numbers/nvim/plugin/statusline.lua

-- setup truncation limits
local truncation_limit = 120

-- is buffer horizontally truncated
Is_htruncated = function(width)
	local current_width = vim.api.nvim_win_get_width(0)
	return current_width < width
end

-- diagnostics symbol config
local symbol_config = {
	indicator_hint = " ",
	indicator_info = " ",
	indicator_warning = "  ",
	indicator_error = "  ",
}

-- statusline colors
local statusline_colors = {
	active = "%#StatusLine#",
	inactive = "%#StatusLineNC#",
	git = "%#diffChanged#",
	err = "%#DiagnosticSignError#",
	warn = "%#DiagnosticSignWarn#",
	nfo = "%#DiagnosticSignInfo#",
	hnt = "%#DiagnosticSignHint#",
	line_col = "%#Delimiter#",
	percentage = "%#Delimiter#",
}

-- get git information of current file
local get_git_status = function()
	local meta = {}
	local gitsigns_summary = vim.b.gitsigns_status_dict
	if not gitsigns_summary then
		return ""
	end
	meta["branch"] = gitsigns_summary["head"]
	meta["added"] = gitsigns_summary["added"]
	meta["modified"] = gitsigns_summary["changed"]
	meta["removed"] = gitsigns_summary["removed"]
	if Is_htruncated(truncation_limit) then
		return string.format(" %s", meta["branch"])
	else
		return string.format("   %s +%s ~%s -%s", meta["branch"], meta["added"], meta["modified"], meta["removed"])
	end
end

-- get current file name
local get_filename = function()
	if Is_htruncated(truncation_limit) then
		return "%t "
	end
	return "%<%F "
end

-- get current line/col
local get_line_col = function()
	return " %l:%c"
end

-- get current percentage through file
local get_percentage = function()
	if Is_htruncated(truncation_limit) then
		return ""
	else
		return " %p%%"
	end
end

local get_flags = function()
	return "%h%w%m "
end

-- get current file diagnostics
local get_diagnostics = function()
	if #vim.lsp.buf_get_clients(0) == 0 then
		return ""
	end

	local status_parts = {}
	if not Is_htruncated(truncation_limit) then
		local warnings = vim.diagnostic.get(0, { severity = vim.diagnostic.severity.WARN })
		local hints = vim.diagnostic.get(0, { severity = vim.diagnostic.severity.HINT })
		local infos = vim.diagnostic.get(0, { severity = vim.diagnostic.severity.INFO })
		local errors = vim.diagnostic.get(0, { severity = vim.diagnostic.severity.ERROR })

		if errors > 0 then
			table.insert(status_parts, statusline_colors.err .. symbol_config.indicator_error .. errors)
		end

		if warnings > 0 then
			table.insert(status_parts, statusline_colors.warn .. symbol_config.indicator_warning .. warnings)
		end

		if infos > 0 then
			table.insert(status_parts, statusline_colors.nfo .. symbol_config.indicator_info .. infos)
		end

		if hints > 0 then
			table.insert(status_parts, statusline_colors.hnt .. symbol_config.indicator_hint .. hints)
		end
	end

	local status_diagnostics = vim.trim(table.concat(status_parts, " "))
	if status_diagnostics ~= "" then
		return status_diagnostics .. " "
	end
	return ""
end

-- inactive statusline
local statusline_inactive = function()
	local flags = get_flags()
	local filename = get_filename()
	local line_col = get_line_col()
	local percentage = get_percentage()

	return table.concat({
		statusline_colors.inactive,
		flags,
		filename,
		"%=% ",
		line_col,
		percentage,
	})
end

-- active statusline
local statusline_normal = function()
	-- local diagnostics = get_diagnostics()
	local flags = statusline_colors.active .. get_flags()
	local filename = statusline_colors.active .. get_filename()
	local git = statusline_colors.git .. get_git_status()
	local line_col = statusline_colors.line_col .. get_line_col()
	local percentage = statusline_colors.percentage .. get_percentage()

	return table.concat({
		-- diagnostics,
		flags,
		"%=% ",
		filename,
		"%=% ",
		git,
		line_col,
		percentage,
	})
end

-- module
M = {}

-- generate statusline
StatusLine = function()
	return statusline_normal()
end
M.StatusLine = StatusLine

-- generate inactive statusline
StatusLineInactive = function()
	return statusline_inactive()
end
M.StatusLineInactive = StatusLineInactive

return M