Add support for --stdout-format to bdep-status command

8 files changed, 466 insertions, 89 deletions

diff --git a/bdep/common.cli b/bdep/common.cli
index cdf0e2c..1e95084 100644
--- a/bdep/common.cli
+++ b/bdep/common.cli
@@ -78,6 +78,14 @@ namespace bdep
        \li|Even more detailed information.||"
     }
 
+    bdep::stdout_format --stdout-format = bdep::stdout_format::lines
+    {
+      "<format>",
+      "Representation format to use for printing to \cb{stdout}. Valid values
+       for this option are \cb{lines} (default) and \cb{json}. See the JSON
+       OUTPUT section below for details on the \cb{json} format."
+    }
+
     size_t --jobs|-j
     {
       "<num>",
@@ -231,4 +239,72 @@ namespace bdep
       "Don't load default options files."
     }
   };
+
+  {
+    "",
+    "
+    \h|JSON OUTPUT|
+
+    Commands that support the JSON output specify their formats as a
+    serialized representation of a C++ \cb{struct} or an array thereof. For
+    example:
+
+    \
+    struct package
+    {
+      string name;
+    };
+
+    struct configuration
+    {
+      uint64_t         id;
+      string           path;
+      optional<string> name;
+      bool             default;
+      vector<package>  packages;
+    };
+    \
+
+    An example of the serialized JSON representation of \cb{struct}
+    \cb{configuration}:
+
+    \
+    {
+      \"id\": 1,
+      \"path\": \"/tmp/hello-gcc\",
+      \"name\": \"gcc\",
+      \"default\": true,
+      \"packages\": [
+        {
+          \"name\": \"hello\"
+        }
+      ]
+    }
+    \
+
+    This sections provides details on the overall properties of such formats
+    and the semantics of the \cb{struct} serialization.
+
+    The order of members in a JSON object is fixed as specified in the
+    corresponding \cb{struct}. While new members may be added in the
+    future (and should be ignored by older consumers), the semantics of the
+    existing members (including whether the top-level entry is an object or
+    array) may not change.
+
+    An object member is required unless its type is \cb{optional<>},
+    \cb{bool}, or \cb{vector<>} (array). For \cb{bool} members absent means
+    \cb{false}. For \cb{vector<>} members absent means empty. An empty
+    top-level array is always present.
+
+    For example, the following JSON text is a possible serialization of
+    the above \cb{struct} \cb{configuration}:
+
+    \
+    {
+      \"id\": 1,
+      \"path\": \"/tmp/hello-gcc\"
+    }
+    \
+    "
+  }
 }
diff --git a/bdep/config.cli b/bdep/config.cli
index 7181ebc..ac67a54 100644
--- a/bdep/config.cli
+++ b/bdep/config.cli
@@ -132,8 +132,8 @@ namespace bdep
          The \cb{list} subcommand prints the list of build configurations
          associated with the project. Unless one or more configurations are
          specified explicitly, \cb{list} prints all the associate
-         configurations. Note that the output is written to \cb{STDOUT}, not
-         \cb{STDERR}.|
+         configurations. Note that the output is written to \cb{stdout}, not
+         \cb{stderr}.|
 
      \li|\cb{move}
 
diff --git a/bdep/options-types.hxx b/bdep/options-types.hxx
index fffb2a4..3c2a792 100644
--- a/bdep/options-types.hxx
+++ b/bdep/options-types.hxx
@@ -6,6 +6,11 @@
 
 namespace bdep
 {
+  enum class stdout_format
+  {
+    lines,
+    json
+  };
 }
 
 #endif // BDEP_OPTIONS_TYPES_HXX
diff --git a/bdep/status.cli b/bdep/status.cli
index 38e70e0..7abd7f3 100644
--- a/bdep/status.cli
+++ b/bdep/status.cli
@@ -42,10 +42,76 @@ namespace bdep
      \c{\b{--immediate}|\b{-i}} or \c{\b{--recursive}|\b{-r}} options,
      respectively.
 
