#pragma once

#include <map>
#include "hash.hh"
#include "store-api.hh"
#include "types.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, 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 BasicDerivation {
  DerivationOutputs outputs; /* keyed on symbolic IDs */
  PathSet inputSrcs;         /* inputs that are sources */
  string platform;
  Path builder;
  Strings args;
  StringPairs env;

  virtual ~BasicDerivation(){};

  /* Return the path corresponding to the output identifier `id' in
     the given derivation. */
  Path findOutput(const string& id) const;

  bool isBuiltin() const;

  /* Return true iff this is a fixed-output derivation. */
  bool isFixedOutput() const;

  /* Return the output paths of a derivation. */
  PathSet outputPaths() const;
};

struct Derivation : BasicDerivation {
  DerivationInputs inputDrvs; /* inputs that are sub-derivations */

  /* Print a derivation. */
  std::string unparse() const;
};

class Store;

/* Write a derivation to the Nix store, and return its path. */
Path writeDerivation(ref<Store> store, const Derivation& drv,
                     const string& name, RepairFlag repair = NoRepair);

/* Read a derivation from a file. */
Derivation readDerivation(const Path& drvPath);

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

Hash hashDerivationModulo(Store& store, Derivation drv);

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

extern DrvHashes drvHashes;  // FIXME: global, not thread-safe

/* Split a string specifying a derivation and a set of outputs
   (/nix/store/hash-foo!out1,out2,...) into the derivation path and
   the outputs. */
typedef std::pair<string, std::set<string> > DrvPathWithOutputs;
DrvPathWithOutputs parseDrvPathWithOutputs(const string& s);

Path makeDrvPathWithOutputs(const Path& drvPath,
                            const std::set<string>& outputs);

bool wantOutput(const string& output, const std::set<string>& wanted);

struct Source;
struct Sink;

Source& readDerivation(Source& in, Store& store, BasicDerivation& drv);
Sink& operator<<(Sink& out, const BasicDerivation& drv);

std::string hashPlaceholder(const std::string& outputName);

}  // namespace nix