neovim-flake/modules/git/config.nix

{
  config,
  lib,
  ...
}: let
  inherit (builtins) toJSON;
  inherit (lib.modules) mkIf mkMerge;
  inherit (lib.nvim.binds) addDescriptionsToMappings mkSetExprBinding mkSetLuaBinding;
  inherit (lib.nvim.dag) entryAnywhere;
  # TODO: move this to its own module
  inherit (lib) pushDownDefault;

  cfg = config.vim.git;

  self = import ./git.nix {inherit lib config;};
  gsMappingDefinitions = self.options.vim.git.gitsigns.mappings;

  gsMappings = addDescriptionsToMappings cfg.gitsigns.mappings gsMappingDefinitions;
in {
  config = mkIf cfg.enable (mkMerge [
    (mkIf cfg.gitsigns.enable (mkMerge [
      {
        vim.startPlugins = ["gitsigns-nvim"];

        vim.maps.normal = mkMerge [
          (mkSetExprBinding gsMappings.nextHunk ''
            function()
              if vim.wo.diff then return ${toJSON gsMappings.nextHunk.value} end

              vim.schedule(function() package.loaded.gitsigns.next_hunk() end)

              return '<Ignore>'
            end
          '')
          (mkSetExprBinding gsMappings.previousHunk ''
            function()
              if vim.wo.diff then return ${toJSON gsMappings.previousHunk.value} end

              vim.schedule(function() package.loaded.gitsigns.prev_hunk() end)

              return '<Ignore>'
            end
          '')

          (mkSetLuaBinding gsMappings.stageHunk "package.loaded.gitsigns.stage_hunk")
          (mkSetLuaBinding gsMappings.resetHunk "package.loaded.gitsigns.reset_hunk")
          (mkSetLuaBinding gsMappings.undoStageHunk "package.loaded.gitsigns.undo_stage_hunk")

          (mkSetLuaBinding gsMappings.stageBuffer "package.loaded.gitsigns.stage_buffer")
          (mkSetLuaBinding gsMappings.resetBuffer "package.loaded.gitsigns.reset_buffer")

          (mkSetLuaBinding gsMappings.previewHunk "package.loaded.gitsigns.preview_hunk")

          (mkSetLuaBinding gsMappings.blameLine "function() package.loaded.gitsigns.blame_line{full=true} end")
          (mkSetLuaBinding gsMappings.toggleBlame "package.loaded.gitsigns.toggle_current_line_blame")

          (mkSetLuaBinding gsMappings.diffThis "package.loaded.gitsigns.diffthis")
          (mkSetLuaBinding gsMappings.diffProject "function() package.loaded.gitsigns.diffthis('~') end")

          (mkSetLuaBinding gsMappings.toggleDeleted "package.loaded.gitsigns.toggle_deleted")
        ];

        vim.maps.visual = mkMerge [
          (mkSetLuaBinding gsMappings.stageHunk "function() package.loaded.gitsigns.stage_hunk {vim.fn.line('.'), vim.fn.line('v')} end")
          (mkSetLuaBinding gsMappings.resetHunk "function() package.loaded.gitsigns.reset_hunk {vim.fn.line('.'), vim.fn.line('v')} end")
        ];

        vim.binds.whichKey.register = pushDownDefault {
          "<leader>g" = "+Gitsigns";
        };

        vim.luaConfigRC.gitsigns = entryAnywhere ''
          require('gitsigns').setup{}
        '';
      }

      (mkIf cfg.gitsigns.codeActions {
        vim.lsp.null-ls.enable = true;
        vim.lsp.null-ls.sources.gitsigns-ca = ''
          table.insert(
            ls_sources,
            null_ls.builtins.code_actions.gitsigns
          )
        '';
      })
    ]))
  ]);
}