Add: diff colors and dynamic diff window width sizing

.config/nvim/lua/cole/set.lua

@@ -1,21 +1,76 @@
---Line numbers
+-- Line numbers
 vim.opt.nu = true
 vim.opt.relativenumber = true
 
---Formatting
+-- Formatting
 vim.opt.tabstop = 4
 vim.opt.shiftwidth = 4
 vim.opt.expandtab = true
 
 vim.opt.smartindent = true
 
---Search
+-- Search
 vim.opt.hlsearch = false
 vim.opt.incsearch = true
 
---Scroll settings
-vim.opt.scrolloff = 8 --Always 8 lines above
+-- Scroll settings
+vim.opt.scrolloff = 8 -- Always 8 lines above
 
---Color scheme
+-- Color scheme
 vim.cmd.colorscheme("habamax")
 
+-- Diff: Muted Red on Crimson
+vim.api.nvim_set_hl(0, "DiffAdd", {
+    bg = "#1e3a1e",
+    fg = "NONE"
+}) -- added lines: muted green
+vim.api.nvim_set_hl(0, "DiffDelete", {
+    bg = "#3d1a1a",
+    fg = "#6b3a3a"
+}) -- deleted lines: muted red
+vim.api.nvim_set_hl(0, "DiffChange", {
+    bg = "#3a1c1c",
+    fg = "NONE"
+}) -- changed lines: light red wash
+vim.api.nvim_set_hl(0, "DiffText", {
+    bg = "#8b2035",
+    fg = "NONE",
+    bold = true
+}) -- char diff: saturated red (crimson)
+
+-- Dynamic diff window width sizing
+vim.api.nvim_create_autocmd("VimEnter", {
+    callback = function()
+        if not vim.wo.diff then
+            return
+        end
+
+        -- Calculate the longest display-width line in the left (current) buffer.
+        local lines = vim.api.nvim_buf_get_lines(0, 0, -1, false)
+        local max_len = 0
+        for _, line in ipairs(lines) do
+            local len = vim.fn.strdisplaywidth(line)
+            if len > max_len then
+                max_len = len
+            end
+        end
+
+        -- Account for gutter columns (line numbers, sign column, fold column).
+        local gutter = 0
+        if vim.wo.number or vim.wo.relativenumber then
+            gutter = gutter + vim.wo.numberwidth
+        end
+        if vim.wo.signcolumn ~= "no" then
+            gutter = gutter + 2
+        end
+        gutter = gutter + vim.wo.foldcolumn
+
+        local desired = max_len + gutter + 1 -- +1 for the right edge padding
+
+        -- Cap at exactly half the terminal width.
+        local half = math.floor(vim.o.columns / 2)
+        local width = math.min(desired, half)
+
+        vim.api.nvim_win_set_width(0, width)
+    end
+})