import traceback
from flask import Blueprint, request, jsonify, current_app
from flask_jwt_extended import jwt_required, get_jwt, get_jwt_identity
from app.services.purchase_service import PurchaseService
from app.utils.decorators import permission_required, prevent_double_submit

purchase_bp = Blueprint('purchase', __name__, url_prefix='/api/v1/purchase')


def get_current_user_id():
    """获取当前登录用户ID"""
    identity = get_jwt_identity()
    return identity


def get_current_user_role():
    """获取当前用户角色"""
    claims = get_jwt()
    return claims.get('role')


def _user_has_purchase_perm():
    """检查当前用户是否有 inbound_purchase 权限（菜单或任意操作权限）"""
    claims = get_jwt()
    role = claims.get('role', '')
    user_company = claims.get('company_name', '')
    if role.upper() in ('SUPER_ADMIN', 'SUPERVISOR'):
        return True
    from app.services.auth_service import AuthService
    perm_dict = AuthService.get_user_permissions(role, company_name=user_company)
    all_perms = perm_dict.get('menus', []) + perm_dict.get('elements', [])
    return 'inbound_purchase' in all_perms or any(
        p.startswith('inbound_purchase:') for p in all_perms
    )


def _filter_purchase_prices(item_dict):
    """Fail-Closed: 无价格权限则剥离采购价格字段"""
    from app.services.auth_service import AuthService
    claims = get_jwt()
    role = claims.get('role', '')
    if role.upper() in ('SUPER_ADMIN', 'SUPERVISOR'):
        return
    perm_dict = AuthService.get_user_permissions(role, company_name=claims.get('company_name', ''))
    all_perms = perm_dict.get('menus', []) + perm_dict.get('elements', [])
    if 'inbound_purchase:unit_price' not in all_perms:
        item_dict.pop('unit_price', None)
        item_dict.pop('pre_tax_unit_price', None)
        item_dict.pop('post_tax_unit_price', None)
    if 'inbound_purchase:total_price' not in all_perms:
        item_dict.pop('total_price', None)
    if 'inbound_purchase:tax_rate' not in all_perms:
        item_dict.pop('tax_rate', None)


# --------------------------------------------------------
# 1. 采购申请列表
# GET /api/v1/purchase
# --------------------------------------------------------
@purchase_bp.route('', methods=['GET'])
@jwt_required()
def get_purchase_list():
    """采购申请列表：有权限看同公司全部，无权限只看自己的"""
    try:
        page = int(request.args.get('page', 1))
        per_page = int(request.args.get('limit', 20))
        status = request.args.get('status')
        status = int(status) if status not in (None, '', 'all') else None

        # 搜索参数（与出库/报废记录同一套语义，便于用户迁移习惯）
        keyword = (request.args.get('keyword') or '').strip()
        search_type = (request.args.get('search_type') or 'all').strip()
        start_date = (request.args.get('start_date') or '').strip()
        end_date = (request.args.get('end_date') or '').strip()

        user_id = get_current_user_id()
        can_view_all = _user_has_purchase_perm()

        result = PurchaseService.get_purchase_list(
            page=page,
            per_page=per_page,
            requester_id=None if can_view_all else user_id,
            status=status,
            keyword=keyword,
            search_type=search_type,
            start_date=start_date,
            end_date=end_date,
        )

        # ★ 字段级价格过滤
        for item in (result.get('items') or []):
            _filter_purchase_prices(item)

        return jsonify({'code': 200, 'msg': '获取成功', 'data': result})
    except Exception as e:
        traceback.print_exc()
        return jsonify({'code': 500, 'msg': f'获取失败: {str(e)}'}), 500


# --------------------------------------------------------
# 2. 创建采购申请
# POST /api/v1/purchase
# --------------------------------------------------------
@purchase_bp.route('', methods=['POST'])
@jwt_required()
@prevent_double_submit(lock_timeout=5)
def create_purchase_request():
    """创建采购申请（任何登录用户可提交）"""
    try:
        data = request.get_json()
        if not data:
            return jsonify({'code': 400, 'msg': '无有效数据'}), 400

        user_id = get_current_user_id()

