AceleraDEV

CeaserChyper.java

package com.ironijunior;

import com.fasterxml.jackson.annotation.JsonProperty;
import com.fasterxml.jackson.databind.ObjectMapper;
import lombok.Getter;
import lombok.Setter;
import lombok.ToString;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.http.HttpEntity;
import org.springframework.http.MediaType;
import org.springframework.http.client.MultipartBodyBuilder;
import org.springframework.util.MultiValueMap;
import org.springframework.web.reactive.function.BodyInserters;
import org.springframework.web.reactive.function.client.WebClient;

import java.io.File;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.nio.file.attribute.FileAttribute;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

/**
 * Application's main class
 */
@SpringBootApplication
public class Application {

	private static final String TOKEN = "29895a1a0cdb9051322421ddc10a6a1673fb498b";
	private static final int A_ASCII = 97;
	private static final int Z_ASCII = 122;

	public static void main(String[] args) {
		SpringApplication.run(Application.class, args);

		WebClient client = WebClient.builder().build();
		System.out.println(">>>> Running");
		client.get().uri("https://api.codenation.dev/v1/challenge/dev-ps/generate-data?token=" + TOKEN)
		.exchange()
		.subscribe(clientResponse -> {
			clientResponse.bodyToMono(Answer.class)
					.map(answer -> {
						String decypher = decypherAnswer(answer);
						answer.setDecifrado(decypher);
						return answer;
					})
					.map(answer -> {
						answer.setResumoCriptografico(generateSha1(answer.getDecifrado()));
						return answer;
					})
					.map(answer -> {
						MultiValueMap<String, HttpEntity<?>> map = null;
						try(FileWriter file = new FileWriter("C://Temp//answer.json")) {
							file.write(new ObjectMapper().writeValueAsString(answer));
							file.flush();
						} catch (IOException e) {
							e.printStackTrace();
						}
						return answer;
					})
					.subscribe(System.out::println);
		});
	}

	private static String decypherAnswer(Answer answer) {
		StringBuilder sb = new StringBuilder();
		int limit = Z_ASCII - answer.getNumeroCasas();
		for (char c: answer.getCifrado().toCharArray()) {
			int ascii = (int)c;

			if (isLetter(ascii)) {
				if (ascii > limit) {
					int rest = answer.getNumeroCasas() - (Z_ASCII - ascii) - 1; //-1 bc should consider the a
					ascii = A_ASCII + rest;
				} else {
					ascii += answer.getNumeroCasas();
				}
			}
			sb.append((char) ascii);
		}
		return sb.toString();
	}

	private static boolean isLetter(int ascii) {
		return ascii >= A_ASCII && ascii <= Z_ASCII;
	}

	private static String generateSha1(String value) {
		MessageDigest mDigest = null;
		try {
			mDigest = MessageDigest.getInstance("SHA1");
		} catch (NoSuchAlgorithmException e) {
			e.printStackTrace();
		}
		byte[] result = mDigest.digest(value.getBytes());
		StringBuilder sb = new StringBuilder();
		for (byte b : result) {
			sb.append(Integer.toString((b & 0xff) + 0x100, 16).substring(1));
		}
		return sb.toString();
	}

}

@Getter
@Setter
@ToString
class Answer {
	@JsonProperty("numero_casas")
	private Integer numeroCasas;
	private String token;
	private String cifrado;
	private String decifrado;
	@JsonProperty("resumo_criptografico")
	private String resumoCriptografico;
}