local utilities = {}

---@param color string
local function color_to_rgb(color)
	local function byte(value, offset)
		return bit.band(bit.rshift(value, offset), 0xFF)
	end

	local new_color = vim.api.nvim_get_color_by_name(color)
	if new_color == -1 then
		new_color = vim.opt.background:get() == "dark" and 000 or 255255255
	end

	return { byte(new_color, 16), byte(new_color, 8), byte(new_color, 0) }
end

---@param color string Palette key or hex value
local function parse_color(color)
	if color == nil then
		return print("Invalid color")
	end

	color = color:lower()

	if not color:find("#") and color ~= "NONE" then
		color = require("rose-pine.palette")[color] or vim.api.nvim_get_color_by_name(color)
	end

	return color
end

---@param fg string Foreground color
---@param bg string Background color
---@param alpha number Between 0 (background) and 1 (foreground)
local function blend(fg, bg, alpha)
	local fg_rgb = color_to_rgb(fg)
	local bg_rgb = color_to_rgb(bg)

	local function blend_channel(i)
		local ret = (alpha * fg_rgb[i] + ((1 - alpha) * bg_rgb[i]))
		return math.floor(math.min(math.max(0, ret), 255) + 0.5)
	end

	return string.format("#%02X%02X%02X", blend_channel(1), blend_channel(2), blend_channel(3))
end

---@param group string
---@param highlight table<string, any>
function utilities.highlight(group, highlight, blend_on)
	local fg = highlight.fg and parse_color(highlight.fg) or "NONE"
	local bg = highlight.bg and parse_color(highlight.bg) or "NONE"
	local sp = highlight.sp and parse_color(highlight.sp) or "NONE"

	if highlight.blend ~= nil and (highlight.blend >= 0 and highlight.blend <= 100) and bg ~= nil then
		bg = blend(bg, blend_on or require("rose-pine.palette").base, highlight.blend / 100)
	end

	highlight.fg = fg
	highlight.bg = bg
	highlight.sp = sp
	-- highlight = vim.tbl_extend("force", highlight, { fg = fg, bg = bg, sp = sp })

	vim.api.nvim_set_hl(0, group, highlight)
end

return utilities