.get('MAIL_STORAGE_PATH', 'email_data')
            emails_dir = os.path.join(email_data_dir, 'emails')
            
            if os.path.exists(emails_dir):
                for file_name in os.listdir(emails_dir):
                    if file_name.endswith('.eml'):
                        file_path = os.path.join(emails_dir, file_name)
                        file_info = {
                            'name': file_name,
                            'path': file_path,
                            'size': os.path.getsize(file_path),
                            'modified': datetime.fromtimestamp(os.path.getmtime(file_path)).isoformat()
                        }
                        
                        # 尝试读取文件内容并检查是否包含收件人地址
                        try:
                            with open(file_path, 'r', encoding='utf-8', errors='replace') as f:
                                content = f.read(10000)  # 只读取前10000个字符用于检查
                                if email_address.lower() in content.lower():
                                    file_info['contains_address'] = True
                                    result['files'].append(file_info)
                        except Exception as e:
                            file_info['error'] = str(e)
                            result['files'].append(file_info)
            
            # 检查日志
            log_file = current_app.config.get('LOG_FILE', os.path.join('logs', 'email_system.log'))
            if os.path.exists(log_file):
                try:
                    with open(log_file, 'r', encoding='utf-8', errors='replace') as f:
                        # 从日志尾部读取最后200行
                        lines = f.readlines()[-200:]
                        for line in lines:
                            if email_address.lower() in line.lower():
                                result['logs'].append(line.strip())
                except Exception as e:
                    result['logs'] = [f"读取日志出错: {str(e)}"]
            
            return jsonify({
                'success': True,
                'debug_info': result
            }), 200
            
        finally:
            db.close()
    
    except Exception as e:
        current_app.logger.error(f"调试邮件出错: {str(e)}")
        return jsonify({
            'success': False,
            'error': '服务器错误',
            'message': str(e)
        }), 500

# 创建邮箱接口
@api_bp.route('/add_mailbox', methods=['POST', 'GET'])
def add_mailbox():
    """
    创建新邮箱，如果域名不存在则自动创建
    
    查询参数（GET方式）或表单参数（POST方式）:
    - email: 邮箱地址 (例如: testaa@nosqli.com)
    - description: 邮箱描述 (可选)
    """
    try:
        # 获取参数
        if request.method == 'POST':
            data = request.json or {}
            email_address = data.get('email')
            description = data.get('description', '')
        else:  # GET方式
            email_address = request.args.get('email')
            description = request.args.get('description', '')
        
        # 验证邮箱地址
        if not email_address or '@' not in email_address:
            return jsonify({
                'success': False,
                'error': '无效的邮箱地址',
                'message': '请提供有效的邮箱地址，格式为user@domain.com'
            }), 400
        
        # 解析邮箱地址
        username, domain_name = email_address.split('@', 1)
        
        # 创建或查找域名和邮箱
        db = get_session()
        try:
            # 查找域名
            domain = db.query(Domain).filter_by(name=domain_name).first()
            
            # 如果域名不存在，创建域名
            if not domain:
                current_app.logger.info(f"域名 {domain_name} 不存在，开始创建")
                domain = Domain(
                    name=domain_name,
                    description=f"自动创建的域名 {domain_name}",
                    active=True
                )
                db.add(domain)
                db.commit()
                current_app.logger.info(f"域名 {domain_name} 创建成功，ID: {domain.id}")
            
            # 查询邮箱是否已存在
            mailbox = db.query(Mailbox).filter_by(
                domain_id=domain.id,
                address=username
            ).first()
            
            # 如果邮箱已存在，返回已存在信息
            if mailbox:
                return jsonify({
                    'success': True,
                    'message': f'邮箱 {email_address} 已存在',
                    'mailbox': {
                        'id': mailbox.id,
                        'address': mailbox.address,
                        'domain_id': mailbox.domain_id,
                        'full_address': f"{mailbox.address}@{domain_name}",
                        'description': mailbox.description
                    }
                }), 200
            
            # 创建邮箱
            mailbox = Mailbox(
                domain_id=domain.id,
                address=username,
                description=description or f"自动创建的邮箱 {email_address}"
            )
            db.add(mailbox)
            db.commit()
            
            # 返回成功信息
            return jsonify({
                'success': True,
                'message': f'邮箱 {email_address} 创建成功',
                'mailbox': {
                    'id': mailbox.id,
                    'address': mailbox.address,
                    'domain_id': mailbox.domain_id,
                    'full_address': f"{mailbox.address}@{domain_name}",
                    'description': mailbox.description
                }
            }), 201
            
        finally:
            db.close()
    
    except Exception as e:
        current_app.logger.error(f"创建邮箱出错: {str(e)}")
        return jsonify({
            'success': False,
            'error': '服务器错误',
            'message': str(e)
        }), 500

