package sqlancer;

import java.io.FileWriter;
import java.io.IOException;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;
import java.util.Set;

public interface DatabaseProvider<G extends GlobalState<O>, O> {

    void generateAndTestDatabase(G globalState) throws SQLException;

    G generateGlobalState();

    // TODO: should be type G
    Connection createDatabase(GlobalState<?> globalState) throws SQLException;

    /**
     * The DBMS name is used to name the log directory and command to test the respective DBMS.
     */
    String getDBMSName();

    // TODO: remove this
    default void printDatabaseSpecificState(FileWriter writer, StateToReproduce state) {

    }

    StateToReproduce getStateToReproduce(String databaseName);

    O getCommand();

    static boolean isEqualDouble(String first, String second) {
        try {
            double val = Double.parseDouble(first);
            double secVal = Double.parseDouble(second);
            return equals(val, secVal);
        } catch (Exception e) {
            return false;
        }
    }

    static boolean equals(double a, double b) {
        if (a == b) {
            return true;
        }
        // If the difference is less than epsilon, treat as equal.
        return Math.abs(a - b) < 0.0001 * Math.max(Math.abs(a), Math.abs(b));
    }

    static List<String> getResultSetFirstColumnAsString(String queryString, Set<String> errors, Connection con,
            GlobalState<?> state) throws SQLException {
        if (state.getOptions().logEachSelect()) {
            // TODO: refactor me
            state.getLogger().writeCurrent(queryString);
            try {
                state.getLogger().getCurrentFileWriter().flush();
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
        QueryAdapter q = new QueryAdapter(queryString, errors);
        List<String> resultSet = new ArrayList<>();
        ResultSet result = null;
        try {
            result = q.executeAndGet(con);
            if (result == null) {
                throw new IgnoreMeException();
            }
            while (result.next()) {
                resultSet.add(result.getString(1));
            }
            result.getStatement().close();
        } catch (Exception e) {
            if (e instanceof IgnoreMeException) {
                throw e;
            }
            if (e instanceof NumberFormatException) {
                // https://github.com/tidb-challenge-program/bug-hunting-issue/issues/57
                throw new IgnoreMeException();
            }
            if (e.getMessage() == null) {
                throw new AssertionError(queryString, e);
            }
            for (String error : errors) {
                if (e.getMessage().contains(error)) {
                    throw new IgnoreMeException();
                }
            }
            throw new AssertionError(queryString, e);
        } finally {
            if (result != null && !result.isClosed()) {
                result.getStatement().close();
                result.close();
            }
        }
        return resultSet;
    }

}