/*
-- Copyright 1994, Oracle Taiwan Inc., All Rights Reserved.
--
-- Program to modify the language id in Oracle7 export file.
--
-- Version 1.01.04, Mar 20, 1994, James Ko, Oracle Taiwan.
--                  Add ZHS16CGB231280 (id 850) for China.
--
-- Version 1.01.03, Feb 09, 1994, James Ko, Oracle Taiwan.
--                  Change langinfo struct to static for declaration.
--                  Bypass compiler complains on this.
--
-- Version 1.01.02, Dec 29, 1994, James Ko, Oracle Taiwan.
--                  Change print out of charset symbol in the loop.
--
-- Version 1.01.01, Dec 29, 1994, James Ko, Oracle Taiwan.
--                  Add ASCII lang_id and character set into lang_info
--                  to support the reverse of export file from BIG5 to
--                  ASCII.
--
-- Version 1.00.01, Nov 04, 1994, Richard Lin, Oracle Taiwan.
--                  Tested OK on real export file.
--
-- Version 0.01, Beta, Nov 03, 1994. James Ko, Oracle Taiwan.
--
*/
#include <stdio.h>
#include <ctype.h>
#include <string.h>

#define BUF_SIZE   1024
#define LNAME_SIZE 32

main( argc, argv )
char *argv[];
int   argc;
{
	FILE *inf, *outf;
	long fsize;
 	int  size;
	int  langid;
	int  loop, last, count;
	int  iosize   = BUF_SIZE;
	int  buf_size = BUF_SIZE;
	char buf[BUF_SIZE];
	char langname[LNAME_SIZE];
	char ofname[256];

	struct langdef {
		int id;
		char *name;
		char *ext;
	} *langptr;

	static struct langdef langinfo[] = {
                  1, "US7ASCII",        ".ascii",
		850, "ZHS16CGB231280",  ".cgb",
		860, "ZHT32EUC",        ".euc",
		861, "ZHT32SOPS",       ".sops",
		862, "ZHT16DBT",        ".dbt",
		863, "ZHT32TRIS",       ".tris",
		865, "ZHT16BIG5",       ".big5"
	};
	
	printf("\n\nOracle7 Export File Charset Fix Utility, V1.01.04\n");

	loop = sizeof(langinfo) / sizeof(struct langdef);

	if ( argc < 2 ) {
	    printf("\nUsage: %s dump_file_name language_id\n\n", argv[0]);
	    printf("Valid language id - ");
	    for ( count = 0, langptr = &langinfo[0]; 
	          count < loop; count++, langptr++ ) {
                  printf("%s ", langptr->name);
            }
	    printf("\n\n");
	    exit(1);
	}

	/*
	-- Map langguage_name to id and append ext to output file name
	*/
	strcpy(ofname, argv[1]);
	strncpy(langname, argv[2], LNAME_SIZE);
	for ( count = 0; count < strlen(langname); count++ ) {
	    langname[count] = (char) toupper(langname[count]);
	}

	for ( count = 0, langptr = &langinfo[0]; 
	      count < loop; count++, langptr++ ) {
	    if ( strcmp(langptr->name, langname) == 0 ) {
	    	langid = langptr->id;
	        strcat(ofname, langptr->ext);
		break;
	    } 
	}

	if ( count == loop ) {
	    printf("\n\nInvalid language ID, program terminated\n");
	    exit(3);
	}
		
	printf("\n\nOutput file name %s,", ofname);

	/*
	-- Open files
	*/
	if ( (inf = fopen (argv[1], "r")) == NULL ) {
	    printf("\n\nOpen file %s error, program terminated\n", argv[1]);
	    exit(1);
	}
	if ( (outf = fopen (ofname, "w+")) == NULL ) {
	    printf("\n\nOpen file %s error, program terminated\n", ofname);
	    exit(1);
	}

	/*
	-- Get input file size and rewind it
	*/
	fseek(inf, 0L, 2);
	fsize = ftell(inf);
	printf(" size is %d bytes.\n\n", fsize);
	rewind(inf);

	loop = fsize / buf_size;
	last = fsize % buf_size;

	for ( count = 0; count < loop; count++ ) {
	    if ( (size = fread (buf, 1, iosize, inf)) == iosize ) {
		/*
		-- Update the language id, it is at the 2nd and 3rd byte
		*/
		if ( count == 0 ) {
		    buf[1] = langid / 256;
		    buf[2] = langid % 256;
	        }
	        if ( (size = fwrite (buf, 1, iosize, outf)) != iosize ) {
		    printf("\n\nFile write error, program terminated!\n");
		    printf("Expected size %d, real size %d\n", iosize, size);
		    exit(2);
	        }
	    } else {
		printf("\n\nFile read error, program terminated!\n");
		printf("Expected size %d, real size %d\n", iosize, size);
		exit(1);
	    }
	}

	if ( (iosize = last) != 0 ) {
	    if ( (size = fread (buf, 1, iosize, inf)) != iosize ) {
		printf("\n\nFile read error, program terminated!\n");
		printf("Expected size %d, real size %d\n", iosize, size);
		exit(1);
	    }
	    if ( (size = fwrite (buf, 1, iosize, outf)) != iosize ) {
		printf("\n\nFile write error, program terminated!\n");
		printf("Expected size %d, real size %d\n", iosize, size);
		exit(2);
	    }
	}

	fclose(inf);
	fclose(outf);
}