From 9b3a9ece1ea2630cf912b9202a06cc7e05d9f7d7 Mon Sep 17 00:00:00 2001
From: Martin Larsson <larssonmartin1998@gmail.com>
Date: Mon, 13 Jan 2025 12:08:07 +0100
Subject: [PATCH] Add a way to cache default keymaps, impl function for adding
 temporary keymaps (i.e keymaps during debugging) which saves original keymaps
 if it overrides them at restores them upon deletion.

---
 home/.config/nvim/lua/plugs/nvim-dap.lua |  2 +-
 home/.config/nvim/lua/utils.lua          | 90 ++++++++++++++++++------
 2 files changed, 71 insertions(+), 21 deletions(-)

diff --git a/home/.config/nvim/lua/plugs/nvim-dap.lua b/home/.config/nvim/lua/plugs/nvim-dap.lua
index 4103114..ea09c95 100644
--- a/home/.config/nvim/lua/plugs/nvim-dap.lua
+++ b/home/.config/nvim/lua/plugs/nvim-dap.lua
@@ -79,7 +79,7 @@ return {
         local function enter_debug_mode()
             dapui.open()
             if not are_stepping_keymaps_active then
-                utils.add_keymaps(stepping_keymaps)
+                utils.add_temporary_keymaps(stepping_keymaps)
                 are_stepping_keymaps_active = true
             end
 
diff --git a/home/.config/nvim/lua/utils.lua b/home/.config/nvim/lua/utils.lua
index 17c5e32..ff806ba 100644
--- a/home/.config/nvim/lua/utils.lua
+++ b/home/.config/nvim/lua/utils.lua
@@ -1,5 +1,7 @@
 local M = {}
 
+local overridden_default_keymaps = {}
+
 local function is_single_keymap_table(map_table)
     assert(map_table)
     return map_table.n or map_table.t or map_table.i or map_table.v or map_table.x or map_table.o
@@ -73,44 +75,92 @@ function M.add_opts_to_all_mappings(mappings, opts)
     end
 end
 
+local function pass_keymap_tbl_to_fn(maps, fn)
+    if is_single_keymap_table(maps) then
+        fn(maps)
+    else
+        for _, map_table in pairs(maps) do
+            fn(map_table)
+        end
+    end
+end
+
+local function get_keymaps(mode, buffer)
+    if buffer then
+        return vim.api.nvim_buf_get_keymap(buffer, mode)
+    end
+
+    return vim.api.nvim_get_keymap(mode)
+end
+
+function M.add_temporary_keymaps(maps)
+    assert(maps)
+
+    pass_keymap_tbl_to_fn(maps, function(map_table)
+        for mode, entries in pairs(map_table) do
+            -- We make an assumptino here which is that all the entries are buffers, or not buffers.
+            -- Meaning, we only check the first entry and trust that the rest are the same.
+            local result = get_keymaps(mode, (function()
+                for _, entry in pairs(entries) do
+                    -- nil buffer is treated as a global keymap
+                    return entry.buffer
+                end
+            end)())
+
+            for code, _ in pairs(entries) do
+                for _, map in ipairs(result) do
+                    if map.lhs == code then
+                        if not overridden_default_keymaps[mode] then
+                            overridden_default_keymaps[mode] = {}
+                        end
+
+                        overridden_default_keymaps[mode][code] = {
+                            cmd = map.callback or map.rhs,
+                            opts = {
+                                noremap = map.noremap == 1,
+                                expr = map.expr == 1,
+                                silent = map.silent == 1,
+                                nowait = map.nowait == 1,
+                                script = map.script == 1,
+                                buffer = type(map.buffer) == "number" and map.buffer or nil,
+                            },
+                        }
+                    end
+                end
+            end
+        end
+    end)
+
+    M.add_keymaps(maps)
+end
+
 function M.add_keymaps(maps)
     assert(maps)
 
-    local function set_keymaps(map_table)
+    pass_keymap_tbl_to_fn(maps, function(map_table)
         for mode, entries in pairs(map_table) do
             for code, info in pairs(entries) do
                 vim.keymap.set(mode, code, info.cmd, info.opts)
             end
         end
-    end
-
-    if is_single_keymap_table(maps) then
-        set_keymaps(maps)
-    else
-        for _, map_table in pairs(maps) do
-            set_keymaps(map_table)
-        end
-    end
+    end)
 end
 
 function M.remove_keymaps(maps)
     assert(maps)
 
-    local function del_keymaps(map_table)
+    pass_keymap_tbl_to_fn(maps, function(map_table)
         for mode, entries in pairs(map_table) do
+            local overriden_mode = overridden_default_keymaps[mode]
             for code, _ in pairs(entries) do
                 vim.keymap.del(mode, code)
+
+                if overriden_mode and overriden_mode[code] then
+                    vim.keymap.set(mode, code, overriden_mode[code].cmd, overriden_mode[code].opts)
+                end
             end
         end
-    end
-
-    if is_single_keymap_table(maps) then
-        del_keymaps(maps)
-    else
-        for _, map_table in pairs(maps) do
-            del_keymaps(map_table)
-        end
-    end
+    end)
 end
 
 function M.is_buf_filetype(bufnr, filetype)