nvim/lua/config/lualine.lua

local fn = vim.fn

local function get_coc_lsp_client()
    local clients = vim.g.coc_service_initialized and
                        vim.fn['CocAction']('services') or {}
    for _, client in pairs(clients) do
        if client['state'] == 'running' then
            local client_name = client['id']
            -- Remove 'languageserver.' prefix if it exists
            client_name = client_name:gsub('^languageserver%.', '')
            return client_name
        end
    end
    return ''
end

local function spell()
    if vim.o.spell then return string.format("[SPELL]") end

    return ""
end

--- show indicator for Chinese IME
local function ime_state()
    if vim.g.is_mac then
        local layout = fn.libcall(vim.g.XkbSwitchLib, "Xkb_Switch_getXkbLayout",
                                  "")
        local res = fn.match(layout, [[\v(Squirrel\.Rime|SCIM.ITABC)]])
        if res ~= -1 then return "[CN]" end
    end

    return ""
end

local diff = function()
    local git_status = vim.b.gitsigns_status_dict
    if git_status == nil then return end

    local modify_num = git_status.changed
    local remove_num = git_status.removed
    local add_num = git_status.added

    local info = {added = add_num, modified = modify_num, removed = remove_num}
    -- vim.print(info)
    return info
end

local virtual_env = function()
    -- only show virtual env for Python
    if vim.bo.filetype ~= "python" then return "" end

    local conda_env = os.getenv("CONDA_DEFAULT_ENV")
    local venv_path = os.getenv("VIRTUAL_ENV")

    if venv_path == nil then
        if conda_env == nil then
            return ""
        else
            return string.format("  %s (conda)", conda_env)
        end
    else
        local venv_name = vim.fn.fnamemodify(venv_path, ":t")
        return string.format("  %s (venv)", venv_name)
    end
end

require("lualine").setup {
    options = {
        icons_enabled = true,
        theme = "auto",
        globalstatus = true,
        component_separators = '',
        section_separators = {left = '', right = ''},
        disabled_filetypes = {},
        always_divide_middle = true
    },
    sections = {
        lualine_a = {{"mode"}},
        lualine_b = {
            {
                "branch",
                fmt = function(name, _)
                    -- truncate branch name in case the name is too long
                    return string.sub(name, 1, 20)
                end,
                color = {gui = "italic,bold"},
                separator = {right = ""}
            }, {virtual_env, color = {fg = "black", bg = "#F1CA81"}}
        },
        lualine_c = {
            {"filename", symbols = {readonly = "[🔒]"}},
            {"diff", source = diff},
            {"%S", color = {gui = "bold", fg = "cyan"}},
            {spell, color = {fg = "black", bg = "#a7c080"}}
        },
        lualine_x = {
            {ime_state, color = {fg = "black", bg = "#f46868"}},
            {get_coc_lsp_client, icon = " LSP:"}, {
                "diagnostics",
                sources = {"nvim_diagnostic"},
                symbols = {
                    error = "🆇 ",
                    warn = "⚠️ ",
                    info = "ℹ️ ",
                    hint = " "
                }
            }
        },
        lualine_y = {
            {"encoding", fmt = string.upper},
            {"fileformat", symbols = {unix = "", dos = "", mac = ""}},
            "filetype"
        },
        lualine_z = {"progress"}
    },
    inactive_sections = {
        lualine_a = {},
        lualine_b = {},
        lualine_c = {"filename"},
        lualine_x = {"location"},
        lualine_y = {},
        lualine_z = {}
    },
    tabline = {},
    extensions = {"quickfix", "fugitive", "nvim-tree"}
}