        # 必填校验
        required = ['name', 'quantity', 'purchase_date', 'approver_id']
        for field in required:
            if field not in data or str(data.get(field, '')).strip() == '':
                return jsonify({'code': 400, 'msg': f'缺少必填字段: {field}'}), 400

        # 图片必填强校验
        images = data.get('images')
        if not images or (isinstance(images, list) and len(images) == 0):
            return jsonify({'code': 400, 'msg': '请上传采购凭证/物品图片'}), 400

        purchase = PurchaseService.create_purchase_request(data, requester_id=user_id)

        # ★ Fail-Closed: 创建响应剥离价格字段
        resp = purchase.to_dict()
        for k in ('unit_price', 'total_price', 'tax_rate'):
            resp.pop(k, None)

        return jsonify({
            'code': 200,
            'msg': '创建成功',
            'data': resp
        }), 200

    except ValueError as e:
        return jsonify({'code': 400, 'msg': str(e)}), 400
    except Exception as e:
        traceback.print_exc()
        return jsonify({'code': 500, 'msg': f'服务器内部错误: {str(e)}'}), 500


# --------------------------------------------------------
# 3. 获取采购申请详情
# GET /api/v1/purchase/<id>
# --------------------------------------------------------
@purchase_bp.route('/<int:purchase_id>', methods=['GET'])
@jwt_required()
def get_purchase_detail(purchase_id):
    """采购申请详情：自己的无需权限，别人的需要 inbound_purchase"""
    try:
        purchase = PurchaseService.get_purchase_by_id(purchase_id)
        if not purchase:
            return jsonify({'code': 404, 'msg': '采购申请不存在'}), 404

        user_id = get_current_user_id()
        if purchase['requester_id'] != user_id and not _user_has_purchase_perm():
            return jsonify({'code': 403, 'msg': '无权查看此申请'}), 403

        _filter_purchase_prices(purchase)
        return jsonify({'code': 200, 'msg': '获取成功', 'data': purchase}), 200
    except Exception as e:
        return jsonify({'code': 500, 'msg': str(e)}), 500


# --------------------------------------------------------
# 3.5 按批次查询采购申请（同一批提交的多条记录，批次=request_no去掉末尾流水号）
# GET /api/v1/purchase/batch/<batch_key>
# --------------------------------------------------------
@purchase_bp.route('/batch/<path:batch_key>', methods=['GET'])
@jwt_required()
def get_purchase_by_batch(batch_key):
    """按批次前缀（request_no 去掉末尾4位流水号）查询同一批的所有记录"""
    try:
        from app.models.purchase import PurchaseRequest
        records = PurchaseRequest.query.filter(
            PurchaseRequest.request_no.like(f"{batch_key}-%")
        ).order_by(PurchaseRequest.request_no.asc()).all()

        user_id = get_current_user_id()
        has_perm = _user_has_purchase_perm()

        items = []
        for r in records:
            d = r.to_dict()
            # 非本人且无权限时，价格字段剥离
            if d['requester_id'] != user_id and not has_perm:
                for k in ('unit_price', 'total_price', 'tax_rate'):
                    d.pop(k, None)
            items.append(d)

        return jsonify({'code': 200, 'msg': '获取成功', 'data': {'batch_key': batch_key, 'items': items}}), 200
    except Exception as e:
        traceback.print_exc()
        return jsonify({'code': 500, 'msg': str(e)}), 500


