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

#include <bpkg/pkg-command.hxx>

#include <libbutl/path-pattern.hxx>

#include <libbuild2/file.hxx>
#include <libbuild2/context.hxx>

#include <bpkg/package.hxx>
#include <bpkg/package-odb.hxx>
#include <bpkg/database.hxx>
#include <bpkg/diagnostics.hxx>
#include <bpkg/manifest-utility.hxx>

using namespace std;
using namespace butl;

namespace bpkg
{
  void
  pkg_command (const string& cmd,
               const common_options& o,
               const string& cmd_v,
               const strings& cvars,
               const vector<pkg_command_vars>& ps)
  {
    tracer trace ("pkg_command");

    l4 ([&]{trace << "command: " << cmd;});

    // This one is a bit tricky: we can only update all the packages at once
    // if they don't have any package-specific variables and don't require to
    // change the current working directory to the package directory. But
    // let's try to handle this with the same logic (being clever again).
    //
    string bspec;

    auto run = [&trace, &o, &cvars, &bspec] (const strings& vars = strings ())
    {
      if (!bspec.empty ())
      {
        bspec += ')';
        l4 ([&]{trace << "buildspec: " << bspec;});

        run_b (o,
               verb_b::normal,
               (o.jobs_specified ()
                ? strings ({"-j", to_string (o.jobs ())})
                : strings ()),
               cvars,
               vars,
               bspec);

        bspec.clear ();
      }
    };

    unique_ptr<build2::context> ctx; // Create lazily.

    for (const pkg_command_vars& pv: ps)
    {
      if (!pv.vars.empty () || pv.cwd)
        run (); // Run previously collected packages.

      if (bspec.empty ())
      {
        bspec = cmd;

        if (!cmd_v.empty ())
        {
          bspec += "-for-";
          bspec += cmd_v;
        }

        bspec += '(';
      }

      const shared_ptr<selected_package>& p (pv.pkg);

      assert (p->state == package_state::configured &&
              p->substate != package_substate::system);
      assert (p->out_root &&
              p->src_root); // Should be present since configured, not system.

      dir_path out_root (p->effective_out_root (pv.config_orig));
      l4 ([&]{trace << p->name << " out_root: " << out_root;});

      // Figure out if the source directory is forwarded to this out_root. If
      // it is, then we need to build via src_root. Failed that, backlinks
      // won't be created.
      //
      if (*p->out_root != *p->src_root)
      {
        dir_path src_root (p->effective_src_root (pv.config_orig));

        // For us to switch to src_root, it should not only be configured as
        // forwarded, but also be forwarded to our out_root. So we actually
        // need to first check if the build/bootstrap/out-root.build (or its
        // alt naming equivalent) exists and, if so, extract the out_root
        // value and compare it to ours. This is all done by bootstrap_fwd()
        // from libbuild2 so seeing that we act as a special build system
        // driver, we might as well use that. Note that this could potentially
        // be improved by only creating context if the file exists.
        //
        try
        {
          if (ctx == nullptr)
            ctx.reset (new build2::context ());

          optional<bool> altn;
          if (build2::bootstrap_fwd (*ctx, src_root, altn) == out_root)
          {
            out_root = move (src_root);
            l4 ([&]{trace << p->name << " src_root: " << out_root;});
          }
        }
        catch (const build2::failed&)
        {
          throw failed (); // Assume the diagnostics has already been issued.
        }
      }

      if (bspec.back () != '(')
        bspec += ' ';

      // Use path representation to get canonical trailing slash.
      //
      bspec += '\'';
      bspec += (!pv.cwd ? out_root : current_dir).representation ();
      bspec += '\'';

      if (!pv.vars.empty () || pv.cwd)
      {
        // Run this package, changing the current working directory to the
        // package directory, if requested. Note that we do it this way
        // instead of changing the working directory of the process for
        // diagnostics.
        //
        auto owdg = make_guard (
          [owd = pv.cwd ? change_wd (out_root) : dir_path ()] ()
          {
            if (!owd.empty ())
              change_wd (owd);
          });

        run (pv.vars);
      }
    }

    run ();
  }

  static void
  collect_dependencies (const shared_ptr<selected_package>& p,
                        bool recursive,
                        bool package_cwd,
                        vector<pkg_command_vars>& ps,
                        bool allow_host_type)
  {
    for (const auto& pr: p->prerequisites)
    {
      if (!allow_host_type)
      {
        database& db (pr.first.database ());

        if (db.type == host_config_type || db.type == build2_config_type)
          continue;
      }

      shared_ptr<selected_package> d (pr.first.load ());

      // The selected package can only be configured if all its dependencies
      // are configured.
      //
      assert (d->state == package_state::configured);

      // Skip configured as system and duplicate dependencies.
      //
      if (d->substate != package_substate::system &&
          find_if (ps.begin (), ps.end (),
                   [&d] (const pkg_command_vars& i) {return i.pkg == d;}) ==
          ps.end ())
      {
        database& db (pr.first.database ());

