from fastapi import HTTPException, UploadFile
from sqlalchemy.orm import Session
from ..models.vector import VectorData
import json
import os
import datetime  # 统一使用模块导入，避免冲突
from decimal import Decimal
from typing import List
import uuid
import tempfile
import struct
from sqlalchemy.sql import text
import binascii


# 导入shapely库用于解析WKB
try:
    from shapely import wkb
    from shapely.geometry import mapping
    SHAPELY_AVAILABLE = True
except ImportError:
    SHAPELY_AVAILABLE = False


class DecimalEncoder(json.JSONEncoder):
    """处理Decimal类型的JSON编码器"""
    def default(self, obj):
        if isinstance(obj, Decimal):
            return float(obj)
        return super(DecimalEncoder, self).default(obj)


def get_vector_data(db: Session, vector_id: int):
    """通过ID获取一条矢量数据记录"""
    vector_data = db.query(VectorData).filter(VectorData.id == vector_id).first()
    if not vector_data:
        raise HTTPException(status_code=404, detail="矢量数据不存在")
    
    # 手动构建返回字典
    result = {}
    for column in vector_data.__table__.columns:
        value = getattr(vector_data, column.name)
        # 处理特殊类型
        if isinstance(value, Decimal):
            value = float(value)
        elif isinstance(value, datetime.datetime):  # 修复datetime判断
            value = value.isoformat()
        elif str(column.type).startswith('geometry'):
            # 如果是几何类型，直接使用字符串表示
            if value is not None:
                value = str(value)
        result[column.name] = value
    
    return result


def get_vector_data_batch(db: Session, vector_ids: List[int]):
    """批量获取矢量数据记录"""
    vector_data_list = db.query(VectorData).filter(VectorData.id.in_(vector_ids)).all()
    if not vector_data_list:
        raise HTTPException(status_code=404, detail="未找到指定的矢量数据")
    
    result = []
    for vector_data in vector_data_list:
        item = {}
        for column in vector_data.__table__.columns:
            value = getattr(vector_data, column.name)
            # 处理特殊类型
            if isinstance(value, Decimal):
                value = float(value)
            elif isinstance(value, datetime.datetime):  # 修复datetime判断
                value = value.isoformat()
            elif str(column.type).startswith('geometry'):
                if value is not None:
                    value = str(value)
            item[column.name] = value
        result.append(item)
    
    return result


async def import_vector_data(file: UploadFile, db: Session) -> dict:
    """导入GeoJSON文件到数据库"""
    try:
        # 读取文件内容
        content = await file.read()
        data = json.loads(content)

        # 验证GeoJSON格式
        if not isinstance(data, dict) or data.get("type") != "FeatureCollection":
            raise ValueError("无效的GeoJSON格式")

        features = data.get("features", [])
        if not features:
            raise ValueError("GeoJSON文件中没有要素数据")

        # 获取表的所有列名
        columns = [column.name for column in VectorData.__table__.columns]

        # 导入每个要素
        imported_count = 0
        for feature in features:
            if not isinstance(feature, dict) or feature.get("type") != "Feature":
                continue

            # 获取属性
            properties = feature.get("properties", {})

            # 创建新记录
            vector_data = VectorData()

            # 设置每个字段的值（除了id）
            for column in columns:
                if column == 'id':  # 跳过id字段
                    continue
                if column in properties:
                    value = properties[column]
                    # 如果值是字典或列表，转换为JSON字符串
                    if isinstance(value, (dict, list)):
                        value = json.dumps(value, ensure_ascii=False)
                    setattr(vector_data, column, value)

            # 设置几何数据（优先使用geometry字段，如果没有则使用geom字段）
            geometry = feature.get("geometry")
            if geometry:
                geometry_str = json.dumps(geometry, ensure_ascii=False)
                setattr(vector_data, 'geom', geometry_str)
            elif 'geom' in properties:
                setattr(vector_data, 'geometry', properties['geom'])

            try:
                db.add(vector_data)
                imported_count += 1
            except Exception as e:
                continue

        # 提交事务
        try:
            db.commit()
        except Exception as e:
            db.rollback()
            raise ValueError(f"数据库操作失败: {str(e)}")

        return {
            "message": f"成功导入 {imported_count} 条记录",
            "imported_count": imported_count
        }

    except json.JSONDecodeError as e:
        raise ValueError(f"无效的JSON格式: {str(e)}")
    except Exception as e:
        db.rollback()
        raise ValueError(f"导入失败: {str(e)}")


def export_vector_data(db: Session, vector_id: int):
    """导出指定ID的矢量数据为GeoJSON格式并保存到文件"""
    vector_data = get_vector_data(db, vector_id)
    return _export_vector_data_to_file([vector_data], f"export_{vector_id}", "surveydata")


def export_vector_data_batch(db: Session, vector_ids: List[int]):
    """批量导出矢量数据为GeoJSON格式并保存到文件"""
    vector_data_list = get_vector_data_batch(db, vector_ids)
    return _export_vector_data_to_file(vector_data_list, f"export_batch_{'_'.join(map(str, vector_ids))}", "surveydata")


def export_all_vector_data(db: Session, table_name: str = "surveydata"):
    """导出指定的矢量数据表为GeoJSON格式并保存到文件"""
    try:
        query = text(f'SELECT * FROM "{table_name}"')
        result = db.execute(query)
        columns = [col.name for col in result.cursor.description]
        vector_data_list = [dict(zip(columns, row)) for row in result.fetchall()]  # 类型修正
        return _export_vector_data_to_file(vector_data_list, f"export_{table_name}", table_name)
    except Exception as e:
        raise HTTPException(
            status_code=500,
            detail=f"查询表{table_name}失败：{str(e)}"
        )


def parse_geom_field(geom_value) -> dict:
    """解析 geom 字段为 GeoJSON 格式的 geometry"""
    try:
        geom_str = str(geom_value)
        
