finance-analyzer/src/main/java/de/arminwolf/financeanalyzer/service/FileService.java

package de.arminwolf.financeanalyzer.service;

import com.fasterxml.jackson.core.type.TypeReference;
import com.fasterxml.jackson.databind.ObjectMapper;
import de.arminwolf.financeanalyzer.conf.Configuration;
import de.arminwolf.financeanalyzer.dao.TransactionDAO;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.io.File;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.Arrays;
import java.util.Objects;
import java.util.Optional;
import java.util.stream.Stream;

@Service
public class FileService {


	public static final String       CONFIGURATION_JSON = "configuration.json";
	@Autowired
	private             CacheService cacheService;


	public Configuration getConfiguration() {
		File workingDirectory      = getOrCreateWorkingDirectory();
		Path configurationFilePath = Paths.get(workingDirectory.toPath().toString(), CONFIGURATION_JSON);

		System.out.printf("Loading '%s'\n", configurationFilePath);
		ObjectMapper objectMapper = new ObjectMapper();
		try {
			return objectMapper.readValue(configurationFilePath.toFile(), Configuration.class);
		} catch (IOException e) {
			System.out.printf("Error while accesing '%s'\n", configurationFilePath);
		}

		return new Configuration();
	}


	public Optional<String> getJsonFileName() {
		File       workingDirectory = getOrCreateWorkingDirectory();
		final Path jsonFilePath     = Paths.get(workingDirectory.toPath().toString(), "finance-analyzer.json");
		if (!jsonFilePath.toFile().exists()) {
			return Optional.empty();
		} else {
			String absolutePath = jsonFilePath.toAbsolutePath().toString();
			System.out.println("Absolute Path of json file: " + absolutePath);
			return Optional.of(absolutePath);
		}
	}


	public boolean isJsonPresent() {
		File orCreateWorkingDirectory = getOrCreateWorkingDirectory();
		return getJsonFiles(orCreateWorkingDirectory).findFirst().isPresent();
	}


	private Stream<String> getJsonFiles(final File orCreateWorkingDirectory) {
		return Arrays.stream(Objects.requireNonNull(orCreateWorkingDirectory.list((dir, name) -> name.endsWith(".json"))));
	}


	public TransactionDAO[] getJsonFile() {
		File       workingDirectory = getOrCreateWorkingDirectory();
		final Path jsonFilePath     = Paths.get(workingDirectory.toPath().toString(), "finance-analyzer.json");
		if (!jsonFilePath.toFile().exists()) {
			throw new IllegalStateException("Could not load json file.");
		} else {

			System.out.printf("Loading '%s'\n", jsonFilePath);
			ObjectMapper objectMapper = new ObjectMapper();
			try {
				return objectMapper.readValue(jsonFilePath.toFile(), new TypeReference<TransactionDAO[]>() {
				});
			} catch (IOException e) {
				System.out.printf("Error while accesing '%s'\n", jsonFilePath);
			}
		}

		return new TransactionDAO[0];
	}


	public File getOrCreateWorkingDirectory() {
		if (Objects.isNull(cacheService.get("workingDirectory"))) {
			final String userHomeAsString = System.getProperty("user.home");
			System.out.printf("Looking for working Directory '.finance-analyser' in user home (%s).\n", userHomeAsString);
			Path    path   = Paths.get(userHomeAsString.concat(File.separator).concat(".finance-analyser"));
			boolean exists = Files.exists(path);
			if (exists) {
				return path.toFile();
			} else {
				Path directory = null;
				try {
					directory = Files.createDirectory(path);
					cacheService.put("workingDirectory", directory.toFile());
					return directory.toFile();
				} catch (IOException e) {
					System.err.println("Could not create directory in user home.. Permission issue?" + e.getMessage());
				}
				throw new IllegalStateException("Could not create working directory. Please fix the permissions.");
			}
		} else {
			return (File) cacheService.get("workingDirectory");
		}
	}


	public void saveConfiguration(final Configuration configuration) {
		File         workingDirectory = getOrCreateWorkingDirectory();
		Path         path             = Paths.get(workingDirectory.getPath(), CONFIGURATION_JSON);
		if (path.toFile().exists()) {
			System.out.println("Configuration file already exists. Overwriting it.");
			try {
				Files.delete(path);
			} catch (IOException e) {
				System.out.println("Could not delete existing configuration file." + e.getMessage());
			}
		}
		ObjectMapper objectMapper     = new ObjectMapper();
		try {
			objectMapper.writeValue(path.toFile(), configuration);
		} catch (IOException e) {
			System.err.println("Could not save configuration file." + e.getMessage());
		}
	}

}