import json
import os
import uuid
from datetime import datetime
from flask import Flask, jsonify, request, send_from_directory
from flask_cors import CORS

app = Flask(__name__, static_folder='../platform', static_url_path='')
CORS(app)

BASE_DIR = os.path.dirname(os.path.abspath(__file__))
DB_DIR = os.path.join(BASE_DIR, 'db')


def load_json(filename):
    path = os.path.join(DB_DIR, filename)
    if not os.path.exists(path):
        return []
    with open(path, 'r', encoding='utf-8') as f:
        return json.load(f)


def save_json(filename, data):
    path = os.path.join(DB_DIR, filename)
    with open(path, 'w', encoding='utf-8') as f:
        json.dump(data, f, ensure_ascii=False, indent=2)


# ── helpers ──

def gen_id(prefix='ORD'):
    return f"{prefix}-{uuid.uuid4().hex[:8].upper()}"


def calc_distance(lat1, lng1, lat2, lng2):
    from math import radians, cos, sin, asin, sqrt
    r = 6371
    d_lat = radians(lat2 - lat1)
    d_lng = radians(lng2 - lng1)
    a = sin(d_lat/2)**2 + cos(radians(lat1)) * cos(radians(lat2)) * sin(d_lng/2)**2
    return round(2 * r * asin(sqrt(a)), 1)


def calc_price(dist_km, weight_kg, urgency):
    base = dist_km * 12 + weight_kg * 5
    if urgency == 'urgent':
        base *= 1.3
    elif urgency == 'ASAP':
        base *= 1.5
    return max(int(base), 30)


# ── static files ──

@app.route('/')
def index():
    return send_from_directory(app.static_folder, 'index.html')


# ── Auth ──

@app.route('/api/login', methods=['POST'])
def login():
    data = request.get_json()
    phone = data.get('phone', '')
    role = data.get('role', 'demander')
    users = load_json('users.json')
    user = next((u for u in users if u['phone'] == phone), None)
    if not user:
        user = {
            'id': gen_id('U'),
            'name': phone[-4:],
            'role': role,
            'phone': phone,
            'company': '',
            'avatar': phone[-1],
            'credit_score': 800,
            'created_at': datetime.now().strftime('%Y-%m-%d %H:%M:%S')
        }
        users.append(user)
        save_json('users.json', users)
    return jsonify({'code': 0, 'data': user})


# ── Users ──

@app.route('/api/users/<user_id>')
def get_user(user_id):
    users = load_json('users.json')
    user = next((u for u in users if u['id'] == user_id), None)
    if not user:
        return jsonify({'code': 404, 'msg': '用户不存在'}), 404
    return jsonify({'code': 0, 'data': user})


@app.route('/api/users/<user_id>', methods=['PUT'])
def update_user(user_id):
    users = load_json('users.json')
    idx = next((i for i, u in enumerate(users) if u['id'] == user_id), None)
    if idx is None:
        return jsonify({'code': 404, 'msg': '用户不存在'}), 404
    data = request.get_json()
    for k in ['name', 'company', 'phone']:
        if k in data:
            users[idx][k] = data[k]
    save_json('users.json', users)
    return jsonify({'code': 0, 'data': users[idx]})


# ── Drones ──

@app.route('/api/drones')
def list_drones():
    drones = load_json('drones.json')
    status = request.args.get('status')
    user_id = request.args.get('user_id')
    if status:
        drones = [d for d in drones if d['status'] == status]
    if user_id:
        drones = [d for d in drones if d['user_id'] == user_id]
    return jsonify({'code': 0, 'data': drones})


@app.route('/api/drones/available')
def available_drones():
    drones = load_json('drones.json')
    available = [d for d in drones if d['status'] == 'available']
    return jsonify({'code': 0, 'data': available})


@app.route('/api/drones', methods=['POST'])
def add_drone():
    data = request.get_json()
    drones = load_json('drones.json')
    drone = {
        'id': gen_id('D'),
        'name': data.get('name', '未知机型'),
        'model': data.get('model', '通用'),
        'max_weight': data.get('max_weight', 10),
        'range_km': data.get('range_km', 10),
        'status': 'available',
        'location': data.get('location', '未设置'),
        'total_flights': 0,
        'user_id': data.get('user_id'),
        'price_per_km': data.get('price_per_km', 15),
        'insurance_expiry': data.get('insurance_expiry', '2026-12-31')
    }
    drones.append(drone)
    save_json('drones.json', drones)
    return jsonify({'code': 0, 'data': drone}), 201


