pdf-translate-web/app.py

"""
PDF翻译网站主应用
"""

import os
import json
import uuid
import hashlib
from datetime import datetime, date
from functools import wraps
from flask import Flask, request, jsonify, render_template, send_file, session, redirect, url_for
from flask_sqlalchemy import SQLAlchemy
from werkzeug.utils import secure_filename

from config import *
from models import (db, User, Translation, TranslationCache, GuestTranslation, 
                   DataPackage, UserPackage, DynamicConfig)
from services import TranslationService, CacheService, TranslationTask
from admin import admin_bp

# ==================== 创建应用 ====================
app = Flask(__name__)
app.config['SECRET_KEY'] = SECRET_KEY
app.config['SQLALCHEMY_DATABASE_URI'] = DATABASE_URL
app.config['SQLALCHEMY_TRACK_MODIFICATIONS'] = False
app.config['MAX_CONTENT_LENGTH'] = MAX_FILE_SIZE

# 初始化数据库
db.init_app(app)

# 注册后台管理蓝图
app.register_blueprint(admin_bp)

# 初始化服务
cache_service = CacheService(CACHE_DIR, CACHE_EXPIRE_DAYS)

# ==================== 辅助函数 ====================
def get_current_user():
    """获取当前用户"""
    user_id = session.get('user_id')
    if user_id:
        return User.query.get(user_id)
    return None


def get_or_create_guest():
    """获取或创建访客记录"""
    session_id = session.get('guest_id')
    if not session_id:
        session_id = str(uuid.uuid4())
        session['guest_id'] = session_id
    
    guest = GuestTranslation.query.filter_by(session_id=session_id).first()
    if not guest:
        guest = GuestTranslation(
            session_id=session_id,
            ip_address=request.remote_addr
        )
        db.session.add(guest)
        db.session.commit()
    
    return guest


def check_guest_limit(guest):
    """检查访客翻译限制"""
    today = date.today()
    if guest.last_translate_date != today:
        guest.daily_count = 0
        guest.last_translate_date = today
        db.session.commit()
    
    limit = USER_LIMITS['guest']['daily_translations']
    if guest.daily_count >= limit:
        return False, f"今日翻译次数已达上限（{limit}次），请登录获取更多次数"
    
    return True, "OK"


def allowed_file(filename):
    """检查文件类型"""
    return '.' in filename and filename.lower().endswith('.pdf')


def compute_file_hash(file_content):
    """计算文件哈希"""
    return hashlib.md5(file_content).hexdigest()


# ==================== 路由: 页面 ====================
@app.route('/')
def index():
    """首页"""
    user = get_current_user()
    if user:
        limits = USER_LIMITS.get(user.user_type, USER_LIMITS['free'])
        daily_remaining = limits['daily_translations'] - user.daily_count if limits['daily_translations'] > 0 else '无限'
        max_pages = limits['max_pages'] if limits['max_pages'] > 0 else '无限'
    else:
        guest = get_or_create_guest()
        limits = USER_LIMITS['guest']
        daily_remaining = limits['daily_translations'] - guest.daily_count
        max_pages = limits['max_pages']
    
    return render_template('index.html', 
        user=user,
        limits=limits,
        daily_remaining=daily_remaining,
        max_pages=max_pages,
        plans=MEMBERSHIP_PLANS
    )


@app.route('/translate/<int:translation_id>')
def translation_detail(translation_id):
    """翻译详情页"""
    user = get_current_user()
    translation = Translation.query.get(translation_id)
    
    if not translation:
        return "翻译记录不存在", 404
    
    # 权限检查
    if user and translation.user_id != user.id:
        return "无权访问", 403
    
    if not user and not translation.user_id:
        # guest记录，检查session
        pass
    
    return render_template('translation.html', 
        translation=translation,
        user=user
    )