        # 处理PostGIS WKB格式的点数据
        if geom_str and geom_str.startswith('0101000020'):
            binary_geom = bytes.fromhex(geom_str[2:])
            byte_order = struct.unpack('B', binary_geom[:1])[0]
            endian = '<' if byte_order == 1 else '>'

            if len(binary_geom) >= 1 + 16:
                coord_bytes = binary_geom[-16:]
                x, y = struct.unpack(f'{endian}dd', coord_bytes)
                return {
                    "type": "Point",
                    "coordinates": [x, y]
                }
            else:
                print(f"数据长度不足: {geom_str}. 长度: {len(binary_geom)}")
        # 处理WKT格式
        elif geom_str and (geom_str.startswith('POINT') or 
                          geom_str.startswith('LINESTRING') or 
                          geom_str.startswith('POLYGON') or
                          geom_str.startswith('MULTIPOINT') or
                          geom_str.startswith('MULTILINESTRING') or
                          geom_str.startswith('MULTIPOLYGON')):
            print(f"检测到WKT格式几何数据: {geom_str[:30]}...")
            return None
        # 处理EWKT格式
        elif geom_str and geom_str.startswith('SRID='):
            print(f"检测到EWKT格式几何数据: {geom_str[:30]}...")
            return None
        # 处理十六进制WKB格式
        elif geom_str and all(c in '0123456789ABCDEFabcdef' for c in geom_str):
            print(f"检测到十六进制WKB格式几何数据: {geom_str[:30]}...")
            
            if SHAPELY_AVAILABLE:
                try:
                    if len(geom_str) % 2 != 0:
                        geom_str = '0' + geom_str
                    binary_data = binascii.unhexlify(geom_str)
                    shape = wkb.loads(binary_data)
                    return mapping(shape)
                except Exception as e:
                    print(f"Shapely解析WKB失败: {e}")
            
            try:
                from ..database import engine
                with engine.connect() as connection:
                    query = text("SELECT ST_AsGeoJSON(ST_GeomFromWKB(decode($1, 'hex'))) AS geojson")
                    result = connection.execute(query, [geom_str]).fetchone()
                    if result and result.geojson:
                        return json.loads(result.geojson)
            except Exception as e:
                print(f"使用PostgreSQL解析WKB失败: {e}")
                return None
        else:
            from ..database import engine
            try:
                with engine.connect() as connection:
                    query = text("SELECT ST_AsGeoJSON(ST_Force2D($1::geometry)) AS geojson")
                    result = connection.execute(query, [geom_value]).fetchone()
                    if result and result.geojson:
                        return json.loads(result.geojson)
            except Exception as e:
                print(f"使用ST_AsGeoJSON转换几何数据失败: {e}")
                print(f"未识别的几何数据格式: {geom_str[:50]}...")
                
    except (ValueError, IndexError, struct.error) as e:
        print(f"解析几何字段失败: {geom_str if 'geom_str' in locals() else geom_value}. 错误: {e}")
    
    return None


def _export_vector_data_to_file(vector_data_list, base_filename: str, table_name: str = "surveydata"):
    """将矢量数据列表导出为 GeoJSON 文件（修复后）"""
    try:
        features = []
        for data in vector_data_list:
            # 1. 处理空间信息（从longitude和latitude生成点坐标）
            longitude = data.get('longitude')
            latitude = data.get('latitude')
            
            # 跳过经纬度无效的数据
            if not (isinstance(longitude, (int, float)) and isinstance(latitude, (int, float))):
                print(f"跳过无效数据：经度={longitude}（类型{type(longitude)}），纬度={latitude}（类型{type(latitude)}）")
                continue
            
            # 生成标准GeoJSON点 geometry
            geometry = {
                "type": "Point",
                "coordinates": [longitude, latitude]  # [经度, 纬度]
            }
            
            # 2. 处理属性信息（处理特殊类型）
            properties = {}
            for key, value in data.items():
                # 处理日期时间类型
                if isinstance(value, datetime.datetime):
                    properties[key] = value.strftime("%Y-%m-%d %H:%M:%S")
                # 处理'nan'特殊值
                elif value == 'nan':
                    properties[key] = None
                # 处理Decimal类型
                elif isinstance(value, Decimal):
                    properties[key] = float(value)
                # 处理其他值
                else:
                    properties[key] = value
            
            # 3. 组合成GeoJSON要素
            feature = {
                "type": "Feature",
                "geometry": geometry,
                "properties": properties
            }
            features.append(feature)
        
        # 4. 生成完整GeoJSON
        geojson_data = {
            "type": "FeatureCollection",
            "features": features
        }
        
        # 创建临时目录并保存文件
        temp_dir = tempfile.mkdtemp()
        timestamp = datetime.datetime.now().strftime("%Y%m%d_%H%M%S")
        filename = f"{base_filename}_{timestamp}.geojson"
        file_path = os.path.join(temp_dir, filename)
        
        # 写入文件（使用自定义编码器处理Decimal）
        with open(file_path, "w", encoding="utf-8") as f:
            json.dump(geojson_data, f, ensure_ascii=False, indent=2, cls=DecimalEncoder)
        
        # 返回结果
        return {
            "message": "数据导出成功",
            "file_path": file_path,
            "temp_dir": temp_dir,
            "data": geojson_data
        }
        
    except Exception as e:
        error_data = data if 'data' in locals() else "未知数据"
        print(f"生成矢量数据时出错：{str(e)}，出错数据：{error_data}")
        raise