tabby.lua

-- Tabby
-- https://github.com/UserEast/nightfox.nvim/tree/main/mics/tabby.lua
--
-- This file is a complete example of creating the tabby configuration shown in the readme of
-- nightfox. This configuration generates its own highlight groups from the currently applied
-- colorscheme. These highlight groups are regenreated on colorscheme changes.
--
-- Required plugins:
--    - `nanozuki/tabby.nvim`
--
-- This file is required to be in your `lua` folder of your config.  Your colorscheme should also
-- be applied before this file is sourced. This file cannot be located `lua/tabby.lua` as this
-- would clash with the actual plugin require path.
--
--
-- # Example:
--
-- ```lua
-- vim.cmd("colorscheme nightfox")
-- require('user.ui.tabby')
-- ```
--
-- This assumes that this file is located at `lua/user/ui/tabby.lua`

local fmt = string.format

----------------------------------------------------------------------------------------------------
-- Colors

---Convert color number to hex string
---@param n number
---@return string
local hex = function(n)
  if n then
    return fmt("#%06x", n)
  end
end

---Parse `style` string into nvim_set_hl options
---@param style string
---@return table
local function parse_style(style)
  if not style or style == "NONE" then
    return {}
  end

  local result = {}
  for token in string.gmatch(style, "([^,]+)") do
    result[token] = true
  end

  return result
end

---Get highlight opts for a given highlight group name
---@param name string
---@return table
local function get_highlight(name)
  local hl = vim.api.nvim_get_hl_by_name(name, true)
  if hl.link then
    return get_highlight(hl.link)
  end

  local result = parse_style(hl.style)
  result.fg = hl.foreground and hex(hl.foreground)
  result.bg = hl.background and hex(hl.background)
  result.sp = hl.special and hex(hl.special)

  return result
end

---Set highlight group from provided table
---@param groups table
local function set_highlights(groups)
  for group, opts in pairs(groups) do
    vim.api.nvim_set_hl(0, group, opts)
  end
end

---Generate a color palette from the current applied colorscheme
---@return table
local function generate_pallet_from_colorscheme()
  -- stylua: ignore
  local color_map = {
    black   = { index = 0, default = "#393b44" },
    red     = { index = 1, default = "#c94f6d" },
    green   = { index = 2, default = "#81b29a" },
    yellow  = { index = 3, default = "#dbc074" },
    blue    = { index = 4, default = "#719cd6" },
    magenta = { index = 5, default = "#9d79d6" },
    cyan    = { index = 6, default = "#63cdcf" },
    white   = { index = 7, default = "#dfdfe0" },
  }

  local pallet = {}
  for name, value in pairs(color_map) do
    local global_name = "terminal_color_" .. value.index
    pallet[name] = vim.g[global_name] and vim.g[global_name] or value.default
  end

  pallet.sl = get_highlight("StatusLine")
  pallet.tab = get_highlight("TabLine")
  pallet.sel = get_highlight("TabLineSel")
  pallet.fill = get_highlight("TabLineFill")

  return pallet
end

---Generate user highlight groups based on the curent applied colorscheme
---
---NOTE: This is a global because I dont known where this file will be in your config
---and it is needed for the autocmd below
_G._genreate_user_tabline_highlights = function()
  local pal = generate_pallet_from_colorscheme()

  -- stylua: ignore
  local sl_colors = {
    Black   = { fg = pal.black,   bg = pal.white },
    Red     = { fg = pal.red,     bg = pal.sl.bg },
    Green   = { fg = pal.green,   bg = pal.sl.bg },
    Yellow  = { fg = pal.yellow,  bg = pal.sl.bg },
    Blue    = { fg = pal.blue,    bg = pal.sl.bg },
    Magenta = { fg = pal.magenta, bg = pal.sl.bg },
    Cyan    = { fg = pal.cyan,    bg = pal.sl.bg },
    White   = { fg = pal.white,   bg = pal.black },
  }

  local colors = {}
  for name, value in pairs(sl_colors) do
    colors["User" .. name] = { fg = value.fg, bg = value.bg, bold = true }
    colors["UserRv" .. name] = { fg = value.bg, bg = value.fg, bold = true }
  end

  local groups = {
    -- tabline
    UserTLHead = { fg = pal.fill.bg, bg = pal.cyan },
    UserTLHeadSep = { fg = pal.cyan, bg = pal.fill.bg },
    UserTLActive = { fg = pal.sel.fg, bg = pal.sel.bg, bold = true },
    UserTLActiveSep = { fg = pal.sel.bg, bg = pal.fill.bg },
    UserTLBoldLine = { fg = pal.tab.fg, bg = pal.tab.bg, bold = true },
    UserTLLineSep = { fg = pal.tab.bg, bg = pal.fill.bg },
  }

  set_highlights(vim.tbl_extend("force", colors, groups))
end

_genreate_user_tabline_highlights()

vim.api.nvim_create_augroup("UserTablineHighlightGroups", { clear = true })
vim.api.nvim_create_autocmd({ "SessionLoadPost", "ColorScheme" }, {
  callback = function()
    _genreate_user_tabline_highlights()
  end,
})

----------------------------------------------------------------------------------------------------
-- Feline

local filename = require("tabby.filename")

local cwd = function()
  return "  " .. vim.fn.fnamemodify(vim.fn.getcwd(), ":t") .. " "
end

local line = {
  hl = "TabLineFill",
  layout = "active_wins_at_tail",
  head = {
    { cwd, hl = "UserTLHead" },
    { "", hl = "UserTLHeadSep" },
  },
  active_tab = {
    label = function(tabid)
      return {
        "  " .. tabid .. " ",
        hl = "UserTLActive",
      }
    end,
    left_sep = { "", hl = "UserTLActiveSep" },
    right_sep = { "", hl = "UserTLActiveSep" },
  },
  inactive_tab = {
    label = function(tabid)
      return {
        "  " .. tabid .. " ",
        hl = "UserTLBoldLine",
      }
    end,
    left_sep = { "", hl = "UserTLLineSep" },
    right_sep = { "", hl = "UserTLLineSep" },
  },
  top_win = {
    label = function(winid)
      return {
        "  " .. filename.unique(winid) .. " ",
        hl = "TabLine",
      }
    end,
    left_sep = { "", hl = "UserTLLineSep" },
    right_sep = { "", hl = "UserTLLineSep" },
  },
  win = {
    label = function(winid)
      return {
        "  " .. filename.unique(winid) .. " ",
        hl = "TabLine",
      }
    end,
    left_sep = { "", hl = "UserTLLineSep" },
    right_sep = { "", hl = "UserTLLineSep" },
  },
  tail = {
    { "", hl = "UserTLHeadSep" },
    { "  ", hl = "UserTLHead" },
  },
}

require("tabby").setup({
  tabline = line,
})