# --------------------------------------------------------
# 4. 审批采购申请
# PATCH /api/v1/purchase/<id>/approve
# --------------------------------------------------------
@purchase_bp.route('/<int:purchase_id>/approve', methods=['PATCH'])
@jwt_required()
@prevent_double_submit(lock_timeout=5)
@permission_required('inbound_purchase:operation')
def approve_purchase_request(purchase_id):
    """审批采购申请：必须有操作权限（inbound_purchase:operation）"""
    try:
        user_id = get_current_user_id()

        data = request.get_json() or {}
        action = data.get('action', 'approve')
        reject_reason = data.get('reject_reason')

        if action not in ('approve', 'reject', 'close'):
            return jsonify({'code': 400, 'msg': '无效的审批操作'}), 400

        if action == 'reject' and not reject_reason:
            return jsonify({'code': 400, 'msg': '驳回时必须提供原因'}), 400

        purchase = PurchaseService.approve_purchase_request(
            purchase_id=purchase_id,
            user_id=user_id,
            action=action,
            reject_reason=reject_reason
        )

        msg = '审批通过' if action == 'approve' else ('已驳回' if action == 'reject' else '已完结')
        # ★ Fail-Closed: 审批响应剥离价格字段
        resp = purchase.to_dict()
        for k in ('unit_price', 'total_price', 'tax_rate'):
            resp.pop(k, None)
        return jsonify({'code': 200, 'msg': msg, 'data': resp}), 200

    except ValueError as e:
        return jsonify({'code': 400, 'msg': str(e)}), 400
    except Exception as e:
        traceback.print_exc()
        return jsonify({'code': 500, 'msg': f'服务器内部错误: {str(e)}'}), 500


# --------------------------------------------------------
# 5. 获取可选审批人列表
# GET /api/v1/purchase/approvers
# --------------------------------------------------------
@purchase_bp.route('/next-batch-seq', methods=['GET'])
@jwt_required()
def get_next_batch_seq():
    """获取今日下一个采购批次号（前端提交一批时调用，同批所有行共享）"""
    try:
        next_seq = PurchaseService.get_next_batch_seq()
        return jsonify({'code': 200, 'msg': '获取成功', 'data': {'batch_seq': next_seq}}), 200
    except Exception as e:
        traceback.print_exc()
        return jsonify({'code': 500, 'msg': str(e)}), 500


@purchase_bp.route('/batch-approve', methods=['POST'])
@jwt_required()
@permission_required('inbound_purchase:operation')
def batch_approve_purchase():
    """
    批量审批采购申请（解决循环提交导致的多条记录需多次审批问题）

    请求体:
    {
        "ids": [1, 2, 3],            // 按 ID 列表审批
        或
        "batch_key": "PUR-20260831-1021",  // 按批次前缀审批整批（同批流水号连续）
        "action": "approve" | "reject",
        "reject_reason": "驳回原因（reject 时必填）"
    }
    """
    try:
        user_id = get_current_user_id()
        data = request.get_json() or {}
        ids = data.get('ids', [])
        batch_key = data.get('batch_key')
        action = data.get('action', 'approve')
        reject_reason = data.get('reject_reason')

        # 若传 batch_key（request_no 去掉末尾流水号的前缀），查出该批次对应状态的记录
        if batch_key:
            from app.models.purchase import PurchaseRequest
            # 完结本批 → 找「已通过(1)」的单；审批/驳回 → 找「待审批(0)」的单
            target_status = 1 if action == 'close' else 0
            records = PurchaseRequest.query.filter(
                PurchaseRequest.request_no.like(f"{batch_key}-%"),
                PurchaseRequest.status == target_status
            ).all()
            ids = [r.id for r in records]
            if not ids:
                status_text = '已通过' if action == 'close' else '待审批'
                return jsonify({'code': 400, 'msg': f'该批次没有{status_text}的记录'}), 400

        if not ids or not isinstance(ids, list):
            return jsonify({'code': 400, 'msg': 'ids 或 batch_key 不能为空'}), 400
        if action not in ('approve', 'reject', 'close'):
            return jsonify({'code': 400, 'msg': '无效的审批操作'}), 400
        if action == 'reject' and not reject_reason:
            return jsonify({'code': 400, 'msg': '驳回时必须提供原因'}), 400

        success_ids = []
        error_items = []
        for pid in ids:
            try:
                purchase = PurchaseService.approve_purchase_request(
                    purchase_id=pid,
                    user_id=user_id,
                    action=action,
                    reject_reason=reject_reason
                )
                success_ids.append(purchase.id)
            except ValueError as e:
                error_items.append({'id': pid, 'msg': str(e)})
            except Exception as e:
                traceback.print_exc()
                error_items.append({'id': pid, 'msg': str(e)})

