--[[
    BASIC-SETTINGS.LUA
    
    This file contains fundamental Neovim settings that don't require plugins.
    These are applied to Neovim globally and affect the core editing experience.
    
    In Lua (this file), we use:
    - vim.opt.* for options that take values
    - vim.g.* for global variables
    - vim.go.* for global option shorthand
]]

-- ============================================================================
-- TREESITTER (Built-in Neovim 0.10+ features)
-- ============================================================================
-- Enable Treesitter syntax highlighting (native in Neovim 0.10+)
-- This replaces the old nvim-treesitter highlight module
vim.api.nvim_create_autocmd("FileType", {
	pattern = "*",
	callback = function()
		if vim.bo.buftype == "" and vim.bo.filetype ~= "" then
			pcall(vim.treesitter.start)
		end
	end,
	desc = "Enable Treesitter highlighting",
})

-- ============================================================================
-- FOLDING SETTINGS (Code folding)
-- ============================================================================
-- NOTE: In Neovim 0.10+, Treesitter folding must be set per-buffer via FileType autocmd
-- Setting it globally causes the foldexpr to evaluate before Treesitter attaches

-- Foldlevel: Higher number = more folds are open by default
-- 1-2 means you'll see folds by default; 99 means all folds are open
vim.opt.foldlevel = 99
vim.opt.foldlevelstart = 99

-- Setup Treesitter folding for each buffer after filetype is detected
-- This ensures the parser is loaded before foldexpr evaluates
vim.api.nvim_create_autocmd("FileType", {
	pattern = "*",
	callback = function()
		-- Only set folding for file buffers with Treesitter support
		if vim.bo.buftype == "" then
			vim.wo.foldmethod = "expr"
			vim.wo.foldexpr = "v:lua.vim.treesitter.foldexpr()"
		end
	end,
	desc = "Setup Treesitter folding per filetype",
})

-- ============================================================================
-- LINE NUMBERS
-- ============================================================================
-- Show line numbers (absolute numbering)
vim.opt.number = true

-- Show relative line numbers (helps with motions like 5j, 3k, etc.)
-- When combined with 'number', the current line shows absolute number
-- vim.opt.relativenumber = true

-- ============================================================================
-- INDENTATION SETTINGS
-- ============================================================================
-- Tabstop: How many spaces a TAB character counts for
-- When viewing a file, TABs appear as this many spaces
vim.opt.tabstop = 4

-- Shiftwidth: How many spaces to use for auto-indentation and >> << commands
vim.opt.shiftwidth = 4

-- Expandtab: Convert TABs to spaces when typing
-- true = pressing TAB inserts spaces; false = inserts actual TAB characters
-- Recommendation: Use true (spaces) for better portability across systems
vim.opt.expandtab = true

-- Smartindent: Auto-indent based on file type and syntax
-- Automatically adds indent after lines ending with specific characters
vim.opt.smartindent = true

-- ============================================================================
-- UI/UX SETTINGS
-- ============================================================================
-- Show line length marker (optional, helps keep lines under 80/120 chars)
-- Uncomment if you want: vim.opt.colorcolumn = "80"

-- Enable cursor line highlighting (subtle background on current line)
vim.opt.cursorline = true

-- Enable cursor column highlighting (column where cursor is)
vim.opt.cursorcolumn = true

-- Better command-line completion (popup menu for completions)
vim.opt.wildmenu = true

-- Ignore case when searching UNLESS you include an uppercase letter
vim.opt.ignorecase = true
vim.opt.smartcase = true

-- Highlight search matches as you type
vim.opt.incsearch = true

-- When search reaches end, wrap back to beginning
vim.opt.wrapscan = true

-- Show matching brackets/parentheses
vim.opt.showmatch = true

-- How long (ms) to show matching bracket
vim.opt.matchtime = 2

-- Show current mode in last line (like -- INSERT --)
vim.opt.showmode = true

-- Show incomplete commands at bottom
vim.opt.showcmd = true

-- Command line height (number of lines for command area)
vim.opt.cmdheight = 1

-- Always show status line (even in single window)
vim.opt.laststatus = 3

-- Don't redraw while executing macros (faster)
vim.opt.lazyredraw = false

-- Don't show mode in the window title (cleaner)
vim.opt.title = false

-- ============================================================================
-- EDITING BEHAVIOR
-- ============================================================================
-- Enable mouse support (click to move cursor, resize splits)
vim.opt.mouse = "a"

-- Allow backspace to delete indent, eol, and start of line
vim.opt.backspace = "indent,eol,start"

-- Auto-read file when changed externally (e.g., by another program)
vim.opt.autoread = true

-- Auto-write when switching buffers or leaving
-- 'a' = auto-write for all buffers; uncomment if you want:
-- vim.opt.autowrite = true

-- Remember moreundo for longer undo history
vim.opt.undofile = true

-- ============================================================================
-- SPLIT AND TAB SETTINGS
-- ============================================================================
-- Split below (instead of above) when creating horizontal splits
vim.opt.splitbelow = true

-- Split right (instead of left) when creating vertical splits
vim.opt.splitright = true

-- ============================================================================
-- PERFORMANCE SETTINGS
-- ============================================================================
-- Faster terminal response
vim.opt.timeout = true
vim.opt.timeoutlen = 300  -- Time in ms to wait for a mapped sequence

-- Async handling for some operations
vim.opt.ttimeoutlen = 10

-- ============================================================================
-- LEADER KEY
-- ============================================================================
-- The <Leader> key is used as a prefix for custom keybindings
-- By convention, space is commonly used as the leader key
vim.g.mapleader = " "

-- ============================================================================
-- TERMINAL SETTINGS
-- ============================================================================
-- Exit terminal mode with Escape
vim.keymap.set("t", "<Esc>", [[<C-\><C-n>]], {
    desc = "Exit terminal mode"
})

-- Alternative: Exit with Alt key combinations as well
vim.keymap.set("t", "<A-x>", [[<C-\><C-n>]], {
    desc = "Exit terminal mode with Alt"
})

-- ============================================================================
-- CLIPBOARD (System clipboard integration)
-- ============================================================================
-- Use system clipboard for yank/paste
-- Requires +clipboard feature (check with: :echo has('clipboard'))
if vim.fn.has("clipboard") == 1 then
    -- Use system clipboard for all yank/delete/paste operations
    vim.opt.clipboard = "unnamedplus"
end