# https://github.com/jheinen/GR.jl

# significant contributions by @jheinen


const _gr_attr = merge_with_base_supported([
    :annotations,
    :background_color_legend, :background_color_inside, :background_color_outside,
    :foreground_color_legend, :foreground_color_grid, :foreground_color_axis,
    :foreground_color_text, :foreground_color_border,
    :label,
    :seriescolor, :seriesalpha,
    :linecolor, :linestyle, :linewidth, :linealpha,
    :markershape, :markercolor, :markersize, :markeralpha,
    :markerstrokewidth, :markerstrokecolor, :markerstrokealpha,
    :fillrange, :fillcolor, :fillalpha,
    :bins,
    :layout,
    :title, :window_title,
    :guide, :lims, :ticks, :scale, :flip,
    :tickfont, :guidefont, :legendfont,
    :grid, :legend, :legendtitle, :colorbar,
    :marker_z, :levels,
    :ribbon, :quiver,
    :orientation,
    :overwrite_figure,
    :polar,
    :aspect_ratio,
    :normalize, :weights,
    :inset_subplots,
    :bar_width,
    :arrow,
])
const _gr_seriestype = [
    :path, :scatter,
    :heatmap, :pie, :image,
    :contour, :path3d, :scatter3d, :surface, :wireframe,
    :shape
]
const _gr_style = [:auto, :solid, :dash, :dot, :dashdot, :dashdotdot]
const _gr_marker = _allMarkers
const _gr_scale = [:identity, :log10]
is_marker_supported(::GRBackend, shape::Shape) = true

function add_backend_string(::GRBackend)
    """
    Pkg.add("GR")
    Pkg.build("GR")
    """
end

function _initialize_backend(::GRBackend; kw...)
    @eval begin
        import GR
        export GR
    end
end

# --------------------------------------------------------------------------------------

const gr_linetype = KW(
    :auto => 1,
    :solid => 1,
    :dash => 2,
    :dot => 3,
    :dashdot => 4,
    :dashdotdot => -1
)

const gr_markertype = KW(
    :auto => 1,
    :none => -1,
    :circle => -1,
    :rect => -7,
    :diamond => -13,
    :utriangle => -3,
    :dtriangle => -5,
    :ltriangle => -18,
    :rtriangle => -17,
    :pentagon => -21,
    :hexagon => -22,
    :heptagon => -23,
    :octagon => -24,
    :cross => 2,
    :xcross => 5,
    :+ => 2,
    :x => 5,
    :star4 => -25,
    :star5 => -26,
    :star6 => -27,
    :star7 => -28,
    :star8 => -29,
    :vline => -30,
    :hline => -31
)

const gr_halign = KW(
    :left => 1,
    :hcenter => 2,
    :right => 3
)

const gr_valign = KW(
    :top => 1,
    :vcenter => 3,
    :bottom => 5
)

const gr_font_family = Dict(
    "times" => 1,
    "helvetica" => 5,
    "courier" => 9,
    "bookman" => 14,
    "newcenturyschlbk" => 18,
    "avantgarde" => 22,
    "palatino" => 26
)

# --------------------------------------------------------------------------------------

function gr_getcolorind(c)
    GR.settransparency(float(alpha(c)))
    convert(Int, GR.inqcolorfromrgb(red(c), green(c), blue(c)))
end

gr_set_linecolor(c)   = GR.setlinecolorind(gr_getcolorind(_cycle(c,1)))
gr_set_fillcolor(c)   = GR.setfillcolorind(gr_getcolorind(_cycle(c,1)))
gr_set_markercolor(c) = GR.setmarkercolorind(gr_getcolorind(_cycle(c,1)))
gr_set_textcolor(c)   = GR.settextcolorind(gr_getcolorind(_cycle(c,1)))

# --------------------------------------------------------------------------------------


# draw line segments, splitting x/y into contiguous/finite segments
# note: this can be used for shapes by passing func `GR.fillarea`
function gr_polyline(x, y, func = GR.polyline; arrowside=:none)
    iend = 0
    n = length(x)
    while iend < n-1
        # set istart to the first index that is finite
        istart = -1
        for j = iend+1:n
            if isfinite(x[j]) && isfinite(y[j])
                istart = j
                break
            end
        end

        if istart > 0
            # iend is the last finite index
            iend = -1
            for j = istart+1:n
                if isfinite(x[j]) && isfinite(y[j])
                    iend = j
                else
                    break
                end
            end
        end

        # if we found a start and end, draw the line segment, otherwise we're done
        if istart > 0 && iend > 0
            func(x[istart:iend], y[istart:iend])
            if arrowside in (:head,:both)
                GR.drawarrow(x[iend-1], y[iend-1], x[iend], y[iend])
            end
            if arrowside in (:tail,:both)
                GR.drawarrow(x[istart+1], y[istart+1], x[istart], y[istart])
            end
        else
            break
        end
    end
end

gr_inqtext(x, y, s::Symbol) = gr_inqtext(x, y, string(s))

function gr_inqtext(x, y, s)
    if length(s) >= 2 && s[1] == '$' && s[end] == '$'
        GR.inqtextext(x, y, s[2:end-1])
    elseif search(s, '\\') != 0 || search(s, '_') != 0 || search(s, '^') != 0
        GR.inqtextext(x, y, s)
    else
        GR.inqtext(x, y, s)
    end
end

gr_text(x, y, s::Symbol) = gr_text(x, y, string(s))

function gr_text(x, y, s)
    if length(s) >= 2 && s[1] == '$' && s[end] == '$'
        GR.mathtex(x, y, s[2:end-1])
    elseif search(s, '\\') != 0 || search(s, '_') != 0 || search(s, '^') != 0
        GR.textext(x, y, s)
    else
        GR.text(x, y, s)
    end
end

