// file      : bpkg/pkg-verify.cxx -*- C++ -*-
// license   : MIT; see accompanying LICENSE file

#include <bpkg/pkg-verify.hxx>

#include <iostream> // cout

#include <libbutl/manifest-parser.hxx>
#include <libbutl/manifest-serializer.hxx>

#include <bpkg/archive.hxx>
#include <bpkg/diagnostics.hxx>
#include <bpkg/satisfaction.hxx>
#include <bpkg/manifest-utility.hxx>

using namespace std;
using namespace butl;

namespace bpkg
{
  vector<manifest_name_value>
  pkg_verify (const common_options& co,
              manifest_parser& p,
              const path& what,
              int diag_level)
  {
    manifest_name_value nv (p.next ());

    // Make sure this is the start and we support the version.
    //
    if (!nv.name.empty ())
      throw manifest_parsing (p.name (), nv.name_line, nv.name_column,
                              "start of package manifest expected");

    if (nv.value != "1")
      throw manifest_parsing (p.name (), nv.value_line, nv.value_column,
                              "unsupported format version");

    vector<manifest_name_value> r;

    // For the depends name, parse the value and if it contains the build2 or
    // bpkg constraints, verify that they are satisfied.
    //
    // Note that if the semantics of the depends value changes we may be
    // unable to parse some of them before we get to build2 or bpkg and issue
    // the user-friendly diagnostics. So we are going to ignore such depends
    // values. But that means that if the user made a mistake in build2/bpkg
    // then we will skip them as well. This, however, is not a problem since
    // the pre-parsed result will then be re-parsed (e.g., by the
    // package_manifest() constructor) which will diagnose any mistakes.
    //
    for (nv = p.next (); !nv.empty (); nv = p.next ())
    {
      if (nv.name == "depends")
      try
      {
        dependency_alternatives da (nv.value);

        if (da.buildtime)
        {
          for (dependency& d: da)
          {
            const package_name& dn (d.name);

            if (dn != "build2" && dn != "bpkg")
              continue;

            if (da.size () != 1)
            {
              if (diag_level != 0)
                error (p.name (), nv.value_line, nv.value_column)
                  << "alternatives in " << dn << " dependency";

              throw failed ();
            }

            if (dn == "build2")
            {
              if (d.constraint && !satisfy_build2 (co, d))
              {
                if (diag_level != 0)
                {
                  diag_record dr (error);
                  dr << "unable to satisfy constraint (" << d << ")";

                  if (!what.empty ())
                    dr << " for package " << what;

                  dr << info << "available build2 version is "
                     << build2_version;
                }

                throw failed ();
              }
            }
            else
            {
              if (d.constraint && !satisfy_bpkg (co, d))
              {
                if (diag_level != 0)
                {
                  diag_record dr (error);
                  dr << "unable to satisfy constraint (" << d << ")";

                  if (!what.empty ())
                    dr << " for package " << what;

                  dr << "available bpkg version is " << bpkg_version;
                }

                throw failed ();
              }
            }
          }
        }
      }
      catch (const invalid_argument&) {} // Ignore

      r.push_back (move (nv));
    }

    // Make sure this is the end.
    //
    nv = p.next ();
    if (!nv.empty ())
      throw manifest_parsing (p.name (), nv.name_line, nv.name_column,
                              "single package manifest expected");

    return r;
  }

  package_manifest
  pkg_verify (const common_options& co,
              const path& af,
              bool iu,
              bool ev,
              bool cd,
              int diag_level)
  try
  {
    dir_path pd (package_dir (af));
    path mf (pd / manifest_file);

    // If the diag level is less than 2, we need to make tar not print any
    // diagnostics. There doesn't seem to be an option to suppress this and
    // the only way is to redirect stderr to something like /dev/null.
    //
    // If things go badly for tar and it starts spitting errors instead of the
    // manifest, the manifest parser will fail. But that's ok since we assume
    // that the child error is always the reason for the manifest parsing
    // failure.
    //
    pair<process, process> pr (start_extract (co, af, mf, diag_level == 2));

    auto wait = [&pr] () {return pr.second.wait () && pr.first.wait ();};

    try
    {
      ifdstream is (move (pr.second.in_ofd), fdstream_mode::skip);
      manifest_parser mp (is, mf.string ());

      package_manifest m (mp.name (),
                          pkg_verify (co, mp, af, diag_level),
                          iu,
                          cd);
      is.close ();

      if (wait ())
      {
        // Verify package archive/directory is <name>-<version>.
        //
        dir_path ed (m.name.string () + "-" + m.version.string ());