@app.route('/history')
def history():
    """翻译历史"""
    user = get_current_user()
    if not user:
        return redirect(url_for('login'))
    
    translations = Translation.query.filter_by(user_id=user.id)\
        .order_by(Translation.created_at.desc()).limit(50).all()
    
    return render_template('history.html', 
        user=user,
        translations=translations
    )


@app.route('/pricing')
def pricing():
    """会员定价页"""
    return render_template('pricing.html', plans=MEMBERSHIP_PLANS)


# ==================== 路由: API ====================
@app.route('/api/upload', methods=['POST'])
def upload_pdf():
    """上传PDF文件"""
    user = get_current_user()
    
    # 检查文件
    if 'file' not in request.files:
        return jsonify({'error': '未上传文件'}), 400
    
    file = request.files['file']
    if file.filename == '':
        return jsonify({'error': '未选择文件'}), 400
    
    if not allowed_file(file.filename):
        return jsonify({'error': '只支持PDF文件'}), 400
    
    # 获取翻译参数
    instruction = request.form.get('instruction', None)  # 用户翻译要求
    
    # 读取文件内容
    file_content = file.read()
    file_hash = compute_file_hash(file_content)
    filename = secure_filename(file.filename)
    
    # 获取页数
    try:
        from pypdf import PdfReader
        import io
        reader = PdfReader(io.BytesIO(file_content))
        page_count = len(reader.pages)
    except Exception as e:
        return jsonify({'error': f'PDF解析失败: {e}'}), 400
    
    # 权限检查
    if user:
        can_translate, msg = user.can_translate(page_count, {'USER_LIMITS': USER_LIMITS})
        if not can_translate:
            return jsonify({'error': msg}), 403
    else:
        guest = get_or_create_guest()
        can_translate, msg = check_guest_limit(guest)
        if not can_translate:
            return jsonify({'error': msg}), 403
        
        # 检查页数限制
        max_pages = USER_LIMITS['guest']['max_pages']
        if page_count > max_pages:
            return jsonify({'error': f'PDF页数超出限制（最大{max_pages}页）'}), 403
    
    # 检查缓存
    cache_path = cache_service.get_cache(file_hash)
    from_cache = False
    
    if cache_path and ENABLE_CACHE and not instruction:
        # 有缓存且无特殊翻译要求，直接使用缓存
        from_cache = True
        output_path = cache_path
    else:
        # 需要翻译
        # 保存上传文件
        upload_dir = os.path.join(UPLOAD_DIR, str(uuid.uuid4()))
        os.makedirs(upload_dir, exist_ok=True)
        upload_path = os.path.join(upload_dir, filename)
        
        with open(upload_path, 'wb') as f:
            f.write(file_content)
        
        # 创建输出路径
        output_dir = os.path.join(OUTPUT_DIR, str(uuid.uuid4()))
        os.makedirs(output_dir, exist_ok=True)
        output_path = os.path.join(output_dir, f"{filename}_translated.md")
        
        # 创建异步翻译任务（先不创建，等translation_id生成后）
        task_id = str(uuid.uuid4())
    
    # 创建翻译记录
    translation = Translation(
        user_id=user.id if user else None,
        file_hash=file_hash,
        original_filename=filename,
        file_size=len(file_content),
        page_count=page_count,
        translate_params=json.dumps({'instruction': instruction}) if instruction else None,
        status='processing' if not from_cache else 'completed',
        progress=0 if not from_cache else 100,
        output_path=output_path,
        from_cache=from_cache
    )
    db.session.add(translation)
    
    # 预先提交获取 translation_id
    if not from_cache:
        db.session.flush()  # 获取 ID 但不提交完整事务
    
    # 创建异步翻译任务（需要翻译时）
    if not from_cache:
        TranslationTask.create_task(
            task_id, upload_path, output_path,
            {'LLM_CONFIG': LLM_CONFIG},
            instruction,
            translation_id=translation.id,
            app=app
        )
    
    # 更新用户/访客计数
    if user:
        user.increment_count()
    else:
        guest.daily_count += 1
        guest.last_translate_date = date.today()
    