@app.route('/api/drones/<drone_id>', methods=['PUT'])
def update_drone(drone_id):
    drones = load_json('drones.json')
    idx = next((i for i, d in enumerate(drones) if d['id'] == drone_id), None)
    if idx is None:
        return jsonify({'code': 404, 'msg': '无人机不存在'}), 404
    data = request.get_json()
    for k in ['name', 'status', 'location', 'price_per_km']:
        if k in data:
            drones[idx][k] = data[k]
    save_json('drones.json', drones)
    return jsonify({'code': 0, 'data': drones[idx]})


# ── Orders ──

@app.route('/api/orders')
def list_orders():
    orders = load_json('orders.json')
    role = request.args.get('role')
    user_id = request.args.get('user_id')
    status = request.args.get('status')

    if role == 'demander' and user_id:
        orders = [o for o in orders if o['demander_id'] == user_id]
    elif role == 'provider' and user_id:
        orders = [o for o in orders if o.get('provider_id') == user_id]

    if status:
        orders = [o for o in orders if o['status'] == status]
    else:
        ordering = {'pending': 0, 'matching': 1, 'accepted': 2,
                    'in_transit': 3, 'completed': 4, 'cancelled': 5}
        orders.sort(key=lambda o: ordering.get(o['status'], 9))

    return jsonify({'code': 0, 'data': orders})


@app.route('/api/orders/pending')
def pending_orders():
    orders = load_json('orders.json')
    pending = [o for o in orders if o['status'] == 'pending']
    return jsonify({'code': 0, 'data': pending})


@app.route('/api/orders', methods=['POST'])
def create_order():
    data = request.get_json()
    orders = load_json('orders.json')

    order = {
        'id': gen_id('ORDER'),
        'from_addr': data['from_addr'],
        'to_addr': data['to_addr'],
        'from_lat': data.get('from_lat', 39.904),
        'from_lng': data.get('from_lng', 116.407),
        'to_lat': data.get('to_lat', 39.904),
        'to_lng': data.get('to_lng', 116.407),
        'cargo': data.get('cargo', '普通包裹'),
        'weight': float(data.get('weight', 1)),
        'price': 0,
        'distance_km': 0,
        'status': 'pending',
        'urgency': data.get('urgency', 'normal'),
        'insurance': float(data.get('insurance', 0)),
        'note': data.get('note', ''),
        'demander_id': data.get('user_id', ''),
        'provider_id': None,
        'drone_id': None,
        'created_at': datetime.now().strftime('%Y-%m-%d %H:%M:%S'),
        'updated_at': datetime.now().strftime('%Y-%m-%d %H:%M:%S'),
        'completed_at': None,
        'rating': None,
        'comment': None
    }

    dist = calc_distance(order['from_lat'], order['from_lng'],
                         order['to_lat'], order['to_lng'])
    price = calc_price(dist, order['weight'], order['urgency'])
    order['distance_km'] = dist
    order['price'] = price

    orders.insert(0, order)
    save_json('orders.json', orders)

    # auto generate quotes from available providers
    auto_generate_quotes(order)

    return jsonify({'code': 0, 'data': order}), 201


def auto_generate_quotes(order):
    drones = load_json('drones.json')
    users = load_json('users.json')
    quotes = load_json('quotes.json')
    available = [d for d in drones if d['status'] == 'available']
    for drone in available[:3]:
        provider = next((u for u in users if u['id'] == drone['user_id']), None)
        if not provider:
            continue
        base_price = order['price']
        variance = 0.8 + (hash(drone['id']) % 40) / 100
        quote = {
            'id': gen_id('Q'),
            'order_id': order['id'],
            'provider_id': drone['user_id'],
            'drone_id': drone['id'],
            'price': int(base_price * variance),
            'eta_minutes': max(int(order['distance_km'] / 1.2 * (0.8 + (hash(drone['name']) % 40) / 100)), 5),
            'distance_km': order['distance_km'],
            'provider_name': provider['name'],
            'drone_name': drone['name'],
            'provider_rating': provider.get('credit_score', 800) / 100 * 0.5 + 2.5,
            'provider_flights': drone['total_flights'],
            'status': 'active',
            'created_at': datetime.now().strftime('%Y-%m-%d %H:%M:%S')
        }
        quote['provider_rating'] = round(min(quote['provider_rating'], 5.0), 1)
        quotes.append(quote)
    save_json('quotes.json', quotes)


