from flask import Blueprint, request, jsonify, make_response
from flask_jwt_extended import get_jwt_identity
from models import db, Task, User
from auth import login_required, admin_required
from datetime import datetime, timedelta
from sqlalchemy import func, and_
import csv
from io import StringIO

statistics_bp = Blueprint('statistics', __name__)

# 个人统计
@statistics_bp.route('/statistics/user/<int:user_id>', methods=['GET'])
@login_required
def get_user_statistics(user_id):
    current_user_id = int(get_jwt_identity())
    current_user = db.session.get(User, current_user_id)
    
    # 非管理员只能查看自己的统计
    if current_user.role != 'admin' and current_user_id != user_id:
        return jsonify({'error': '无权查看他人统计'}), 403
    
    date_from = request.args.get('date_from')
    date_to = request.args.get('date_to')
    group_id = request.args.get('group_id', type=int)
    
    query = Task.query.filter_by(claimed_by=user_id, status='completed')
    
    if group_id:
        query = query.filter_by(group_id=group_id)
    
    if date_from:
        try:
            date_from_obj = datetime.strptime(date_from, '%Y-%m-%d')
            query = query.filter(Task.completed_at >= date_from_obj)
        except:
            pass
    
    if date_to:
        try:
            date_to_obj = datetime.strptime(date_to, '%Y-%m-%d')
            date_to_obj = date_to_obj.replace(hour=23, minute=59, second=59)
            query = query.filter(Task.completed_at <= date_to_obj)
        except:
            pass
    
    # 总完成数
    total_completed = query.count()
    
    # 按日期分组统计
    daily_stats = db.session.query(
        func.date(Task.completed_at).label('date'),
        func.count(Task.id).label('count')
    ).filter(
        Task.claimed_by == user_id,
        Task.status == 'completed'
    )
    
    if date_from:
        daily_stats = daily_stats.filter(Task.completed_at >= date_from_obj)
    if date_to:
        daily_stats = daily_stats.filter(Task.completed_at <= date_to_obj)
    
    daily_stats = daily_stats.group_by(func.date(Task.completed_at)).all()
    
    # 当前认领未完成
    claimed_pending = Task.query.filter_by(
        claimed_by=user_id,
        status='claimed'
    ).count()
    
    user = db.session.get(User, user_id)
    
    return jsonify({
        'user': {
            'id': user.id,
            'username': user.username
        },
        'total_completed': total_completed,
        'claimed_pending': claimed_pending,
        'daily_stats': [
            {
                'date': str(stat.date),
                'count': stat.count
            } for stat in daily_stats
        ]
    })


# 组别排行榜
@statistics_bp.route('/statistics/leaderboard', methods=['GET'])
@login_required
def get_leaderboard():
    group_id = request.args.get('group_id', type=int)
    period = request.args.get('period', 'monthly')  # daily/monthly
    
    now = datetime.utcnow()
    
    if period == 'daily':
        start_date = now.replace(hour=0, minute=0, second=0, microsecond=0)
    else:  # monthly
        start_date = now.replace(day=1, hour=0, minute=0, second=0, microsecond=0)
    
    query = db.session.query(
        User.id,
        User.username,
        func.count(Task.id).label('completed_count')
    ).join(
        Task, Task.claimed_by == User.id
    ).filter(
        Task.status == 'completed',
        Task.completed_at >= start_date
    )
    
    if group_id:
        query = query.filter(Task.group_id == group_id)
    
    leaderboard = query.group_by(User.id, User.username).order_by(
        func.count(Task.id).desc()
    ).limit(20).all()
    
    return jsonify({
        'period': period,
        'leaderboard': [
            {
                'rank': idx + 1,
                'user_id': row.id,
                'username': row.username,
                'completed_count': row.completed_count
            } for idx, row in enumerate(leaderboard)
        ]
    })


# 整体统计（支持管理员和普通用户）
@statistics_bp.route('/statistics/overview', methods=['GET'])
@login_required
def get_overview():
    current_user_id = get_jwt_identity()
    current_user = db.session.get(User, current_user_id)
    group_id = request.args.get('group_id', type=int, default=1)

    # 获取时间范围参数
    date_from = request.args.get('date_from')
    date_to = request.args.get('date_to')

    # 基础查询条件
    base_filter = [Task.group_id == group_id]

    # 普通用户只能看自己的数据
    if current_user.role != 'admin':
        base_filter.append(Task.claimed_by == current_user_id)

    # 解析时间范围
    date_from_obj = None
    date_to_obj = None
    if date_from:
        try:
            date_from_obj = datetime.strptime(date_from, '%Y-%m-%d')
        except:
            pass
    if date_to:
        try:
            date_to_obj = datetime.strptime(date_to, '%Y-%m-%d')
            date_to_obj = date_to_obj.replace(hour=23, minute=59, second=59)
        except:
            pass

