from flask import jsonify, request, current_app
from flask_jwt_extended import jwt_required, get_jwt_identity
from app.models.material import Material
from app.api import bp, ns_materials, api
from app import db
from app.utils.validators import validate_json, validate_decimal
from flask_restx import Resource, fields
from sqlalchemy import distinct

# API 模型定义
material_model = api.model('Material', {
    'name': fields.String(required=True, description='Material name'),
    'unit': fields.String(required=True, description='Unit of measurement'),
    'category': fields.String(required=False, description='Material category'),
    'warning_threshold': fields.Float(required=True, description='Warning threshold quantity'),
    'processed_name': fields.String(required=False, description='Processed material name'),
    'processed_unit': fields.String(required=False, description='Processed material unit'),
    'processed_warning_threshold': fields.Float(required=False, description='Processed material warning threshold'),
    'conversion_ratio': fields.Float(required=False, description='Conversion ratio from raw to processed material')
})

@ns_materials.route('/categories/')
class MaterialCategoriesResource(Resource):
    @api.doc('list_material_categories')
    @jwt_required()
    def get(self):
        """获取所有物料分类列表"""
        try:
            # 从数据库中查询所有不同的分类
            categories_query = db.session.query(distinct(Material.category)).all()
            
            # 提取分类名称，排除空值和None
            db_categories = [category[0] for category in categories_query if category[0]]
            
            # 排序
            db_categories.sort()  # 按字母顺序排序
            
            # 注释掉强制添加"其他"分类的代码，只显示数据库中存在的分类
            # if '其他' not in db_categories:
            #     db_categories.append('其他')
            # else:
            #     # 如果"其他"分类已存在，将其移到最后
            #     db_categories.remove('其他')
            #     db_categories.append('其他')
            
            current_app.logger.debug(f"Found {len(db_categories)} material categories")
            return {'data': db_categories}
        except Exception as e:
            current_app.logger.error(f'Error fetching material categories: {str(e)}')
            return {'message': 'Error fetching material categories'}, 500

@ns_materials.route('/')
class MaterialResource(Resource):
    @api.doc('list_materials')
    @jwt_required()
    def get(self):
        """获取所有物料列表"""
        try:
            materials = Material.query.all()
            result = [{
                'id': m.id,
                'name': m.name,
                'unit': m.unit,
                'category': m.category,
                'warning_threshold': float(m.warning_threshold),
                'processed_name': m.processed_name,
                'processed_unit': m.processed_unit,
                'processed_warning_threshold': float(m.processed_warning_threshold) if m.processed_warning_threshold else None,
                'conversion_ratio': float(m.conversion_ratio) if m.conversion_ratio else None,
                'created_at': m.created_at.isoformat()
            } for m in materials]
            
            # 打印调试信息
            current_app.logger.debug(f"Found {len(result)} materials")
            
            return {'data': result}
            
        except Exception as e:
            current_app.logger.error(f'Error fetching materials: {str(e)}')
            return {'message': 'Error fetching materials'}, 500

    @api.doc('create_material')
    @api.expect(material_model)
    @jwt_required()
    def post(self):
        """创建新物料"""
        try:
            data = request.get_json()
            
            # 验证数据
            warning_threshold = validate_decimal(data['warning_threshold'])
            if warning_threshold is None or warning_threshold <= 0:
                return {'message': 'Invalid warning threshold value'}, 400
            
            # 检查名称是否已存在
            if Material.query.filter_by(name=data['name']).first():
                return {'message': 'Material name already exists'}, 400
            
            # 处理加工物料相关数据
            processed_warning_threshold = None
            if 'processed_warning_threshold' in data and data['processed_warning_threshold']:
                processed_warning_threshold = validate_decimal(data['processed_warning_threshold'])
                if processed_warning_threshold is not None and processed_warning_threshold <= 0:
                    return {'message': 'Invalid processed warning threshold value'}, 400
            
            conversion_ratio = None
            if 'conversion_ratio' in data and data['conversion_ratio']:
                conversion_ratio = validate_decimal(data['conversion_ratio'])
                if conversion_ratio is not None and conversion_ratio <= 0:
                    return {'message': 'Invalid conversion ratio value'}, 400
            