        msg = f'批量审批完成: 成功 {len(success_ids)} 条'
        if error_items:
            msg += f', 失败 {len(error_items)} 条'
        return jsonify({'code': 200, 'msg': msg, 'data': {'success_ids': success_ids, 'errors': error_items}}), 200

    except Exception as e:
        traceback.print_exc()
        return jsonify({'code': 500, 'msg': f'服务器内部错误: {str(e)}'}), 500


@purchase_bp.route('/approvers', methods=['GET'])
@jwt_required()
def get_purchase_approvers():
    """获取可选审批人列表（创建采购申请时选择审批人用）"""
    try:
        from app.models.system import SysUser
        users = SysUser.query.filter(
            SysUser.role.in_(['SUPER_ADMIN', 'SUPERVISOR']),
            SysUser.status == 'active'
        ).all()

        return jsonify({
            'code': 200,
            'msg': '获取成功',
            'data': [
                {'id': u.id, 'username': u.username, 'email': u.email or '', 'role': u.role}
                for u in users
            ]
        }), 200
    except Exception as e:
        return jsonify({'code': 500, 'msg': str(e)}), 500


# --------------------------------------------------------
# 6. 根据名称/规格自动补全
# GET /api/v1/purchase/auto-fill?keyword=xxx
# --------------------------------------------------------
@purchase_bp.route('/auto-fill', methods=['GET'])
@jwt_required()
def auto_fill_purchase():
    """根据名称或规格自动补全另一个字段"""
    try:
        keyword = request.args.get('keyword', '').strip()
        if not keyword:
            return jsonify({'code': 200, 'msg': 'ok', 'data': None}), 200

        result = PurchaseService.auto_fill_from_material(keyword)
        return jsonify({'code': 200, 'msg': 'ok', 'data': result}), 200
    except Exception as e:
        return jsonify({'code': 500, 'msg': str(e)}), 500


# --------------------------------------------------------
# 7. 已审批且未入库的采购单列表（供库管按单入库使用）
# GET /api/v1/purchase/approved-unstocked?page=1&keyword=xxx
# --------------------------------------------------------
@purchase_bp.route('/approved-unstocked', methods=['GET'])
@jwt_required()
@permission_required('inbound_purchase')
def get_approved_unstocked_requests():
    """获取已审批通过且未入库的采购申请列表"""
    try:
        page = int(request.args.get('page', 1))
        per_page = int(request.args.get('limit', 20))
        keyword = request.args.get('keyword', '').strip() or None

        result = PurchaseService.get_approved_requests(
            page=page, per_page=per_page, keyword=keyword
        )

        # ★ 注意：不在此处过滤价格。此端点用于按单入库，
        # 价格数据需随响应传递到入库表单（前端通过 inbound_buy:unit_price 权限控制写入）
        return jsonify({'code': 200, 'msg': '获取成功', 'data': result}), 200
    except Exception as e:
        traceback.print_exc()
        return jsonify({'code': 500, 'msg': f'获取失败: {str(e)}'}), 500


# --------------------------------------------------------
# 8. 物料基础信息搜索（分页）
# GET /api/v1/purchase/search-material?keyword=xxx&page=1
# --------------------------------------------------------
@purchase_bp.route('/search-material', methods=['GET'])
@jwt_required()
def search_material_for_purchase():
    """物料基础信息搜索接口，支持分页，用于采购申请弹窗"""
    try:
        keyword = request.args.get('keyword', '')
        page = request.args.get('page', 1, type=int)
        limit = 20

        result = PurchaseService.search_base_material(keyword, page, limit)
        return jsonify({
            'code': 200,
            'msg': 'success',
            'data': result['items'],
            'total': result['total'],
            'has_next': result['has_next']
        }), 200
    except Exception as e:
        traceback.print_exc()
        return jsonify({'code': 500, 'msg': str(e)}), 500