neovim-flake/modules/dashboard/alpha/config.nix

{
  config,
  lib,
  ...
}: let
  inherit (lib) mkIf nvim;

  cfg = config.vim.dashboard.alpha;
in {
  config = mkIf cfg.enable {
    vim.startPlugins = [
      "alpha-nvim"
      "nvim-web-devicons"
    ];

    # the entire credit for this dashboard configuration to https://github.com/Rishabh672003
    # honestly, excellent work
    vim.luaConfigRC.alpha = nvim.dag.entryAnywhere ''
      local alpha = require("alpha")
      local plenary_path = require("plenary.path")
      local dashboard = require("alpha.themes.dashboard")
      local cdir = vim.fn.getcwd()
      local if_nil = vim.F.if_nil

      local nvim_web_devicons = {
      	enabled = true,
      	highlight = true,
      }

      local function get_extension(fn)
      	local match = fn:match("^.+(%..+)$")
      	local ext = ""
      	if match ~= nil then
      		ext = match:sub(2)
      	end
      	return ext
      end

      local function icon(fn)
      	local nwd = require("nvim-web-devicons")
      	local ext = get_extension(fn)
      	return nwd.get_icon(fn, ext, { default = true })
      end

      local function file_button(fn, sc, short_fn)
      	short_fn = short_fn or fn
      	local ico_txt
      	local fb_hl = {}

      	if nvim_web_devicons.enabled then
      		local ico, hl = icon(fn)
      		local hl_option_type = type(nvim_web_devicons.highlight)
      		if hl_option_type == "boolean" then
      			if hl and nvim_web_devicons.highlight then
      				table.insert(fb_hl, { hl, 0, 3 })
      			end
      		end
      		if hl_option_type == "string" then
      			table.insert(fb_hl, { nvim_web_devicons.highlight, 0, 3 })
      		end
      		ico_txt = ico .. "  "
      	else
      		ico_txt = ""
      	end
      	local file_button_el = dashboard.button(sc, ico_txt .. short_fn, "<cmd>e " .. fn .. " <CR>")
      	local fn_start = short_fn:match(".*[/\\]")
      	if fn_start ~= nil then
      		table.insert(fb_hl, { "Comment", #ico_txt - 2, #fn_start + #ico_txt })
      	end
      	file_button_el.opts.hl = fb_hl
      	return file_button_el
      end

      local default_mru_ignore = { "gitcommit" }

      local mru_opts = {
      	ignore = function(path, ext)
      		return (string.find(path, "COMMIT_EDITMSG")) or (vim.tbl_contains(default_mru_ignore, ext))
      	end,
      }

      --- @param start number
      --- @param cwd string optional
      --- @param items_number number optional number of items to generate, default = 10
      local function mru(start, cwd, items_number, opts)
      	opts = opts or mru_opts
      	items_number = if_nil(items_number, 15)

      	local oldfiles = {}
      	for _, v in pairs(vim.v.oldfiles) do
      		if #oldfiles == items_number then
      			break
      		end
      		local cwd_cond
      		if not cwd then
      			cwd_cond = true
      		else
      			cwd_cond = vim.startswith(v, cwd)
      		end
      		local ignore = (opts.ignore and opts.ignore(v, get_extension(v))) or false
      		if (vim.fn.filereadable(v) == 1) and cwd_cond and not ignore then
      			oldfiles[#oldfiles + 1] = v
      		end
      	end
      	local target_width = 35

      	local tbl = {}
      	for i, fn in ipairs(oldfiles) do
      		local short_fn
      		if cwd then
      			short_fn = vim.fn.fnamemodify(fn, ":.")
      		else
      			short_fn = vim.fn.fnamemodify(fn, ":~")
      		end

      		if #short_fn > target_width then
      			short_fn = plenary_path.new(short_fn):shorten(1, { -2, -1 })
      			if #short_fn > target_width then
      				short_fn = plenary_path.new(short_fn):shorten(1, { -1 })
      			end
      		end

      		local shortcut = tostring(i + start - 1)

      		local file_button_el = file_button(fn, shortcut, short_fn)
      		tbl[i] = file_button_el
      	end
      	return {
      		type = "group",
      		val = tbl,
      		opts = {},
      	}
      end

      local default_header = {
      	type = "text",
      	val = {

      		[[███    ██ ███████  ██████  ██    ██ ██ ███    ███]],
      		[[████   ██ ██      ██    ██ ██    ██ ██ ████  ████]],
      		[[██ ██  ██ █████   ██    ██ ██    ██ ██ ██ ████ ██]],
      		[[██  ██ ██ ██      ██    ██  ██  ██  ██ ██  ██  ██]],
      		[[██   ████ ███████  ██████    ████   ██ ██      ██]],

      		-- [[                               __                ]],
      		-- [[  ___     ___    ___   __  __ /\_\    ___ ___    ]],
      		-- [[ / _ `\  / __`\ / __`\/\ \/\ \\/\ \  / __` __`\  ]],
      		-- [[/\ \/\ \/\  __//\ \_\ \ \ \_/ |\ \ \/\ \/\ \/\ \ ]],
      		-- [[\ \_\ \_\ \____\ \____/\ \___/  \ \_\ \_\ \_\ \_\]],
      		-- [[ \/_/\/_/\/____/\/___/  \/__/    \/_/\/_/\/_/\/_/]],
      	},
      	opts = {
      		position = "center",
      		hl = "Type",
      		-- wrap = "overflow";
      	},
      }

      local section_mru = {
      	type = "group",
      	val = {
      		{
      			type = "text",
      			val = "Recent files",
      			opts = {
      				hl = "SpecialComment",
      				shrink_margin = false,
      				position = "center",
      			},
      		},
      		{ type = "padding", val = 1 },
      		{
      			type = "group",
      			val = function()
      				return { mru(0, cdir) }
      			end,
      			opts = { shrink_margin = false },
      		},
      	},
      }

      local buttons = {
      	type = "group",
      	val = {
      		{ type = "text", val = "Quick links", opts = { hl = "SpecialComment", position = "center" } },
      		{ type = "padding", val = 1 },
          -- TODO: buttons should be added based on whether or not the relevant plugin is available
      		dashboard.button("e", "  New file", "<cmd>ene<CR>"), -- available all the time
      		dashboard.button("SPC F", "󰈞  Find file"), -- telescope
      		dashboard.button("SPC ff", "󰊄  Live grep"), -- telescope
      		dashboard.button("SPC p", "  Projects"), -- any project
      		dashboard.button("q", "󰅚  Quit", "<cmd>qa<CR>"), -- available all the time
      	},
      	position = "center",
      }

      local config = {
      	layout = {
      		{ type = "padding", val = 2 },
      		default_header,
      		{ type = "padding", val = 2 },
      		section_mru,
      		{ type = "padding", val = 2 },
      		buttons,
      	},
      	opts = {
      		margin = 5,
      		setup = function()
      			vim.cmd([[
                  autocmd alpha_temp DirChanged * lua require('alpha').redraw()
                  ]])
      		end,
      	},
      }

      alpha.setup(config)
    '';
  };
}