package com.zy.system.config;

import org.springframework.stereotype.Component;

import javax.annotation.PostConstruct;
import javax.sql.DataSource;
import java.sql.Connection;
import java.sql.DatabaseMetaData;
import java.sql.ResultSet;
import java.sql.Statement;

@Component
public class LicenseSchemaInitializer {

    private final DataSource dataSource;

    public LicenseSchemaInitializer(DataSource dataSource) {
        this.dataSource = dataSource;
    }

    @PostConstruct
    public void init() {
        ensureTable();
        ensureColumn("sys_license_infos", "request_code", "NVARCHAR(2048) NULL");
    }

    private void ensureTable() {
        try (Connection connection = dataSource.getConnection()) {
            if (hasTable(connection, "sys_license_infos")) {
                return;
            }
            try (Statement statement = connection.createStatement()) {
                statement.executeUpdate("CREATE TABLE sys_license_infos ("
                        + "id INT IDENTITY(1,1) NOT NULL PRIMARY KEY, "
                        + "[license] NVARCHAR(MAX) NULL, "
                        + "license_time NVARCHAR(255) NULL, "
                        + "request_code NVARCHAR(2048) NULL, "
                        + "create_time DATETIME NULL)");
            }
        } catch (Exception ignored) {
        }
    }

    private void ensureColumn(String tableName, String columnName, String columnDefinition) {
        try (Connection connection = dataSource.getConnection()) {
            if (!hasTable(connection, tableName) || hasColumn(connection, tableName, columnName)) {
                return;
            }
            try (Statement statement = connection.createStatement()) {
                statement.executeUpdate("ALTER TABLE " + tableName + " ADD " + columnName + " " + columnDefinition);
            }
        } catch (Exception ignored) {
        }
    }

    private boolean hasTable(Connection connection, String tableName) throws Exception {
        DatabaseMetaData metaData = connection.getMetaData();
        try (ResultSet resultSet = metaData.getTables(connection.getCatalog(), null, tableName, new String[]{"TABLE"})) {
            while (resultSet.next()) {
                if (tableName.equalsIgnoreCase(resultSet.getString("TABLE_NAME"))) {
                    return true;
                }
            }
        }
        return false;
    }

    private boolean hasColumn(Connection connection, String tableName, String columnName) throws Exception {
        DatabaseMetaData metaData = connection.getMetaData();
        try (ResultSet resultSet = metaData.getColumns(connection.getCatalog(), null, tableName, columnName)) {
            while (resultSet.next()) {
                if (columnName.equalsIgnoreCase(resultSet.getString("COLUMN_NAME"))) {
                    return true;
                }
            }
        }
        return false;
    }
}