Harpoon files in tabline through Lualine with colored text and switch on click

harpoon_tabline.lua

local colors = require("kanagawa.colors").setup()
local theme_colors = colors.theme

vim.api.nvim_set_hl(0, 'HarpoonActive', { ctermbg = 0, fg = theme_colors.syn.identifier, bg = theme_colors.ui.bg })
vim.api.nvim_set_hl(0, 'HarpoonNumberActive', { ctermbg = 0, fg = theme_colors.syn.number, bg = theme_colors.ui.bg })
vim.api.nvim_set_hl(0, 'HarpoonInactive', { ctermbg = 0, fg = theme_colors.syn.fg, bg = theme_colors.ui.bg_p1 })
vim.api.nvim_set_hl(0, 'HarpoonNumberInactive', { ctermbg = 0, fg = theme_colors.syn.number, bg = theme_colors.ui.bg_p1 })

local function harpoon_files()
  local harpoon = require("harpoon")
  local marks_length = harpoon:list():length()

  local contents = {}
  local current_file_path = vim.fn.fnamemodify(vim.fn.expand("%:p"), ":.")
  for index = 1, marks_length do
    local harpoon_file_path = harpoon:list():get(index).value
    local file_name = harpoon_file_path == "" and "(empty)" or vim.fn.fnamemodify(harpoon_file_path, ':t')

    if current_file_path == harpoon_file_path then
      contents[index] = string.format("%%#HarpoonNumberActive# %s. %%#HarpoonActive#%s ", index, file_name)
    else
      contents[index] = string.format("%%#HarpoonNumberInactive# %s. %%#HarpoonInactive#%s ", index, file_name)
    end
    contents[index] = string.format('%%%s@LualineSwitchHarpoon@%s%%X', index, contents[index])
  end

  return table.concat(contents)
end

vim.cmd([[
  function! LualineSwitchHarpoon(index, mouseclicks, mousebutton, modifiers)
    execute ":lua require(\"harpoon\"):list():select(" .. a:index .. ")"
  endfunction
]])

require('lualine').setup {
  tabline = {
    lualine_a = {
      { harpoon_files }
    },
  },
}