            material = Material(
                name=data['name'],
                unit=data['unit'],
                category=data.get('category', '其他'),
                warning_threshold=warning_threshold,
                processed_name=data.get('processed_name'),
                processed_unit=data.get('processed_unit'),
                processed_warning_threshold=processed_warning_threshold,
                conversion_ratio=conversion_ratio
            )
            
            db.session.add(material)
            db.session.commit()
            
            return jsonify({
                'id': material.id,
                'name': material.name,
                'unit': material.unit,
                'category': material.category,
                'warning_threshold': float(material.warning_threshold),
                'processed_name': material.processed_name,
                'processed_unit': material.processed_unit,
                'processed_warning_threshold': float(material.processed_warning_threshold) if material.processed_warning_threshold else None,
                'conversion_ratio': float(material.conversion_ratio) if material.conversion_ratio else None,
                'created_at': material.created_at.isoformat()
            })
            
        except Exception as e:
            current_app.logger.error(f'Error creating material: {str(e)}')
            db.session.rollback()
            return {'message': 'Error creating material'}, 500

@ns_materials.route('/<int:id>')
class MaterialDetail(Resource):
    @api.doc('update_material')
    @jwt_required()
    def put(self, id):
        """更新物料信息"""
        try:
            material = Material.query.get_or_404(id)
            data = request.get_json()
            
            if 'name' in data and data['name'] != material.name:
                if Material.query.filter_by(name=data['name']).first():
                    return {'message': 'Material name already exists'}, 400
                material.name = data['name']
            
            if 'unit' in data:
                material.unit = data['unit']
                
            if 'category' in data:
                material.category = data['category']
            
            if 'warning_threshold' in data:
                warning_threshold = validate_decimal(data['warning_threshold'])
                if warning_threshold is None or warning_threshold <= 0:
                    return {'message': 'Invalid warning threshold value'}, 400
                material.warning_threshold = warning_threshold
            
            # 更新物料加工相关字段
            if 'processed_name' in data:
                material.processed_name = data['processed_name']
                
            if 'processed_unit' in data:
                material.processed_unit = data['processed_unit']
                
            if 'processed_warning_threshold' in data:
                if data['processed_warning_threshold']:
                    processed_warning_threshold = validate_decimal(data['processed_warning_threshold'])
                    if processed_warning_threshold is not None and processed_warning_threshold <= 0:
                        return {'message': 'Invalid processed warning threshold value'}, 400
                    material.processed_warning_threshold = processed_warning_threshold
                else:
                    material.processed_warning_threshold = None
                    
            if 'conversion_ratio' in data:
                if data['conversion_ratio']:
                    conversion_ratio = validate_decimal(data['conversion_ratio'])
                    if conversion_ratio is not None and conversion_ratio <= 0:
                        return {'message': 'Invalid conversion ratio value'}, 400
                    material.conversion_ratio = conversion_ratio
                else:
                    material.conversion_ratio = None
            
            db.session.commit()
            
            return jsonify({
                'id': material.id,
                'name': material.name,
                'unit': material.unit,
                'category': material.category,
                'warning_threshold': float(material.warning_threshold),
                'processed_name': material.processed_name,
                'processed_unit': material.processed_unit,
                'processed_warning_threshold': float(material.processed_warning_threshold) if material.processed_warning_threshold else None,
                'conversion_ratio': float(material.conversion_ratio) if material.conversion_ratio else None,
                'created_at': material.created_at.isoformat()
            })
            
        except Exception as e:
            current_app.logger.error(f'Error updating material: {str(e)}')
            db.session.rollback()
            return {'message': 'Error updating material'}, 500

    @api.doc('delete_material')
    @jwt_required()
    def delete(self, id):
        """删除物料"""
        try:
            material = Material.query.get_or_404(id)
            
            # 检查是否有关联的库存记录，但不阻止删除
            has_inventory = len(material.inventories) > 0
            
            if has_inventory:
                # 如果有库存记录，先删除所有相关的库存记录
                for inventory in material.inventories:
                    db.session.delete(inventory)
            
            # 删除物料
            db.session.delete(material)
            db.session.commit()
            
            return '', 204
            
        except Exception as e:
            current_app.logger.error(f'Error deleting material: {str(e)}')
            db.session.rollback()
            return {'message': 'Error deleting material'}, 500