@app.route('/api/orders/<order_id>')
def get_order(order_id):
    orders = load_json('orders.json')
    order = next((o for o in orders if o['id'] == order_id), None)
    if not order:
        return jsonify({'code': 404, 'msg': '订单不存在'}), 404
    return jsonify({'code': 0, 'data': order})


@app.route('/api/orders/<order_id>/accept', methods=['POST'])
def accept_order(order_id):
    orders = load_json('orders.json')
    idx = next((i for i, o in enumerate(orders) if o['id'] == order_id), None)
    if idx is None:
        return jsonify({'code': 404, 'msg': '订单不存在'}), 404

    data = request.get_json()
    orders[idx]['status'] = 'accepted'
    orders[idx]['provider_id'] = data.get('provider_id')
    orders[idx]['drone_id'] = data.get('drone_id')
    orders[idx]['updated_at'] = datetime.now().strftime('%Y-%m-%d %H:%M:%S')

    # update drone status
    drone_id = data.get('drone_id')
    if drone_id:
        drones = load_json('drones.json')
        for d in drones:
            if d['id'] == drone_id:
                d['status'] = 'busy'
                break
        save_json('drones.json', drones)

    save_json('orders.json', orders)
    return jsonify({'code': 0, 'data': orders[idx]})


@app.route('/api/orders/<order_id>/transit', methods=['POST'])
def start_transit(order_id):
    orders = load_json('orders.json')
    idx = next((i for i, o in enumerate(orders) if o['id'] == order_id), None)
    if idx is None:
        return jsonify({'code': 404, 'msg': '订单不存在'}), 404
    orders[idx]['status'] = 'in_transit'
    orders[idx]['updated_at'] = datetime.now().strftime('%Y-%m-%d %H:%M:%S')
    save_json('orders.json', orders)
    return jsonify({'code': 0, 'data': orders[idx]})


@app.route('/api/orders/<order_id>/complete', methods=['POST'])
def complete_order(order_id):
    orders = load_json('orders.json')
    idx = next((i for i, o in enumerate(orders) if o['id'] == order_id), None)
    if idx is None:
        return jsonify({'code': 404, 'msg': '订单不存在'}), 404
    orders[idx]['status'] = 'completed'
    orders[idx]['completed_at'] = datetime.now().strftime('%Y-%m-%d %H:%M:%S')
    orders[idx]['updated_at'] = datetime.now().strftime('%Y-%m-%d %H:%M:%S')
    # release drone
    drone_id = orders[idx].get('drone_id')
    if drone_id:
        drones = load_json('drones.json')
        for d in drones:
            if d['id'] == drone_id:
                d['status'] = 'available'
                d['total_flights'] = d.get('total_flights', 0) + 1
                break
        save_json('drones.json', drones)
    save_json('orders.json', orders)
    return jsonify({'code': 0, 'data': orders[idx]})


@app.route('/api/orders/<order_id>/cancel', methods=['POST'])
def cancel_order(order_id):
    orders = load_json('orders.json')
    idx = next((i for i, o in enumerate(orders) if o['id'] == order_id), None)
    if idx is None:
        return jsonify({'code': 404, 'msg': '订单不存在'}), 404
    orders[idx]['status'] = 'cancelled'
    orders[idx]['updated_at'] = datetime.now().strftime('%Y-%m-%d %H:%M:%S')
    drone_id = orders[idx].get('drone_id')
    if drone_id:
        drones = load_json('drones.json')
        for d in drones:
            if d['id'] == drone_id:
                d['status'] = 'available'
                break
        save_json('drones.json', drones)
    save_json('orders.json', orders)
    return jsonify({'code': 0, 'data': orders[idx]})


@app.route('/api/orders/<order_id>/rate', methods=['POST'])
def rate_order(order_id):
    data = request.get_json()
    orders = load_json('orders.json')
    idx = next((i for i, o in enumerate(orders) if o['id'] == order_id), None)
    if idx is None:
        return jsonify({'code': 404, 'msg': '订单不存在'}), 404
    orders[idx]['rating'] = data.get('rating', 5)
    orders[idx]['comment'] = data.get('comment', '')
    save_json('orders.json', orders)
    return jsonify({'code': 0, 'data': orders[idx]})


# ── Quotes ──

@app.route('/api/quotes')
def list_quotes():
    quotes = load_json('quotes.json')
    order_id = request.args.get('order_id')
    if order_id:
        quotes = [q for q in quotes if q['order_id'] == order_id]
    return jsonify({'code': 0, 'data': quotes})


