#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <vicNl.h>

static char vcid[] = "$Id: write_header.c,v 1.1.4.2 2007/10/11 22:40:08 vicadmin Exp $";

void write_header(out_data_file_struct *out_data_files,
		  out_data_struct      *out_data,
                  dmy_struct           *dmy,
                  global_param_struct   global)
/**********************************************************************
	write_header	Ted Bohn		Janurary 2007

  This subroutine writes a header for all output files.

  Modifications:
  2007-Oct-11 Replaced all instances of global.dt with global.out_dt,
	      since out_dt is the time interval used in the output
	      files.							TJB

**********************************************************************/
{
  extern option_struct options;
  int                 file_idx;
  int                 var_idx;
  int                 elem_idx;
  int                 i;
  unsigned short      Identifier;
  unsigned short      Nbytes;
  unsigned short      Nbytes1;
  unsigned short      Nbytes2;
  char                tmp_ALMA_OUTPUT;
  char                Nvars;
  char                tmp_len;
  char               *tmp_str;
  char                tmp_type;
  float               tmp_mult;

  if (options.ALMA_OUTPUT)
    tmp_ALMA_OUTPUT = 1;
  else
    tmp_ALMA_OUTPUT = 0;

  if(options.BINARY_OUTPUT) {  // BINARY

    tmp_str = (char *)calloc(256, sizeof(char));

    // Binary header format:
    //
    // Data        Stored As           Comment
    //
    // Identifier  (unsigned short)*4  0xFFFF, repeated 4 times
    // Nbytes      (unsigned short)*1  Number of bytes in the header,
    //                                 INCLUDING THE IDENTIFIER
    //
    // Part 1: Global Attributes
    // Nbytes1     (unsigned short)*1  Number of bytes in part 1
    // nrecs       (int)*1             Number of records in the file
    // dt          (int)*1             Output time step length in hours
    // startyear   (int)*1             Year of first record
    // startmonth  (int)*1             Month of first record
    // startday    (int)*1             Day of first record
    // starthour   (int)*1             Hour of first record
    // ALMA_OUTPUT (char)*1            0 = standard VIC units; 1 = ALMA units
    // Nvars       (char)*1            Number of variables in the file, including date fields
    //
    // Part 2: Variables
    // Nbytes2     (unsigned short)*1  Number of bytes in part 2
    // For each variable, the following fields: { len varname type mult }
    //   len       (char)*1            Number of characters in varname
    //   varname   (char)*len          Variable name
    //   type      (char)*1            Code identifying variable type
    //   mult      (float)*1           Multiplier for variable

    // Identifier
    Identifier = 0xFFFF;

    // Loop over output files
    for (file_idx = 0; file_idx < options.Noutfiles; file_idx++) {

      // ***** Compute the number of bytes in part 1 *****

      // 1 instance of Nbytes1
      Nbytes1 = sizeof(unsigned short);

      // nrecs
      Nbytes1 += sizeof(int);

      // dt
      Nbytes1 += sizeof(int);

      // start date (year, month, day, hour)
      Nbytes1 += 4*sizeof(int);

      // ALMA_OUTPUT
      Nbytes1 += sizeof(char);

      // Nvars
      Nbytes1 += sizeof(char);

      // ***** Compute the number of bytes in part 2 *****

      // 1 instance of Nbytes2
      Nbytes2 = sizeof(unsigned short);

#if !OUTPUT_FORCE
      // Date fields
      Nbytes2 += sizeof(char) + 4*sizeof(char) + sizeof(char) + sizeof(float); // year
      Nbytes2 += sizeof(char) + 5*sizeof(char) + sizeof(char) + sizeof(float); // month
      Nbytes2 += sizeof(char) + 3*sizeof(char) + sizeof(char) + sizeof(float); // day
      if (global.out_dt < 24)
        Nbytes2 += sizeof(char) + 4*sizeof(char) + sizeof(char) + sizeof(float); // hour
#endif

      // Loop over this output file's data variables
      for (var_idx = 0; var_idx < out_data_files[file_idx].nvars; var_idx++) {
        // Loop over this variable's elements
        for (elem_idx = 0; elem_idx < out_data[out_data_files[file_idx].varid[var_idx]].nelem; elem_idx++) {
          if (out_data[out_data_files[file_idx].varid[var_idx]].nelem > 1)
            sprintf(tmp_str, "%s_%d", out_data[out_data_files[file_idx].varid[var_idx]].varname, elem_idx);
          else
            strcpy(tmp_str, out_data[out_data_files[file_idx].varid[var_idx]].varname); 
          Nbytes2 += sizeof(char) + strlen(tmp_str)*sizeof(char) + sizeof(char) + sizeof(float);
        }
      }

