local M = {}

---@param original table original highlight group
---@param extension table highlight group to extend the original with
---@return table new the result of extending the original with the extension
function M.override(original, extension)
    return vim.tbl_extend("force", {}, original, extension)
end

---@param c string hex color code
---@return table color color as RGB table
function M.rgb(c)
    c = string.lower(c)
    return { tonumber(c:sub(2, 3), 16), tonumber(c:sub(4, 5), 16), tonumber(c:sub(6, 7), 16) }
end

---@param foreground string foreground color
---@param background string|nil background color
---@param alpha number|string number between 0 and 1. 0 results in bg, 1 results in fg
function M.blend(foreground, alpha, background)
    local bg = background or "#000000"
    alpha = type(alpha) == "string" and (tonumber(alpha, 16) / 0xff) or alpha
    local bg = M.rgb(bg)
    local fg = M.rgb(foreground)

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

    return string.format("#%02x%02x%02x", blendChannel(1), blendChannel(2), blendChannel(3))
end

---@param original table table to copy
---@return table new new table
function M.deep_copy(original)
    if type(original) ~= "table" then
        return original
    end

    local new = {}
    for k, v in pairs(original) do
        new[M.deep_copy(k)] = M.deep_copy(v)
    end
    return new
end

return M