@app.route('/api/quotes', methods=['POST'])
def create_quote():
    data = request.get_json()
    quotes = load_json('quotes.json')
    quote = {
        'id': gen_id('Q'),
        'order_id': data['order_id'],
        'provider_id': data['provider_id'],
        'drone_id': data['drone_id'],
        'price': data.get('price', 100),
        'eta_minutes': data.get('eta_minutes', 15),
        'distance_km': data.get('distance_km', 5),
        'provider_name': data.get('provider_name', '未知'),
        'drone_name': data.get('drone_name', '未知机型'),
        'provider_rating': data.get('provider_rating', 4.5),
        'provider_flights': data.get('provider_flights', 0),
        'status': 'active',
        'created_at': datetime.now().strftime('%Y-%m-%d %H:%M:%S')
    }
    quotes.append(quote)
    save_json('quotes.json', quotes)
    return jsonify({'code': 0, 'data': quote}), 201


@app.route('/api/quotes/<quote_id>/accept', methods=['POST'])
def accept_quote(quote_id):
    quotes = load_json('quotes.json')
    q_idx = next((i for i, q in enumerate(quotes) if q['id'] == quote_id), None)
    if q_idx is None:
        return jsonify({'code': 404, 'msg': '报价不存在'}), 404

    quote = quotes[q_idx]
    quotes[q_idx]['status'] = 'accepted'
    save_json('quotes.json', quotes)

    orders = load_json('orders.json')
    o_idx = next((i for i, o in enumerate(orders) if o['id'] == quote['order_id']), None)
    if o_idx is not None:
        orders[o_idx]['status'] = 'accepted'
        orders[o_idx]['provider_id'] = quote['provider_id']
        orders[o_idx]['drone_id'] = quote['drone_id']
        orders[o_idx]['price'] = quote['price']
        orders[o_idx]['updated_at'] = datetime.now().strftime('%Y-%m-%d %H:%M:%S')
        save_json('orders.json', orders)

    return jsonify({'code': 0, 'data': quote})


# ── Dashboard Stats ──

@app.route('/api/dashboard/stats')
def dashboard_stats():
    role = request.args.get('role', 'demander')
    user_id = request.args.get('user_id')
    orders = load_json('orders.json')

    if user_id:
        if role == 'demander':
            orders = [o for o in orders if o['demander_id'] == user_id]
        else:
            orders = [o for o in orders if o.get('provider_id') == user_id]

    total = len(orders)
    pending = len([o for o in orders if o['status'] == 'pending'])
    in_transit = len([o for o in orders if o['status'] in ('accepted', 'in_transit')])
    completed = len([o for o in orders if o['status'] == 'completed'])
    cancelled = len([o for o in orders if o['status'] == 'cancelled'])

    total_revenue = sum(o['price'] for o in orders if o['status'] == 'completed')
    avg_rating = 0
    rated = [o['rating'] for o in orders if o.get('rating')]
    if rated:
        avg_rating = round(sum(rated) / len(rated), 1)

    drones_online = 0
    if role == 'provider':
        user_drones = [d for d in load_json('drones.json') if d.get('user_id') == user_id]
        drones_online = len([d for d in user_drones if d['status'] == 'available'])
    else:
        drones_online = len([d for d in load_json('drones.json') if d['status'] == 'available'])

    stats = {
        'total_orders': total,
        'pending_orders': pending,
        'in_transit_orders': in_transit,
        'completed_orders': completed,
        'cancelled_orders': cancelled,
        'total_revenue': total_revenue,
        'avg_rating': avg_rating,
        'online_drones': drones_online,
        'completion_rate': round(completed / total * 100, 1) if total > 0 else 0
    }
    return jsonify({'code': 0, 'data': stats})


