/*
 * Copyright (C) 2004-2013 ZNC, see the NOTICE file for details.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#ifndef _UTILS_H
#define _UTILS_H

#include <znc/zncconfig.h>
#include <znc/ZNCString.h>
#include <assert.h>
#include <cstdio>
#include <fcntl.h>
#include <map>
#include <sys/file.h>
#include <sys/time.h>
#include <unistd.h>
#include <vector>

static inline void SetFdCloseOnExec(int fd)
{
	int flags = fcntl(fd, F_GETFD, 0);
	if (flags < 0)
		return; // Ignore errors
	// When we execve() a new process this fd is now automatically closed.
	fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
}

static const char g_HexDigits[] = "0123456789abcdef";

class CUtils {
public:
	CUtils();
	~CUtils();

	static CString GetIP(unsigned long addr);
	static unsigned long GetLongIP(const CString& sIP);

	static void PrintError(const CString& sMessage);
	static void PrintMessage(const CString& sMessage, bool bStrong = false);
	static void PrintPrompt(const CString& sMessage);
	static void PrintAction(const CString& sMessage);
	static void PrintStatus(bool bSuccess, const CString& sMessage = "");

#ifndef SWIGPERL
	// TODO refactor this
	static const CString sDefaultHash;
#endif

	static CString GetSaltedHashPass(CString& sSalt);
	static CString GetSalt();
	static CString SaltedMD5Hash(const CString& sPass, const CString& sSalt);
	static CString SaltedSHA256Hash(const CString& sPass, const CString& sSalt);
	static CString GetPass(const CString& sPrompt);
	static bool GetInput(const CString& sPrompt, CString& sRet, const CString& sDefault = "", const CString& sHint = "");
	static bool GetBoolInput(const CString& sPrompt, bool bDefault);
	static bool GetBoolInput(const CString& sPrompt, bool *pbDefault = NULL);
	static bool GetNumInput(const CString& sPrompt, unsigned int& uRet, unsigned int uMin = 0, unsigned int uMax = ~0, unsigned int uDefault = ~0);

	static unsigned long long GetMillTime() {
		struct timeval tv;
		unsigned long long iTime = 0;
		gettimeofday(&tv, NULL);
		iTime = (unsigned long long) tv.tv_sec * 1000;
		iTime += ((unsigned long long) tv.tv_usec / 1000);
		return iTime;
	}
#ifdef HAVE_LIBSSL
	static void GenerateCert(FILE *pOut, const CString& sHost = "");
#endif /* HAVE_LIBSSL */

	static CString CTime(time_t t, const CString& sTZ);
	static CString FormatTime(time_t t, const CString& sFormat, const CString& sTZ);
	static SCString GetTimezones();

private:
protected:
};

class CException {
public:
	typedef enum {
		EX_Shutdown,
		EX_Restart
	} EType;

	CException(EType e) {
		m_eType = e;
	}
	virtual ~CException() {}

	EType GetType() const { return m_eType; }
private:
protected:
	EType  m_eType;
};


/** Generate a grid-like output from a given input.
 *
 *  @code
 *  CTable table;
 *  table.AddColumn("a");
 *  table.AddColumn("b");
 *  table.AddRow();
 *  table.SetCell("a", "hello");
 *  table.SetCell("b", "world");
 *
 *  unsigned int idx = 0;
 *  CString tmp;
 *  while (table.GetLine(idx++, tmp)) {
 *      // Output tmp somehow
 *  }
 *  @endcode
 *
 *  The above code would generate the following output:
 *  @verbatim
+-------+-------+
| a     | b     |
+-------+-------+
| hello | world |
+-------+-------+@endverbatim
 */
class CTable : protected std::vector<std::vector<CString> > {
public:
	CTable() {}
	virtual ~CTable() {}

