#include "util.h"

#include "logging.h"

#include <stddef.h>

#include <stdarg.h>

#include <stdlib.h>

#include <string.h>

#include <stdio.h>

#include <ctype.h>

char *flib_asprintf(const char *fmt, ...) {

	va_list argp;

	va_start(argp, fmt);

	char *result = flib_vasprintf(fmt, argp);

	va_end(argp);

	return result;

}

char *flib_vasprintf(const char *fmt, va_list args) {

	char *result = NULL;

	if(!fmt) {

		flib_log_e("null parameter in flib_vasprintf");

	} else {

		int requiredSize = vsnprintf(NULL, 0, fmt, args)+1;					// Figure out how much memory we need,

		if(requiredSize<0) {

			flib_log_e("Error formatting string with template \"%s\" in flib_vasprintf", fmt);

		} else {

			char *tmpbuf = flib_malloc(requiredSize);						// allocate it

			if(tmpbuf && vsnprintf(tmpbuf, requiredSize, fmt, args)>=0) {	// and then do the actual formatting.

				result = tmpbuf;

				tmpbuf = NULL;

			}

			free(tmpbuf);

		}

	}

	return result;

}

char *flib_strdupnull(const char *str) {

	if(!str) {

		return NULL;

	}

	return flib_asprintf("%s", str);

}

void *flib_bufdupnull(const void *buf, size_t size) {

	if(!buf || size==0) {

		return NULL;

	}

	void *result = flib_malloc(size);

	if(result) {

		memcpy(result, buf, size);

	}

	return result;

}

void *flib_malloc(size_t size) {

	void *result = malloc(size);

	if(!result && size>0) {

		flib_log_e("Out of memory trying to malloc %zu bytes.", size);

	}

	return result;

}

void *flib_calloc(size_t count, size_t elementsize) {

	void *result = calloc(count, elementsize);

	if(!result && count>0 && elementsize>0) {

		flib_log_e("Out of memory trying to calloc %zu objects of %zu bytes each.", count, elementsize);

	}

	return result;

}

void *flib_realloc(void *ptr, size_t size) {

	void *result = realloc(ptr, size);

	if(!result && size>0) {

		flib_log_e("Out of memory trying to realloc %zu bytes.", size);

	}

	return result;

}

static bool isAsciiAlnum(char c) {

	return (c>='0' && c<='9') || (c>='a' && c <='z') || (c>='A' && c <='Z');

}

char *flib_urlencode(const char *inbuf) {

	return flib_urlencode_pred(inbuf, isAsciiAlnum);

}

char *flib_urlencode_pred(const char *inbuf, bool (*needsEscaping)(char c)) {

	if(!inbuf) {

		return NULL;

	}

	size_t insize = strlen(inbuf);

	if(insize > SIZE_MAX/4) {

		flib_log_e("String too long in flib_urlencode: %zu bytes.", insize);

		return NULL;

	}

	char *outbuf = flib_malloc(insize*3+1);

	if(!outbuf) {

		return NULL;

	}

    size_t inpos = 0, outpos = 0;

    while(inbuf[inpos]) {

        if(!needsEscaping(inbuf[inpos])) {

        	outbuf[outpos++] = inbuf[inpos++];

        } else {

            if(snprintf(outbuf+outpos, 4, "%%%02X", (unsigned)((uint8_t*)inbuf)[inpos])<0) {

            	flib_log_e("printf error in flib_urlencode");

            	free(outbuf);

            	return NULL;

            }

            inpos++;

            outpos += 3;

        }

    }

    outbuf[outpos] = 0;

    char *shrunk = realloc(outbuf, outpos+1);

    return shrunk ? shrunk : outbuf;

}

char *flib_urldecode(const char *inbuf) {

	char *outbuf = flib_malloc(strlen(inbuf)+1);

	if(!outbuf) {

		return NULL;

	}

    size_t inpos = 0, outpos = 0;

    while(inbuf[inpos]) {

        if(inbuf[inpos] == '%' && isxdigit(inbuf[inpos+1]) && isxdigit(inbuf[inpos+2])) {

            char temp[3] = {inbuf[inpos+1],inbuf[inpos+2],0};

            outbuf[outpos++] = strtol(temp, NULL, 16);

            inpos += 3;

        } else {

        	outbuf[outpos++] = inbuf[inpos++];

        }

    }

    outbuf[outpos] = 0;

    char *shrunk = realloc(outbuf, outpos+1);

    return shrunk ? shrunk : outbuf;

}