package com.xtremelabs.robolectric.shadows;

import android.location.Location;
import android.os.Bundle;
import com.xtremelabs.robolectric.internal.Implementation;
import com.xtremelabs.robolectric.internal.Implements;

import static com.xtremelabs.robolectric.Robolectric.shadowOf_;

/**
 * Shadow of {@code Location} that treats it primarily as a data-holder
 * todo: support Location's static utility methods
 */

@SuppressWarnings({"UnusedDeclaration"})
@Implements(Location.class)
public class ShadowLocation {
    private long time;
    private String provider;
    private double latitude;
    private double longitude;
    private float accuracy;
    private float bearing;
    private double altitude;
    private float speed;
    private boolean hasAccuracy;
    private boolean hasAltitude;
    private boolean hasBearing;
    private boolean hasSpeed;

    // Cache the inputs and outputs of computeDistanceAndBearing
    // so calls to distanceTo() and bearingTo() can share work
    private double mLat1 = 0.0;
    private double mLon1 = 0.0;
    private double mLat2 = 0.0;
    private double mLon2 = 0.0;
    private float mDistance = 0.0f;
    private float mInitialBearing = 0.0f;
    // Scratchpad
    private final float[] mResults = new float[2];

    private Bundle extras = new Bundle();

    public void __constructor__(Location l) {
        set(l);
    }

    public void __constructor__(String provider) {
        this.provider = provider;
        time = System.currentTimeMillis();
    }

    @Implementation
    public void set(Location l) {
        time = l.getTime();
        provider = l.getProvider();
        latitude = l.getLatitude();
        longitude = l.getLongitude();
        accuracy = l.getAccuracy();
        bearing = l.getBearing();
        altitude = l.getAltitude();
        speed = l.getSpeed();

        hasAccuracy = l.hasAccuracy();
        hasAltitude = l.hasAltitude();
        hasBearing = l.hasBearing();
        hasSpeed = l.hasSpeed();
    }

    @Implementation
    public String getProvider() {
        return provider;
    }

    @Implementation
    public void setProvider(String provider) {
        this.provider = provider;
    }

    @Implementation
    public long getTime() {
        return time;
    }

    @Implementation
    public void setTime(long time) {
        this.time = time;
    }

    @Implementation
    public float getAccuracy() {
        return accuracy;
    }

    @Implementation
    public void setAccuracy(float accuracy) {
        this.accuracy = accuracy;
        this.hasAccuracy = true;
    }

    @Implementation
    public void removeAccuracy() {
        this.accuracy = 0.0f;
        this.hasAccuracy = false;
    }

    @Implementation
    public boolean hasAccuracy() {
        return hasAccuracy;
    }

    @Implementation
    public double getAltitude() {
        return altitude;
    }

    @Implementation
    public void setAltitude(double altitude) {
        this.altitude = altitude;
        this.hasAltitude = true;
    }

    @Implementation
    public void removeAltitude() {
        this.altitude = 0.0d;
        this.hasAltitude = false;
    }

    @Implementation
    public boolean hasAltitude() {
        return hasAltitude;
    }

    @Implementation
    public float getBearing() {
        return bearing;
    }

    @Implementation
    public void setBearing(float bearing) {
        this.bearing = bearing;
        this.hasBearing = true;
    }

    @Implementation
    public void removeBearing() {
        this.bearing = 0.0f;
        this.hasBearing = false;
    }

    @Implementation
    public boolean hasBearing() {
        return hasBearing;
    }


    @Implementation
    public double getLatitude() {
        return latitude;
    }

    @Implementation
    public void setLatitude(double latitude) {
        this.latitude = latitude;
    }

    @Implementation
    public double getLongitude() {
        return longitude;
    }

    @Implementation
    public void setLongitude(double longitude) {
        this.longitude = longitude;
    }

    @Implementation
    public float getSpeed() {
        return speed;
    }

    @Implementation
    public void setSpeed(float speed) {
        this.speed = speed;
        this.hasSpeed = true;
    }

    @Implementation
    public void removeSpeed() {
        this.hasSpeed = false;
        this.speed = 0.0f;
    }

    @Implementation
    public boolean hasSpeed() {
        return hasSpeed;
    }

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

        ShadowLocation that = (ShadowLocation) o;

        if (Double.compare(that.latitude, latitude) != 0) return false;
        if (Double.compare(that.longitude, longitude) != 0) return false;
        if (time != that.time) return false;
        if (provider != null ? !provider.equals(that.provider) : that.provider != null) return false;
        if (accuracy != that.accuracy) return false;
        return true;
    }