# ── Agent analysis (AI simulation) ──

@app.route('/api/agent/analyze', methods=['POST'])
def agent_analyze():
    data = request.get_json()
    action = data.get('action', '')

    if action == 'credit_check':
        orders = load_json('orders.json')
        flags = []
        for o in orders:
            if o['status'] == 'cancelled':
                flags.append({
                    'order_id': o['id'],
                    'issue': '订单被取消',
                    'severity': '轻微',
                    'suggestion': '建议关注取消原因'
                })
            if o.get('rating') and o['rating'] <= 2:
                flags.append({
                    'order_id': o['id'],
                    'issue': '低分评价',
                    'severity': '中等',
                    'suggestion': '建议回访用户了解问题'
                })
        return jsonify({'code': 0, 'data': {'issues': flags, 'summary': f'发现 {len(flags)} 个值得关注的问题'}})

    elif action == 'pricing_suggestion':
        orders = load_json('orders.json')
        from datetime import datetime
        now = datetime.now()
        hour = now.hour
        if 10 <= hour <= 12 or 17 <= hour <= 19:
            multiplier = 1.2
            reason = '当前为高峰时段，建议加价20%'
        elif 22 <= hour or hour <= 6:
            multiplier = 1.3
            reason = '当前为夜间时段，建议加价30%'
        else:
            multiplier = 1.0
            reason = '当前为平峰时段，维持基础费率'
        return jsonify({
            'code': 0,
            'data': {
                'multiplier': multiplier,
                'reason': reason,
                'suggestion': f'建议当前时段基础费率调整为 {multiplier}x'
            }
        })

    elif action == 'anomaly_detect':
        orders = load_json('orders.json')
        anomalies = []
        for o in orders:
            if o['status'] == 'in_transit':
                duration_hours = (datetime.now() - datetime.strptime(o['created_at'], '%Y-%m-%d %H:%M:%S')).total_seconds() / 3600
                if duration_hours > 1:
                    anomalies.append({
                        'order_id': o['id'],
                        'type': '配送超时',
                        'detail': f'配送已超过{duration_hours:.1f}小时',
                        'suggestion': '建议联系承运方确认配送状态'
                    })
        return jsonify({'code': 0, 'data': {'anomalies': anomalies, 'count': len(anomalies)}})

    return jsonify({'code': 400, 'msg': '未知的分析类型'})


# ── Agent management (for future real AI integration) ──

@app.route('/api/agent/settings', methods=['GET'])
def agent_settings():
    path = os.path.join(DB_DIR, 'agent_settings.json')
    if not os.path.exists(path):
        default = {
            'providers': {
                'health_check_enabled': True,
                'auto_reconciliation': True,
                'cert_reminder_days': 30
            },
            'pricing': {
                'dynamic_pricing_enabled': True,
                'max_surge_multiplier': 2.0,
                'peak_hours': ['10:00-12:00', '17:00-20:00']
            },
            'anomaly': {
                'auto_handle_l1': True,
                'auto_handle_l2': False,
                'notification_channels': ['sms', 'app']
            },
            'credit': {
                'fraud_detection_enabled': True,
                'min_rating_threshold': 3,
                'auto_penalty': True
            }
        }
        save_json('agent_settings.json', default)
        return jsonify({'code': 0, 'data': default})
    return jsonify({'code': 0, 'data': load_json('agent_settings.json')})


@app.route('/api/agent/settings', methods=['PUT'])
def update_agent_settings():
    data = request.get_json()
    save_json('agent_settings.json', data)
    return jsonify({'code': 0, 'msg': 'Agent设置已更新'})


# ── Logging ──

@app.route('/api/logs')
def get_logs():
    path = os.path.join(DB_DIR, 'logs.json')
    if not os.path.exists(path):
        return jsonify({'code': 0, 'data': []})
    logs = load_json('logs.json')
    logs.sort(key=lambda x: x.get('timestamp', ''), reverse=True)
    return jsonify({'code': 0, 'data': logs[:100]})


@app.route('/api/logs', methods=['POST'])
def add_log():
    data = request.get_json()
    logs = load_json('logs.json') if os.path.exists(os.path.join(DB_DIR, 'logs.json')) else []
    log = {
        'id': gen_id('LOG'),
        'type': data.get('type', 'info'),
        'message': data.get('message', ''),
        'timestamp': datetime.now().strftime('%Y-%m-%d %H:%M:%S')
    }
    logs.append(log)
    save_json('logs.json', logs)
    return jsonify({'code': 0, 'data': log}), 201


# ── Health ──

@app.route('/api/health')
def health():
    return jsonify({'status': 'ok', 'timestamp': datetime.now().strftime('%Y-%m-%d %H:%M:%S')})


if __name__ == '__main__':
    print("""
    ╔══════════════════════════════════════════╗
    ║       空运宝 - 后端服务 v1.0            ║
    ║   Listening at: http://localhost:5000    ║
    ║   API: http://localhost:5000/api/...    ║
    ╚══════════════════════════════════════════╝
    """)
    app.run(host='0.0.0.0', port=5000, debug=True)