-     The status of each package is printed on a separate line. Note that the
-     status is written to \cb{STDOUT}, not \cb{STDERR}. The semantics of
-     <dep-spec> and the format of the status line are described in
+     In the default output format (see the \cb{--stdout-format} common
+     option), the status of each package is printed on a separate line. Note
+     that the status is written to \cb{stdout}, not \cb{stderr}. The semantics
+     of <dep-spec> and the format of the status line are described in
      \l{bpkg-pkg-status(1)}.
+
+     If the output format is \cb{json}, then the output is a JSON array of
+     objects which are the serialized representation of the following C++
+     \cb{struct} \cb{configuration_package_status}:
+
+     \
+     struct configuration
+     {
+       uint64_t         id;
+       string           path;
+       optional<string> name;
+     };
+
+     struct configuration_package_status
+     {
+       configuration configuration;
+       vector<package_status> packages;
+     };
+     \
+
+     For example:
+
+     \
+     [
+       {
+         \"configuration\": {
+           \"id\": 1,
+           \"path\": \"/tmp/hello-gcc\",
+           \"name\": \"gcc\"
+         },
+         \"packages\": [
+           {
+             \"name\": \"hello\",
+             \"status\": \"configured\",
+             \"version\": \"1.0.0\",
+             \"hold_package\": true,
+             \"available_versions\": [
+               {
+                 \"version\": \"1.0.1\"
+               },
+               {
+                 \"version\": \"2.0.0\"
+               }
+             ],
+             \"dependencies\": [
+               {
+                 \"name\": \"libhello\",
+                 \"status\": \"configured\",
+                 \"version\": \"1.0.2\"
+               }
+             ]
+           }
+         ]
+       }
+     ]
+     \
+
+     See the JSON OUTPUT section in \l{bdep-common-options(1)} for details on
+     the overall properties of this format and the semantics of the
+     \cb{struct} serialization.
+
+     Refer to the \cb{list} subcommand of \l{bdep-config(1)} for details on
+     the \cb{struct} \cb{configuration} members. Refer to
+     \l{bpkg-pkg-status(1)} for the definition of \cb{struct}
+     \cb{package_status}.
      "
   }
 
diff --git a/bdep/status.cxx b/bdep/status.cxx
index b64a9a4..d932e58 100644
--- a/bdep/status.cxx
+++ b/bdep/status.cxx
@@ -5,6 +5,8 @@
 
 #include <iostream> // cout
 
+#include <libbutl/json/serializer.hxx>
+
 #include <bdep/project.hxx>
 #include <bdep/database.hxx>
 #include <bdep/diagnostics.hxx>
@@ -15,12 +17,39 @@ using namespace std;
 
