/*
 * Copyright 2017 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package android.telephony;

import static android.text.TextUtils.formatSimple;

import android.annotation.NonNull;
import android.annotation.Nullable;
import android.os.Parcel;
import android.telephony.gsm.GsmCellLocation;
import android.util.ArraySet;

import java.util.Collection;
import java.util.Collections;
import java.util.Objects;
import java.util.Set;

/**
 * CellIdentity is to represent a unique TD-SCDMA cell
 */
public final class CellIdentityTdscdma extends CellIdentity {
    private static final String TAG = CellIdentityTdscdma.class.getSimpleName();
    private static final boolean DBG = false;

    private static final int MAX_LAC = 65535;
    private static final int MAX_CID = 268435455;
    private static final int MAX_CPID = 127;
    private static final int MAX_UARFCN = 65535;

    // 16-bit Location Area Code, 0..65535, CellInfo.UNAVAILABLE if unknown.
    private final int mLac;
    // 28-bit UMTS Cell Identity described in TS 25.331, 0..268435455, CellInfo.UNAVAILABLE
    // if unknown.
    private final int mCid;
    // 8-bit Cell Parameters ID described in TS 25.331 sec 10.3.6.9,
    // 0..127, CellInfo.UNAVAILABLE if unknown.
    private final int mCpid;
    // 16-bit UMTS Absolute RF Channel Number described in TS 25.101 sec. 5.4.3
    private final int mUarfcn;

    // a list of additional PLMN-IDs reported for this cell
    private final ArraySet<String> mAdditionalPlmns;

    private ClosedSubscriberGroupInfo mCsgInfo;

    /**
     * @hide
     */
    public CellIdentityTdscdma() {
        super(TAG, CellInfo.TYPE_TDSCDMA, null, null, null, null);
        mLac = CellInfo.UNAVAILABLE;
        mCid = CellInfo.UNAVAILABLE;
        mCpid = CellInfo.UNAVAILABLE;
        mUarfcn = CellInfo.UNAVAILABLE;
        mAdditionalPlmns = new ArraySet<>();
        mCsgInfo = null;
        mGlobalCellId = null;
    }

    /**
     * @param mcc 3-digit Mobile Country Code in string format
     * @param mnc 2 or 3-digit Mobile Network Code in string format
     * @param lac 16-bit Location Area Code, 0..65535, CellInfo.UNAVAILABLE if unknown
     * @param cid 28-bit UMTS Cell Identity described in TS 25.331, 0..268435455,
     *        CellInfo.UNAVAILABLE if unknown
     * @param cpid 8-bit Cell Parameters ID described in TS 25.331, 0..127,
     *        CellInfo.UNAVAILABLE if unknown
     * @param uarfcn 16-bit UMTS Absolute RF Channel Number described in TS 25.101 sec. 5.4.3
     * @param alphal long alpha Operator Name String or Enhanced Operator Name String
     * @param alphas short alpha Operator Name String or Enhanced Operator Name String
     * @param additionalPlmns a list of additional PLMN IDs broadcast by the cell
     * @param csgInfo info about the closed subscriber group broadcast by the cell
     *
     * @hide
     */
    public CellIdentityTdscdma(@Nullable String mcc, @Nullable String mnc, int lac, int cid,
            int cpid, int uarfcn, @Nullable String alphal, @Nullable String alphas,
            @NonNull Collection<String> additionalPlmns,
            @Nullable ClosedSubscriberGroupInfo csgInfo) {
        super(TAG, CellInfo.TYPE_TDSCDMA, mcc, mnc, alphal, alphas);
        mLac = inRangeOrUnavailable(lac, 0, MAX_LAC);
        mCid = inRangeOrUnavailable(cid, 0, MAX_CID);
        mCpid = inRangeOrUnavailable(cpid, 0, MAX_CPID);
        mUarfcn = inRangeOrUnavailable(uarfcn, 0, MAX_UARFCN);
        mAdditionalPlmns = new ArraySet<>(additionalPlmns.size());
        for (String plmn : additionalPlmns) {
            if (isValidPlmn(plmn)) {
                mAdditionalPlmns.add(plmn);
            }
        }
        mCsgInfo = csgInfo;
        updateGlobalCellId();
    }

    private CellIdentityTdscdma(@NonNull CellIdentityTdscdma cid) {
        this(cid.mMccStr, cid.mMncStr, cid.mLac, cid.mCid,
                cid.mCpid, cid.mUarfcn, cid.mAlphaLong,
                cid.mAlphaShort, cid.mAdditionalPlmns, cid.mCsgInfo);
    }

    /** @hide */
    @Override
    public @NonNull CellIdentityTdscdma sanitizeLocationInfo() {
        return new CellIdentityTdscdma(mMccStr, mMncStr, CellInfo.UNAVAILABLE, CellInfo.UNAVAILABLE,
                CellInfo.UNAVAILABLE, CellInfo.UNAVAILABLE, mAlphaLong, mAlphaShort,
                mAdditionalPlmns, null);
    }

    @NonNull CellIdentityTdscdma copy() {
        return new CellIdentityTdscdma(this);
    }

    /** @hide */
    @Override
    protected void updateGlobalCellId() {
        mGlobalCellId = null;
        String plmn = getPlmn();
        if (plmn == null) return;

        if (mLac == CellInfo.UNAVAILABLE || mCid == CellInfo.UNAVAILABLE) return;

        mGlobalCellId = plmn + formatSimple("%04x%04x", mLac, mCid);
    }

    /**
     * Get Mobile Country Code in string format
     * @return Mobile Country Code in string format, null if unknown
     */
    @Nullable
    public String getMccString() {
        return mMccStr;
    }