	/** Adds a new column to the table.
	 *  Please note that you should add all columns before starting to fill
	 *  the table!
	 *  @param sName The name of the column.
	 *  @return false if a column by that name already existed.
	 */
	bool AddColumn(const CString& sName);

	/** Adds a new row to the table.
	 *  After calling this you can fill the row with content.
	 *  @return The index of this row
	 */
	size_type AddRow();

	/** Sets a given cell in the table to a value.
	 *  @param sColumn The name of the column you want to fill.
	 *  @param sValue The value to write into that column.
	 *  @param uRowIdx The index of the row to use as returned by AddRow().
	 *                 If this is not given, the last row will be used.
	 *  @return True if setting the cell was successful.
	 */
	bool SetCell(const CString& sColumn, const CString& sValue, size_type uRowIdx = ~0);

	/** Get a line of the table's output
	 *  @param uIdx The index of the line you want.
	 *  @param sLine This string will receive the output.
	 *  @return True unless uIdx is past the end of the table.
	 */
	bool GetLine(unsigned int uIdx, CString& sLine) const;

	/** Return the width of the given column.
	 *  Please note that adding and filling new rows might change the
	 *  result of this function!
	 *  @param uIdx The index of the column you are interested in.
	 *  @return The width of the column.
	 */
	CString::size_type GetColumnWidth(unsigned int uIdx) const;

	/// Completely clear the table.
	void Clear();

	/// @return The number of rows in this table, not counting the header.
	using std::vector<std::vector<CString> >::size;

	/// @return True if this table doesn't contain any rows.
	using std::vector<std::vector<CString> >::empty;
private:
	unsigned int GetColumnIndex(const CString& sName) const;

protected:
	std::vector<CString>            m_vsHeaders;
	std::map<CString, CString::size_type> m_msuWidths;  // Used to cache the width of a column
};


#ifdef HAVE_LIBSSL
#include <openssl/aes.h>
#include <openssl/blowfish.h>
#include <openssl/md5.h>
//! does Blowfish w/64 bit feedback, no padding
class CBlowfish {
public:
	/**
	 * @param sPassword key to encrypt with
	 * @param iEncrypt encrypt method (BF_DECRYPT or BF_ENCRYPT)
	 * @param sIvec what to set the ivector to start with, default sets it all 0's
	 */
	CBlowfish(const CString & sPassword, int iEncrypt, const CString & sIvec = "");
	~CBlowfish();

	//! output must be freed
	static unsigned char *MD5(const unsigned char *input, u_int ilen);

	//! returns an md5 of the CString (not hex encoded)
	static CString MD5(const CString & sInput, bool bHexEncode = false);

	//! output must be the same size as input
	void Crypt(unsigned char *input, unsigned char *output, u_int ibytes);

	//! must free result
	unsigned char * Crypt(unsigned char *input, u_int ibytes);
	CString Crypt(const CString & sData);

private:
	unsigned char  *m_ivec;
	BF_KEY          m_bkey;
	int             m_iEncrypt, m_num;
};

#endif /* HAVE_LIBSSL */

/**
 * @class TCacheMap
 * @author prozac <prozac@rottenboy.com>
 * @brief Insert an object with a time-to-live and check later if it still exists
 */
template<typename K, typename V = bool>
class TCacheMap {
public:
	TCacheMap(unsigned int uTTL = 5000) {
		m_uTTL = uTTL;
	}

	virtual ~TCacheMap() {}

	/**
	 * @brief This function adds an item to the cache using the default time-to-live value
	 * @param Item the item to add to the cache
	 */
	void AddItem(const K& Item) {
		AddItem(Item, m_uTTL);
	}

	/**
	 * @brief This function adds an item to the cache using a custom time-to-live value
	 * @param Item the item to add to the cache
	 * @param uTTL the time-to-live for this specific item
	 */
	void AddItem(const K& Item, unsigned int uTTL) {
		AddItem(Item, V(), uTTL);
	}