 namespace bdep
 {
-  static void
-  cmd_status (const cmd_status_options& o,
-              const dir_path& prj,
-              const dir_path& cfg,
-              const strings& pkgs,
-              bool fetch)
+  // If the specified package list is not empty, then return only those
+  // packages which are initialized in the specified configuration. Otherwise,
+  // return all packages that have been initialized in this configuration.
+  //
+  static strings
+  config_packages (const configuration& cfg, const package_locations& pkgs)
+  {
+    strings r;
+
+    bool all (pkgs.empty ());
+    for (const package_state& s: cfg.packages)
+    {
+      if (all ||
+          find_if (pkgs.begin (),
+                   pkgs.end (),
+                   [&s] (const package_location& p)
+                   {
+                     return p.name == s.name;
+                   }) != pkgs.end ())
+        r.push_back (s.name.string ());
+    }
+
+    return r;
+  }
+
+  static process
+  start_bpkg_status (const cmd_status_options& o,
+                     int out,
+                     const dir_path& prj,
+                     const dir_path& cfg,
+                     const strings& pkgs,
+                     bool fetch,
+                     const char* format)
   {
     // Shallow fetch the project to make sure we show latest iterations and
     // pick up any new repositories.
@@ -38,16 +67,202 @@ namespace bdep
     // Don't show the hold status since the only packages that will normally
     // be held are the project's. But do show dependency constraints.
     //
-    run_bpkg (2,
-              o,
-              "status",
-              "-d", cfg,
-              "--no-hold",
-              "--constraint",
-              (o.old_available () ? "--old-available" : nullptr),
-              (o.immediate () ? "--immediate" :
-               o.recursive () ? "--recursive" : nullptr),
-              pkgs);
+    return start_bpkg (2 /* verbosity */,
+                       o,
+                       out,
+                       2 /* stderr */,
+                       "status",
+                       "-d", cfg,
+                       "--no-hold",
+                       "--constraint",
+                       (o.old_available () ? "--old-available" : nullptr),
+                       (o.immediate () ? "--immediate" :
+                        o.recursive () ? "--recursive" : nullptr),
+                       "--stdout-format", format,
+                       pkgs);
+  }
+
+  static void
+  cmd_status_lines (const cmd_status_options& o,
+                    const project_packages& prj_pkgs,
+                    const configurations& cfgs,
+                    const strings& dep_pkgs)
+  {
+    tracer trace ("status_lines");
+
+    // Print status in each configuration, skipping fetching repositories in
+    // those where no package statuses needs to be printed.
+    //
+    bool first (true);
+    for (const shared_ptr<configuration>& c: cfgs)
+    {
+      // Collect the packages to print, unless the dependency packages are
+      // specified.
+      //
+      strings pkgs;
+
+      if (dep_pkgs.empty ())
+        pkgs = config_packages (*c, prj_pkgs.packages);
+
+      // If we are printing multiple configurations, separate them with a
+      // blank line and print the configuration name/directory.
+      //
+      if (verb && cfgs.size () > 1)
+      {
+        cout << (first ? "" : "\n")
+             << "in configuration " << *c << ':' << endl;
+
+        first = false;
+      }
+
+      if (!c->packages.empty () && (!pkgs.empty () || !dep_pkgs.empty ()))
+      {
+        const dir_path& prj (prj_pkgs.project);
+
+        bool fetch (o.fetch () || o.fetch_full ());
+
+        if (fetch)
+          cmd_fetch (o, prj, c, o.fetch_full ());
+
+        // Status for either packages or their dependencies must be printed,
+        // but not for both.
+        //
+        assert (pkgs.empty () == !dep_pkgs.empty ());
+
+        process pr (start_bpkg_status (o,
+                                       1 /* stdout */,
+                                       prj,
+                                       c->path,
+                                       !pkgs.empty () ? pkgs : dep_pkgs,
+                                       !fetch,
+                                       "lines"));
+
+        finish_bpkg (o, pr);
+      }
+      else
+      {
+        if (verb)
+        {
+          diag_record dr (info);
+
+          if (c->packages.empty ())
+            dr << "no packages ";
+          else
+            dr << "none of specified packages ";
+
+          dr << "initialized in configuration " << *c << ", skipping";
+        }
+      }
+    }
+  }
+
+  static void
+  cmd_status_json (const cmd_status_options& o,
+                   const project_packages& prj_pkgs,
+                   const configurations& cfgs,
+                   const strings& dep_pkgs)
+  {
+    tracer trace ("status_json");
+
+    butl::json::stream_serializer ss (cout);
+
+    ss.begin_array ();
+
+    // Print status in each configuration, skipping fetching repositories in
+    // those where no package statuses need to be printed.
+    //
+    for (const shared_ptr<configuration>& c: cfgs)
+    {
+      // Collect the packages to print, unless the dependency packages are
+      // specified.
+      //
+      strings pkgs;
+
+      if (dep_pkgs.empty ())
+        pkgs = config_packages (*c, prj_pkgs.packages);
+
+      ss.begin_object ();
+      ss.member_name ("configuration");
+      ss.begin_object ();
+      ss.member ("id", *c->id);
+      ss.member ("path", c->path.string ());
+
+      if (c->name)
+        ss.member ("name", *c->name);
+
+      ss.end_object ();
+
+      if (!c->packages.empty () && (!pkgs.empty () || !dep_pkgs.empty ()))
+      {
+        const dir_path& prj (prj_pkgs.project);
+
+        bool fetch (o.fetch () || o.fetch_full ());
+
+        if (fetch)
+          cmd_fetch (o, prj, c, o.fetch_full ());
+
+        // Status for either packages or their dependencies must be printed,
+        // but not for both.
+        //
+        assert (pkgs.empty () == !dep_pkgs.empty ());
+
+        // Save the JSON representation of package statuses into a string from
+        // bpkg-status' stdout and use it as a pre-serialized value for the
+        // packages member of the configuration packages status object.
+        //
+        string ps;
+
+        fdpipe pipe (open_pipe ()); // Text mode seems appropriate.
+
+        process pr (start_bpkg_status (o,
+                                       pipe.out.get (),
+                                       prj,
+                                       c->path,
+                                       !pkgs.empty () ? pkgs : dep_pkgs,
+                                       !fetch,
+                                       "json"));
+
+        // Shouldn't throw, unless something is severely damaged.
+        //
+        pipe.out.close ();
+
+        bool io (false);
+        try
+        {
+          ifdstream is (move (pipe.in));
+          ps = is.read_text ();
+          is.close ();
+        }
+        catch (const io_error&)
+        {
+          // Presumably the child process failed and issued diagnostics so let
+          // finish_bpkg() try to deal with that first.
+          //
+          io = true;
+        }
+
+        finish_bpkg (o, pr, io);
+
+        // Trim the trailing newline, which must be present. Let's however
+        // check that it is, for good measure.
+        //
+        if (!ps.empty () && ps.back () == '\n')
+          ps.pop_back ();
+
+        ss.member_name ("packages");
+        ss.value_json_text (ps);
+      }
+      else
+      {
+        // Not that unlike in the lines output we don't tell the user that
+        // there are no packages.
+      }
+
+      ss.end_object ();
+    }
+
+    ss.end_array ();
+    cout << endl;
   }
 
