nvim/lua/settings.lua

-- Minimal settings for bootstrap and Phase 3.2

-- Disable unused language providers early; enable later only if a plugin requires them
vim.g.loaded_ruby_provider = 0
vim.g.loaded_perl_provider = 0
vim.g.loaded_node_provider = 0

-- Auto-detect system theme (Linux/GNOME)
local function set_background_from_system()
  local handle = io.popen('gsettings get org.gnome.desktop.interface color-scheme 2>/dev/null')
  if handle then
    local result = handle:read("*a")
    handle:close()
    
    if result:match("dark") then
      vim.o.background = 'dark'
    else
      vim.o.background = 'light'
    end
  end
end

-- Set background based on system theme on startup
set_background_from_system()

-- Handle SIGUSR1 signal to update theme when system theme changes
-- External watcher script (scripts/theme-watcher.sh) sends this signal
vim.api.nvim_create_autocmd('Signal', {
  pattern = 'SIGUSR1',
  callback = function()
    set_background_from_system()
  end,
  desc = 'Update colorscheme when system theme changes',
})

-- Store initial working directory as project root
-- Used by netrw navigation to return to project root after following symlinks
vim.g.project_root = vim.fn.getcwd()

-- Prevent automatic directory changes when switching files
vim.opt.autochdir = false -- Keep working directory at project root

-- Enable project-local configuration files
vim.opt.exrc = true -- Load .nvim.lua from project root
vim.opt.secure = true -- Prompt before loading untrusted files

-- Custom tabline configuration
-- Load utils module for custom tabline function
local utils = require('utils')

-- Configure number of parent directories to show in full (default: 1)
-- Examples:
--   1: /path/to/my/project/src/file.txt → pat/to/my/project/src/file.txt
--   2: /path/to/my/project/src/file.txt → pat/to/my/project/src/file.txt
utils.tabline_full_parents = 1

-- Configure number of characters to show for shortened directories (default: 3)
-- Examples:
--   3: /path/to/my → pat/to/my
--   1: /path/to/my → p/t/m
utils.tabline_shorten_length = 4

-- Use custom tabline function
vim.opt.tabline = '%!v:lua.require("utils").custom_tabline()'
vim.opt.showtabline = 1 -- Show tabline only when there are 2+ tabs

-- Phase 3.2: non-plugin settings (legacy values where specified)
-- Completion UI for nvim-cmp
vim.opt.completeopt = { "menu", "menuone", "noselect" }

-- Built-in completion popup style (for Ctrl-X Ctrl-N/F completions)
-- Use floating window with border for native completion
vim.opt.pumblend = 0 -- No transparency
-- Note: Native completion (pumvisible) doesn't support custom borders like LSP floats
-- The Pmenu* highlight groups control its appearance

-- Spelling
vim.opt.spell = true
vim.opt.spelllang = { "en_gb" }
vim.opt.spelloptions = { "camel,noplainbuffer" }

-- Search behavior
vim.opt.ignorecase = true -- Case-insensitive search by default
vim.opt.smartcase = true -- Case-sensitive when search contains uppercase letters
vim.opt.incsearch = true -- Show matches as you type
vim.opt.hlsearch = true -- Highlight all search matches

-- Keyword characters (add $ for PHP/shell variables, - for CSS/HTML/config files)
vim.opt.iskeyword:append("$")
vim.opt.iskeyword:append("-")

-- Terminal and color support
vim.opt.termguicolors = true -- Enable 24-bit RGB color (required for colored underlines)

-- Visuals
vim.opt.showbreak = "  ↳"
vim.opt.listchars = {
	eol = "¬",
	tab = "│ ",
	trail = "~",
	extends = ">",
	precedes = "<",
	space = "·",
}

-- Enable line numbers and relative line numbers
vim.opt.number = true
vim.opt.relativenumber = true

-- Scrolloff settings
vim.opt.scrolloff = 4

-- Phase 6.2: UX settings
vim.opt.signcolumn = "yes" -- Always show sign column (for LSP diagnostics, git signs, etc.)
vim.opt.cursorline = true -- Highlight current line
vim.opt.colorcolumn = "80,120" -- Visual guides at 80 and 120 characters

-- Phase 9.4: Default indentation (per-filetype overrides in after/ftplugin/)
vim.opt.tabstop = 4 -- Display tabs as 4 spaces
vim.opt.shiftwidth = 4 -- Indent by 4
vim.opt.softtabstop = 4 -- Backspace removes 4 spaces
vim.opt.expandtab = true -- Use spaces by default (overridden per-filetype)
vim.opt.autoindent = true -- Copy indent from current line when starting new line
vim.opt.smartindent = true -- Smart autoindenting (C-like programs, PHP, etc.)

-- Persistent undo
vim.opt.undofile = true -- Enable persistent undo
vim.opt.undodir = vim.fn.stdpath("config") .. "/undodir" -- Store undo files in config directory

-- LSP diagnostics configuration
vim.diagnostic.config({
	virtual_text = {
		spacing = 4,
		prefix = "●",
		-- Show severity (ERROR, WARN, INFO, HINT)
		format = function(diagnostic)
			return string.format("%s: %s", diagnostic.source or "", diagnostic.message)
		end,
	},
	signs = false, -- Disable signs (redundant with background highlights and virtual text)
	underline = true, -- Use background highlights on problematic text
	update_in_insert = false, -- Don't update diagnostics while typing
	severity_sort = true, -- Sort by severity (errors first)
	float = {
		border = "single",
		source = "always", -- Show diagnostic source
		header = "",
		prefix = "",
	},
})

-- Configure LSP floating windows with borders and padding
-- Custom border with box-drawing characters flush to window edges
-- Using heavy/light box-drawing characters positioned at cell edges
local border = {
	{ "🭽", "FloatBorder" }, -- top-left corner
	{ "▔", "FloatBorder" }, -- top horizontal line (at top edge)
	{ "🭾", "FloatBorder" }, -- top-right corner
	{ "▕", "FloatBorder" }, -- right vertical line (at right edge)
	{ "🭿", "FloatBorder" }, -- bottom-right corner
	{ "▁", "FloatBorder" }, -- bottom horizontal line (at bottom edge)
	{ "🭼", "FloatBorder" }, -- bottom-left corner
	{ "▏", "FloatBorder" }, -- left vertical line (at left edge)
}

-- Override the default open_floating_preview to add padding by modifying content
local orig_util_open_floating_preview = vim.lsp.util.open_floating_preview
function vim.lsp.util.open_floating_preview(contents, syntax, opts, ...)
	opts = opts or {}
	opts.border = opts.border or border
	
	-- Add padding by wrapping content with empty lines and spacing
	if type(contents) == "table" and #contents > 0 then
		-- Add empty lines at top and bottom
		table.insert(contents, 1, "")
		table.insert(contents, 1, "")
		table.insert(contents, "")
		table.insert(contents, "")
		
		-- Add horizontal padding (spaces) to each content line
		for i = 3, #contents - 2 do
			if type(contents[i]) == "string" then
				contents[i] = "  " .. contents[i] .. "  "
			end
		end
	end
	
	return orig_util_open_floating_preview(contents, syntax, opts, ...)
end

vim.lsp.handlers["textDocument/hover"] = vim.lsp.with(vim.lsp.handlers.hover, {
	border = border,
})
vim.lsp.handlers["textDocument/signatureHelp"] = vim.lsp.with(vim.lsp.handlers.signature_help, {
	border = border,
})