# const _invisible = RGBA(0,0,0,0)
#
# const _themes = KW(
#     :default => KW(
#         :bg         => :white,
#         :bglegend   => :match,
#         :bginside   => :match,
#         :bgoutside  => :match,
#         :fg         => :auto,
#         :fglegend   => :match,
#         :fggrid     => :match,
#         :fgaxis     => :match,
#         :fgtext     => :match,
#         :fgborder   => :match,
#         :fgguide    => :match,
#     )
# )

# function add_theme(sym::Symbol, theme::KW)
#     _themes[sym] = theme
# end
#
# # add a new theme, using an existing theme as the base
# function add_theme(sym::Symbol;
#                    base      = :default,  # start with this theme
#                    bg        = _themes[base][:bg],
#                    bglegend  = _themes[base][:bglegend],
#                    bginside  = _themes[base][:bginside],
#                    bgoutside = _themes[base][:bgoutside],
#                    fg        = _themes[base][:fg],
#                    fglegend  = _themes[base][:fglegend],
#                    fggrid    = _themes[base][:fggrid],
#                    fgaxis    = _themes[base][:fgaxis],
#                    fgtext    = _themes[base][:fgtext],
#                    fgborder  = _themes[base][:fgborder],
#                    fgguide   = _themes[base][:fgguide],
#                    kw...)
#     _themes[sym] = merge(KW(
#         :bg => bg,
#         :bglegend  => bglegend,
#         :bginside  => bginside,
#         :bgoutside => bgoutside,
#         :fg        => fg,
#         :fglegend  => fglegend,
#         :fggrid    => fggrid,
#         :fgaxis    => fgaxis,
#         :fgtext    => fgtext,
#         :fgborder  => fgborder,
#         :fgguide   => fgguide,
#     ), KW(kw))
# end
#
# add_theme(:ggplot2,
#     bglegend = :lightgray,
#     bginside = :lightgray,
#     fg       = :black,
#     fggrid   = :white,
#     fgborder = _invisible,
#     fgaxis   = _invisible
# )

function theme(s::Symbol; kw...)
    thm = PlotThemes._themes[s]
    PlotUtils._default_gradient[] = s
    default(;
        bg       = thm.bg_secondary,
        bginside = thm.bg_primary,
        fg       = thm.lines,
        fgtext   = thm.text,
        fgguide  = thm.text,
        fglegend = thm.text,
        palette  = thm.palette,
        kw...
    )
end

@deprecate set_theme(s) theme(s)