package nodomain.freeyourgadget.gadgetbridge.database;

import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.widget.Toast;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.util.ArrayList;

import nodomain.freeyourgadget.gadgetbridge.GB;
import nodomain.freeyourgadget.gadgetbridge.GBActivitySample;
import nodomain.freeyourgadget.gadgetbridge.charts.ActivityKind;
import nodomain.freeyourgadget.gadgetbridge.database.schema.ActivityDBCreationScript;
import nodomain.freeyourgadget.gadgetbridge.model.ActivitySample;
import nodomain.freeyourgadget.gadgetbridge.model.SampleProvider;

import static nodomain.freeyourgadget.gadgetbridge.database.DBConstants.DATABASE_NAME;
import static nodomain.freeyourgadget.gadgetbridge.database.DBConstants.KEY_INTENSITY;
import static nodomain.freeyourgadget.gadgetbridge.database.DBConstants.KEY_PROVIDER;
import static nodomain.freeyourgadget.gadgetbridge.database.DBConstants.KEY_STEPS;
import static nodomain.freeyourgadget.gadgetbridge.database.DBConstants.KEY_TIMESTAMP;
import static nodomain.freeyourgadget.gadgetbridge.database.DBConstants.KEY_TYPE;
import static nodomain.freeyourgadget.gadgetbridge.database.DBConstants.TABLE_GBACTIVITYSAMPLES;

public class ActivityDatabaseHandler extends SQLiteOpenHelper {

    private static final Logger LOG = LoggerFactory.getLogger(ActivityDatabaseHandler.class);

    private static final int DATABASE_VERSION = 5;

    public ActivityDatabaseHandler(Context context) {
        super(context, DATABASE_NAME, null, DATABASE_VERSION);
    }

    @Override
    public void onCreate(SQLiteDatabase db) {
        try {
            ActivityDBCreationScript script = new ActivityDBCreationScript();
            script.createSchema(db);
        } catch (RuntimeException ex) {
            GB.toast("Error creating database.", Toast.LENGTH_SHORT, GB.ERROR, ex);
        }
    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        try {
            for (int i = oldVersion + 1; i <= newVersion; i++) {
                DBUpdateScript updater = getUpdateScript(db, i);
                if (updater != null) {
                    LOG.info("upgrading activity database to version " + i);
                    updater.upgradeSchema(db);
                }
            }
            LOG.info("activity database is now at version " + newVersion);
        } catch (RuntimeException ex) {
            GB.toast("Error upgrading database.", Toast.LENGTH_SHORT, GB.ERROR, ex);
            throw ex; // reject upgrade
        }
    }

    @Override
    public void onDowngrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        try {
            for (int i = oldVersion; i >= newVersion; i--) {
                DBUpdateScript updater = getUpdateScript(db, i);
                if (updater != null) {
                    LOG.info("downgrading activity database to version " + (i - 1));
                    updater.downgradeSchema(db);
                }
            }
            LOG.info("activity database is now at version " + newVersion);
        } catch (RuntimeException ex) {
            GB.toast("Error downgrading database.", Toast.LENGTH_SHORT, GB.ERROR, ex);
            throw ex; // reject downgrade
        }
    }

    private DBUpdateScript getUpdateScript(SQLiteDatabase db, int version) {
        try {
            Class<?> updateClass = getClass().getClassLoader().loadClass(getClass().getPackage().getName() + ".schema.ActivityDBUpdate_" + version);
            return (DBUpdateScript) updateClass.newInstance();
        } catch (ClassNotFoundException e) {
            return null;
        } catch (InstantiationException | IllegalAccessException e) {
            throw new RuntimeException("Error instantiating DBUpdate class for version " + version, e);
        }
    }

    public void addGBActivitySample(ActivitySample sample) {
        try (SQLiteDatabase db = this.getWritableDatabase()) {
            ContentValues values = new ContentValues();
            values.put(KEY_TIMESTAMP, sample.getTimestamp());
            values.put(KEY_PROVIDER, sample.getProvider().getID());
            values.put(KEY_INTENSITY, sample.getRawIntensity());
            values.put(KEY_STEPS, sample.getSteps());
            values.put(KEY_TYPE, sample.getRawKind());

            db.insert(TABLE_GBACTIVITYSAMPLES, null, values);
        }
    }

    /**
     * Adds the a new sample to the database
     * @param timestamp the timestamp of the same, second-based!
     * @param provider the SampleProvider ID
     * @param intensity the sample's raw intensity value
     * @param steps the sample's steps value
     * @param kind the raw activity kind of the sample
     */
    public void addGBActivitySample(int timestamp, byte provider, short intensity, byte steps, byte kind) {
        try (SQLiteDatabase db = this.getWritableDatabase()) {
            ContentValues values = new ContentValues();
            values.put(KEY_TIMESTAMP, timestamp);
            values.put(KEY_PROVIDER, provider);
            values.put(KEY_INTENSITY, intensity);
            values.put(KEY_STEPS, steps);
            values.put(KEY_TYPE, kind);

            db.insert(TABLE_GBACTIVITYSAMPLES, null, values);
        }
    }

    public ArrayList<ActivitySample> getSleepSamples(int timestamp_from, int timestamp_to, SampleProvider provider) {
        return getGBActivitySamples(timestamp_from, timestamp_to, ActivityKind.TYPE_SLEEP, provider);
    }

    public ArrayList<ActivitySample> getActivitySamples(int timestamp_from, int timestamp_to, SampleProvider provider) {
        return getGBActivitySamples(timestamp_from, timestamp_to, ActivityKind.TYPE_ACTIVITY, provider);
    }

    public ArrayList<ActivitySample> getAllActivitySamples(int timestamp_from, int timestamp_to, SampleProvider provider) {
        return getGBActivitySamples(timestamp_from, timestamp_to, ActivityKind.TYPE_ALL, provider);
    }

    /**
     * Returns all available activity samples from between the two timestamps (inclusive), of the given
     * provided and type(s).
     *
     * @param timestamp_from
     * @param timestamp_to
     * @param activityTypes  ORed combination of #TYPE_DEEP_SLEEP, #TYPE_LIGHT_SLEEP, #TYPE_ACTIVITY
     * @param provider the producer of the samples to be sought
     * @return
     */
    private ArrayList<ActivitySample> getGBActivitySamples(int timestamp_from, int timestamp_to, int activityTypes, SampleProvider provider) {
        if (timestamp_to == -1) {
            timestamp_to = Integer.MAX_VALUE; // dont know what happens when I use more than max of a signed int
        }
        ArrayList<ActivitySample> samples = new ArrayList<ActivitySample>();
        final String where = "(provider=" + provider.getID() + " and timestamp>=" + timestamp_from + " and timestamp<=" + timestamp_to + getWhereClauseFor(activityTypes, provider) + ")";
        final String order = "timestamp";
        try (SQLiteDatabase db = this.getReadableDatabase()) {
            Cursor cursor = db.query(TABLE_GBACTIVITYSAMPLES, null, where, null, null, null, order);

            if (cursor.moveToFirst()) {
                do {
                    GBActivitySample sample = new GBActivitySample(
                            provider,
                            cursor.getInt(cursor.getColumnIndex(KEY_TIMESTAMP)),
                            cursor.getShort(cursor.getColumnIndex(KEY_INTENSITY)),
                            cursor.getShort(cursor.getColumnIndex(KEY_STEPS)),
                            (byte) cursor.getShort(cursor.getColumnIndex(KEY_TYPE)));
                    samples.add(sample);
                } while (cursor.moveToNext());
            }
        }

        return samples;
    }

    private String getWhereClauseFor(int activityTypes, SampleProvider provider) {
        if (activityTypes == ActivityKind.TYPE_ALL) {
            return ""; // no further restriction
        }

        StringBuilder builder = new StringBuilder(" and (");
        byte[] dbActivityTypes = ActivityKind.mapToDBActivityTypes(activityTypes, provider);
        for (int i = 0; i < dbActivityTypes.length; i++) {
            builder.append(" type=").append(dbActivityTypes[i]);
            if (i + 1 < dbActivityTypes.length) {
                builder.append(" or ");
            }
        }
        builder.append(')');
        return builder.toString();
    }
}