import { BadRequestException, Injectable } from '@nestjs/common';
import { OracleDBService } from 'src/db/db.service';
import { AuthLoginDTO } from './auth.dto';
import * as oracledb from 'oracledb'

@Injectable()
export class AuthService {

    constructor(private readonly oracleDBService: OracleDBService) { }

    async login(body:AuthLoginDTO) {
        let connection;
        let rows = [];
        let crows:any = [];
        try {
            connection = await this.oracleDBService.getConnection()
            if (!connection) {
                throw new Error('No DB Connected')
            }

            const result = await connection.execute(
                `BEGIN
                    USERLOGIN_PKG.ValidateUser(:p_emailaddr,:p_password,:p_login_cursor);
                END;`,
                {
                    p_emailaddr: {
                        val: body.p_emailaddr,
                        type: oracledb.DB_TYPE_NVARCHAR
                    },
                    p_password: {
                        val: body.p_password,
                        type: oracledb.DB_TYPE_NVARCHAR
                    },
                    p_login_cursor: {
                        type: oracledb.CURSOR,
                        dir: oracledb.BIND_OUT
                    }
                },
                {
                    outFormat: oracledb.OUT_FORMAT_OBJECT
                }
            );

            if (result.outBinds && result.outBinds.p_login_cursor) {
                const cursor = result.outBinds.p_login_cursor; 
                let rowsBatch;

                do {
                    rowsBatch = await cursor.getRows(100); 
                    rows = rows.concat(rowsBatch);
                } while (rowsBatch.length > 0);

                await cursor.close();
            } else {
                return new BadRequestException({Error:"Error executing request try after some time!"});
            }

            if(rows[0]["ERRORMESG"]){
                return {error:"Invalid username or password!"}
            }
            return {msg:"Logged in successfully"}

        } catch (err) {
            console.error('Error fetching users: ', err.message);
            return {error:"Invalid username or password"}
        } finally { }


    }
}