	/**
	 * @brief This function adds an item to the cache using the default time-to-live value
	 * @param Item the item to add to the cache
	 * @param Val The value associated with the key Item
	 */
	void AddItem(const K& Item, const V& Val) {
		AddItem(Item, Val, m_uTTL);
	}

	/**
	 * @brief This function adds an item to the cache using a custom time-to-live value
	 * @param Item the item to add to the cache
	 * @param Val The value associated with the key Item
	 * @param uTTL the time-to-live for this specific item
	 */
	void AddItem(const K& Item, const V& Val, unsigned int uTTL) {
		if (!uTTL) {             // If time-to-live is zero we don't want to waste our time adding it
			RemItem(Item);   // Remove the item incase it already exists
			return;
		}

		m_mItems[Item] = value(CUtils::GetMillTime() + uTTL, Val);
	}

	/**
	 * @brief Performs a Cleanup() and then checks to see if your item exists
	 * @param Item The item to check for
	 * @return true if item exists
	 */
	bool HasItem(const K& Item) {
		Cleanup();
		return (m_mItems.find(Item) != m_mItems.end());
	}

	/**
	 * @brief Performs a Cleanup() and returns a pointer to the object, or NULL
	 * @param Item The item to check for
	 * @return Pointer to the item or NULL if there is no suitable one
	 */
	V* GetItem(const K& Item) {
		Cleanup();
		iterator it = m_mItems.find(Item);
		if (it == m_mItems.end())
			return NULL;
		return &it->second.second;
	}

	/**
	 * @brief Removes a specific item from the cache
	 * @param Item The item to be removed
	 * @return true if item existed and was removed, false if it never existed
	 */
	bool RemItem(const K& Item) {
		return m_mItems.erase(Item);
	}

	/**
	 * @brief Cycles through the queue removing all of the stale entries
	 */
	void Cleanup() {
		iterator it = m_mItems.begin();

		while (it != m_mItems.end()) {
			if (CUtils::GetMillTime() > (it->second.first)) {
				m_mItems.erase(it++);
			} else {
				++it;
			}
		}
	}

	/**
	 * @brief Clear all entries
	 */
	void Clear() {
		m_mItems.clear();
	}

	// Setters
	void SetTTL(unsigned int u) { m_uTTL = u; }
	// !Setters
	// Getters
	unsigned int GetTTL() const { return m_uTTL; }
	// !Getters
protected:
	typedef std::pair<unsigned long long, V> value;
	typedef typename std::map<K, value>::iterator iterator;
	std::map<K, value>   m_mItems;   //!< Map of cached items.  The value portion of the map is for the expire time
	unsigned int         m_uTTL;     //!< Default time-to-live duration
};

/**
 * @class CSmartPtr
 * @author prozac <prozac@rottenboy.com>
 * @brief This is a standard reference counting pointer.  Be careful not to have two of these point to the same raw pointer or one will be deleted while the other still thinks it is valid.
 */
template<typename T>
class CSmartPtr {
public:
	/**
	 * @brief Standard constructor, points to nothing
	 */
	CSmartPtr() {
		m_pType = NULL;
		m_puCount = NULL;
	}

	/**
	 * @brief Attach to an existing raw pointer, be CAREFUL not to have more than one CSmartPtr attach to the same raw pointer or bad things will happen
	 * @param pRawPtr The raw pointer to attach to
	 */
	CSmartPtr(T* pRawPtr) {
		m_pType = NULL;
		m_puCount = NULL;

		Attach(pRawPtr);
	}

	/**
	 * @brief Copy constructor, will copy the raw pointer and counter locations and increment the reference counter
	 * @param CopyFrom A reference of another CSmartPtr to copy from
	 */
	CSmartPtr(const CSmartPtr<T>& CopyFrom) {
		m_pType = NULL;
		m_puCount = NULL;

		*this = CopyFrom;
	}

	/**
	 * @brief Destructor will Release() the raw pointer and delete it if this was the last reference
	 */
	~CSmartPtr() {
		Release();
	}

