#include <algorithm>
#include <array>

#include "libmain/common-args.hh"
#include "libmain/shared.hh"
#include "libstore/store-api.hh"
#include "libutil/json.hh"
#include "nix/command.hh"

using namespace nix;

struct CmdPathInfo final : StorePathsCommand, MixJSON {
  bool showSize = false;
  bool showClosureSize = false;
  bool humanReadable = false;
  bool showSigs = false;

  CmdPathInfo() {
    mkFlag('s', "size", "print size of the NAR dump of each path", &showSize);
    mkFlag('S', "closure-size",
           "print sum size of the NAR dumps of the closure of each path",
           &showClosureSize);
    mkFlag('h', "human-readable",
           "with -s and -S, print sizes like 1K 234M 5.67G etc.",
           &humanReadable);
    mkFlag(0, "sigs", "show signatures", &showSigs);
  }

  std::string name() override { return "path-info"; }

  std::string description() override {
    return "query information about store paths";
  }

  Examples examples() override {
    return {
        Example{"To show the closure sizes of every path in the current NixOS "
                "system closure, sorted by size:",
                "nix path-info -rS /run/current-system | sort -nk2"},
        Example{"To show a package's closure size and all its dependencies "
                "with human readable sizes:",
                "nix path-info -rsSh nixpkgs.rust"},
        Example{"To check the existence of a path in a binary cache:",
                "nix path-info -r /nix/store/7qvk5c91...-geeqie-1.1 --store "
                "https://cache.nixos.org/"},
        Example{"To print the 10 most recently added paths (using --json and "
                "the jq(1) command):",
                "nix path-info --json --all | jq -r "
                "'sort_by(.registrationTime)[-11:-1][].path'"},
        Example{"To show the size of the entire Nix store:",
                "nix path-info --json --all | jq 'map(.narSize) | add'"},
        Example{"To show every path whose closure is bigger than 1 GB, sorted "
                "by closure size:",
                "nix path-info --json --all -S | jq 'map(select(.closureSize > "
                "1e9)) | sort_by(.closureSize) | map([.path, .closureSize])'"},
    };
  }

  void printSize(unsigned long long value) {
    if (!humanReadable) {
      std::cout << fmt("\t%11d", value);
      return;
    }

    static const std::array<char, 9> idents{
        {' ', 'K', 'M', 'G', 'T', 'P', 'E', 'Z', 'Y'}};
    size_t power = 0;
    double res = value;
    while (res > 1024 && power < idents.size()) {
      ++power;
      res /= 1024;
    }
    std::cout << fmt("\t%6.1f%c", res, idents.at(power));
  }

  void run(ref<Store> store, Paths storePaths) override {
    size_t pathLen = 0;
    for (auto& storePath : storePaths) {
      pathLen = std::max(pathLen, storePath.size());
    }

    if (json) {
      JSONPlaceholder jsonRoot(std::cout);
      store->pathInfoToJSON(jsonRoot,
                            // FIXME: preserve order?
                            PathSet(storePaths.begin(), storePaths.end()), true,
                            showClosureSize, AllowInvalid);
    }

    else {
      for (auto storePath : storePaths) {
        auto info = store->queryPathInfo(storePath);
        storePath = info->path;  // FIXME: screws up padding

        std::cout << storePath;

        if (showSize || showClosureSize || showSigs) {
          std::cout << std::string(
              std::max(0, (int)pathLen - (int)storePath.size()), ' ');
        }

        if (showSize) {
          printSize(info->narSize);
        }

        if (showClosureSize) {
          printSize(store->getClosureSize(storePath).first);
        }

        if (showSigs) {
          std::cout << '\t';
          Strings ss;
          if (info->ultimate) {
            ss.push_back("ultimate");
          }
          if (!info->ca.empty()) {
            ss.push_back("ca:" + info->ca);
          }
          for (auto& sig : info->sigs) {
            ss.push_back(sig);
          }
          std::cout << concatStringsSep(" ", ss);
        }

        std::cout << std::endl;
      }
    }
  }
};

static RegisterCommand r1(make_ref<CmdPathInfo>());