#include <string.h>
#include <sys/socket.h>

#include "multiaddr/varhexutils.h"
#include "multiaddr/varint.h"
#include "multiaddr/protocols.h"
#include "multiaddr/protoutils.h"
#include "multiaddr/multiaddr.h"

int strpos(char *haystack, char *needle)
{
	char *p = strstr(haystack, needle);
	if (p)
	{
		return p - haystack;
	}
	else
	{
		return -1;   // Not found = -1.
	}
}

/**
 * Construct a new MultiAddress struct
 * @returns an empty MultiAddress struct
 */
struct MultiAddress* multiaddress_new() {
	struct MultiAddress* out = (struct MultiAddress*)malloc(sizeof(struct MultiAddress));
	if (out != NULL) {
		out->bsize = 0;
		out->bytes = NULL;
		out->string = NULL;
	}
	return out;
}

/**
 * construct a new MultiAddress from bytes
 * @param byteaddress the byte array
 * @param size the size of the byte array
 * @returns a new MultiAddress struct filled in, or NULL on error
 */
struct MultiAddress* multiaddress_new_from_bytes(const uint8_t* byteaddress, int size)//Construct new address from bytes
{
	struct MultiAddress* out = multiaddress_new();
	if (out != NULL) {
		if(byteaddress!=NULL)
		{
			out->bytes = malloc(size);
			if (out->bytes == NULL) {
				multiaddress_free(out);
				return NULL;
			}
			out->bsize = size;
			memcpy(out->bytes, byteaddress, size);
			if(!bytes_to_string(&out->string,byteaddress,size))
			{
				multiaddress_free(out);
				return NULL;
			}
		} else {
			multiaddress_free(out);
			return NULL;
		}
	}
	return out;
}

struct MultiAddress* multiaddress_new_from_string(const char* straddress)//Construct new address from string
{
	struct MultiAddress* out = multiaddress_new();
	if (out != NULL) {
		out->string = malloc(strlen(straddress) + 1);
		if (out->string == NULL) {
			multiaddress_free(out);
			return NULL;
		}
		strcpy(out->string, straddress);

		if (string_to_bytes(&(out->bytes), &out->bsize, out->string, strlen(out->string)) == 0 )
		{
			multiaddress_free(out);
			return NULL;
		}
	}
	return out;
}

int multiaddress_is_ip(const struct MultiAddress* in) {
	if (in->bytes > 0) {
		int byte = in->bytes[0];

		if (byte == 4 || byte == 41)
			return 1;
	}
	return 0;
}
int multiaddress_is_ip4(const struct MultiAddress* in) {
	return in->bytes[0] == 4;
}

int multiaddress_is_ip6(const struct MultiAddress* in) {
	return in->bytes[0] == 41;
}


int multiaddress_get_ip_family(const struct MultiAddress* in) {
	if (in->bytes[0] == 4)
		return AF_INET;
	if (in->bytes[0] == 41)
		return AF_INET6;
	return 0;
}

/***
 * Pulls the textual representation of the IP address from a multihash
 * @param in the multihash to parse
 * @param ip where to put the ip address
 * @returns true(1) on success, otherwise 0
 */
int multiaddress_get_ip_address(const struct MultiAddress* in, char** ip) {
	// the incoming address is not what was expected
	if (strncmp(in->string, "/ip4/", 5) != 0 && strncmp(in->string, "/ip6/", 5) != 0)
		return 0;
	if (strstr(in->string, "/tcp/") == NULL && strstr(in->string, "/udp/") == NULL)
		return 0;
	// ip
	char* str = malloc(strlen(in->string));
	if (str == NULL)
		return 0;
	strcpy(str, &in->string[5]); // gets rid of /ip4/
	char* pos = strchr(str, '/');
	pos[0] = 0;
	*ip = malloc(strlen(str) + 1);
	strcpy(*ip, str);
	free(str);
	return 1;
}

/***
 * Pulls the IP port from a multiaddress
 * @param in the multiaddress
 * @param port where to put the port
 * @returns the port, or a negative number for an error
 */
int multiaddress_get_ip_port(const struct MultiAddress* in) {
	char* ptr = strstr(in->string, "/tcp/");
	if (ptr == NULL)
		ptr = strstr(in->string, "/udp/");
	if (ptr == NULL)
		return -1;
	ptr += 5;
	char* end_ptr = strstr(ptr, "/");
	if (end_ptr == NULL) {
		return atoi(ptr);
	}
	char str[end_ptr - ptr + 1];
	memcpy(str, ptr, end_ptr - ptr);
	str[end_ptr-ptr] = '\0';
	return atoi(str);
}

char* multiaddress_get_peer_id(const struct MultiAddress* in) {
	char* result = NULL;
	int str_len = 0;
	char* slash = NULL;
	char* ptr = NULL;

	ptr = strstr(in->string, "/ipfs/");
	if (ptr != NULL && ptr[6] != 0) {
		ptr += 6;
		str_len = strlen(ptr);
		slash = strchr(ptr, '/');
		if (slash != NULL) {
			str_len = slash - ptr;
		}
		if (str_len > 0) {
			result = malloc(str_len + 1);
			if (result != NULL) {
				memset(result, 0, str_len + 1);
				memcpy(result, ptr, str_len);
			}
		}
	}
	return result;
}

void multiaddress_free(struct MultiAddress* in) {
	if (in != NULL) {
		if (in->bytes != NULL)
			free(in->bytes);
		if (in->string != NULL)
			free(in->string);
		free(in);
		in = NULL;
	}
}