    # 更新缓存记录
    if from_cache:
        cache_record = TranslationCache.query.filter_by(file_hash=file_hash).first()
        if cache_record:
            cache_record.increment_hit()
    
    db.session.commit()
    
    return jsonify({
        'success': True,
        'translation_id': translation.id,
        'file_hash': file_hash,
        'page_count': page_count,
        'from_cache': from_cache,
        'task_id': task_id if not from_cache else None,
        'message': '使用缓存结果' if from_cache else '翻译任务已创建'
    })


@app.route('/api/status/<int:translation_id>')
def translation_status(translation_id):
    """获取翻译状态"""
    translation = Translation.query.get(translation_id)
    
    if not translation:
        return jsonify({'error': '翻译记录不存在'}), 404
    
    # 如果有task_id，检查任务状态
    if translation.status == 'processing':
        # 这里可以查询TranslationTask
        pass
    
    return jsonify({
        'id': translation.id,
        'status': translation.status,
        'progress': translation.progress,
        'from_cache': translation.from_cache,
        'error': translation.error_message
    })


@app.route('/api/task/<task_id>')
def task_status(task_id):
    """获取任务状态"""
    task = TranslationTask.get_task(task_id)
    
    if not task:
        return jsonify({'error': '任务不存在'}), 404
    
    return jsonify(task)


@app.route('/api/result/<int:translation_id>')
def get_result(translation_id):
    """获取翻译结果"""
    user = get_current_user()
    translation = Translation.query.get(translation_id)
    
    if not translation:
        return jsonify({'error': '翻译记录不存在'}), 404
    
    if translation.status != 'completed':
        return jsonify({'error': '翻译未完成'}), 400
    
    # 检查输出文件
    if not translation.output_path or not os.path.exists(translation.output_path):
        return jsonify({'error': '翻译结果文件不存在'}), 404
    
    # 读取结果
    with open(translation.output_path, 'r', encoding='utf-8') as f:
        content = f.read()
    
    return jsonify({
        'id': translation.id,
        'filename': translation.original_filename,
        'content': content,
        'output_path': translation.output_path
    })


@app.route('/api/download/<int:translation_id>')
def download_result(translation_id):
    """下载翻译结果"""
    user = get_current_user()
    translation = Translation.query.get(translation_id)
    
    if not translation or not translation.output_path:
        return jsonify({'error': '翻译记录不存在'}), 404
    
    if not os.path.exists(translation.output_path):
        return jsonify({'error': '文件不存在'}), 404
    
    filename = f"{translation.original_filename}_translated.md"
    return send_file(translation.output_path, as_attachment=True, download_name=filename)


@app.route('/api/retranslate/<int:translation_id>', methods=['POST'])
def retranslate(translation_id):
    """重新翻译"""
    user = get_current_user()
    if not user:
        return jsonify({'error': '请登录后使用此功能'}), 401
    
    translation = Translation.query.get(translation_id)
    if not translation or translation.user_id != user.id:
        return jsonify({'error': '无权操作'}), 403
    
    # 检查功能权限
    limits = USER_LIMITS.get(user.user_type, USER_LIMITS['free'])
    if 'retranslate' not in limits['features']:
        return jsonify({'error': '会员功能，请升级'}), 403
    
    instruction = request.json.get('instruction', '')
    
    # 查找原文件
    # 这里需要从原始上传路径恢复，简化处理
    
    # 创建新翻译记录
    new_translation = Translation(
        user_id=user.id,
        file_hash=translation.file_hash,
        original_filename=translation.original_filename,
        file_size=translation.file_size,
        page_count=translation.page_count,
        translate_params=json.dumps({'instruction': instruction}),
        status='processing',
        parent_id=translation_id,
        retranslate_request=instruction
    )
    db.session.add(new_translation)
    db.session.commit()
    
    # TODO: 实际翻译逻辑
    
    return jsonify({
        'success': True,
        'translation_id': new_translation.id,
        'message': '重译任务已创建'
    })


