local opt = vim.opt

-- Line numbers
opt.number = true
opt.relativenumber = false

-- Search
opt.ignorecase = true
opt.smartcase = true
opt.hlsearch = true
opt.incsearch = true

-- Tabs / indentation
opt.expandtab = true
opt.shiftwidth = 4
opt.tabstop = 4
opt.smartindent = true

-- Undo
opt.undofile = true

-- UI
opt.termguicolors = true
opt.signcolumn = "yes"
opt.scrolloff = 8
opt.splitbelow = true
opt.splitright = true
opt.equalalways = false
opt.cursorline = true

-- Per-window buffer tabs (winbar)
-- Track which buffers were opened in each window
_G.win_bufs = {}

function _G.track_buf()
    local win = vim.api.nvim_get_current_win()
    local buf = vim.api.nvim_get_current_buf()
    if not vim.bo[buf].buflisted or vim.bo[buf].filetype == "oil" then return end
    if not _G.win_bufs[win] then _G.win_bufs[win] = {} end
    -- Remove if already tracked, then add to end
    for i, b in ipairs(_G.win_bufs[win]) do
        if b == buf then table.remove(_G.win_bufs[win], i) break end
    end
    table.insert(_G.win_bufs[win], buf)
end

function _G.get_win_bufs()
    local win = vim.api.nvim_get_current_win()
    local bufs = {}
    for _, buf in ipairs(_G.win_bufs[win] or {}) do
        if vim.api.nvim_buf_is_valid(buf) and vim.bo[buf].buflisted then
            table.insert(bufs, buf)
        end
    end
    _G.win_bufs[win] = bufs
    return bufs
end

function _G.winbar_tabs()
    local bufs = _G.get_win_bufs()
    if #bufs == 0 then return "" end
    local current = vim.api.nvim_get_current_buf()
    local parts = {}
    for _, buf in ipairs(bufs) do
        local name = vim.fn.fnamemodify(vim.api.nvim_buf_get_name(buf), ":t")
        if name == "" then name = "[No Name]" end
        local mod = vim.bo[buf].modified and " +" or ""
        if buf == current then
            table.insert(parts, "%#TabLineSel# " .. name .. mod .. " %#WinBar#")
        else
            table.insert(parts, " " .. name .. mod .. " ")
        end
    end
    return table.concat(parts, "|")
end

vim.api.nvim_create_autocmd("BufEnter", {
    group = vim.api.nvim_create_augroup("track_win_bufs", { clear = true }),
    callback = function() _G.track_buf() end,
})

opt.winbar = "%{%v:lua.winbar_tabs()%}"

-- Clipboard (system)
opt.clipboard = "unnamedplus"

-- Statusline (with git branch)
function _G.git_branch()
    local branch = vim.fn.system("git -C " .. vim.fn.shellescape(vim.fn.expand("%:p:h")) .. " branch --show-current 2>/dev/null")
    branch = branch:gsub("%s+", "")
    if branch == "" then return "" end
    return " " .. branch .. " |"
end
opt.statusline = " %f %m%r%=%{v:lua.git_branch()} %l:%c %p%% "

-- Misc
opt.updatetime = 250
opt.mouse = "a"