#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <stdbool.h>
#include <time.h>

#define DATA_FILENAME "data.txt"
#define ROOT 5
#define BASE 10
#define REVERSE_FILE_ROOT_5 "immortal_base10_power2_branch5_digits%d"
#define REVERSE_FILE_ROOT_6 "immortal_base10_power2_branch6_digits%d"

// ------------------------------------------------------------------------------------------------------

static inline void mygetline(char* line, size_t size, FILE* myfile) {
	if (fgets(line, size, myfile) == NULL) {
		line = "";
		return;
	}

	size_t ln = strlen(line) - 1;
	if (line[ln] == '\n') line[ln] = '\0';

	ln = strlen(line) - 1;
	if (line[ln] == '\r') line[ln] = '\0';

	return;
}

int main(void) {
	#define SIGNATURE "Immortal Number Report File Version 3.00"
	#define END_SIG "END OF REPORT"

	/*unsigned*/ char* a;

	unsigned /* long long */ int a_size = 0;
	unsigned /* long long */ int top = -1; // u
	unsigned /* long long */ int digits = -1; // u+1

	//bool a_empty;

	char line[255];
	FILE* myfile = fopen(DATA_FILENAME, "r");
	if (myfile) {
		// __try {
			top = -1;
			digits = -1;

			mygetline(line, sizeof line, myfile);
			if (strcmp(line, SIGNATURE) != 0 /* not equal */) {
				fprintf(stderr, "Load error: Wrong format signature. Expecting '%s' but is '%s'.\n", SIGNATURE, line);
				fclose(myfile);
				return EXIT_FAILURE;
			}

			mygetline(line, sizeof line, myfile); // Minor. signature
			mygetline(line, sizeof line, myfile); // ""

			mygetline(line, sizeof line, myfile); // "(Starting time)"
			mygetline(line, sizeof line, myfile);
			mygetline(line, sizeof line, myfile); // ""

			mygetline(line, sizeof line, myfile); // "(Save timestamp)"
			mygetline(line, sizeof line, myfile); // Timestamp
			mygetline(line, sizeof line, myfile); // ""

			mygetline(line, sizeof line, myfile); // "(Base)"
			mygetline(line, sizeof line, myfile); // 10
			unsigned int base = atoi(line);
			if (base != BASE) {
				fprintf(stderr, "This edition can only work with base = %d.\n", BASE);
				fclose(myfile);
				return EXIT_FAILURE;
			}
			mygetline(line, sizeof line, myfile); // ""

			mygetline(line, sizeof line, myfile); // "(Root)"
			mygetline(line, sizeof line, myfile); // 5
			unsigned int root = atoi(line);
			if (root != ROOT) {
				fprintf(stderr, "This edition can only work with root = %d.\n", ROOT);
				fclose(myfile);
				return EXIT_FAILURE;
			}
			mygetline(line, sizeof line, myfile); // ""

			mygetline(line, sizeof line, myfile); // "(Digits)"
			mygetline(line, sizeof line, myfile);
			digits = atoi(line);
			mygetline(line, sizeof line, myfile); // ""

			mygetline(line, sizeof line, myfile); // "(r)"
			mygetline(line, sizeof line, myfile);
			mygetline(line, sizeof line, myfile); // ""

			a_size = digits;
			a = (/*unsigned*/ char*) calloc(a_size, sizeof(/*unsigned*/ char));
			if (a == NULL) {
				fprintf(stderr, "Memory allocation failed!\n");
				fclose(myfile);
				return EXIT_FAILURE;
			}

			mygetline(line, sizeof line, myfile); // "(Reversed notation)"
			do {
				mygetline(line, sizeof line, myfile);
				for (unsigned int i = 0; i < strlen(line); ++i) {
					/*unsigned*/ char toadd = line[i] - '0';

					if (digits == top + 1) {
						fprintf(stderr, "Corrupt: Formal and actual length mismatch!\n");
						fclose(myfile);
						return EXIT_FAILURE;
					}

					// Cannot overflow if input file is OK.
					a[++top] = toadd;
					//a_empty = false;
				}
			} while (strcmp(line, "") != 0 /* not equal */);

			if (digits != top + 1) {
				fprintf(stderr, "Corrupt: Formal and actual length mismatch!\n");
				fclose(myfile);
				return EXIT_FAILURE;
			}

			mygetline(line, sizeof line, myfile);

			if (strcmp(line, END_SIG) != 0 /* not equal */) {
				fprintf(stderr, "Corrupt: End-signature mismatch.\n");
				fclose(myfile);
				return EXIT_FAILURE;
			}
		// } __finally {
			fclose(myfile);
		// }
	} else {
		fprintf(stderr, "Cannot open file!\n");
		return EXIT_FAILURE;
	}

	char fn[255];

	// Base 5

	sprintf(fn, REVERSE_FILE_ROOT_5, digits);
	FILE* outfile;
	outfile = fopen(fn, "w");
	if (!outfile) {
		fprintf(stderr, "ERROR: Cannot open file %s for writing\n", REVERSE_FILE_ROOT_6);
		return EXIT_FAILURE;
	}

	// __try {
		for (int i = top; i >= 0; --i) {
			/*unsigned*/ char xa = a[i];
			fprintf(outfile, "%d", xa);
		}
	// } __finally {
		fclose(outfile);
	// }

	// Base 6 (converted)

	sprintf(fn, REVERSE_FILE_ROOT_6, digits);
	outfile = fopen(fn, "w");
	if (!outfile) {
		fprintf(stderr, "ERROR: Cannot open file %s for writing\n", REVERSE_FILE_ROOT_6);
		return EXIT_FAILURE;
	}

	// __try {
		for (int i = top; i >= 0; --i) {
			/*unsigned*/ char xa = a[i];
			if (i == 0) xa = 11 - xa; else xa = 9 - xa;
			fprintf(outfile, "%d", xa);
		}
	// } __finally {
		fclose(outfile);
	// }

	free(a);

	return EXIT_SUCCESS;
}