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

#include <platon/str/charsets.h>
#include <platon/str/strconv.h>
#include <platon/str/strplus.h>
#include <platon/str/strctype.h>

/* Compilation against libplaton library:
   gcc -pedantic -L ../../platon/ -I ../../ -o strconv strconv.c -lplaton
*/

#define BUFSIZE	512
#if 0
#  define ARGV0	(strrchr(argv[0], '/') != NULL \
		? strrchr(argv[0], '/') + 1 : argv[0])
#endif

struct charset_struct
{
	char name[20];
	char *charset;
};

const struct charset_struct charsets[] = {
	{"ascii",			charset_ascii		},
	{"plain",			charset_ascii		},
	{"iso88592",		charset_iso88592	},
	{"iso8859-2",		charset_iso88592	},
	{"iso-8859-2",		charset_iso88592	},
	{"cp1250",			charset_cp1250		},
	{"cp-1250",			charset_cp1250		},
	{"windows1250",		charset_cp1250		},
	{"windows-1250",	charset_cp1250		},
	{"keybcs2",			charset_keybcs2		},
	{"universum",		charset_universum	},
	{"koi8cz",			charset_koi8cz		},
	{"pclatin1a",		charset_pclatin1a	},
	{"pclatin2",		charset_pclatin2	},
	{"*",				NULL				}
};

int main(int argc, char **argv)
{
	FILE *f;
	char buf[BUFSIZE], *src_charset, *dest_charset;
	register int i, idx, count, errors;
#ifndef ARGV0
	char *ARGV0 = strrchr(argv[0], '/') != NULL
		? strrchr(argv[0], '/') + 1 : argv[0];
#endif

	if (argc > 1 && ! strcmp(argv[1], "-l")) {
		char *tmp_charset = NULL;
		printf("List of available charsets and its aliases:\n");
		for (i = 0; charsets[i].charset != NULL; i++) {
			if (charsets[i].charset != tmp_charset) {
				printf("\n  ");
				tmp_charset = charsets[i].charset;
			} else {
				printf(", ");
			}
			printf("%s", charsets[i].name);
		}
		printf("\n\n");
		return 0;
	}

	if (argc < 4) {
		fprintf(stderr, "Usage: %s [ -l ] <src_charset> <dest_charset> <filename> ...\n",
				ARGV0);
		return 1;
	}

	/* Source charset initialization */
	src_charset = NULL;
	while (strchr(argv[1], '_') != NULL)
		*(strchr(argv[1], '_')) = '-';
	argv[1] = strtolower(argv[1]);
	argv[1] = str_trim(argv[1]);
	for (i = 0; charsets[i].charset != NULL; i++) {
		if (! strcmp(charsets[i].name, argv[1])) {
			src_charset = charsets[i].charset;
			break;
		}
	}
	if (src_charset == NULL) {
		fprintf(stderr, "%s: unknown source charset: %s\n", ARGV0, argv[1]);
		return 4;
	}

	/* Destination charset initialization */
	dest_charset = NULL;
	while (strchr(argv[2], '_') != NULL)
		*(strchr(argv[2], '_')) = '-';
	argv[2] = strtolower(argv[2]);
	argv[2] = str_trim(argv[2]);
	for (i = 0; charsets[i].charset != NULL; i++) {
		if (! strcmp(charsets[i].name, argv[2])) {
			dest_charset = charsets[i].charset;
			break;
		}
	}
	if (dest_charset == NULL) {
		fprintf(stderr, "%s: unknown destination charset: %s\n", ARGV0, argv[2]);
		return 4;
	}

	if (src_charset == dest_charset) {
		fprintf(stderr, "%s: source and destination charsets are the same\n", ARGV0);
		return 8;
	}

	/*
	 * Main loop
	 */

	for (errors = 0, idx = 3; idx < argc; idx++) {

		if ((f = fopen(argv[idx], "r+")) == NULL) {
			fprintf(stderr, "%s: can't open file '%s'\n", ARGV0, argv[3]);
			errors++;
			continue;
		}

		i = -1;
		count = 0;

		do {
			count = fread(buf, sizeof(char), BUFSIZE - 1, f);
			buf[count] = '\0';

			strconv(buf, src_charset, dest_charset);

			fseek(f, -count, SEEK_CUR);

			if (count != fwrite(buf, sizeof(char), count, f)) {
				fclose(f);
				fprintf(stderr, "%s: file '%s' write error\n", ARGV0, argv[idx]);
				i = -1;
				break;
			}

			i++;
		} while (count == BUFSIZE - 1);

		fclose(f);

		if (i < 0) {
			errors++;
			continue;
		}

		printf("%s: file '%s' with size %ld successfully converted\n",
				ARGV0, argv[idx],
				(long) (i * (BUFSIZE - 1)) + (long) count);
	}

	return errors ? 2 : 0;
}