      // ***** Compute the total number of bytes in the header *****

      // 4 instances of Identifier, plus 1 instance of Nbytes, plus number of bytes in parts 1 and 2
      Nbytes = 4*sizeof(unsigned short) + sizeof(unsigned short) + Nbytes1 + Nbytes2;

      // ***** Write the header *****

      // 4 instances of Identifier
      for (i=0; i<4; i++)
        fwrite(&Identifier, sizeof(unsigned short), 1, out_data_files[file_idx].fh);

      // Nbytes
      fwrite(&Nbytes, sizeof(unsigned short), 1, out_data_files[file_idx].fh);

      // Nbytes1
      fwrite(&Nbytes1, sizeof(unsigned short), 1, out_data_files[file_idx].fh);

      // nrecs
      fwrite(&(global.nrecs), sizeof(int), 1, out_data_files[file_idx].fh);

      // dt
      fwrite(&(global.out_dt), sizeof(int), 1, out_data_files[file_idx].fh);

      // start date (year, month, day, hour)
      fwrite(&(dmy->year), sizeof(int), 1, out_data_files[file_idx].fh);
      fwrite(&(dmy->month), sizeof(int), 1, out_data_files[file_idx].fh);
      fwrite(&(dmy->day), sizeof(int), 1, out_data_files[file_idx].fh);
      fwrite(&(dmy->hour), sizeof(int), 1, out_data_files[file_idx].fh);

      // ALMA_OUTPUT
      fwrite(&tmp_ALMA_OUTPUT, sizeof(char), 1, out_data_files[file_idx].fh);

      // Nvars
      Nvars = out_data_files[file_idx].nvars;
#if !OUTPUT_FORCE
      if (global.out_dt < 24)
        Nvars += 4;
      else
        Nvars += 3;
#endif
      fwrite(&Nvars, sizeof(char), 1, out_data_files[file_idx].fh);

      // Nbytes2
      fwrite(&Nbytes2, sizeof(unsigned short), 1, out_data_files[file_idx].fh);

#if !OUTPUT_FORCE
      // Date fields
      tmp_type = OUT_TYPE_INT;
      tmp_mult = 1.;

      // year
      strcpy(tmp_str,"YEAR");
      tmp_len = strlen(tmp_str);
      fwrite(&tmp_len, sizeof(char), 1, out_data_files[file_idx].fh);
      fwrite(tmp_str, sizeof(char), tmp_len, out_data_files[file_idx].fh);
      fwrite(&tmp_type, sizeof(char), 1, out_data_files[file_idx].fh);
      fwrite(&tmp_mult, sizeof(float), 1, out_data_files[file_idx].fh);

      // month
      strcpy(tmp_str,"MONTH");
      tmp_len = strlen(tmp_str);
      fwrite(&tmp_len, sizeof(char), 1, out_data_files[file_idx].fh);
      fwrite(tmp_str, sizeof(char), tmp_len, out_data_files[file_idx].fh);
      fwrite(&tmp_type, sizeof(char), 1, out_data_files[file_idx].fh);
      fwrite(&tmp_mult, sizeof(float), 1, out_data_files[file_idx].fh);

      // day
      strcpy(tmp_str,"DAY");
      tmp_len = strlen(tmp_str);
      fwrite(&tmp_len, sizeof(char), 1, out_data_files[file_idx].fh);
      fwrite(tmp_str, sizeof(char), tmp_len, out_data_files[file_idx].fh);
      fwrite(&tmp_type, sizeof(char), 1, out_data_files[file_idx].fh);
      fwrite(&tmp_mult, sizeof(float), 1, out_data_files[file_idx].fh);

      if (global.out_dt < 24) {
        // hour
        strcpy(tmp_str,"HOUR");
        tmp_len = strlen(tmp_str);
        fwrite(&tmp_len, sizeof(char), 1, out_data_files[file_idx].fh);
        fwrite(tmp_str, sizeof(char), tmp_len, out_data_files[file_idx].fh);
        fwrite(&tmp_type, sizeof(char), 1, out_data_files[file_idx].fh);
        fwrite(&tmp_mult, sizeof(float), 1, out_data_files[file_idx].fh);
      }

