#include <os.h>

#define BUFFER_SIZE 512

#define OS_PATH			"/phoenix/install/TI-Nspire.tnc"
#define NLAUNCH_PATH	"/phoenix/install/phoenix.tns"

char buffer[BUFFER_SIZE];
char* ospath[]={OS_PATH,NLAUNCH_PATH};
#define NPATH sizeof(ospath)/sizeof(char*)

#define TYPE_SIZE 8
#define BASE_SIZE 10
#define VERSION_SIZE 10
#define EXT_SIZE 4

#define DHEADER_SIZE 30
#define EHEADER_SIZE 46

typedef struct {
	char base[BASE_SIZE];
	char ext[EXT_SIZE];
	char version[VERSION_SIZE];
} osheader_s;

int isFile(char* path) {
	struct stat s;
	s.st_mode=0;
	return !stat(path, &s);
}


void (*reset)();
void (*reset)()= (void*)0;

char* getTypeExt(char* typestr, char* ext) {
	*typestr=0;
	switch(ext[1]) {
		case 'c':
			strcat(typestr," CX");
			break;
		case 'm':
			strcat(typestr," CM");
	}
	if(ext[2]=='c')
		strcat(typestr," CAS");
	return typestr;
}

void getOSInfos(char* file, osheader_s* osheader) {
	memset(osheader,0,sizeof(osheader_s));
	FILE* h=fopen(file,"rb");
	if(h) {
		fscanf(h,"%s %s ",osheader->base, osheader->version);
		osheader->base[BASE_SIZE-1]=0;
		fclose(h);
	}
}

unsigned int size = 0;

char* zipfooter = 0;
int ifooter = -1;
int itoc = -1;
int datasize = 0;
int onumfiles = 0;
int footersize = 0;
int sizeoffset = -1;

int getInt(char* buf, int n)
{	unsigned int r = 0;
	int i;
	for(i=n-1;i>=0;i--)
	{	r = r<<8;
		r += buf[i];
	}
	return r;
}

int searchFile(FILE* h, char* str, int size, int start, int end)
{	int l = strlen(str);
	char* tmp = malloc(l+1);
	int i = start;
	int f=-1;
	if(tmp) {
		f=0;
		tmp[l]=0;
		if(start>size-l)	start	= size-l;
		if(end>size-l)		end	= size-l;
		if(start<0)		start = 0;
		if(end<0)		end = 0;
		fseek(h,start,SEEK_SET);
		while(((i>=start && i<=end) || (i<=start && i>=end)) && !f)
		{	fread(tmp,1,l,h);
			if(!strcmp(tmp,str))
				f=1;
			else if(end<start)	i=i-1;
			else			i=i+1;
			if(l!=1 || end<start)	fseek(h,i,SEEK_SET);
		}
		free(tmp);
	}
	if(f<0)	return -1;
	else	return i;
}

int testOS(FILE* h)
{	int i, zipoffset;
	sizeoffset = searchFile(h," ",size,0,size-1);
	if(sizeoffset<0) return 0;
	sizeoffset = searchFile(h," ",size,sizeoffset+1,size-1);
	if(sizeoffset<0) return 0;
	sizeoffset++;
	ifooter = searchFile(h,"PK\x05\x06",size,size-22,0);
	if(ifooter<0) return 0;
	fseek(h,ifooter,SEEK_SET);
	footersize = size-ifooter;
	zipfooter = malloc(footersize);
	if(!zipfooter)	return 0;
	if(fread(zipfooter,1,footersize,h)!=footersize)	return 0;
	onumfiles = getInt(zipfooter+8,2);
	free(zipfooter);
	itoc = ifooter-3;
	for(i=0;i<onumfiles;i++)
	{	itoc = searchFile(h,"PK\x01\x02",size,itoc-1,itoc-EHEADER_SIZE-255*3);
		if(itoc<0)	return 0;
	}
	zipoffset=searchFile(h,"PK\x03\x04",size,0,itoc-1);
	return (0<=zipoffset);
}

int main(int argc, char** argv) {
	int i, ok=0, ios=0, zipoffset=0;
	FILE* h=0;
	
	if(argc==1) {
		char* progname=0;
		for(i=strlen(argv[0])-1;i>=0 && !progname;i--)
			if(argv[0][i]=='/')
				progname=argv[0]+i+1;
		if(progname)
		{	for(i=strlen(progname)-1;i>=0;i--)
				if(progname[i]=='.') {
					progname[i]=0;
					i=0;
				}
			cfg_register_fileext("tcc",progname);
			cfg_register_fileext("tco",progname);
			cfg_register_fileext("tmc",progname);
			cfg_register_fileext("tmo",progname);
			cfg_register_fileext("tnc",progname);
			cfg_register_fileext("tno",progname);
			cfg_register_fileext("tlo",progname);
			sprintf(buffer,"%s installed !",progname);
			show_msgbox("Info", buffer);
		}
	}
	else {
		while(ios<NPATH && !ok) {
			h = fopen(ospath[ios],"rb");
			size=0;
			ok=0;
			if(h) {
				fseek(h,0,SEEK_END);
				size = ftell(h);
				if(testOS(h))
					ok=1;
				fclose(h);
			}
			if(!ok)
				ios++;
		}
		if(ok) {
			int result=0;
			char typestr[TYPE_SIZE];
			char typestrold[TYPE_SIZE];
			osheader_s osheader_old;
			osheader_s osheader_new;
			getOSInfos(argv[1],&osheader_new);
			getOSInfos(ospath[ios],&osheader_old);
			sprintf(buffer,"Do you want to install %s%s %s OS image ?\nIf minOS>%s, you may also need to reset minOS.\nIf I am not a %s%s, or if this is a 3.6+ altered OS image, you'll also need an appropriate boot helper.",osheader_new.base,getTypeExt(typestr,osheader_new.ext),osheader_new.version,osheader_new.version,osheader_new.base,typestr);
			result=show_msgbox_2b("Install OS ?", buffer, "Yes", "No");
			if(result==1) {
				sprintf(buffer,"Do you want to backup your current %s%s %s OS ?",osheader_old.base,getTypeExt(typestrold,osheader_old.ext),osheader_old.version);
				result=show_msgbox_3b("Save OS ?", buffer, "Yes", "No", "Cancel");
				if(result!=3) {
					h=fopen(argv[1],"rb");
					if(h) {
						zipoffset = searchFile(h,"PK\x03\x04",size,0,size-4);
						if(zipoffset)
							zipoffset=getZipFileDataOffset(argv[1],zipoffset,"TI-Nspire.img");
						if(zipoffset)
							zipoffset = searchFile(h,"PK\x03\x04",size,zipoffset,size-4);
						fclose(h);
					}
					if(zipoffset) {
						extract_zip(argv[1],"/",0,zipoffset);
						if(result==1) {
							sprintf(buffer,"/documents/%s.%s.tns",osheader_old.version,osheader_old.ext);
							remove(buffer);
							rename(ospath[ios],buffer);
							sprintf(buffer,"Your current %s%s %s OS image has been backuped to /documents/%s.%s.\n",osheader_old.base,typestrold,osheader_old.version,osheader_old.version,osheader_old.ext);
						}
						else {
							remove(ospath[ios]);
							*buffer=0;
						}
						rename(argv[1],ospath[ios]);
						strcat(buffer,"New OS image injected and extracted.\nReset the calculator to use it.\nDo you want to reset now ?");
						result=show_msgbox_2b("Reset ?", buffer, "Yes", "No");
						if(result==1)
							reset();
					}
				}
			}
		}
	}
}