package src.main;

import java.time.LocalDate;

import java.util.AbstractMap;
import java.util.HashMap;
import java.util.List;
import java.io.IOException;
import java.lang.Object;
import java.nio.charset.StandardCharsets;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.nio.file.StandardCopyOption;

import org.json.JSONObject;

import java.util.Scanner;
import java.util.stream.Collectors;
import java.util.stream.Stream;

import java.util.Map;

import src.main.utilities.JsonUtils;


public class ConfigManager {

    private static final Path CONFIGS_DIR = Paths.get("src/resources/configs");
    private static final Path CONFIGS_BACKUP_DIR = Paths.get("src/resources/configs/backups");

    // Map entry of database config contents and file path
    private static final Map.Entry<String, String[]> DATABASE_CONFIG = new AbstractMap.SimpleEntry<String, String[]>("database.json", 
    new String[] {
        "address",
        "port",
        "username",
        "password",
        "ssl",
        "defaultTable"
    });

    // Default constructor
    public ConfigManager() {

    }

    // Boolean constructor for instanciating first time setup
    public ConfigManager(boolean firstTimeSetup) {

        makeBackups(CONFIGS_DIR, CONFIGS_BACKUP_DIR);
        
        if(!Files.exists(Path.of(CONFIGS_DIR.toString(), DATABASE_CONFIG.getKey())) || firstTimeSetup) {
            writeConfig(Paths.get(CONFIGS_DIR.toString(), DATABASE_CONFIG.getKey()), DATABASE_CONFIG.getValue());
        }

    }

    // Writes the config content to the config path
    private void writeConfig(Path configPath, String[] configContent) {

        Scanner inputScanner = new Scanner(System.in);
        HashMap<String, Object> configData = new HashMap<String, Object>();

        for (String entry : configContent) {
            getUserInputConfig(configData, inputScanner, entry);
        }
        
        JSONObject json = new JSONObject(configData);
        
        try {
            Files.writeString(configPath, json.toString(), StandardCharsets.UTF_8);
        } catch (IOException error) {
            error.printStackTrace();
        }

    }

    // Reads out the config based on the config file Path
    public HashMap<String, Object> readConfig(Path configPath) {
        
        HashMap<String, Object> configContents = new HashMap<String, Object>();

        try {
            String configContent = new String(Files.readAllBytes(configPath));
            JSONObject jsonObject = new JSONObject(configContent);
            configContents = JsonUtils.jsonToHashMap(jsonObject);
        } catch (Exception error) {
            error.printStackTrace();
        }

        return configContents;
    }

    // Reads out the config based on the config file String
    public HashMap<String, Object> readConfig(String config) {
        
        // Checks if the string passed is of type .json
        if (config.length() > 5 && config.substring(config.length() - 4) == ".json") {
            System.out.println("Getting config ");
        }

        Path configPath = Path.of(CONFIGS_DIR.toString(), config);
        HashMap<String, Object> configContents = new HashMap<String, Object>();

        try {
            String configContent = new String(Files.readAllBytes(configPath));
            JSONObject jsonObject = new JSONObject(configContent);
            configContents = JsonUtils.jsonToHashMap(jsonObject);
        } catch (Exception error) {
            error.printStackTrace();
        }

        return configContents;
    }

    private void makeBackups(Path source, Path destination) {
        // Ensure the source path exists.
        if (!Files.exists(source) || !Files.isDirectory(source)) {
            System.err.println("Source directory does not exist or is not a directory.");
            return;
        }
        // Ensure the destination exists, if not create it
        if (!Files.exists(destination)) {
            try {
            // Create destination directory.
            Files.createDirectories(destination);
            } catch (IOException error) {
                error.printStackTrace();
                System.err.println("Failed to create destination address \"" + destination.toString() + "\"");
                return;
            }
        }
        // Attempt to copy files from source to destination
        try (Stream<Path> pathStream = Files.list(source)) {
            // Get a list of files, filter out non-file types
            List<Path> fileList = pathStream
                .filter(Files::isRegularFile)
                .collect(Collectors.toList());

            // Copy the file to the backup directory, replacing existing ones
            for(Path filePath : fileList) {
                String newFileName = filePath.getFileName().toString() + LocalDate.now();
                System.out.println(newFileName);
                System.out.println(Path.of(destination.toString(), newFileName).toString());
                Files.copy(filePath, Path.of(destination.toString(), newFileName), StandardCopyOption.REPLACE_EXISTING);
            }

        } catch (IOException e) {
            e.printStackTrace();
            System.err.println("Failed to copy file ");
        }
        
    }

    private void getUserInputConfig(HashMap<String, Object> config, Scanner scanner, String configEntry) {

        System.out.println("Please enter " + configEntry);
        config.put(configEntry, scanner.nextLine());

    }

}