    @Override @Implementation
    public int hashCode() {
        int result;
        long temp;
        result = (int) (time ^ (time >>> 32));
        result = 31 * result + (provider != null ? provider.hashCode() : 0);
        temp = latitude != +0.0d ? Double.doubleToLongBits(latitude) : 0L;
        result = 31 * result + (int) (temp ^ (temp >>> 32));
        temp = longitude != +0.0d ? Double.doubleToLongBits(longitude) : 0L;
        result = 31 * result + (int) (temp ^ (temp >>> 32));
        temp = accuracy != 0f ? Float.floatToIntBits(accuracy) : 0;
        result = 31 * result + (int) (temp ^ (temp >>> 32));
        return result;
    }

    @Override @Implementation
    public String toString() {
        return "Location{" +
                "time=" + time +
                ", provider='" + provider + '\'' +
                ", latitude=" + latitude +
                ", longitude=" + longitude +
                ", accuracy=" + accuracy +
                '}';
    }

    private static void computeDistanceAndBearing(double lat1, double lon1,
            double lat2, double lon2, float[] results) {
        // Based on http://www.ngs.noaa.gov/PUBS_LIB/inverse.pdf
        // using the "Inverse Formula" (section 4)

        int MAXITERS = 20;
        // Convert lat/long to radians
        lat1 *= Math.PI / 180.0;
        lat2 *= Math.PI / 180.0;
        lon1 *= Math.PI / 180.0;
        lon2 *= Math.PI / 180.0;

        double a = 6378137.0; // WGS84 major axis
        double b = 6356752.3142; // WGS84 semi-major axis
        double f = (a - b) / a;
        double aSqMinusBSqOverBSq = (a * a - b * b) / (b * b);

        double L = lon2 - lon1;
        double A = 0.0;
        double U1 = Math.atan((1.0 - f) * Math.tan(lat1));
        double U2 = Math.atan((1.0 - f) * Math.tan(lat2));

        double cosU1 = Math.cos(U1);
        double cosU2 = Math.cos(U2);
        double sinU1 = Math.sin(U1);
        double sinU2 = Math.sin(U2);
        double cosU1cosU2 = cosU1 * cosU2;
        double sinU1sinU2 = sinU1 * sinU2;

        double sigma = 0.0;
        double deltaSigma = 0.0;
        double cosSqAlpha = 0.0;
        double cos2SM = 0.0;
        double cosSigma = 0.0;
        double sinSigma = 0.0;
        double cosLambda = 0.0;
        double sinLambda = 0.0;

        double lambda = L; // initial guess
        for (int iter = 0; iter < MAXITERS; iter++) {
            double lambdaOrig = lambda;
            cosLambda = Math.cos(lambda);
            sinLambda = Math.sin(lambda);
            double t1 = cosU2 * sinLambda;
            double t2 = cosU1 * sinU2 - sinU1 * cosU2 * cosLambda;
            double sinSqSigma = t1 * t1 + t2 * t2; // (14)
            sinSigma = Math.sqrt(sinSqSigma);
            cosSigma = sinU1sinU2 + cosU1cosU2 * cosLambda; // (15)
            sigma = Math.atan2(sinSigma, cosSigma); // (16)
            double sinAlpha = (sinSigma == 0) ? 0.0 :
                cosU1cosU2 * sinLambda / sinSigma; // (17)
            cosSqAlpha = 1.0 - sinAlpha * sinAlpha;
            cos2SM = (cosSqAlpha == 0) ? 0.0 :
                cosSigma - 2.0 * sinU1sinU2 / cosSqAlpha; // (18)

            double uSquared = cosSqAlpha * aSqMinusBSqOverBSq; // defn
            A = 1 + (uSquared / 16384.0) * // (3)
                (4096.0 + uSquared *
                 (-768 + uSquared * (320.0 - 175.0 * uSquared)));
            double B = (uSquared / 1024.0) * // (4)
                (256.0 + uSquared *
                 (-128.0 + uSquared * (74.0 - 47.0 * uSquared)));
            double C = (f / 16.0) *
                cosSqAlpha *
                (4.0 + f * (4.0 - 3.0 * cosSqAlpha)); // (10)
            double cos2SMSq = cos2SM * cos2SM;
            deltaSigma = B * sinSigma * // (6)
                (cos2SM + (B / 4.0) *
                 (cosSigma * (-1.0 + 2.0 * cos2SMSq) -
                  (B / 6.0) * cos2SM *
                  (-3.0 + 4.0 * sinSigma * sinSigma) *
                  (-3.0 + 4.0 * cos2SMSq)));