# 简化的URL路径，直接通过邮箱地址获取邮件
@api_bp.route('/email', methods=['GET'])
def get_email_by_address():
    """
    通过邮箱地址获取邮件的简化URL
    等同于 /decoded_emails?email={email_address}&latest=0
    
    查询参数:
    - email: 邮箱地址 (必填)
    - latest: 是否只返回最新的邮件 (1表示是，0表示否，默认0)
    """
    # 重用已有的解码邮件接口
    return get_decoded_emails()

@api_bp.route('/decoded_emails', methods=['GET'])
def get_decoded_emails():
    """
    获取指定邮箱地址的所有邮件，并返回解码后的内容
    
    查询参数:
    - email: 邮箱地址 (例如: testaa@nosqli.com)
    - latest: 是否只返回最新的邮件 (1表示是，0表示否，默认0)
    - limit: 返回邮件数量 (默认10)
    - offset: 查询起始位置 (默认0)
    """
    try:
        # 获取查询参数
        email_address = request.args.get('email')
        latest = request.args.get('latest', '0') == '1'
        limit = int(request.args.get('limit', 10))
        offset = int(request.args.get('offset', 0))
        
        # 验证邮箱地址是否有效
        if not email_address or '@' not in email_address:
            return jsonify({
                'success': False,
                'error': '无效的邮箱地址',
                'message': '请提供有效的邮箱地址，格式为user@domain.com'
            }), 400
        
        # 解析邮箱地址
        username, domain_name = email_address.split('@', 1)
        
        # 查询数据库
        db = get_session()
        try:
            # 查找域名
            domain = db.query(Domain).filter_by(name=domain_name).first()
            if not domain:
                return jsonify({
                    'success': False,
                    'error': '域名不存在',
                    'message': f'域名 {domain_name} 不存在'
                }), 404
            
            # 查找邮箱
            mailbox = db.query(Mailbox).filter_by(
                domain_id=domain.id,
                address=username
            ).first()
            
            if not mailbox:
                return jsonify({
                    'success': False,
                    'error': '邮箱不存在',
                    'message': f'邮箱 {email_address} 不存在'
                }), 404
            
            # 获取邮件
            query = db.query(Email).filter_by(mailbox_id=mailbox.id)
            
            # 按接收时间排序，最新的在前
            query = query.order_by(Email.received_at.desc())
            
            # 如果只要最新的一封
            if latest:
                emails = query.limit(1).all()
            else:
                emails = query.limit(limit).offset(offset).all()
            
            # 处理结果
            result_emails = []
            for email_obj in emails:
                # 获取原始邮件文件路径
                email_file_path = os.path.join(
                    current_app.config.get('MAIL_STORAGE_PATH', 'email_data'),
                    'emails',
                    f'email_{email_obj.id}.eml'
                )
                
                # 解码邮件内容
                decoded_email = decode_email(email_obj, email_file_path)
                result_emails.append(decoded_email)
            
            # 返回结果
            return jsonify({
                'success': True,
                'email_address': email_address,
                'total_emails': query.count(),
                'emails': result_emails
            }), 200
            
        finally:
            db.close()
    
    except Exception as e:
        current_app.logger.error(f"获取解码邮件出错: {str(e)}")
        return jsonify({
            'success': False,
            'error': '服务器错误',
            'message': str(e)
        }), 500


@api_bp.route('/decoded_email/<int:email_id>', methods=['GET'])
def get_decoded_email_by_id(email_id):
    """获取指定ID的解码邮件内容"""
    try:
        db = get_session()
        try:
            # 获取邮件对象
            email_obj = db.query(Email).filter_by(id=email_id).first()
            
            if not email_obj:
                return jsonify({
                    'success': False,
                    'error': '邮件不存在',
                    'message': f'ID为{email_id}的邮件不存在'
                }), 404
            
            # 获取原始邮件文件路径
            email_file_path = os.path.join(
                current_app.config.get('MAIL_STORAGE_PATH', 'email_data'),
                'emails',
                f'email_{email_obj.id}.eml'
            )
            
            # 解码邮件内容
            decoded_email = decode_email(email_obj, email_file_path)
            
            # 返回结果
            return jsonify({
                'success': True,
                'email': decoded_email
            }), 200
            
        finally:
            db.close()
    
    except Exception as e:
        current_app.logger.error(f"获取解码邮件出错: {str(e)}")
        return jsonify({
            'success': False,
            'error': '服务器错误',
            'message': str(e)
        }), 500


def decode_email(email_obj, email_file_path):
    """解析并解码邮件内容"""
    # 创建基本邮件信息
    result = {
        'id': email_obj.id,
        'subject': email_obj.subject,
        'sender': email_obj.sender,
        'recipients': email_obj.recipients,
        'received_at': email_obj.received_at.isoformat() if email_obj.received_at else None,
        'read': email_obj.read,
        'has_attachments': len(email_obj.attachments) > 0 if hasattr(email_obj, 'attachments') else False
    }
    