	// Overloaded operators
	T& operator *() const { assert(m_pType); return *m_pType; }
	T* operator ->() const { assert(m_pType); return m_pType; }

	/**
	 * @brief Attach() to a raw pointer
	 * @param pRawPtr The raw pointer to keep track of, ***WARNING*** Do _NOT_ allow more than one CSmartPtr keep track of the same raw pointer
	 * @return Reference to self
	 */
	CSmartPtr<T>& operator =(T* pRawPtr) { Attach(pRawPtr); return *this; }

	/**
	 * @brief Copies an existing CSmartPtr adding another reference to the counter
	 * @param CopyFrom A reference to another CSmartPtr to be copied
	 * @return Reference to self
	 */
	CSmartPtr<T>& operator =(const CSmartPtr<T>& CopyFrom) {
		if (&CopyFrom != this) {              // Check for assignment to self
			Release();                    // Release the current pointer

			if (CopyFrom.IsNull()) {      // If the source raw pointer is null
				return *this;         // Then just bail out
			}

			m_pType = CopyFrom.m_pType;   // Make our pointers reference the same raw pointer and counter
			m_puCount = CopyFrom.m_puCount;

			assert(m_puCount);            // We now point to something valid, so increment the counter
			(*m_puCount)++;
		}

		return *this;
	}
	// !Overloaded operators

	/**
	 * @brief Implicit type conversion to bool for things like if (!ptr) {} and if (ptr) {}
	 * @return @see IsNull()
	 */
	operator bool() const {
		return !IsNull();
	}

	/**
	 * @brief Check to see if the underlying raw pointer is null
	 * @return Whether or not underlying raw pointer is null
	 */
	bool IsNull() const {
		return (m_pType == NULL);
	}

	/**
	 * @brief Attach to a given raw pointer, it will Release() the current raw pointer and assign the new one
	 * @param pRawPtr The raw pointer to keep track of, ***WARNING*** Do _NOT_ allow more than one CSmartPtr keep track of the same raw pointer
	 * @return Reference to self
	 */
	CSmartPtr<T>& Attach(T* pRawPtr) {
		if (pRawPtr != m_pType) {                        // Check for assignment to self
			Release();                               // Release the current pointer
			m_pType = pRawPtr;                       // Point to the passed raw pointer

			if (m_pType) {                           // If the passed pointer was valid
				m_puCount = new unsigned int(1); // Create a new counter starting at 1 (us)
			}
		}

		return *this;
	}

	/**
	 * @brief Releases the underlying raw pointer and cleans up if we were the last reference to said pointer
	 */
	void Release() {
		if (m_pType) {              // Only release if there is something to be released
			assert(m_puCount);
			(*m_puCount)--;     // Decrement our counter

			if (!*m_puCount) {  // If we were the last reference to this pointer, then clean up
				delete m_puCount;
				delete m_pType;
			}

			m_pType = NULL;     // Get rid of our references
			m_puCount = NULL;
		}
	}

	// Getters
	T* GetPtr() const { return m_pType; }
	unsigned int GetCount() const { return (m_puCount) ? *m_puCount : 0; }
	// !Getters
private:
	T*            m_pType;      //!< Raw pointer to the class being referenced
	unsigned int* m_puCount;    //!< Counter of how many CSmartPtr's are referencing the same raw pointer
};

template<typename T>
bool operator ==(T* lhs, const CSmartPtr<T>& rhs) { return (lhs == rhs.GetPtr()); }

template<typename T>
bool operator ==(const CSmartPtr<T>& lhs, T* rhs) { return (lhs.GetPtr() == rhs); }

template<typename T>
bool operator ==(const CSmartPtr<T>& lhs, const CSmartPtr<T>& rhs) { return (lhs.GetPtr() == rhs.GetPtr()); }

#endif // !_UTILS_H