--
--  Copyright (C) 2014-2022, AdaCore
--  SPDX-License-Identifier: Apache-2.0
--

--  This package provides helpers to deal with GNAT's configurations pragmas
--  files.

with Ada.Containers.Hashed_Maps;

with GNATCOLL.Projects; use GNATCOLL.Projects;
with GPR2.Project.Tree;
with GPR2.Project.View;

with Libadalang.Analysis; use Libadalang.Analysis;

package Libadalang.Config_Pragmas is

   package Unit_Maps is new Ada.Containers.Hashed_Maps
     (Key_Type        => Analysis_Unit,
      Element_Type    => Analysis_Unit,
      Hash            => Hash,
      Equivalent_Keys => "=");
   --  Map analysis unit to the local configuration pragmas file that applies
   --  to it.

   type Config_Pragmas_Mapping is record
      Local_Pragmas : Unit_Maps.Map;
      --  Mappings that associate a local configuration pragmas file (element)
      --  to each analysis unit (key) for which it applies.

      Global_Pragmas : Analysis_Unit;
      --  Configuration pragmas file that applies to all analysis units, or
      --  ``No_Analysis_Unit`` if there is no such file.
   end record;

   procedure Set_Mapping
     (Context : Analysis_Context; Mapping : Config_Pragmas_Mapping);
   --  Assign in ``Context`` configuration pragmas files to analysis units as
   --  described in ``Mapping``.
   --
   --  This raises a ``Precondition_Failure`` exception if:
   --
   --  * ``Context`` is null;
   --  * any analysis unit in ``Mapping`` does not belong to ``Context``;
   --  * ``Local_Pragmas`` has a ``No_Analysis`` key or element.

   function Import_From_Project
     (Context    : Analysis_Context;
      Project    : Project_Tree'Class;
      Subproject : Project_Type := No_Project) return Config_Pragmas_Mapping;
   --  Load configuration pragmas files referenced in ``Project`` and its
   --  sub-projects and return a mapping that describes for each analysis unit
   --  owned by ``Project`` which configuration pragmas files applies to it.
   --
   --  If ``Subproject`` is not ``No_Project``, restrict the exploration of
   --  local configuration pragmas files to that project (global ones are still
   --  found in the root project).

   procedure Import_From_Project
     (Context    : Analysis_Context;
      Project    : Project_Tree'Class;
      Subproject : Project_Type := No_Project);
   --  Shortcut for ``Import_From_Project/Set_Mapping`` calls

   --------------------
   -- GPR2 based API --
   --------------------

   --  .. ATTENTION:: This is an experimental feature, so even if it is exposed
   --  to allow experiments, it is totally unsupported and the API is very
   --  likely to change in the future.

   function Import_From_Project
     (Context : Analysis_Context;
      Tree    : GPR2.Project.Tree.Object;
      View    : GPR2.Project.View.Object := GPR2.Project.View.Undefined)
      return Config_Pragmas_Mapping;
   --  Load configuration pragmas files referenced in ``Tree`` and its
   --  sub-projects and return a mapping that describes for each analysis unit
   --  owned by ``Tree`` which configuration pragmas files applies to it.
   --
   --  If ``View`` is not ``Undefined``, restrict the exploration of local
   --  configuration pragmas files to that project (global ones are still found
   --  in the root project).

   procedure Import_From_Project
     (Context : Analysis_Context;
      Tree    : GPR2.Project.Tree.Object;
      View    : GPR2.Project.View.Object := GPR2.Project.View.Undefined);
   --  Shortcut for ``Import_From_Project/Set_Mapping`` calls

   -------------------
   -- Debug helpers --
   -------------------

   procedure Dump (Mapping : Config_Pragmas_Mapping);
   --  Dump the content of ``Mapping`` on the standard output

end Libadalang.Config_Pragmas;