    # 各状态任务数量
    status_query = db.session.query(
        Task.status,
        func.count(Task.id).label('count')
    ).filter(and_(*base_filter)).group_by(Task.status)
    status_counts = status_query.all()

    # 今日完成
    today = datetime.utcnow().replace(hour=0, minute=0, second=0, microsecond=0)
    today_filter = base_filter + [
        Task.status == 'completed',
        Task.completed_at >= today
    ]
    today_completed = Task.query.filter(and_(*today_filter)).count()

    # 本月完成
    month_start = datetime.utcnow().replace(day=1, hour=0, minute=0, second=0, microsecond=0)
    month_filter = base_filter + [
        Task.status == 'completed',
        Task.completed_at >= month_start
    ]
    month_completed = Task.query.filter(and_(*month_filter)).count()

    # 趋势图（根据时间范围或默认最近7天）
    if date_from_obj:
        trend_start = date_from_obj
    else:
        trend_start = datetime.utcnow() - timedelta(days=7)

    trend_filter = base_filter + [
        Task.status == 'completed',
        Task.completed_at >= trend_start
    ]
    if date_to_obj:
        trend_filter.append(Task.completed_at <= date_to_obj)

    trend = db.session.query(
        func.date(Task.completed_at).label('date'),
        func.count(Task.id).label('count')
    ).filter(and_(*trend_filter)).group_by(func.date(Task.completed_at)).all()
    # 计算时间范围内的总完成数
    completed_filter = base_filter + [Task.status == 'completed']
    if date_from_obj:
        completed_filter.append(Task.completed_at >= date_from_obj)
    if date_to_obj:
        completed_filter.append(Task.completed_at <= date_to_obj)
    total_completed = Task.query.filter(and_(*completed_filter)).count()

    # 当前认领未完成数
    claimed_filter = base_filter + [Task.status == 'claimed']
    claimed_pending = Task.query.filter(and_(*claimed_filter)).count()
    return jsonify({
        'status_counts': {row.status: row.count for row in status_counts},
        'today_completed': today_completed,
        'month_completed': month_completed,
        'total_completed': total_completed,
        'claimed_pending': claimed_pending,
        'is_admin': current_user.role == 'admin',
        'trend': [
            {'date': str(row.date), 'count': row.count} for row in trend
        ]
    })


# 导出统计数据（CSV格式）
@statistics_bp.route('/statistics/export', methods=['GET'])
@login_required
def export_statistics():
    current_user_id = get_jwt_identity()
    current_user = db.session.get(User, current_user_id)
    group_id = request.args.get('group_id', type=int, default=1)
    date_from = request.args.get('date_from')
    date_to = request.args.get('date_to')

    # 构建查询条件
    query = Task.query.filter_by(group_id=group_id, status='completed')

    # 普通用户只能导出自己的数据
    if current_user.role != 'admin':
        query = query.filter_by(claimed_by=current_user_id)

    # 时间范围筛选
    if date_from:
        try:
            date_from_obj = datetime.strptime(date_from, '%Y-%m-%d')
            query = query.filter(Task.completed_at >= date_from_obj)
        except:
            pass

    if date_to:
        try:
            date_to_obj = datetime.strptime(date_to, '%Y-%m-%d')
            date_to_obj = date_to_obj.replace(hour=23, minute=59, second=59)
            query = query.filter(Task.completed_at <= date_to_obj)
        except:
            pass

    tasks = query.order_by(Task.completed_at.desc()).all()

    # 生成CSV
    output = StringIO()
    writer = csv.writer(output)

    # 写入表头
    writer.writerow(['任务ID', '剧集名称', '优先级', '认领人', '种子ID', '完成时间', '认领时间', '耗时(小时)'])

    # 写入数据
    for task in tasks:
        duration = ''
        if task.claimed_at and task.completed_at:
            delta = task.completed_at - task.claimed_at
            duration = f'{delta.total_seconds() / 3600:.1f}'

        claimer_name = task.claimer.username if task.claimer else '-'

        writer.writerow([
            task.id,
            task.series_name,
            task.priority or '-',
            claimer_name,
            task.torrent_id or '-',
            task.completed_at.strftime('%Y-%m-%d %H:%M:%S') if task.completed_at else '-',
            task.claimed_at.strftime('%Y-%m-%d %H:%M:%S') if task.claimed_at else '-',
            duration
        ])

    # 创建响应
    response = make_response(output.getvalue())
    response.headers['Content-Type'] = 'text/csv; charset=utf-8-sig'
    response.headers['Content-Disposition'] = f'attachment; filename=statistics_{datetime.now().strftime("%Y%m%d_%H%M%S")}.csv'

    return response