From c34d0afa71eadd459d34b88bd75d427eef0d25d9 Mon Sep 17 00:00:00 2001
From: Martin Larsson <larssonmartin1998@gmail.com>
Date: Mon, 3 Jun 2024 00:07:14 +0200
Subject: [PATCH] [WIP] Start work on a simple windows swapping feature, much
 like how tiling window managers work

---
 home/.config/nvim/init.lua | 102 +++++++++++++++++++++++++++++++++++++
 1 file changed, 102 insertions(+)

diff --git a/home/.config/nvim/init.lua b/home/.config/nvim/init.lua
index fa5e6ce..f25cb55 100644
--- a/home/.config/nvim/init.lua
+++ b/home/.config/nvim/init.lua
@@ -33,3 +33,105 @@ require("terminal").setup()
 
 -- See ":help vim.highlight.on_yank()"
 setup_yank_highlight()
+
+-- Extract to plugin later
+local function is_floating_window(window)
+    return vim.api.nvim_win_get_config(window).relative ~= ""
+end
+
+local function is_window_resizable(window)
+    local config = vim.api.nvim_win_get_config(window)
+    return not config.winfixwidth and not config.winfixheight
+end
+
+local function get_total_num_windows_open()
+    return #vim.api.nvim_tabpage_list_wins(0)
+end
+
+local function get_adjacent_window(dir_char)
+    assert(dir_char == "h" or dir_char == "j" or dir_char == "k" or dir_char == "l", "Invalid direction character")
+    local current_window = vim.api.nvim_get_current_win()
+    assert(current_window, "Current window is nil")
+
+    vim.cmd("wincmd " .. dir_char)
+    local new_window = vim.api.nvim_get_current_win()
+    vim.api.nvim_set_current_win(current_window)
+
+    assert(vim.api.nvim_get_current_win() == current_window, "Cursor moved to a different window")
+    return new_window
+end
+
+local function is_current_window_at_edge(dir_char)
+    return vim.api.nvim_get_current_win() == get_adjacent_window(dir_char)
+end
+
+local function swap_buffer_between_windows(window_a, window_b)
+    assert(window_a and window_b, "Invalid window")
+
+    local buffer_a = vim.api.nvim_win_get_buf(window_a)
+    local buffer_b = vim.api.nvim_win_get_buf(window_b)
+    vim.api.nvim_win_set_buf(window_a, buffer_b)
+    vim.api.nvim_win_set_buf(window_b, buffer_a)
+
+    assert(vim.api.nvim_win_get_buf(window_a) == buffer_b and vim.api.nvim_win_get_buf(window_b) == buffer_a,
+        "Failed to swap buffers")
+end
+
+local function swap_window(dir_char)
+    assert(dir_char == "h" or dir_char == "j" or dir_char == "k" or dir_char == "l", "Invalid direction character")
+    local current_window = vim.api.nvim_get_current_win()
+    assert(current_window, "Current window is nil")
+
+    local required_num_windows = 2
+    if get_total_num_windows_open() < required_num_windows then
+        return
+    end
+
+    if is_floating_window(current_window) then
+        return
+    end
+
+    if is_current_window_at_edge(dir_char) then
+        return
+    end
+
+    if not is_window_resizable(current_window) then
+        return
+    end
+
+    local adjacent_window = get_adjacent_window(dir_char)
+    if not is_window_resizable(adjacent_window) then
+        return
+    end
+
+    swap_buffer_between_windows(current_window, adjacent_window)
+end
+
+require("utils").add_keymaps({
+    n = {
+        -- ["<C-S>Left"] = {
+        ["h"] = {
+            cmd = function()
+                swap_window("h")
+            end
+        },
+        -- ["<C-S>Down"] = {
+        ["j"] = {
+            cmd = function()
+                swap_window("j")
+            end
+        },
+        -- ["<C-S>Up"] = {
+        ["k"] = {
+            cmd = function()
+                swap_window("k")
+            end
+        },
+        -- ["<C-S>Right"] = {
+        ["l"] = {
+            cmd = function()
+                swap_window("l")
+            end
+        },
+    },
+})