#include "hello.hpp"

#include <string>

using namespace std;

// Constructor
HelloWorld::HelloWorld () : 
		m_strHelloWorld ("Hello World!\n"),
		m_strPath ("/hello") {
	// nothing yet
}

int HelloWorld::getattr (const char *path, struct stat *stbuf) {
	int res = 0;
	string strPath (path); // convert the path into a std::string

	// Zero out the file stat buffer
	memset (stbuf, 0, sizeof (struct stat));
	if (strPath == "/") {
		stbuf->st_mode = S_IFDIR | 0755;
		stbuf->st_nlink = 2;
	}
	// Compare the private variable of the HelloWorld object to the
	// passed-in path parameter from fuse
	else if (self->m_strPath == strPath) {
		stbuf->st_mode = S_IFREG | 0444; // read-only
		stbuf->st_nlink = 1;
		stbuf->st_size = self->m_strHelloWorld.length();
	}
	else {
		res = -ENOENT;
	}

	return res;
}

int HelloWorld::readdir(const char *path, void *buf, fuse_fill_dir_t filler,
		off_t offset, struct fuse_file_info *fi) {
	string strPath (path);
	(void) offset;
	(void) fi;

	if(strPath != "/")
		return -ENOENT;

	filler(buf, ".", NULL, 0);
	filler(buf, "..", NULL, 0);

	// self->m_strPath contains the std::string "/hello"
	// Applying .c_str() returns a const char * containing "/hello"
	// Adding 1 to that pointer skips the '/' character and thus outputs
	// just "hello"
	filler(buf, self->m_strPath.c_str() + 1, NULL, 0);

	return 0;
}

int HelloWorld::open(const char *path, struct fuse_file_info *fi) {
	string strPath (path);

	// The only file that exists is "/hello"
	if(strPath != self->m_strPath)
		return -ENOENT;

	// Only allow read-only access
	if((fi->flags & 3) != O_RDONLY)
		return -EACCES;

	return 0;
}

int HelloWorld::read(const char *path, char *buf, size_t size, off_t offset,
		struct fuse_file_info *fi) {
	string strPath (path);
	size_t len;
	(void) fi;

	if(strPath != self->m_strPath)
		return -ENOENT;

	len = self->m_strHelloWorld.length ();
	if (offset < len) {
		if (offset + size > len)
			size = len - offset;
		memcpy (buf, self->m_strHelloWorld.c_str () + offset, size);
	} else
		size = 0;

	return size;
}