package de.srsoftware.widerhall.data;

import de.srsoftware.widerhall.Util;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.security.InvalidKeyException;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.time.LocalDate;
import java.util.*;

import static de.srsoftware.widerhall.data.Database.*;
import static de.srsoftware.widerhall.Constants.*;

public class User {
    public static final String TABLE_NAME = "Users";
    private static final Logger LOG = LoggerFactory.getLogger(User.class);

    private String email, salt, hashedPass, name;

    public User(String email, String name, String salt, String hashedPass) {
        this.email = email;
        this.name = name;
        this.salt = salt;
        this.hashedPass = hashedPass;
    }

    /*********** field accessors ***************/
    public String email() {
        return email;
    }

    public String hashedPassword() {
        return hashedPass;
    }

    public String name() {
        return name;
    }

    public String salt(){
        return salt;
    }

    /************** end of field accessors ****************/

    public static User create(String email, String name, String password) throws SQLException {
        String salt = null;
        String hashedPass = null;
        if (password != null) {
            salt = Util.sha256(email + name + LocalDate.now());
            hashedPass = Util.sha256(password + salt);
        }
        return new User(email,name,salt,hashedPass).save();
    }

    public static void createTable() throws SQLException {
        var sql = new StringBuilder()
                .append("CREATE TABLE ").append(TABLE_NAME)
                .append(" (")
                .append(EMAIL).append(" ").append(VARCHAR).append(" NOT NULL PRIMARY KEY, ")
                .append(SALT).append(" ").append(VARCHAR).append(", ")
                .append(HASHED_PASS).append(" ").append(VARCHAR).append(", ")
                .append(NAME).append(" ").append(VARCHAR)
                .append(");");
        Database.open().query(sql).run();
    }

    public boolean is(String test){
        if (test == null) return false;
        return test.equals(name) || test.equals(email);
    }


    public static List<User> loadAll() throws SQLException {
        return loadAll(null);
    }

    public static List<User> loadAll(Collection<String> emails) throws SQLException {
        var userList = new ArrayList<User>();
        var query = Database.open().select(TABLE_NAME);
        if (emails != null && !emails.isEmpty()) query.where(EMAIL,emails);
        var rs = query.exec();
        while (rs.next()) userList.add(new User(
                    rs.getString(EMAIL),
                    rs.getString(NAME),
                    rs.getString(SALT),
                    rs.getString(HASHED_PASS)));
        return userList;
    }



    public static User loadUser(String email, String password) throws InvalidKeyException, SQLException {
        ResultSet rs = Database.open()
                .select(TABLE_NAME)
                .where(EMAIL,email)
                .exec();
        try {
            if (rs.next()) {
                email = rs.getString(EMAIL);
                var name = rs.getString(NAME);
                var hashedPassword = rs.getString(HASHED_PASS);
                var salt = rs.getString(SALT);
                var loadedUser = new User(email, name, salt, hashedPassword);
                if (loadedUser.matching(password)) return loadedUser;
            } else if (noUsers()){
                return User.create(email,"Admin",password);
            }
        } finally {
            rs.close();
        }

        throw new InvalidKeyException();
    }


    private boolean matching(String password) {
        if (hashedPass == null) return password == null;
        return hashedPass.equals(Util.sha256(password+salt));
    }


    public static boolean noUsers() throws SQLException {
        var rs = Database.open().select(TABLE_NAME,"count(*)").exec();
        try {
            if (rs.next()) {
                return rs.getInt(1) < 1;
            }
        } finally {
            rs.close();
        }
        return false;
    }

    public Map<String,String> safeMap(){
        return Map.of(NAME,name,EMAIL,email,PASSWORD,hashedPassword() == null ? "no" : "yes");
    }

    private User save() throws SQLException {
        var values = new HashMap<String,Object>();
        values.put(EMAIL,email);
        values.put(NAME,name);
        if (salt != null) values.put(SALT,salt);
        if (hashedPass != null) values.put(HASHED_PASS,hashedPass);
        Database.open().insertInto(TABLE_NAME)
                .values(values)
                .run();
        return this;
    }
}