#include "Structs.h"
#include "Helper.h"

namespace FAT32 {

	/** combine a DirectoryEntry with its absolute location on disk */
	class DirHandle {

		friend class File;
		friend class DirIterator;


		template <typename BlockDev> friend class FS;

		/** the absolute byte location on the disk where the underlying DirEntry is stored */
		AbsPos posOnDisk;

		/** the FAT32 entry format */
		DirEntry entry;

		/** is this a valid handle? */
		bool valid;

	public:

		/** ctor for an invalid handle */
		DirHandle() : valid(false) {}

		/** ctor for a valid handle */
		DirHandle(AbsPos posOnDisk, DirEntry* entry) : posOnDisk(posOnDisk), entry(*entry), valid(true) {}

		static DirHandle invalid() {return DirHandle();}

		/** is this a valid handle? */
		bool isValid() const {return valid;}


		/** get the entry's size */
		uint32_t getSize() const		{return entry.size;}

		/** get the entry's name (filename / foldername) */
		std::string getName() const {

			char buf[16];

			// the name
			uint8_t pos = 0;
			for (uint8_t i = 0; i < 8; ++i) {if (entry.name[i] != ' ') {buf[pos++] = entry.name[i];}}

			// the extension (if any, folder have none)
			if (entry.ext[0] != ' ') {
				buf[pos++] = '.';
				for (uint8_t i = 0; i < 3; ++i) {if ( entry.ext[i] != ' ') {buf[pos++] =  entry.ext[i];}}
			}

			// null terminate and return
			buf[pos] = 0;

			std::string str(buf);
			toLower(str);
			return str;

		}

		bool isUnused() const			{return entry.name[0] == 0xE5;}
		bool isDirectory() const		{return entry.attr.bits.directory;}
		bool isEndOfDirectory() const	{return entry.name[0] == 0x00;}
		bool isLongFileName() const		{return (entry.attr.raw & 0b1111) == 0b1111;}

		bool isDot() const				{return entry.name[0] == '.' && entry.name[1] == ' ';}
		bool isDotDot() const			{return entry.name[0] == '.' && entry.name[1] == '.' && entry.name[2] == ' ';}

		ClusterNr getFirstCluster() const	{return entry.firstClusterHi<<16 | entry.firstClusterLo<<0;}

		bool hasExtension(const char* ext) const {
			const size_t len = strlen(ext);
			if (len > 3) {return false;}
			for (int i = 0; i < len; ++i) {
				if (asciitolower(entry.ext[i]) != asciitolower(ext[i])) {return false;}
			}
			for (int i = len; i < 3; ++i) {
				if (entry.ext[i] != ' ') {return false;}
			}
			return true;
		}

	private:

		void setSize(uint32_t size)		{entry.size = size;}

		/** this entry is an end-of-directory marker */
		void setEndOfDirectory() {
			entry.name[0] = 0x00;
		}

		/** this entry is a directory */
		void setDirectory()				{
			setSize(0);
			entry.attr.bits.directory = 1;
		}

		/** this entry is the '.' pointer (to self) */
		void setDot(ClusterNr myClusterNr) {
			setSize(0);
			entry.attr.bits.directory = 1;		// not explicitly pointed out within manual, but e.g. linux needs it
			memcpy(entry.name83, ".          ", 8+3);
			setFirstCluster(myClusterNr);
		}

		/** this entry is the '.' pointer (to parent) */
		void setDotDot(ClusterNr parentClusterNr) {
			setSize(0);
			entry.attr.bits.directory = 1;		// not explicitly pointed out within manual, but e.g. linux needs it
			memcpy(entry.name83, "..         ", 8+3);
			setFirstCluster(parentClusterNr);
		}

		void setFirstCluster(ClusterNr nr)	{entry.firstClusterHi = (uint16_t)(nr << 16); entry.firstClusterLo = (uint16_t)(nr << 0);}

		void setName(const std::string& str) {

			// "zero" fill name and extension (0x20)
			memset(entry.name83, ' ', 11);

			auto pos = str.find('.');

			// name
			for (size_t i = 0; i < min(8, min(pos, str.length())); ++i) {
				if (i >= 8) {break;}
				entry.name[i] = str[i];
			}

			// extension (if any, folders have none)
			if (pos != std::string::npos) {
				uint32_t extLen = min(3, str.length() - pos - 1);
				for (size_t i = 0; i < extLen; ++i) {
					if (i >= 3) {break;}
					entry.ext[i] = str[i+pos+1];
				}
			}

		}

	};

}