package info.peper.vz.rest;

import java.io.BufferedReader;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.time.Instant;
import java.time.ZoneId;
import java.time.format.DateTimeFormatter;
import java.time.temporal.ChronoUnit;
import java.time.temporal.TemporalAccessor;
import java.util.LinkedList;
import java.util.List;

public class FillAggregateTableMain2 {

	private static final DateTimeFormatter DTF = DateTimeFormatter.ISO_LOCAL_DATE_TIME.withZone(ZoneId.systemDefault());
	private static final int[] CHANNELS_TO_USE = new int[] {1, 4, };
	private static final List<AggregateToSave> SAVELIST = new LinkedList<AggregateToSave>();
	
	private static class AggregateToSave {
		private final long startTs;
		private final long endTs;
		private final long valuePos;
		private final long valueNeg;
		private final int channelId;
		
		private AggregateToSave(long startTs, long endTs, long valuePos, long valueNeg, int channelId) {
			super();
			this.startTs = startTs;
			this.endTs = endTs;
			this.valuePos = valuePos;
			this.valueNeg = valueNeg;
			this.channelId = channelId;
		}

		private long getStartTs() {
			return startTs;
		}

		private long getEndTs() {
			return endTs;
		}

		private long getValuePos() {
			return valuePos;
		}

		private long getValueNeg() {
			return valueNeg;
		}

		private int getChannelId() {
			return channelId;
		}
	}
	
	public static void main(String[] args) throws Exception {
		try (final Connection con = DriverManager.getConnection(
				"jdbc:mariadb://mariadb.fritz.box/volkszaehler",
				"vz",
				getPassword())) {
//			long startTimeStamp = getTimestamp("2025-01-01T09:00:00");
			final long startTimeStamp = getTimestamp("2022-05-20T09:00:00");
			final long finalEndTimeStamp = getTimestamp("2025-03-01T00:00:00");
			for (int channelId : CHANNELS_TO_USE) {
				processChannel(startTimeStamp, finalEndTimeStamp, 60*1000, channelId, con);
			}
			System.out.println("Saving... " + SAVELIST.size());
//			saveValues(con);
//			for (AggregateToSave ats : SAVELIST) {
//				saveValues(con, ats.startTs, ats.endTs, ats.channelId, new long[] {ats.valuePos, ats.valueNeg});
//				System.out.println("####");
//			}
		}
	}
	
	private static void processChannel(final long startTimestamp,
			final long endTimestamp,
			final long interval,
			final int channelId,
			final Connection con) throws SQLException {
		long currentTimestamp = startTimestamp;
		long intervalStartTimestamp = startTimestamp;
		long intervalEndTimestamp = startTimestamp + interval;
		long intervalPos = 0;
		long intervalNeg = 0;
		try (final PreparedStatement stmt = con.prepareStatement("SELECT * FROM volkszaehler.data WHERE channel_id=? AND timestamp>? ORDER BY timestamp;")) {
			stmt.setInt(1, channelId);
			stmt.setLong(2, startTimestamp);
			stmt.setFetchSize(1000);
			boolean noNextRecord = false;
			try (final ResultSet rs = stmt.executeQuery()) {
				long sumDiff = 0;
				while (noNextRecord || (currentTimestamp <= endTimestamp && rs.next())) {
					noNextRecord = false;
					final long timestamp = rs.getLong("timestamp");
					final long value;
					if (rs.getDouble("value") >= 0 && rs.getDouble("value") < 1) {
						value = 0;
					} else {
						value = rs.getLong("value");
					}
					final long tsDiff;
					if (timestamp < intervalEndTimestamp) {
						tsDiff = timestamp - currentTimestamp;
					} else {
						tsDiff = intervalEndTimestamp - currentTimestamp;
					}
//					final long tsDiff = Math.min(timestamp - currentTimestamp, intervalEndTimestamp - currentTimestamp);
					sumDiff += tsDiff;
					currentTimestamp = timestamp;
					if (value > 0) {
						intervalPos += (value * tsDiff);
					} else if (value < 0) {
						intervalNeg += (-value * tsDiff);
					}
					if (timestamp >= intervalEndTimestamp) {
						if (sumDiff != interval) {
							System.err.println("sumDiff: " + sumDiff + " / interval: " + interval);
						}
						sumDiff = 0;
						if (intervalStartTimestamp % (86400000*10) == 0) {
							System.out.println(
									DTF.format(Instant.ofEpochMilli(intervalStartTimestamp)) + " - " + 
									DTF.format(Instant.ofEpochMilli(intervalEndTimestamp)) + " / " +
									(intervalPos/3600) + " / " +
									(intervalNeg/3600));
						}
						SAVELIST.add(new AggregateToSave(intervalStartTimestamp, intervalEndTimestamp, intervalPos/3600, intervalNeg/3600, channelId));
						intervalStartTimestamp += interval;
						intervalEndTimestamp += interval;
						currentTimestamp = intervalStartTimestamp;
						intervalPos = 0;
						intervalNeg = 0;
						noNextRecord = true;
					}
				}
			}
		}
	}

	private static String getPassword() throws IOException {
		try (final InputStream is = new FileInputStream("db-password.txt")) {
			final BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(is));
			return bufferedReader.readLine();
		}
	}

	private static long getTimestamp(final String dateTime) {
		final TemporalAccessor tempAccessor = DTF.parse(dateTime);
		final Instant instant = Instant.from(tempAccessor);
		return Instant.EPOCH.until(instant, ChronoUnit.MILLIS);
	}
	
	private static void saveValues(final Connection con,
			final long startTimestamp,
			final long endTimestamp,
			final int channelId,
			final long[] values) throws SQLException {
		try (final PreparedStatement stmt = con.prepareStatement("INSERT INTO tobias_aggregate (channel_id, timestamp_start, timestamp_end, sum_positive, sum_negative) VALUES (?, ?, ?, ?, ?)")) {
			stmt.setInt(1, channelId);
			stmt.setLong(2, startTimestamp);
			stmt.setLong(3, endTimestamp);
			stmt.setLong(4, values[0]);
			stmt.setLong(5, values[1]);
			stmt.execute();
		}
	}
	
	private static void saveValues(final Connection con) throws SQLException {
		try (final PreparedStatement stmt = con.prepareStatement("INSERT INTO tobias_aggregate (channel_id, timestamp_start, timestamp_end, sum_positive, sum_negative) VALUES (?, ?, ?, ?, ?)")) {
			int i = 0;
			for (AggregateToSave ats : SAVELIST) {
				stmt.setInt(1, ats.channelId);
				stmt.setLong(2, ats.startTs);
				stmt.setLong(3, ats.endTs);
				stmt.setLong(4, ats.valuePos);
				stmt.setLong(5, ats.valueNeg);
				stmt.addBatch();
				i++;
				if (i % 100000 == 0) {
					System.out.println(i);
					stmt.executeBatch();
				}
			}
			stmt.executeBatch();
		}
	}
}