    # 从数据库中直接获取验证码
    if hasattr(email_obj, 'verification_code') and email_obj.verification_code:
        result['verification_code'] = email_obj.verification_code
    
    if hasattr(email_obj, 'verification_link') and email_obj.verification_link:
        result['verification_link'] = email_obj.verification_link
    
    # 如果邮件对象有文本内容或HTML内容，直接使用
    if hasattr(email_obj, 'body_text') and email_obj.body_text:
        result['body_text'] = email_obj.body_text
    
    if hasattr(email_obj, 'body_html') and email_obj.body_html:
        result['body_html'] = email_obj.body_html
    
    # 如果有原始邮件文件，尝试解析
    if os.path.exists(email_file_path):
        try:
            # 解析.eml文件
            with open(email_file_path, 'r', encoding='utf-8', errors='replace') as f:
                msg = email.message_from_file(f, policy=policy.default)
            
            # 如果没有从数据库获取到内容，尝试从文件解析
            if 'body_text' not in result or 'body_html' not in result:
                body_text = ""
                body_html = ""
                
                # 处理多部分邮件
                if msg.is_multipart():
                    for part in msg.iter_parts():
                        content_type = part.get_content_type()
                        
                        if content_type == "text/plain":
                            try:
                                body_text = part.get_content()
                            except Exception:
                                payload = part.get_payload(decode=True)
                                if payload:
                                    charset = part.get_content_charset() or 'utf-8'
                                    try:
                                        body_text = payload.decode(charset, errors='replace')
                                    except:
                                        body_text = payload.decode('utf-8', errors='replace')
                        
                        elif content_type == "text/html":
                            try:
                                body_html = part.get_content()
                            except Exception:
                                payload = part.get_payload(decode=True)
                                if payload:
                                    charset = part.get_content_charset() or 'utf-8'
                                    try:
                                        body_html = payload.decode(charset, errors='replace')
                                    except:
                                        body_html = payload.decode('utf-8', errors='replace')
                else:
                    # 处理单部分邮件
                    content_type = msg.get_content_type()
                    try:
                        if content_type == "text/plain":
                            body_text = msg.get_content()
                        elif content_type == "text/html":
                            body_html = msg.get_content()
                    except Exception:
                        payload = msg.get_payload(decode=True)
                        if payload:
                            charset = msg.get_content_charset() or 'utf-8'
                            try:
                                decoded = payload.decode(charset, errors='replace')
                                if content_type == "text/plain":
                                    body_text = decoded
                                elif content_type == "text/html":
                                    body_html = decoded
                            except:
                                pass
                
                # 如果找到了内容，添加到结果中
                if body_text and 'body_text' not in result:
                    result['body_text'] = body_text
                
                if body_html and 'body_html' not in result:
                    result['body_html'] = body_html
            
            # 如果仍然没有提取到验证码，尝试从内容中提取
            if 'verification_code' not in result:
                verification_code = extract_verification_code(result.get('body_text', ''), result.get('body_html', ''))
                if verification_code:
                    result['verification_code'] = verification_code
        
        except Exception as e:
            current_app.logger.error(f"解析邮件文件出错: {str(e)}")
    
    return result


def extract_verification_code(body_text, body_html):
    """从邮件内容中提取验证码"""
    # 首先尝试从HTML中提取
    if body_html:
        # 常用的验证码模式
        patterns = [
            r'letter-spacing:\s*\d+px[^>]*>([^<]+)<',  # 特殊样式的验证码
            r'<div[^>]*>(\d{6})</div>',               # 6位数字验证码在div中
            r'验证码[：:]\s*([A-Z0-9]{4,8})',          # 中文标记的验证码
            r'code[^\d]+(\d{4,8})',                   # 英文标记的验证码
            r'\b([A-Z0-9]{6})\b'                      # 6位大写字母或数字
        ]
        
        for pattern in patterns:
            matches = re.findall(pattern, body_html)
            if matches:
                return matches[0].strip()
    
    # 如果HTML中没找到，尝试从纯文本中提取
    if body_text:
        patterns = [
            r'验证码[：:]\s*([A-Z0-9]{4,8})',          # 中文格式
            r'code[^\d]+(\d{4,8})',                   # 英文格式
            r'\b(\d{6})\b'                            # 6位数字
        ]
        
        for pattern in patterns:
            matches = re.findall(pattern, body_text)
            if matches:
                return matches[0].strip()
    
    return None


# 系统诊断接口
@api_bp.route('/system_check', methods=['GET'])
def system_check():
    """
    系统诊断接口：检查邮件系统各组件状态
    """
    try:
        result = {
            'timestamp': datetime.now().isoformat(),
            'system_status': 'normal',
            'components': {},
            'recent_activity': {},
            'mailboxes': [],
            'storage': {}
        }
        
