#ifndef __DERIVATIONS_H
#define __DERIVATIONS_H

#include <map>

#include "types.hh"
#include "hash.hh"


namespace nix {


/* Extension of derivations in the Nix store. */
const string drvExtension = ".drv";


/* Abstract syntax of derivations. */

struct DerivationOutput
{
    Path path;
    string hashAlgo; /* hash used for expected hash computation */
    string hash; /* expected hash, may be null */
    DerivationOutput()
    {
    }
    DerivationOutput(Path path, string hashAlgo, string hash)
    {
        this->path = path;
        this->hashAlgo = hashAlgo;
        this->hash = hash;
    }
    void parseHashInfo(bool & recursive, HashType & hashType, Hash & hash) const;
};

typedef std::map<string, DerivationOutput> DerivationOutputs;

/* For inputs that are sub-derivations, we specify exactly which
   output IDs we are interested in. */
typedef std::map<Path, StringSet> DerivationInputs;

typedef std::map<string, string> StringPairs;

struct Derivation
{
    DerivationOutputs outputs; /* keyed on symbolic IDs */
    DerivationInputs inputDrvs; /* inputs that are sub-derivations */
    PathSet inputSrcs; /* inputs that are sources */
    string platform;
    Path builder;
    Strings args;
    StringPairs env;
};


/* Write a derivation to the Nix store, and return its path. */
Path writeDerivation(const Derivation & drv, const string & name);

/* Parse a derivation. */
Derivation parseDerivation(const string & s);

/* Print a derivation. */
string unparseDerivation(const Derivation & drv);

/* Check whether a file name ends with the extensions for
   derivations. */
bool isDerivation(const string & fileName);

/* Return true iff this is a fixed-output derivation. */
bool isFixedOutputDrv(const Derivation & drv);

Hash hashDerivationModulo(Derivation drv);

/* Memoisation of hashDerivationModulo(). */
typedef std::map<Path, Hash> DrvHashes;

extern DrvHashes drvHashes;

}


#endif /* !__DERIVATIONS_H */