        if (pd != ed)
        {
          if (diag_level != 0)
            error << "package archive/directory name mismatch in " << af <<
              info << "extracted from archive '" << pd << "'" <<
              info << "expected from manifest '" << ed << "'";

          throw failed ();
        }

        // Expand the *-file manifest values, if requested.
        //
        if (ev)
        {
          m.load_files (
            [&pd, &co, &af, diag_level] (const string& n, const path& p)
            {
              path f (pd / p);
              string s (extract (co, af, f, diag_level != 0));

              if (s.empty ())
              {
                if (diag_level != 0)
                  error << n << " manifest value in package archive "
                        << af << " references empty file " << f;

                throw failed ();
              }

              return s;
            },
            iu);
        }

        return m;
      }

      // Child exited with an error, fall through.
    }
    // Ignore these exceptions if the child process exited with
    // an error status since that's the source of the failure.
    //
    catch (const manifest_parsing& e)
    {
      if (wait ())
      {
        if (diag_level != 0)
          error (e.name, e.line, e.column) << e.description <<
            info << "package archive " << af;

        throw failed ();
      }
    }
    catch (const io_error&)
    {
      if (wait ())
      {
        if (diag_level != 0)
          error << "unable to extract " << mf << " from " << af;

        throw failed ();
      }
    }

    // We should only get here if the child exited with an error
    // status.
    //
    assert (!wait ());

    // While it is reasonable to assuming the child process issued
    // diagnostics, tar, specifically, doesn't mention the archive
    // name.
    //
    if (diag_level == 2)
      error << af << " does not appear to be a bpkg package";

    throw not_package ();
  }
  catch (const process_error& e)
  {
    // Note: this is not an "invalid package" case, so no diag check.
    //
    fail << "unable to extract manifest file from " << af << ": " << e
         << endf;
  }

  package_manifest
  pkg_verify (const common_options& co,
              const dir_path& d,
              bool iu,
              const function<package_manifest::translate_function>& tf,
              int diag_level)
  {
    // Parse the manifest.
    //
    path mf (d / manifest_file);

    if (!exists (mf))
    {
      if (diag_level == 2)
        error << "no manifest file in package directory " << d;

      throw not_package ();
    }

    try
    {
      ifdstream ifs (mf);
      manifest_parser mp (ifs, mf.string ());

      package_manifest m (mp.name (),
                          pkg_verify (co, mp, d, diag_level),
                          tf,
                          iu);

      // We used to verify package directory is <name>-<version> but it is
      // not clear why we should enforce it in this case (i.e., the user
      // provides us with a package directory).
      //
      // dir_path ed (m.name + "-" + m.version.string ());
      //
      // if (d.leaf () != ed)
      // {
      //   if (diag_level != 0)
      //     error << "invalid package directory name '" << d.leaf () << "'" <<
      //       info << "expected from manifest '" << ed << "'";
      //
      //   throw failed ();
      // }

      return m;
    }
    catch (const manifest_parsing& e)
    {
      if (diag_level != 0)
        error (e.name, e.line, e.column) << e.description;

      throw failed ();
    }
    catch (const io_error& e)
    {
      if (diag_level != 0)
        error << "unable to read from " << mf << ": " << e;

      throw failed ();
    }
  }

  int
  pkg_verify (const pkg_verify_options& o, cli::scanner& args)
  {
    tracer trace ("pkg_verify");

    if (!args.more ())
      fail << "archive path argument expected" <<
        info << "run 'bpkg help pkg-verify' for more information";

    path a (args.next ());

    if (!exists (a))
      fail << "archive file '" << a << "' does not exist";

    l4 ([&]{trace << "archive: " << a;});

    // If we were asked to run silent, don't yap about the reason
    // why the package is invalid. Just return the error status.
    //
    try
    {
      package_manifest m (pkg_verify (o,
                                      a,
                                      o.ignore_unknown (),
                                      o.deep () /* expand_values */,
                                      o.deep () /* complete_depends */,
                                      o.silent () ? 0 : 2));

      if (o.manifest ())
      {
        try
        {
          manifest_serializer s (cout, "stdout");
          m.serialize (s);
        }
        catch (const manifest_serialization& e)
        {
          fail << "unable to serialize manifest: " << e.description;
        }
        catch (const io_error&)
        {
          fail << "unable to write to stdout";
        }
      }
      else if (verb && !o.silent () && !o.no_result ())
        text << "valid package " << m.name << " " << m.version;

      return 0;
    }
    catch (const failed& e)
    {
      return e.code;
    }
  }
}