   int
@@ -90,79 +305,18 @@ namespace bdep
       cfgs = move (cs.first);
     }
 
-    // Print status in each configuration, skipping those where no package
-    // statuses needs to be printed.
-    //
-    bool first (true);
-    for (const shared_ptr<configuration>& c: cfgs)
+    switch (o.stdout_format ())
     {
-      // Collect the packages to print, unless the dependency packages are
-      // specified.
-      //
-      // If no packages were explicitly specified, then we print the status
-      // for all that have been initialized in the configuration. Otherwise,
-      // only for specified packages initialized in the (specified)
-      // configurations.
-      //
-      strings pkgs;
-
-      if (dep_pkgs.empty ())
+    case stdout_format::lines:
       {
-        const package_locations& ps (pp.packages);
-        bool all (ps.empty ());
-
-        for (const package_state& s: c->packages)
-        {
-          if (all ||
-              find_if (ps.begin (),
-                       ps.end (),
-                       [&s] (const package_location& p)
-                       {
-                         return p.name == s.name;
-                       }) != ps.end ())
-            pkgs.push_back (s.name.string ());
-        }
+        cmd_status_lines (o, pp, cfgs, dep_pkgs);
+        break;
       }
-
-      // If we are printing multiple configurations, separate them with a
-      // blank line and print the configuration name/directory.
-      //
-      if (verb && cfgs.size () > 1)
+    case stdout_format::json:
       {
-        cout << (first ? "" : "\n")
-             << "in configuration " << *c << ':' << endl;
-
-        first = false;
+        cmd_status_json (o, pp, cfgs, dep_pkgs);
+        break;
       }
-
-      if (c->packages.empty () || (pkgs.empty () && dep_pkgs.empty ()))
-      {
-        if (verb)
-        {
-          diag_record dr (info);
-
-          if (c->packages.empty ())
-            dr << "no packages ";
-          else
-            dr << "none of specified packages ";
-
-          dr << "initialized in configuration " << *c << ", skipping";
-        }
-
-        continue;
-      }
-
-      bool fetch (o.fetch () || o.fetch_full ());
-
-      if (fetch)
-        cmd_fetch (o, prj, c, o.fetch_full ());
-
-      // Status for either packages or their dependencies must be printed, but
-      // not for both.
-      //
-      assert (pkgs.empty () == !dep_pkgs.empty ());
-
-      cmd_status (o, prj, c->path, !pkgs.empty () ? pkgs : dep_pkgs, !fetch);
     }
 
