package io.trygvis.android.bt;

import android.bluetooth.BluetoothDevice;
import android.bluetooth.BluetoothGatt;
import android.bluetooth.BluetoothGattCallback;
import android.bluetooth.BluetoothGattCharacteristic;
import android.bluetooth.BluetoothGattDescriptor;
import android.database.sqlite.SQLiteDatabase;
import android.util.Log;

import java.util.Date;

import static io.trygvis.android.bt.BtSequence.SequenceResult.detour;
import static io.trygvis.android.bt.BtSequence.SequenceResult.fail;
import static io.trygvis.android.bt.BtSequence.SequenceResult.waitForNextEvent;

public class BtDevice<A> implements Comparable<BtDevice> {
    private final static String TAG = BtDevice.class.getSimpleName();

    private final DefaultBtService btService;
    private final BluetoothDevice bluetoothDevice;
    private BluetoothGatt gatt;
    private Integer rssi;
    private A tag;
    private final String address;

    private final long id;
    private final boolean seenBefore;
    private final Date firstSeen;
    private Date lastSeen;
    /**
     * If seen in last scan.
     */
    private boolean recentlySeen;
    private boolean connected;
    private final WrappingBluetoothGattCallback wrappingCallback = new WrappingBluetoothGattCallback();

    private BtBluetoothGattCallback callback;

    BtDevice(DefaultBtService btService, BluetoothDevice bluetoothDevice, SQLiteDatabase db,
             BtService.BtDbIntegration<A> btDbIntegration, long id, Integer rssi,
             boolean seenBefore, Date firstSeen, Date lastSeen, boolean recentlySeen) {
        this.btService = btService;
        this.bluetoothDevice = bluetoothDevice;
        this.id = id;
        this.rssi = rssi;
        this.seenBefore = seenBefore;
        this.firstSeen = firstSeen;
        this.lastSeen = lastSeen;
        this.recentlySeen = recentlySeen;

        this.tag = btDbIntegration.createTag(db, this);
        this.address = bluetoothDevice.getAddress();
    }

    public long getId() {
        return id;
    }

    public A getTag() {
        return tag;
    }

    public String getAddress() {
        return address;
    }

    public String getName() {
        return bluetoothDevice.getName();
    }

    public Integer getRssi() {
        return rssi;
    }

    public boolean isSeenBefore() {
        return seenBefore;
    }

    public Date getFirstSeen() {
        return firstSeen;
    }

    public Date getLastSeen() {
        return lastSeen;
    }

    public void setLastSeen(Date lastSeen) {
        this.lastSeen = lastSeen;
    }

    public boolean isRecentlySeen() {
        return recentlySeen;
    }

    public void setRecentlySeen(boolean recentlySeen) {
        this.recentlySeen = recentlySeen;
    }

    /**
     * The first handler must handle a onDirect().
     * <p>
     * Services will be discovered.
     */
    public synchronized void withConnection(BtSequence sequence) {
        if (callback != null) {
            throw new RuntimeException("The current callback is not done.");
        }

        Log.i(TAG, "withConnection(), address=" + address + ", connected: " + (gatt != null));

        BtSequence newSequence;
        if (gatt == null) {
            newSequence = new BtSequence().
                    ignoreFailureForNext().
                    onConnectionStateChange((gatt, status, newState) -> {
                        Log.i(TAG, "defaultConnectCallback: status=" + status + ", newState=" + newState);

                        btService.sendBroadcast(btService.createDeviceConnection(address));

                        if (status == BluetoothGatt.GATT_SUCCESS && newState == BluetoothGatt.STATE_CONNECTED) {
                            Log.i(TAG, "Connected to " + address + ", discovering services");
                            return gatt.discoverServices() ? waitForNextEvent() : fail();
                        } else {
                            Log.i(TAG, "Could not connect to " + address + ", trying again");

                            return detour(new BtSequence().onConnectionStateChange((gatt2, status2, newState2) -> {
                                if (status2 == BluetoothGatt.GATT_SUCCESS && newState2 == BluetoothGatt.STATE_CONNECTED) {
                                    Log.i(TAG, "Connected to " + address + ", discovering services");
                                    return gatt.discoverServices() ? waitForNextEvent() : fail();
                                }

                                Log.i(TAG, "Could still not connect to " + address + ", failing.");

                                return fail();
                            }));
                        }
                    }).
                    onServicesDiscovered(gatt -> {
                        Log.i(TAG, "Services discovered, has " + gatt.getServices().size() + " services");
                        return detour(sequence);
                    });
        } else {
            newSequence = sequence;
        }

        BtSequencer sequencer = new BtSequencer(bluetoothDevice.getAddress(), newSequence.
                onFinally(success -> {
                    Log.i(TAG, "Promise done, device is available again: address=" + address + ", success=" + success);
                    callback = null;
                }));
        callback = new BtBluetoothGattCallback(sequencer);

        if (gatt == null) {
            gatt = bluetoothDevice.connectGatt(btService, false, wrappingCallback);
        } else {
            sequencer.onDirect();
        }
    }

    public boolean connected() {
        return connected;
    }

    @Override
    public String toString() {
        return "BtDevice{address=" + address + '}';
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) {
            return true;
        }
        if (o == null || getClass() != o.getClass()) {
            return false;
        }

        BtDevice other = (BtDevice) o;

        return address.equals(other.getAddress());
    }

    @Override
    public int hashCode() {
        return address.hashCode();
    }

    @Override
    public int compareTo(BtDevice that) {
        return address.compareTo(that.address);
    }

    private class WrappingBluetoothGattCallback extends BluetoothGattCallback {

        @Override
        public void onConnectionStateChange(BluetoothGatt gatt, int status, int newState) {
            Log.i(TAG, "Wrapping: onConnectionStateChange: " +
                    "address=" + gatt.getDevice().getAddress() + ", " +
                    "status=" + status + ", " +
                    "newState=" + newState);

            boolean oldConnected = connected;

            BtDevice.this.connected = status == BluetoothGatt.GATT_SUCCESS &&
                    newState == BluetoothGatt.STATE_CONNECTED;

            if (oldConnected && BtDevice.this.connected) {
                Log.i(TAG, "Wrapping: Extra 'onConnectionStateChange' event, ignoring. gatt=" + gatt);
                return;
            }

            try {
                if (callback != null) {
                    callback.onConnectionStateChange(gatt, status, newState);
                }
            } finally {
                if (!BtDevice.this.connected) {
                    if (oldConnected) {
                        Log.i(TAG, "Wrapping: Lost connection, removing gatt. gatt=" + gatt);
                    } else {
                        Log.i(TAG, "Wrapping: Lost connection, was not connected. gatt=" + gatt);
                    }

                    BtDevice.this.gatt = null;
                } else {
                    Log.i(TAG, "Wrapping: connected");
                }
            }
        }

        @Override
        public void onServicesDiscovered(BluetoothGatt gatt, int status) {
            if (callback != null) {
                callback.onServicesDiscovered(gatt, status);
            }
        }

        @Override
        public void onCharacteristicRead(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic, int status) {
            if (callback != null) {
                callback.onCharacteristicRead(gatt, characteristic, status);
            }
        }

        @Override
        public void onCharacteristicWrite(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic, int status) {
            if (callback != null) {
                callback.onCharacteristicWrite(gatt, characteristic, status);
            }
        }

        @Override
        public void onCharacteristicChanged(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic) {
            if (callback != null) {
                callback.onCharacteristicChanged(gatt, characteristic);
            }
        }

        @Override
        public void onDescriptorRead(BluetoothGatt gatt, BluetoothGattDescriptor descriptor, int status) {
            if (callback != null) {
                callback.onDescriptorRead(gatt, descriptor, status);
            }
        }

        @Override
        public void onDescriptorWrite(BluetoothGatt gatt, BluetoothGattDescriptor descriptor, int status) {
            if (callback != null) {
                callback.onDescriptorWrite(gatt, descriptor, status);
            }
        }

        @Override
        public void onReliableWriteCompleted(BluetoothGatt gatt, int status) {
            if (callback != null) {
                callback.onReliableWriteCompleted(gatt, status);
            }
        }

        @Override
        public void onReadRemoteRssi(BluetoothGatt gatt, int rssi, int status) {
            if (callback != null) {
                callback.onReadRemoteRssi(gatt, rssi, status);
            }
        }
    }
}