#pragma once

#include <gcrypt.h>

#include "types.hh"
#include "serialise.hh"


namespace nix {


extern const string base32Chars;

typedef enum {
    htUnknown = 0,
    htMD5 = GCRY_MD_MD5,
    htSHA1 = GCRY_MD_SHA1,
    htSHA256 = GCRY_MD_SHA256,
    htSHA512 = GCRY_MD_SHA512,
    htSHA3_256 = GCRY_MD_SHA3_256,
    htSHA3_512 = GCRY_MD_SHA3_512,
    htBLAKE2s_256 = GCRY_MD_BLAKE2S_256
} HashType;

struct Hash
{
    static const unsigned int maxHashSize = 64;
    unsigned int hashSize;
    unsigned char hash[maxHashSize];

    HashType type;

    /* Create an unusable hash object. */
    Hash();

    /* Create a zero-filled hash object. */
    Hash(HashType type);

    /* Check whether two hash are equal. */
    bool operator == (const Hash & h2) const;

    /* Check whether two hash are not equal. */
    bool operator != (const Hash & h2) const;

    /* For sorting. */
    bool operator < (const Hash & h) const;
};


/* Convert a hash to a hexadecimal representation. */
string printHash(const Hash & hash);

/* Parse a hexadecimal representation of a hash code. */
Hash parseHash(HashType ht, const string & s);

/* Returns the length of a base-32 hash representation. */
unsigned int hashLength32(const Hash & hash);

/* Convert a hash to a base-32 representation. */
string printHash32(const Hash & hash);

/* Print a hash in base-16 if it's MD5, or base-32 otherwise. */
string printHash16or32(const Hash & hash);

/* Parse a base-32 representation of a hash code. */
Hash parseHash32(HashType ht, const string & s);

/* Parse a base-16 or base-32 representation of a hash code. */
Hash parseHash16or32(HashType ht, const string & s);

/* Verify that the given string is a valid hash code. */
bool isHash(const string & s);

/* Compute the hash of the given string. */
Hash hashString(HashType ht, const string & s);

/* Compute the hash of the given file. */
Hash hashFile(HashType ht, const Path & path);

/* Compute the hash of the given path.  The hash is defined as
   (essentially) hashString(ht, dumpPath(path)). */
struct PathFilter;
extern PathFilter defaultPathFilter;
typedef std::pair<Hash, unsigned long long> HashResult;
HashResult hashPath(HashType ht, const Path & path,
    PathFilter & filter = defaultPathFilter);

/* Compress a hash to the specified number of bytes by cyclically
   XORing bytes together. */
Hash compressHash(const Hash & hash, unsigned int newSize);

/* Parse a string representing a hash type. */
HashType parseHashType(const string & s);

/* And the reverse. */
string printHashType(HashType ht);


struct Ctx;

class HashSink : public BufferedSink
{
private:
    HashType ht;
    Ctx * ctx;
    unsigned long long bytes;

public:
    HashSink(HashType ht);
    HashSink(const HashSink & h);
    ~HashSink();
    void write(const unsigned char * data, size_t len);
    HashResult finish();
    HashResult currentHash();
};


}
ef='/guix/commit/AUTHORS?id=e7c48ee9519aa5cd094f3326a4caeccba072e9fd'>Clean up 'THANKS' and 'AUTHORS'.</a><span class='msg-avail'>...<span class='msg-tooltip'>* THANKS: Add Konrad Hinsen, Cyprien Nicolas, Yakkala Yagnesh Raghava
  and Alexander Shendi.  Remove Federico Beffa, Marek Benc, John
  Darrington, rekado, Cyrill Schenkel and Andy Wingo because they are
  placed in AUTHORS.  Move Amirouche Boubekki and Alex Kost to ...
* AUTHORS: ... here.  Add Arne Babenhauserheide, Ian Denhardt, Kevin
  Lemonnier, Mathieu Lirzin, Pierre-Antoine Rault and Ben Woodcroft.
  Fix some names and emails.
</span></span></td><td>Alex Kost</td></tr>
<tr><td><span title='2015-06-27 20:26:06 +0300'>2015-06-27</span></td><td><a href='/guix/commit/AUTHORS?id=1d642af9872949633b1084f53352f3c851f41810'>Add Claes Wallin to 'AUTHORS'.</a></td><td>Alex Kost</td></tr>
<tr><td><span title='2015-04-26 21:38:37 -0400'>2015-04-26</span></td><td><a href='/guix/commit/AUTHORS?id=6bc24063155d897c6c80a192e48bd9f61cb9014e'>gnu: Add guile-minikanren.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/packages/guile.scm (guile-minikanren): New variable.
</span></span></td><td>Christopher Allan Webber</td></tr>