     return 0;
diff --git a/bdep/types-parsers.cxx b/bdep/types-parsers.cxx
index 7707b3c..8f693fa 100644
--- a/bdep/types-parsers.cxx
+++ b/bdep/types-parsers.cxx
@@ -68,5 +68,22 @@ namespace bdep
       xs = true;
       parse_path (x, s);
     }
+
+    void parser<stdout_format>::
+    parse (stdout_format& r, bool& xs, scanner& s)
+    {
+      const char* o (s.next ());
+
+      if (!s.more ())
+        throw missing_value (o);
+
+      string v (s.next ());
+
+      if      (v == "lines") r = stdout_format::lines;
+      else if (v == "json")  r = stdout_format::json;
+      else throw invalid_value (o, v);
+
+      xs = true;
+    }
   }
 }
diff --git a/bdep/types-parsers.hxx b/bdep/types-parsers.hxx
index 9e76237..3da355c 100644
--- a/bdep/types-parsers.hxx
+++ b/bdep/types-parsers.hxx
@@ -48,6 +48,19 @@ namespace bdep
       static void
       merge (dir_path& b, const dir_path& a) {b = a;}
     };
+
+    template <>
+    struct parser<stdout_format>
+    {
+      static void
+      parse (stdout_format&, bool&, scanner&);
+
+      static void
+      merge (stdout_format& b, const stdout_format& a)
+      {
+        b = a;
+      }
+    };
   }
 }
 
diff --git a/tests/status.testscript b/tests/status.testscript
index bf4339b..2977e4f 100644
--- a/tests/status.testscript
+++ b/tests/status.testscript
@@ -30,6 +30,23 @@ deinit += -d prj
 
   $* >'prj configured 0.1.0-a.0.19700101000000';
 
+  $* --stdout-format 'json' >>/~"%EOO%";
+    [
+      {
+        "configuration": {
+          "id": 1,
+          "path": "$~/prj-cfg",
+          "name": "cfg"
+        },
+        "packages": [
+      {
+    %.+
+      }
+    ]
+      }
+    ]
+    EOO
+
   $deinit 2>>/"EOE"
     deinitializing in project $~/prj/
     synchronizing:
@@ -55,6 +72,35 @@ deinit += -d prj
     prj configured 0.1.0-a.0.19700101000000
     EOO
 
+  $* --all --stdout-format 'json' >>/~"%EOO%";
+    [
+      {
+        "configuration": {
+          "id": 1,
+          "path": "$~/prj-cfg1",
+          "name": "cfg1"
+        },
+        "packages": [
+      {
+    %.+
+      }
+    ]
+      },
+      {
+        "configuration": {
+          "id": 2,
+          "path": "$~/prj-cfg2",
+          "name": "cfg2"
+        },
+        "packages": [
+      {
+    %.+
+      }
+    ]
+      }
+    ]
+    EOO
+
   $deinit 2>>/"EOE"
     deinitializing in project $~/prj/
     synchronizing: