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

//////////
#include <openssl/sha.h>
#include <openssl/bio.h>
/////////

/*
 * range of the chars in the randomly generated string
 *
 * 33 = '!'
 * 127 = '~'
 *
 */

#define CHAR_START '1'
#define CHAR_END   '9'

//#define MEASURE_FUNC string_bit_count
//#define MEASURE_FUNC string_bit_count2
//#define MEASURE_FUNC string_bit_count3
#define MEASURE_FUNC   sha1_int_from_string

/*
 * returns dynamically allocated random string
 * with a strlen between minLen and maxLen
 * the memory size is strlen + 1 
 *
 */

char* rand_word(unsigned minLen, unsigned maxLen);
/*
 * uses rand returned value >= min and value <= max
 */
unsigned rand_between(unsigned min, unsigned max);

/*
 * returns an array of dynamically allocated strings
 * length of array is n + 1, the last value is NULL
 */
char** random_strings(size_t n, unsigned minLen, unsigned maxLen);

/*
 * returns strlen without newline
 * removes terminates string at newline position
 */
size_t remove_newline(char* str);

/*max line size with newline and terminating 0*/ 
#define MAX_LINE_SIZE 1024
/*
 * nRead, out:  allowed to be NULL
 * 	nRead represents actually read strings, without trailing NULL
 * 	e.g. if 0 strings are read, nRead will be 0, and the returned array will be {NULL}
 * returns string array, null terminated
 *
 */
char** read_strings(const char* fileName,  size_t* nRead);

/*
 * count set bits in string s
 */
int string_bit_count(char* s);
int string_bit_count2(const char* s);
int string_bit_count3(const char* s);
int sha1_int_from_string(const char* s);

/*
 * returns malloced memory of size memSize
 * if it fails, it exits with 7 the programm
 *
 */
void* non_null_malloc(size_t memSize);

int string_sort_func(const void* a, const void* b);

void usage_and_exit();

#define PRE_STR_HELPER(token) #token
#define PRE_STR(token) PRE_STR_HELPER(token) 

void usage_and_exit() {
		printf("usage\n");
		printf("<prog> measure <filename>\n"); 
		printf("<prog> sort <filename>\n"); 
		printf("<prog> generate <n> <min> <max>\n"); 
		exit(1); 
}
int main(int argc, char* argv[]) 
{
	_Bool generate = 0;
	_Bool measure  = 0;
	_Bool sort  = 0;
	if(argc < 2 ) { 
		usage_and_exit();
	}
	measure = strcmp(argv[1], "measure")  == 0;
	generate  = strcmp(argv[1], "generate") == 0;
	sort  = strcmp(argv[1], "sort") == 0;
	if((!generate) && (!measure) && (!sort)) {
		usage_and_exit();
	}
	if(measure) {
		if(argc != 3 ) { 
			usage_and_exit();
		}
		char** array = read_strings(argv[2], NULL);
		char** p = array;
		unsigned long long counter = 0;
		clock_t t1, t0 = clock();
		for(; *p; ++p) {
			counter += MEASURE_FUNC(*p);
		}
		t1 = clock();
		printf("measure file: <%s>\n", argv[2]);
		printf("measure function: <%s>\n", PRE_STR(MEASURE_FUNC));
		printf("counter = %llu\n", counter);
		printf("time = %lf ms\n", (t1 - t0) / (double) CLOCKS_PER_SEC * 1000.0);

	} else if(generate) {
		if(argc != 5 ) { 
			usage_and_exit();
		}
		unsigned n, minLen, maxLen; 
		sscanf(argv[2], "%u", &n);
		sscanf(argv[3], "%u", &minLen);
		sscanf(argv[4], "%u", &maxLen);
		char** words = random_strings(n, minLen, maxLen);
		for(int i=0; i<n; ++i) {
			printf("%s\n", words[i]);
		}
	} else if(sort) {
		if(argc != 3 ) { 
			usage_and_exit();
		}
		size_t nRead = 0;
		char** array = read_strings(argv[2], &nRead);
		qsort(array, nRead, sizeof(char*), string_sort_func);

		for(size_t i=0; i < nRead; ++i) {
			printf("%s\n", array[i]);
		}
	}
}





size_t remove_newline(char* str) {
	size_t pos = 0;
	while(str[pos] && str[pos] != '\n') ++pos;
	str[pos] = '\0';
	return pos;
}


char** random_strings(size_t n, unsigned minLen, unsigned maxLen) {
	char** array = (char**) non_null_malloc(sizeof(char*) * (n+1));
	for(size_t i=0; i<n; ++i) {
		array[i] = rand_word(minLen, maxLen);
	}
	array[n] = NULL;
	return array;
}

void* non_null_malloc(size_t memSize) {
	char* m = malloc(memSize);
	if(!m) {
		perror("non_malloc_failed");
		exit(7);
	}
	return m;
}
unsigned rand_between(unsigned min, unsigned max) {
	int rv = rand();
	unsigned urv = rv < 0? -1*rv : rv;
	unsigned v = (rv % ((max+1) - min)) + min;
	return v;
}
char* rand_word(unsigned minLen, unsigned maxLen) {
	unsigned len = rand_between(minLen, maxLen);
	char* s    = non_null_malloc(len+1);
	for(size_t i=0; i<len; ++i) {
		s[i] = rand_between(CHAR_START, CHAR_END);
	}
	s[len] = '\0';
	return s;
}
int string_bit_count(char* s) {
	//printf("<%s>\n", s);
	int count = 0;
	int len = strlen(s);
	for(int i=0; i<len; ++i) {
		for(int k=0; k<8; ++k) {
			if(s[i] & (1 << k)) {
				++count;
			}
		}
	}
	//printf("count = %d\n", count);
	return count;
}
int string_bit_count3(const char* s) {
	static const unsigned char lookup[] ={0, 1, 1, 2, 1, 2, 2, 3, 1, 2, 2, 3, 2, 3, 3, 4, 1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5, 1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5, 2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, 1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5, 2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, 2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, 3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7, 1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5, 2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, 2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, 3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7, 2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, 3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7, 3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7, 4, 5, 5, 6, 5, 6, 6, 7, 5, 6, 6, 7, 6, 7, 7, 8};
	int len = strlen(s);
	int count = 0;
	for(int i=0; i<len; ++i) {
		count += lookup[s[i]];
	}
	return count;
}
int string_bit_count2(const char* s) {
	static const unsigned char lookup[] ={0, 1, 1, 2, 1, 2, 2, 3, 1, 2, 2, 3, 2, 3, 3, 4, 1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5, 1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5, 2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, 1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5, 2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, 2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, 3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7, 1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5, 2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, 2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, 3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7, 2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, 3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7, 3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7, 4, 5, 5, 6, 5, 6, 6, 7, 5, 6, 6, 7, 6, 7, 7, 8};
	int count = 0;
	const char* p = s;
	for(; *p; ++p) {
		count += lookup[*p];
	}
	return count;
}

int string_sort_func(const void* a, const void* b) {
	 char* sa = *((char**) a);
	 char* sb = *((char**) b);
	 return strcmp(sa, sb);
}
char** read_strings(const char* fileName, size_t* nRead) {
	size_t len;
	char* sp;
	FILE* f = fopen(fileName, "r");
	if(!f) { perror("unable to open file"); exit(1); }
	char* buff = non_null_malloc(MAX_LINE_SIZE);
	size_t out_array_len = 16 * sizeof(char*);
	size_t out_array_pos = 0;
	char** out_array = non_null_malloc(out_array_len);
	out_array[0] = NULL;
	while(! feof(f)) {
			buff[0] = '\0';
			if(! fgets(buff, MAX_LINE_SIZE, f)) {
				break;
			}
			len = remove_newline(buff);
			if(len > 0) {
				sp = non_null_malloc(len+1);
				memcpy(sp, buff, len+1);
				if(out_array_pos + 1 > out_array_len / sizeof(char*)) {
					out_array_len = out_array_len * 2;
					out_array = realloc(out_array, out_array_len);
					if(! out_array) { perror("allocation failed"); exit(1); }
				}
				out_array[out_array_pos++] = sp;
				out_array[out_array_pos] = NULL;
			}
	}
	fclose(f);
	if(nRead) *nRead = out_array_pos;
	return out_array;

}

int sha1_int_from_string(const char* s) {
        SHA_CTX c;
        SHA1_Init(&c);
        char sha1_bytes[20];
        SHA1_Update(&c, s, strlen(s));
        SHA1_Final(sha1_bytes, &c);
	int count = 0;
	for(int i=0; i<20; ++i) {
		count += sha1_bytes[i];
	}
	return count;
}