            lambda = L +
                (1.0 - C) * f * sinAlpha *
                (sigma + C * sinSigma *
                 (cos2SM + C * cosSigma *
                  (-1.0 + 2.0 * cos2SM * cos2SM))); // (11)

            double delta = (lambda - lambdaOrig) / lambda;
            if (Math.abs(delta) < 1.0e-12) {
                break;
            }
        }

        float distance = (float) (b * A * (sigma - deltaSigma));
        results[0] = distance;
        if (results.length > 1) {
            float initialBearing = (float) Math.atan2(cosU2 * sinLambda,
                cosU1 * sinU2 - sinU1 * cosU2 * cosLambda);
            initialBearing *= 180.0 / Math.PI;
            results[1] = initialBearing;
            if (results.length > 2) {
                float finalBearing = (float) Math.atan2(cosU1 * sinLambda,
                    -sinU1 * cosU2 + cosU1 * sinU2 * cosLambda);
                finalBearing *= 180.0 / Math.PI;
                results[2] = finalBearing;
            }
        }
    }

    /**
     * Computes the approximate distance in meters between two
     * locations, and optionally the initial and final bearings of the
     * shortest path between them.  Distance and bearing are defined using the
     * WGS84 ellipsoid.
     *
     * <p> The computed distance is stored in results[0].  If results has length
     * 2 or greater, the initial bearing is stored in results[1]. If results has
     * length 3 or greater, the final bearing is stored in results[2].
     *
     * @param startLatitude the starting latitude
     * @param startLongitude the starting longitude
     * @param endLatitude the ending latitude
     * @param endLongitude the ending longitude
     * @param results an array of floats to hold the results
     *
     * @throws IllegalArgumentException if results is null or has length < 1
     */
    @Implementation
    public static void distanceBetween(double startLatitude, double startLongitude,
        double endLatitude, double endLongitude, float[] results) {
        if (results == null || results.length < 1) {
            throw new IllegalArgumentException("results is null or has length < 1");
        }
        computeDistanceAndBearing(startLatitude, startLongitude,
            endLatitude, endLongitude, results);
    }

    /**
     * Returns the approximate distance in meters between this
     * location and the given location.  Distance is defined using
     * the WGS84 ellipsoid.
     *
     * @param dest the destination location
     * @return the approximate distance in meters
     */
    @Implementation
    public float distanceTo(Location dest) {
        // See if we already have the result
        synchronized (mResults) {
            if (latitude != mLat1 || longitude != mLon1 ||
                dest.getLatitude() != mLat2 || dest.getLongitude() != mLon2) {
                computeDistanceAndBearing(latitude, longitude,
                    dest.getLatitude(), dest.getLongitude(), mResults);
                mLat1 = latitude;
                mLon1 = longitude;
                mLat2 = dest.getLatitude();
                mLon2 = dest.getLongitude();
                mDistance = mResults[0];
                mInitialBearing = mResults[1];
            }
            return mDistance;
        }
    }

    /**
     * Returns the approximate initial bearing in degrees East of true
     * North when traveling along the shortest path between this
     * location and the given location.  The shortest path is defined
     * using the WGS84 ellipsoid.  Locations that are (nearly)
     * antipodal may produce meaningless results.
     *
     * @param dest the destination location
     * @return the initial bearing in degrees
     */
    @Implementation
    public float bearingTo(Location dest) {
        synchronized (mResults) {
            // See if we already have the result
            if (latitude != mLat1 || longitude != mLon1 ||
                            dest.getLatitude() != mLat2 || dest.getLongitude() != mLon2) {
                computeDistanceAndBearing(latitude, longitude,
                    dest.getLatitude(), dest.getLongitude(), mResults);
                mLat1 = latitude;
                mLon1 = longitude;
                mLat2 = dest.getLatitude();
                mLon2 = dest.getLongitude();
                mDistance = mResults[0];
                mInitialBearing = mResults[1];
            }
            return mInitialBearing;
        }
    }

    @Implementation
    public Bundle getExtras() {
        return extras;
    }

    @Implementation
    public void setExtras(Bundle extras) {
        this.extras = extras;
    }
}