    /**
     * Get Mobile Network Code in string format
     * @return Mobile Network Code in string format, null if unknown
     */
    @Nullable
    public String getMncString() {
        return mMncStr;
    }

    /**
     * @return a 5 or 6 character string (MCC+MNC), null if any field is unknown
     */
    @Nullable
    public String getMobileNetworkOperator() {
        return (mMccStr == null || mMncStr == null) ? null : mMccStr + mMncStr;
    }

    /**
     * @return 16-bit Location Area Code, 0..65535,
     *         {@link android.telephony.CellInfo#UNAVAILABLE UNAVAILABLE} if unavailable.
     */
    public int getLac() {
        return mLac;
    }

    /**
     * @return 28-bit UMTS Cell Identity described in TS 25.331, 0..268435455,
     *         {@link android.telephony.CellInfo#UNAVAILABLE UNAVAILABLE} if unavailable.
     */
    public int getCid() {
        return mCid;
    }

    /**
     * @return 8-bit Cell Parameters ID described in TS 25.331, 0..127,
     *         {@link android.telephony.CellInfo#UNAVAILABLE UNAVAILABLE} if unavailable.
     */
    public int getCpid() {
        return mCpid;
    }

    /**
     * @return 16-bit UMTS Absolute RF Channel Number,
     *         {@link android.telephony.CellInfo#UNAVAILABLE UNAVAILABLE} if unavailable.
     */
    public int getUarfcn() {
        return mUarfcn;
    }

    /** @hide */
    @Override
    public int getChannelNumber() {
        return mUarfcn;
    }

    /**
     * @return a list of additional PLMN IDs supported by this cell.
     */
    @NonNull
    public Set<String> getAdditionalPlmns() {
        return Collections.unmodifiableSet(mAdditionalPlmns);
    }

    /**
     * @return closed subscriber group information about the cell if available, otherwise null.
     */
    @Nullable
    public ClosedSubscriberGroupInfo getClosedSubscriberGroupInfo() {
        return mCsgInfo;
    }

    /** @hide */
    @NonNull
    @Override
    public GsmCellLocation asCellLocation() {
        GsmCellLocation cl = new GsmCellLocation();
        int lac = mLac != CellInfo.UNAVAILABLE ? mLac : -1;
        int cid = mCid != CellInfo.UNAVAILABLE ? mCid : -1;
        cl.setLacAndCid(lac, cid);
        cl.setPsc(-1); // There is no PSC for TD-SCDMA; not using this for CPI to stem shenanigans
        return cl;
    }

    @Override
    public boolean equals(Object other) {
        if (this == other) {
            return true;
        }

        if (!(other instanceof CellIdentityTdscdma)) {
            return false;
        }

        CellIdentityTdscdma o = (CellIdentityTdscdma) other;
        return  mLac == o.mLac
                && mCid == o.mCid
                && mCpid == o.mCpid
                && mUarfcn == o.mUarfcn
                && mAdditionalPlmns.equals(o.mAdditionalPlmns)
                && Objects.equals(mCsgInfo, o.mCsgInfo)
                && super.equals(other);
    }

    @Override
    public int hashCode() {
        return Objects.hash(mLac, mCid, mCpid, mUarfcn,
                mAdditionalPlmns.hashCode(), mCsgInfo, super.hashCode());
    }

    @Override
    public String toString() {
        return new StringBuilder(TAG)
        .append(":{ mMcc=").append(mMccStr)
        .append(" mMnc=").append(mMncStr)
        .append(" mAlphaLong=").append(mAlphaLong)
        .append(" mAlphaShort=").append(mAlphaShort)
        .append(" mLac=").append(mLac)
        .append(" mCid=").append(mCid)
        .append(" mCpid=").append(mCpid)
        .append(" mUarfcn=").append(mUarfcn)
        .append(" mAdditionalPlmns=").append(mAdditionalPlmns)
        .append(" mCsgInfo=").append(mCsgInfo)
        .append("}").toString();
    }

    /** Implement the Parcelable interface */
    @Override
    public int describeContents() {
        return 0;
    }

    /** Implement the Parcelable interface */
    @Override
    public void writeToParcel(Parcel dest, int flags) {
        if (DBG) log("writeToParcel(Parcel, int): " + toString());
        super.writeToParcel(dest, CellInfo.TYPE_TDSCDMA);
        dest.writeInt(mLac);
        dest.writeInt(mCid);
        dest.writeInt(mCpid);
        dest.writeInt(mUarfcn);
        dest.writeArraySet(mAdditionalPlmns);
        dest.writeParcelable(mCsgInfo, flags);
    }

    /** Construct from Parcel, type has already been processed */
    private CellIdentityTdscdma(Parcel in) {
        super(TAG, CellInfo.TYPE_TDSCDMA, in);
        mLac = in.readInt();
        mCid = in.readInt();
        mCpid = in.readInt();
        mUarfcn = in.readInt();
        mAdditionalPlmns = (ArraySet<String>) in.readArraySet(null);
        mCsgInfo = in.readParcelable(null, android.telephony.ClosedSubscriberGroupInfo.class);

        updateGlobalCellId();
        if (DBG) log(toString());
    }

    /** Implement the Parcelable interface */
    @SuppressWarnings("hiding")
    @NonNull
    public static final Creator<CellIdentityTdscdma> CREATOR =
            new Creator<CellIdentityTdscdma>() {
                @Override
                public @NonNull CellIdentityTdscdma createFromParcel(Parcel in) {
                    in.readInt();   // skip
                    return createFromParcelBody(in);
                }

                @Override
                public @NonNull CellIdentityTdscdma[] newArray(int size) {
                    return new CellIdentityTdscdma[size];
                }
            };

    /** @hide */
    protected static CellIdentityTdscdma createFromParcelBody(Parcel in) {
        return new CellIdentityTdscdma(in);
    }
}