@app.route('/api/compare/<int:translation_id>')
def compare_view(translation_id):
    """对比查看"""
    user = get_current_user()
    if not user:
        return jsonify({'error': '请登录后使用此功能'}), 401
    
    translation = Translation.query.get(translation_id)
    if not translation or translation.user_id != user.id:
        return jsonify({'error': '无权访问'}), 403
    
    # 生成对比文件
    # TODO: 实现对比功能
    
    return jsonify({
        'id': translation.id,
        'original': '原文内容',
        'translated': '译文内容'
    })


# ==================== 路由: 用户系统 ====================
@app.route('/login', methods=['GET', 'POST'])
def login():
    """登录"""
    if request.method == 'GET':
        return render_template('login.html')
    
    data = request.json
    username = data.get('username')
    password = data.get('password')
    
    user = User.query.filter_by(username=username).first()
    if not user or not user.check_password(password):
        return jsonify({'error': '用户名或密码错误'}), 401
    
    session['user_id'] = user.id
    return jsonify({'success': True, 'user': user.to_dict()})


@app.route('/register', methods=['GET', 'POST'])
def register():
    """注册"""
    if request.method == 'GET':
        return render_template('register.html')
    
    data = request.json
    username = data.get('username')
    email = data.get('email')
    password = data.get('password')
    
    # 检查用户是否存在
    if User.query.filter_by(username=username).first():
        return jsonify({'error': '用户名已存在'}), 400
    
    if User.query.filter_by(email=email).first():
        return jsonify({'error': '邮箱已注册'}), 400
    
    # 创建用户
    user = User(username=username, email=email, user_type='free')
    user.set_password(password)
    db.session.add(user)
    db.session.commit()
    
    session['user_id'] = user.id
    return jsonify({'success': True, 'user': user.to_dict()})


@app.route('/logout')
def logout():
    """退出登录"""
    session.pop('user_id', None)
    return redirect(url_for('index'))


@app.route('/api/user/info')
def user_info():
    """用户信息"""
    user = get_current_user()
    if not user:
        return jsonify({'user': None})
    
    limits = USER_LIMITS.get(user.user_type, USER_LIMITS['free'])
    return jsonify({
        'user': user.to_dict(),
        'limits': limits
    })


# ==================== 初始化 ====================
def init_app():
    """初始化应用"""
    # 创建目录
    for dir_name in [UPLOAD_DIR, CACHE_DIR, OUTPUT_DIR]:
        if not os.path.exists(dir_name):
            os.makedirs(dir_name)
    
    # 创建数据库表
    with app.app_context():
        db.create_all()
        
        # 创建默认管理员账号
        admin = User.query.filter_by(username='admin').first()
        if not admin:
            admin = User(
                username='admin',
                email='admin@tphai.com',
                user_type='admin',
                is_admin=True,
                is_active=True
            )
            admin.set_password('admin123')
            db.session.add(admin)
            db.session.commit()
            print("✅ 默认管理员账号已创建: admin / admin123")
        
        # 创建示例数据包套餐
        if DataPackage.query.count() == 0:
            packages = [
                DataPackage(name='入门包', description='适合轻度使用', translation_count=100, price=9.9, original_price=19.9, valid_days=30, sort_order=1),
                DataPackage(name='标准包', description='日常使用首选', translation_count=500, price=39.9, original_price=59.9, valid_days=30, sort_order=2, is_recommended=True),
                DataPackage(name='专业包', description='高频使用更划算', translation_count=2000, price=99.9, original_price=199.9, valid_days=30, sort_order=3),
                DataPackage(name='无限包', description='畅享无限翻译', translation_count=0, price=199.9, original_price=399.9, valid_days=30, sort_order=4),
            ]
            for pkg in packages:
                db.session.add(pkg)
            db.session.commit()
            print("✅ 示例数据包套餐已创建")


if __name__ == '__main__':
    init_app()
    app.run(host='0.0.0.0', port=19000, debug=True)