/*
 * Copyright (C) 2013 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.print;

import android.annotation.IntRange;
import android.annotation.NonNull;
import android.os.Parcel;
import android.os.Parcelable;

/**
 * Represents a range of pages. The start and end page indices of
 * the range are zero based and inclusive.
 */
public final class PageRange implements Parcelable {

    /**
     * Constant for specifying all pages.
     */
    public static final PageRange ALL_PAGES = new PageRange(0, Integer.MAX_VALUE);

    /** @hide */
    public static final PageRange[] ALL_PAGES_ARRAY = new PageRange[]{PageRange.ALL_PAGES};

    private final int mStart;
    private final int mEnd;

    /**
     * Creates a new instance.
     *
     * @param start The start page index (zero based and inclusive).
     * @param end The end page index (zero based and inclusive).
     *
     * @throws IllegalArgumentException If start is less than zero or end
     * is less than zero or start greater than end.
     */
    public PageRange(@IntRange(from = 0) int start, @IntRange(from = 0) int end) {
        if (start < 0) {
            throw new IllegalArgumentException("start cannot be less than zero.");
        }
        if (end < 0) {
            throw new IllegalArgumentException("end cannot be less than zero.");
        }
        if (start > end) {
            throw new IllegalArgumentException("start must be lesser than end.");
        }
        mStart = start;
        mEnd = end;
    }

    private PageRange(@NonNull Parcel parcel) {
        this(parcel.readInt(), parcel.readInt());
    }

    /**
     * Gets the start page index (zero based and inclusive).
     *
     * @return The start page index.
     */
    public @IntRange(from = 0) int getStart() {
        return mStart;
    }

    /**
     * Gets the end page index (zero based and inclusive).
     *
     * @return The end page index.
     */
    public @IntRange(from = 0) int getEnd() {
        return mEnd;
    }

    /**
     * Gets whether a page range contains a a given page.
     *
     * @param pageIndex The page index.
     * @return True if the page is within this range.
     *
     * @hide
     */
    public boolean contains(int pageIndex) {
        return (pageIndex >= mStart) && (pageIndex <= mEnd);
    }

    /**
     * Get the size of this range which is the number of
     * pages it contains.
     *
     * @return The size of the range.
     *
     * @hide
     */
    public int getSize() {
        return mEnd - mStart + 1;
    }

    @Override
    public int describeContents() {
        return 0;
    }

    @Override
    public void writeToParcel(Parcel parcel, int flags) {
        parcel.writeInt(mStart);
        parcel.writeInt(mEnd);
    }

    @Override
    public int hashCode() {
        final int prime = 31;
        int result = 1;
        result = prime * result + mEnd;
        result = prime * result + mStart;
        return result;
    }

    @Override
    public boolean equals(Object obj) {
        if (this == obj) {
            return true;
        }
        if (obj == null) {
            return false;
        }
        if (getClass() != obj.getClass()) {
            return false;
        }
        PageRange other = (PageRange) obj;
        if (mEnd != other.mEnd) {
            return false;
        }
        if (mStart != other.mStart) {
            return false;
        }
        return true;
    }

    @Override
    public String toString() {
        if (mStart == 0 && mEnd == Integer.MAX_VALUE) {
            return "PageRange[<all pages>]";
        }
        StringBuilder builder = new StringBuilder();
        builder.append("PageRange[")
            .append(mStart)
            .append(" - ")
            .append(mEnd)
            .append("]");
        return builder.toString();
    }

    public static final @android.annotation.NonNull Parcelable.Creator<PageRange> CREATOR =
            new Creator<PageRange>() {
        @Override
        public PageRange createFromParcel(Parcel parcel) {
            return new PageRange(parcel);
        }

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