from fastapi import APIRouter, Depends, HTTPException, status, UploadFile, File, Form
from sqlalchemy.orm import Session
from typing import List, Optional
import base64
from ..core.database import get_db
from ..schemas.database import (
    SQLExecuteRequest, SQLExecuteResponse, TableDataRequest,
    TableDataResponse, CreateTableRequest, ImportDataRequest, FileImportFormData
)
from ..services.database import DatabaseService

router = APIRouter(prefix="/database", tags=["数据库管理"])

@router.post("/execute", response_model=SQLExecuteResponse)
def execute_sql(request: SQLExecuteRequest, db: Session = Depends(get_db)):
    """执行SQL语句"""
    result = DatabaseService.execute_sql(db, request.sql)
    return SQLExecuteResponse(**result)

@router.post("/table-data", response_model=TableDataResponse)
def get_table_data(request: TableDataRequest, db: Session = Depends(get_db)):
    """获取表数据"""
    result = DatabaseService.get_table_data(
        db,
        request.table_name,
        request.limit or 100,
        request.offset or 0
    )
    return TableDataResponse(**result)

@router.post("/create-table", response_model=SQLExecuteResponse)
def create_table(request: CreateTableRequest, db: Session = Depends(get_db)):
    """创建表"""
    result = DatabaseService.create_table(
        db,
        request.table_name,
        request.columns,
        request.primary_key
    )
    return SQLExecuteResponse(**result)

@router.post("/drop-table")
def drop_table(request: dict, db: Session = Depends(get_db)):
    """删除表"""
    table_name = request.get("table_name")
    if not table_name:
        raise HTTPException(status_code=400, detail="table_name is required")
    result = DatabaseService.drop_table(db, table_name)
    return SQLExecuteResponse(**result)

@router.post("/import-data", response_model=SQLExecuteResponse)
def import_data(request: ImportDataRequest, db: Session = Depends(get_db)):
    """导入数据"""
    result = DatabaseService.import_data(db, request.table_name, request.data)
    return SQLExecuteResponse(**result)

@router.post("/tables", response_model=SQLExecuteResponse)
def get_table_list():
    """获取所有表名"""
    result = DatabaseService.get_table_list()
    return SQLExecuteResponse(**result)

@router.post("/import-file", response_model=SQLExecuteResponse)
async def import_file(
    file: UploadFile = File(..., description="上传的Excel/CSV文件"),
    table_name: Optional[str] = Form(None, description="自定义表名，如果不提供则使用文件名"),
    force_overwrite: bool = Form(False, description="是否强制覆盖已存在的表"),
    db: Session = Depends(get_db)
):
    """导入Excel/CSV文件到数据库"""
    try:
        # 检查文件类型
        if not file.filename:
            raise HTTPException(status_code=400, detail="文件名不能为空")

        # 处理中文文件名和后缀名 - 更可靠的方法
        try:
            # FastAPI的UploadFile已经正确处理了文件名编码
            filename = file.filename
        except:
            filename = "unknown_file"

        if not filename or filename == "":
            raise HTTPException(status_code=400, detail="文件名不能为空")

        # 提取文件扩展名
        if '.' not in filename:
            raise HTTPException(status_code=400, detail="文件必须有扩展名")

        file_ext = filename.lower().split('.')[-1]

        if file_ext not in ['csv', 'xlsx', 'xls']:
            raise HTTPException(
                status_code=400,
                detail=f"不支持的文件类型: .{file_ext}，仅支持 .csv, .xlsx, .xls"
            )

        # 读取文件内容
        file_content = await file.read()

        # 将文件内容转换为base64（保持与现有FileImportUtils兼容）
        file_content_base64 = base64.b64encode(file_content).decode('utf-8')

        # 调用服务层方法
        result = DatabaseService.import_file_to_database(
            db, filename, file_content_base64, table_name, force_overwrite
        )

        return SQLExecuteResponse(**result)

    except HTTPException:
        raise
    except Exception as e:
        return SQLExecuteResponse(
            success=False,
            message=f"文件导入失败: {str(e)}"
        )