#endif

      // Loop over this output file's data variables
      for (var_idx = 0; var_idx < out_data_files[file_idx].nvars; var_idx++) {
        // Loop over this variable's elements
        for (elem_idx = 0; elem_idx < out_data[out_data_files[file_idx].varid[var_idx]].nelem; elem_idx++) {
          if (out_data[out_data_files[file_idx].varid[var_idx]].nelem > 1)
            sprintf(tmp_str, "%s_%d", out_data[out_data_files[file_idx].varid[var_idx]].varname, elem_idx);
          else
            strcpy(tmp_str, out_data[out_data_files[file_idx].varid[var_idx]].varname); 
          tmp_len = strlen(tmp_str);
          fwrite(&tmp_len, sizeof(char), 1, out_data_files[file_idx].fh);
          fwrite(tmp_str, sizeof(char), tmp_len, out_data_files[file_idx].fh);
          tmp_type = out_data[out_data_files[file_idx].varid[var_idx]].type;
          fwrite(&tmp_type, sizeof(char), 1, out_data_files[file_idx].fh);
          tmp_mult = out_data[out_data_files[file_idx].varid[var_idx]].mult;
          fwrite(&tmp_mult, sizeof(float), 1, out_data_files[file_idx].fh);
        }
      }

    }

  }

  else {  // ASCII

    // ASCII header format:
    //
    // # NRECS: (nrecs)
    // # DT: (dt)
    // # STARTDATE: yyyy-mm-dd hh:00:00
    // # ALMA_OUTPUT: (0 or 1)
    // # NVARS: (Nvars)
    // # VARNAME    VARNAME   VARNAME   ...
    //
    // where
    //    nrecs       = Number of records in the file
    //    dt          = Output time step length in hours
    //    start date  = Date and time of first record of file
    //    ALMA_OUTPUT = Indicates units of the variables; 0 = standard VIC units; 1 = ALMA units
    //    Nvars       = Number of variables in the file, including date fields

    // Loop over output files
    for (file_idx = 0; file_idx < options.Noutfiles; file_idx++) {

      // Header part 1: Global attributes
      Nvars = out_data_files[file_idx].nvars;
#if !OUTPUT_FORCE
      if (global.out_dt < 24)
        Nvars += 4;
      else
        Nvars += 3;
#endif
      fprintf(out_data_files[file_idx].fh, "# NRECS: %d\n", global.nrecs);
      fprintf(out_data_files[file_idx].fh, "# DT: %d\n", global.out_dt);
      fprintf(out_data_files[file_idx].fh, "# STARTDATE: %04d-%02d-%02d %02d:00:00\n",
        dmy->year, dmy->month, dmy->day, dmy->hour);
      fprintf(out_data_files[file_idx].fh, "# ALMA_OUTPUT: %d\n", tmp_ALMA_OUTPUT);
      fprintf(out_data_files[file_idx].fh, "# NVARS: %d\n", Nvars);

      // Header part 2: Variables
      fprintf(out_data_files[file_idx].fh, "# ");

#if !OUTPUT_FORCE
      // Write the date
      if (global.out_dt < 24) {
        // Write year, month, day, and hour
        fprintf(out_data_files[file_idx].fh, "YEAR\tMONTH\tDAY\tHOUR\t");
      }
      else {
        // Only write year, month, and day
        fprintf(out_data_files[file_idx].fh, "YEAR\tMONTH\tDAY\t");
      }
#endif

      // Loop over this output file's data variables
      for (var_idx = 0; var_idx < out_data_files[file_idx].nvars; var_idx++) {
        // Loop over this variable's elements
        for (elem_idx = 0; elem_idx < out_data[out_data_files[file_idx].varid[var_idx]].nelem; elem_idx++) {
          if (!(var_idx == 0 && elem_idx == 0)) {
            fprintf(out_data_files[file_idx].fh, "\t ");
          }
          fprintf(out_data_files[file_idx].fh, "%s", out_data[out_data_files[file_idx].varid[var_idx]].varname);
          if (out_data[out_data_files[file_idx].varid[var_idx]].nelem > 1) {
            fprintf(out_data_files[file_idx].fh, "_%d", elem_idx);
          }
        }
      }
      fprintf(out_data_files[file_idx].fh, "\n");

    }

  }

}