#include "grid.h"
#include <stdio.h>


// min - return the min of two ints
//
int min(int x, int y){
  return (x<y)?x:y;
}

// importGrid - brings grid file into an array
//
GRID *importGrid(char *path)
{
  FILE *inputf;
  int i,j,value, resolution;

  // Validate input file
  if ((inputf = fopen(path, "r"))== NULL){
     printf("flow: can't open %s\n",path);
     exit(1);
  }

  // Input file info into the grid structure
  GRID *g = (GRID *) malloc(sizeof(GRID));
  g->name = path;
  int scan = fscanf(inputf,"%*s%d%*s%d%*s%lf%*s%lf%*s%d%*s%d",
	 &g->ncols,&g->nrows,&g->x,
	 &g->y,&g->cellsize,&g->nodata);
  if(scan==0){
    printf("flow: trouble reading input file!\n");
    exit(1);
  }

  // Dynamically allocate array for data
  if((g->data = (short**) malloc((g->nrows)*sizeof(short*)))==NULL){
     printf("flow: insufficient memory");
     exit(1);
  }
  assert(g->data);
  for(i=0;i<g->nrows;i++){
    if((g->data[i] = (short*) malloc((g->ncols)*sizeof(short)))==NULL){
      printf("flow: insufficient memory");
      exit(1);
    }
    assert(g->data[i]);
  }
  
  // Put data into the array and calculate max & min
  g->min = 9999999;
  g->max = 0;
  for(i=0;i<g->nrows;i++){
    for(j=0;j<g->ncols;j++){
      if(fscanf(inputf,"%d",&value)!=EOF){
	if(value < g->min && value != g->nodata)
	  g->min = value;
	if(value > g->max)
	  g->max = value;
	g->data[i][j]=value;
      }
      else{
	printf("flow: data file is corrupt");
	exit(1);
      }
    }
  }

  // Set resolution as a function of gridsize
  resolution = min(g->ncols,g->nrows)/8;

  // Close file
  fclose(inputf);

  // Return grid
  return g;
}


// writeGrid - write grid structure to file path
//
void writeGrid(GRID *g,char *path){
  FILE *outputf;
  int i,j;

  // Validate output file
  if ((outputf = fopen(path, "w"))== NULL){
     printf("mult: can't write to %s\n",path);
     exit(1);
  }
  
  // Write grid info
  fprintf(outputf,"ncols\t\t%u\n",g->ncols);
  fprintf(outputf,"nrows\t\t%u\n",g->nrows);
  fprintf(outputf,"xllcorner\t%f\n",g->x);
  fprintf(outputf,"yllcorner\t%f\n",g->y);
  fprintf(outputf,"cellsize\t%u\n",g->cellsize);
  fprintf(outputf,"NODATA_value\t%d\n",g->nodata);

  // Write data
  for(i=0;i<g->nrows;i++){
    for(j=0;j<g->ncols;j++){
      fprintf(outputf, "%d ",g->data[i][j]);
    }
    fprintf(outputf, "\n");
  }

  // Close file
  fclose(outputf);
}


// printGrid - Print the grid info 
//
void printGrid(GRID *g){
  printf("\nGrid Info:\n\n");
  printf("Name: %s\n",g->name);
  printf("Number of Columns: %u\n",g->ncols);
  printf("Number of Rows: %u\n",g->nrows);
  printf("Lat Lon X Corner: %f\n",g->x);
  printf("Lat Lon Y Corner: %f\n",g->y);
  printf("Cell size: %u\n",g->cellsize);
  printf("No data value: %d\n",g->nodata);
  printf("Min value: %d\n",g->min);
  printf("Max value: %d\n",g->max);
}


// freeGrid - free memory from grid
//
void freeGrid(GRID *g){
  free(g->name);
  //  free(g->x);
  //free(g->y);
  //free(g->cellsize);
  //free(g->nodata);
  //free(g->max);
  //free(g->min);
  register int i;
  for(i=0;i < g->nrows; i++)
    free(g->data[i]);
  free(g->data);
  //free(g->ncols);
  //free(g->nrows);
  free(g);
}