/**
 * Copy a multiaddress from one memory location to another
 * @param in the source
 * @returns the new struct MultiAddress or NULL if there was a problem (i.e. out of memory)
 */
struct MultiAddress* multiaddress_copy(const struct MultiAddress* in) {
	struct MultiAddress* out = NULL;
	if (in != NULL) {
		out = (struct MultiAddress*)malloc(sizeof(struct MultiAddress));
		if (out != NULL) {
			if (in->bsize > 0) {
				out->bytes = malloc(in->bsize);
				if (out->bytes == NULL) {
					free(out);
					return NULL;
				}
				out->bsize = in->bsize;
				memcpy(out->bytes, in->bytes, out->bsize);
			} // bytes need to be copied
			if (in->string != NULL) {
				out->string = malloc(strlen(in->string) + 1);
				if (out->string == NULL) {
					if (out->bsize > 0)
						free(out->bytes);
					free(out);
					return NULL;
				}
				strcpy(out->string, in->string);
			} // string needs to be copied
		} // structure allocated
	} // good parameters
	return out;
}

/**
 * Put a string into the MultiAddress and recalculate the bytes
 * @param result the struct
 * @param string the new string
 */
int multiaddress_encapsulate(struct MultiAddress* result, char* string)
{
	if(result != NULL && string != NULL)
	{
		// remove the old values
		if (result->bytes != NULL)
			free(result->bytes);
		result->bytes = NULL;
		result->bsize = 0;
		char * exstr;
		if(string[0] == '/')
		{
			exstr = (char *) malloc(strlen(result->string)+1);
		}
		else
		{
			exstr = (char *) malloc(strlen(result->string));
		}
		strcpy(exstr, result->string);
		free(result->string);
		// insert the new values
		result->string = malloc(strlen(string) + strlen(exstr) + 1);
		if (result->string == NULL) {
			multiaddress_free(result);
			return 0;
		}
		strcpy(result->string, exstr);
		free(exstr);
		if(string[0] == '/')
		{
			strcat(result->string, string+1);
		}
		else
		{
			strcat(result->string, string);
		}
		if(string_to_bytes(&result->bytes, &result->bsize, result->string, strlen(result->string)+1) == 0)
		{
			multiaddress_free(result);
			return 0;
		}
	} else {
		return 0;
	}
	return 1;
}

/**
 * Find scri and remove it from the resultant value
 * (ie /ip4/127.0.0.1/tcp/4001 becomes ip4/127.0.0.1 when you call decapsulate(addr, "/tcp")
 * @param result the address to work with
 * @param srci the string to look for
 */
int multiaddress_decapsulate(struct MultiAddress * result, char * srci)
{
	if(result!=NULL && srci!=NULL)
	{
		char * procstr = NULL;
		procstr = result->string;
		int i=0;
		int sz=strlen(procstr);
		char * src = NULL;
		src=srci;
		// change slash to space
		for(i=0;i<sz;i++)
		{
			if(procstr[i] == '/')
			{
				procstr[i]=' ';
			}
		}
		int pos=-1;
		pos=strpos(procstr,src);
		if(pos!=-1)
		{
			// fill rest with 0s
			for(i=pos;i<sz;i++)
			{
				procstr[i] = '\0';
			}
			// replace space with slash
			for(i=0;i<sz;i++)
			{
				if(procstr[i] == ' ')
				{
					procstr[i] = '/';
				}
			}
			//Bytes update
			if (result->bytes != NULL)
				free(result->bytes);
			result->bytes = NULL;
			result->bsize = 0;
			if(string_to_bytes(&result->bytes, &result->bsize, result->string, strlen(result->string)+1) == 0)
			{
				multiaddress_free(result);
				return 0;
			}
			return 1;
		}
		else
		{
			return 0;
		}
		return 0;
	}
	else
	{
		return 0;
	}
}

/**
 * Check to see how these two addresses compare
 * @param a side A
 * @param b side B
 * @returns <0 if B > A; >0 if A > B; 0 if A == B
 */
int multiaddress_compare(const struct MultiAddress* a, const struct MultiAddress* b) {
	if (a == NULL && b == NULL)
		return 0;
	if (a == NULL && b != NULL)
		return -1;
	if (a != NULL && b == NULL)
		return 1;
	int total = b->bsize - a->bsize;
	if (total != 0)
		return total;
	for(size_t i = 0; i < b->bsize; i++) {
		total = b->bytes[i] - a->bytes[i];
		if (total != 0)
			return total;
	}
	return 0;
}

/**
 * Check to see how these two addresses compare, ignoring IP address,
 * only looking at the first /ipfs/ID hash
 * @param a side A
 * @param b side B
 * @returns <0 if B > A; >0 if A > B; 0 if A == B
 */
int multiaddress_compare_id(const struct MultiAddress* a, const struct MultiAddress* b) {
	char* a_id = multiaddress_get_peer_id(a);
	char* b_id = multiaddress_get_peer_id(b);
	if (a_id == NULL && b_id == NULL)
		return 0;
	if (a_id == NULL && b_id != NULL)
		return -1;
	if (a_id != NULL && b_id == NULL)
		return 1;
	int retVal = strcmp(a_id, b_id);
	if (a_id != NULL)
		free(a_id);
	if (b_id != NULL)
		free(b_id);
	return retVal;
}