        // Note: no package-specific variables (global ones still apply).
        //
        ps.push_back (
          pkg_command_vars {
            db.config_orig,
            db.main (),
            d,
            strings () /* vars */,
            package_cwd});

        if (recursive)
          collect_dependencies (d,
                                recursive,
                                package_cwd,
                                ps,
                                allow_host_type);
      }
    }
  }

  int
  pkg_command (const string& cmd,
               const configuration_options& o,
               const string& cmd_v,
               bool recursive,
               bool immediate,
               bool all,
               const strings& all_patterns,
               bool package_cwd,
               bool allow_host_type,
               cli::group_scanner& args)
  {
    tracer trace ("pkg_command");

    const dir_path& c (o.directory ());
    l4 ([&]{trace << "configuration: " << c;});

    // First sort arguments into the package names and variables.
    //
    strings cvars;
    bool sep (false); // Seen '--'.

    struct pkg_arg
    {
      package_name name;
      strings      vars;
    };
    vector<pkg_arg> pkg_args;

    while (args.more ())
    {
      string a (args.next ());

      // If we see the "--" separator, then we are done parsing common
      // variables.
      //
      if (!sep && a == "--")
      {
        sep = true;
        continue;
      }

      if (!sep && a.find ('=') != string::npos)
      {
        // Make sure this is not a (misspelled) package name with an option
        // group.
        //
        if (args.group ().more ())
          fail << "unexpected options group for variable '" << a << "'";

        cvars.push_back (move (trim (a)));
      }
      else
      {
        package_name n (parse_package_name (a, false /* allow_version */));

        // Read package-specific variables.
        //
        strings vars;
        for (cli::scanner& ag (args.group ()); ag.more (); )
        {
          string a (ag.next ());
          if (a.find ('=') == string::npos)
            fail << "unexpected group argument '" << a << "'";

          vars.push_back (move (trim (a)));
        }

        pkg_args.push_back (pkg_arg {move (n), move (vars)});
      }
    }

    // Check that options and arguments are consistent.
    //
    // Note that we can as well count on the option names that correspond to
    // the immediate, recursive, all, and all_patterns parameters.
    //
    {
      diag_record dr;

      if (immediate && recursive)
        dr << fail << "both --immediate|-i and --recursive|-r specified";
      else if (all)
      {
        if (!all_patterns.empty ())
          dr << fail << "both --all|-a and --all-pattern specified";

        if (!pkg_args.empty ())
          dr << fail << "both --all|-a and package argument specified";
      }
      else if (!all_patterns.empty ())
      {
        if (!pkg_args.empty ())
          dr << fail << "both --all-pattern and package argument specified";
      }
      else if (pkg_args.empty ())
        dr << fail << "package name argument expected";

      if (!dr.empty ())
        dr << info << "run 'bpkg help pkg-" << cmd << "' for more information";
    }

    vector<pkg_command_vars> ps;
    {
      database db (c, trace, true /* pre_attach */);

      if (!allow_host_type && (db.type == host_config_type ||
                               db.type == build2_config_type))
      {
        fail << "unable to " << cmd << " from " << db.type
             << " configuration" <<
          info << "use target configuration instead";
      }

      transaction t (db);

      // We need to suppress duplicate dependencies for the recursive command
      // execution.
      //
      session ses;

      auto add =
        [&db, &ps, allow_host_type, recursive, immediate, package_cwd] (
        const shared_ptr<selected_package>& p,
        strings vars)
      {
        ps.push_back (
          pkg_command_vars {db.config_orig,
                            db.main (),
                            p,
                            move (vars),
                            package_cwd});

        // Note that it can only be recursive or immediate but not both.
        //
        if (recursive || immediate)
          collect_dependencies (p,
                                recursive,
                                package_cwd,
                                ps,
                                allow_host_type);
      };

      if (all || !all_patterns.empty ())
      {
        using query = query<selected_package>;

        query q (query::hold_package          &&
                 query::state == "configured" &&
                 query::substate != "system");

        for (shared_ptr<selected_package> p:
               pointer_result (db.query<selected_package> (q)))
        {
          l4 ([&]{trace << *p;});

          if (!all_patterns.empty ())
          {
            for (const string& pat: all_patterns)
            {
              if (path_match (p->name.string (), pat))
              {
                add (p, strings ());
                break;
              }
            }
          }
          else // --all
            add (p, strings ());
        }

        if (ps.empty ())
          info << "nothing to " << cmd;
      }
      else
      {
        for (auto& a: pkg_args)
        {
          shared_ptr<selected_package> p (db.find<selected_package> (a.name));

          if (p == nullptr)
            fail << "package " << a.name << " does not exist in "
                 << "configuration " << c;

          if (p->state != package_state::configured)
            fail << "package " << a.name << db << " is " << p->state <<
              info << "expected it to be configured";

          if (p->substate == package_substate::system)
            fail << "cannot " << cmd << " system package " << a.name << db;

          l4 ([&]{trace << *p << db;});

          add (p, move (a.vars));
        }
      }

      t.commit ();
    }

    pkg_command (cmd, o, cmd_v, cvars, ps);

    if (verb && !o.no_result ())
    {
      for (const pkg_command_vars& pv: ps)
        text << cmd << (cmd.back () != 'e' ? "ed " : "d ") << pv.string ();
    }

    return 0;
  }

  // pkg_command_vars
  //
  string pkg_command_vars::
  string () const
  {
    std::string r (pkg->string ());

    if (!config_main)
      r += " [" + config_orig.representation () + ']';

    return r;
  }
}