* Copyright 1998-2009 University Corporation for Atmospheric Research/Unidata

*

* Portions of this software were developed by the Unidata Program at the

* University Corporation for Atmospheric Research.

*

* Access and use of this software shall impose the following obligations

* and understandings on the user. The user is granted the right, without

* any fee or cost, to use, copy, modify, alter, enhance and distribute

* this software, and any derivative works thereof, and its supporting

* documentation for any purpose whatsoever, provided that this entire

* notice appears in all copies of the software, derivative works and

* supporting documentation.  Further, UCAR requests that the user credit

* UCAR/Unidata in any publications that result from the use of this

* software or in any product that includes this software. The names UCAR

* and/or Unidata, however, may not be used in any advertising or publicity

* to endorse or promote any products or commercial entity unless specific

* written permission is obtained from UCAR/Unidata. The user also

* understands that UCAR/Unidata is not obligated to provide the user with

* any support, consulting, training or assistance of any kind with regard

* to the use, operation and performance of this software nor to provide

* the user with any updates, revisions, new versions or "bug fixes."

*

* THIS SOFTWARE IS PROVIDED BY UCAR/UNIDATA "AS IS" AND ANY EXPRESS OR

* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED

* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE

* DISCLAIMED. IN NO EVENT SHALL UCAR/UNIDATA BE LIABLE FOR ANY SPECIAL,

* INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING

* FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,

* NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION

* WITH THE ACCESS, USE OR PERFORMANCE OF THIS SOFTWARE.

*/

* This class reads in an NEXRAD level III and TDWR file.

* most file need to go through the header part to have enough info to

* construct the netcdf structure of the radar file

*

* @author caron

*/

    final private static boolean useStationDB = false; // use station db for loactions

    static private org.slf4j.Logger log = org.slf4j.LoggerFactory.getLogger(Nidsheader.class);

    final static int  NEXR_PID_READ = 100;

    final static int  DEF_NUM_ELEMS = 640;   /* default num of elements to send         */

    final static int  DEF_NUM_LINES = 480;   /* default num of lines to send            */

    final static int  NEXR_FILE_READ = -1;   /* # flag to read entire NIDS file         */

    final static int  NEXR_DIR_READ = 356 ;  /* just enough bytes for NIDS directory    */

    final static int  READ_BUFFER_SIZE = 1;   /* # of image lines to buffer on read      */

    final static int  ZLIB_BUF_LEN = 4000;   /* max size of an uncompressed ZLIB buffer */

    byte Z_DEFLATED  = 8;

    byte DEF_WBITS  = 15;

    final static int   Other = 0;

    final static int   Base_Reflect = 1;

    final static int   Velocity = 2;

    final static int   Comp_Reflect = 3;

    final static int   Layer_Reflect_Avg = 4;

    final static int   Layer_Reflect_Max = 5;

    final static int   Echo_Tops = 6;

    final static int   Vert_Liquid = 7;

    final static int   Precip_1 = 8;

    final static int   Precip_3 = 9;

    final static int   Precip_Accum = 10;

    final static int   Precip_Array = 11;

    final static int   BaseReflect248 = 12;

    final static int   StrmRelMeanVel = 13;

    final static int   VAD = 14;

    final static int   SPECTRUM = 15;

    final static int   DigitalHybridReflect = 16;

    final static int   DigitalStormTotalPrecip = 17;

    final static int   Reflect1 = 18;

    final static int   Velocity1 = 19;

    final static int   SPECTRUM1 = 20;

    final static int   BaseReflectivityDR = 21;

    final static int   BaseVelocityDV = 22;

    final static int   EnhancedEcho_Tops = 23;

    final static int   DigitalVert_Liquid = 24;

    // message header block

    short mcode = 0;

    short mdate = 0;

    int mtime = 0;

    int mlength = 0;

    short msource = 0;

    short mdestId = 0;

    short mNumOfBlock = 0;

    // production dessciption block

    short divider = 0;

    double latitude = 0.0;

    double lat_min = 0.0;

    double lat_max = 0.0;

    double longitude = 0.0;

    double lon_min = 0.0;

    double lon_max = 0.0;

    double height = 0;

    short pcode = 0;

    short opmode = 0;

    short volumnScanPattern = 0;

    short sequenceNumber = 0;

    short volumeScanNumber = 0;

    short volumeScanDate = 0;

    int volumeScanTime = 0;

    short productDate = 0;

    int productTime = 0;

    short p1 = 0;

    short p2 = 0;

    short elevationNumber = 0;

    short p3 = 0;

    short [] threshold = new short[16];

    short p4 = 0;

    short p5 = 0;

    short p6 = 0;

    short p7 = 0;

    short p8 = 0;

    short p9 = 0;

    short p10 = 0;

    short numberOfMaps = 0;

    int offsetToSymbologyBlock = 0;

    int offsetToGraphicBlock = 0;

    int offsetToTabularBlock = 0;

    int block_length = 0;

    short number_layers = 0;

    String stationId;

    String stationName = "XXX";

    private boolean noHeader;

    DateFormatter formatter = new DateFormatter();

    /**

     * check if this file is a nids / tdwr file

     * @param raf    input file

     * @return  true  if valid

     */

    public boolean isValidFile( ucar.unidata.io.RandomAccessFile raf) {

        try

        {

            long t = raf.length();

            if(t == 0){

                throw new IOException("zero length file ");

            }

        }

        catch ( IOException e )

        {

            return( false );

        }

        try{

            int p = this.readWMO( raf );

            if( p == 0 ) return false; // not unidata radar mosiac gini file

        }

        catch ( IOException e )

        {

            return( false );

        }                                

        return true;

    }

    /**

     * read the header of input file and parsing the WMO part

     * @param raf    input file

     * @return        1 if checking passing

     * @throws IOException

     */

    int readWMO(ucar.unidata.io.RandomAccessFile raf ) throws IOException

    {

        int pos = 0;

        //long     actualSize = 0;

        raf.seek(pos);

        int readLen = 35;

        int rc = 0;

        // Read in the contents of the NEXRAD Level III product head

        byte[] b = new byte[readLen];

        rc = raf.read(b);

        if ( rc != readLen )

        {

            // out.println(" error reading nids product header");

            return 0;

        }

        // new check

        int iarr2_1 = bytesToInt(b[0], b[1], false);

        int iarr2_16 = bytesToInt(b[30], b[31], false);

        int iarr2_10 = bytesToInt(b[18], b[19], false);

        int iarr2_7 = bytesToInt(b[12], b[13], false);

        if ( ( iarr2_1 == iarr2_16 ) &&

             ( ( iarr2_1 >=   16  ) && ( iarr2_1 <= 299) ) &&

             ( iarr2_10  ==   -1 ) &&

             ( iarr2_7   <    10000 ) )  {

             noHeader = true;

             return 1;

        }

        //Get product message header into a string for processing

        String pib = new String(b);

        if(  pib.indexOf("SDUS")!= -1){

            noHeader = false;

            return 1;

        } else if ( raf.getLocation().indexOf(".nids") != -1) {

            noHeader = true;

            return 1;

       // } else if(checkMsgHeader(raf) == 1) {

        //    noHeader = true;

       //     return 1;

        } else

            return 0;

    }

    /**

     * read the compressed data

     *

     * @param offset   offset of the compressed data

     * @param len      length of data to compress

     * @return         uncompressed byte array

     */

    public byte[] getUncompData(int offset, int len){