        # 检查系统资源
        try:
            result['components']['system'] = {
                'cpu_percent': psutil.cpu_percent(),
                'memory_percent': psutil.virtual_memory().percent,
                'disk_usage': psutil.disk_usage('/').percent
            }
        except Exception as e:
            result['components']['system'] = {'error': str(e)}
        
        # 检查数据库状态
        db = get_session()
        try:
            # 获取域名数量
            domain_count = db.query(Domain).count()
            
            # 获取邮箱数量
            mailbox_count = db.query(Mailbox).count()
            
            # 获取邮件数量
            email_count = db.query(Email).count()
            
            # 获取最新邮件
            latest_emails = db.query(Email).order_by(Email.received_at.desc()).limit(5).all()
            
            result['components']['database'] = {
                'status': 'connected',
                'domain_count': domain_count,
                'mailbox_count': mailbox_count,
                'email_count': email_count
            }
            
            # 最近活动
            result['recent_activity']['latest_emails'] = [
                {
                    'id': email.id,
                    'subject': email.subject,
                    'sender': email.sender,
                    'received_at': email.received_at.isoformat() if email.received_at else None
                } for email in latest_emails
            ]
            
            # 获取所有活跃邮箱
            active_mailboxes = db.query(Mailbox).order_by(Mailbox.id).limit(10).all()
            result['mailboxes'] = [
                {
                    'id': mb.id,
                    'address': mb.address,
                    'domain_id': mb.domain_id,
                    'full_address': f"{mb.address}@{mb.domain.name}" if hasattr(mb, 'domain') and mb.domain else f"{mb.address}@unknown",
                    'email_count': db.query(Email).filter_by(mailbox_id=mb.id).count()
                } for mb in active_mailboxes
            ]
            
        except Exception as e:
            result['components']['database'] = {'status': 'error', 'error': str(e)}
        finally:
            db.close()
        
        # 检查存储状态
        email_data_dir = current_app.config.get('MAIL_STORAGE_PATH', 'email_data')
        try:
            emails_dir = os.path.join(email_data_dir, 'emails')
            attachments_dir = os.path.join(email_data_dir, 'attachments')
            
            # 检查目录是否存在
            emails_dir_exists = os.path.exists(emails_dir)
            attachments_dir_exists = os.path.exists(attachments_dir)
            
            # 计算文件数量和大小
            email_files_count = 0
            email_files_size = 0
            if emails_dir_exists:
                for file_name in os.listdir(emails_dir):
                    if file_name.endswith('.eml'):
                        email_files_count += 1
                        email_files_size += os.path.getsize(os.path.join(emails_dir, file_name))
            
            attachment_files_count = 0
            attachment_files_size = 0
            if attachments_dir_exists:
                for file_name in os.listdir(attachments_dir):
                    attachment_files_count += 1
                    attachment_files_size += os.path.getsize(os.path.join(attachments_dir, file_name))
            
            result['storage'] = {
                'emails_dir': {
                    'exists': emails_dir_exists,
                    'path': emails_dir,
                    'file_count': email_files_count,
                    'size_bytes': email_files_size,
                    'size_mb': round(email_files_size / (1024 * 1024), 2) if email_files_size > 0 else 0
                },
                'attachments_dir': {
                    'exists': attachments_dir_exists,
                    'path': attachments_dir,
                    'file_count': attachment_files_count,
                    'size_bytes': attachment_files_size,
                    'size_mb': round(attachment_files_size / (1024 * 1024), 2) if attachment_files_size > 0 else 0
                }
            }
            
            # 检查最近的邮件文件
            if emails_dir_exists and email_files_count > 0:
                files = [(os.path.getmtime(os.path.join(emails_dir, f)), f) 
                         for f in os.listdir(emails_dir) if f.endswith('.eml')]
                files.sort(reverse=True)
                
                result['recent_activity']['latest_files'] = [
                    {
                        'filename': f,
                        'modified': datetime.fromtimestamp(t).isoformat(),
                        'age_seconds': int(time.time() - t)
                    } for t, f in files[:5]
                ]
        
        except Exception as e:
            result['storage'] = {'error': str(e)}
        
        # 整体状态评估
        if ('database' in result['components'] and result['components']['database'].get('status') != 'connected'):
            result['system_status'] = 'warning'
        
        if not emails_dir_exists or not attachments_dir_exists:
            result['system_status'] = 'warning'
        
        return jsonify({
            'success': True,
            'status': result['system_status'],
            'diagnostics': result
        }), 200
    
    except Exception as e:
        current_app.logger.error(f"系统诊断出错: {str(e)}")
        return jsonify({
            'success': False,
            'error': '系统诊断失败',
            'message': str(e)
        }), 500