function gr_polaraxes(rmin, rmax)
    GR.savestate()
    GR.setlinetype(GR.LINETYPE_SOLID)
    GR.setlinecolorind(88)
    tick = 0.5 * GR.tick(rmin, rmax)
    n = round(Int, (rmax - rmin) / tick + 0.5)
    for i in 0:n
        r = float(i) / n
        if i % 2 == 0
            GR.setlinecolorind(88)
            if i > 0
                GR.drawarc(-r, r, -r, r, 0, 359)
            end
            GR.settextalign(GR.TEXT_HALIGN_LEFT, GR.TEXT_VALIGN_HALF)
            x, y = GR.wctondc(0.05, r)
            GR.text(x, y, string(signif(rmin + i * tick, 12)))
        else
            GR.setlinecolorind(90)
            GR.drawarc(-r, r, -r, r, 0, 359)
        end
    end
    for α in 0:45:315
        a = α + 90
        sinf = sin(a * pi / 180)
        cosf = cos(a * pi / 180)
        GR.polyline([sinf, 0], [cosf, 0])
        GR.settextalign(GR.TEXT_HALIGN_CENTER, GR.TEXT_VALIGN_HALF)
        x, y = GR.wctondc(1.1 * sinf, 1.1 * cosf)
        GR.textext(x, y, string(α, "^o"))
    end
    GR.restorestate()
end


# using the axis extrema and limit overrides, return the min/max value for this axis
gr_x_axislims(sp::Subplot) = axis_limits(sp[:xaxis])
gr_y_axislims(sp::Subplot) = axis_limits(sp[:yaxis])
gr_z_axislims(sp::Subplot) = axis_limits(sp[:zaxis])
gr_xy_axislims(sp::Subplot) = gr_x_axislims(sp)..., gr_y_axislims(sp)...

function gr_lims(axis::Axis, adjust::Bool, expand = nothing)
    if expand != nothing
        expand_extrema!(axis, expand)
    end
    lims = axis_limits(axis)
    if adjust
        GR.adjustrange(lims...)
    else
        lims
    end
end


function gr_fill_viewport(vp::AVec{Float64}, c)
    GR.savestate()
    GR.selntran(0)
    GR.setfillintstyle(GR.INTSTYLE_SOLID)
    gr_set_fillcolor(c)
    GR.fillrect(vp...)
    GR.selntran(1)
    GR.restorestate()
end


normalize_zvals(zv::Void) = zv
function normalize_zvals(zv::AVec)
    vmin, vmax = ignorenan_extrema(zv)
    if vmin == vmax
        zeros(length(zv))
    else
        (zv - vmin) ./ (vmax - vmin)
    end
end

# ---------------------------------------------------------

# draw ONE Shape
function gr_draw_marker(xi, yi, msize, shape::Shape)
    sx, sy = coords(shape)
    # convert to ndc coords (percentages of window)
    GR.selntran(0)
    w, h = gr_plot_size
    f = msize / (w + h)
    xi, yi = GR.wctondc(xi, yi)
    GR.fillarea(xi .+ sx .* f,
                yi .+ sy .* f)
    GR.selntran(1)
end

# draw ONE symbol marker
function gr_draw_marker(xi, yi, msize::Number, shape::Symbol)
    GR.setmarkertype(gr_markertype[shape])
    w, h = gr_plot_size
    GR.setmarkersize(0.3msize / ((w + h) * 0.001))
    GR.polymarker([xi], [yi])
end


# draw the markers, one at a time
function gr_draw_markers(series::Series, x, y, msize, mz)
    shapes = series[:markershape]
    if shapes != :none
        for i=1:length(x)
            msi = _cycle(msize, i)
            shape = _cycle(shapes, i)
            cfunc = isa(shape, Shape) ? gr_set_fillcolor : gr_set_markercolor
            cfuncind = isa(shape, Shape) ? GR.setfillcolorind : GR.setmarkercolorind

            # draw a filled in shape, slightly bigger, to estimate a stroke
            if series[:markerstrokewidth] > 0
                cfunc(_cycle(series[:markerstrokecolor], i)) #, series[:markerstrokealpha])
                gr_draw_marker(x[i], y[i], msi + series[:markerstrokewidth], shape)
            end

            # draw the shape
            if mz == nothing
                cfunc(_cycle(series[:markercolor], i)) #, series[:markeralpha])
            else
                # pick a color from the pre-loaded gradient
                ci = round(Int, 1000 + _cycle(mz, i) * 255)
                cfuncind(ci)
                GR.settransparency(_gr_gradient_alpha[ci-999])
            end
            gr_draw_marker(x[i], y[i], msi, shape)
        end
    end
end

function gr_draw_markers(series::Series, x, y)
    isempty(x) && return
    mz = normalize_zvals(series[:marker_z])
    GR.setfillintstyle(GR.INTSTYLE_SOLID)
    gr_draw_markers(series, x, y, series[:markersize], mz)
    if mz != nothing
        gr_colorbar(series[:subplot])
    end
end

# ---------------------------------------------------------

function gr_set_line(lw, style, c) #, a)
    GR.setlinetype(gr_linetype[style])
    w, h = gr_plot_size
    GR.setlinewidth(max(0, lw / ((w + h) * 0.001)))
    gr_set_linecolor(c) #, a)
end



function gr_set_fill(c) #, a)
    gr_set_fillcolor(c) #, a)
    GR.setfillintstyle(GR.INTSTYLE_SOLID)
end

# this stores the conversion from a font pointsize to "percentage of window height" (which is what GR uses)
const _gr_point_mult = zeros(1)

# set the font attributes... assumes _gr_point_mult has been populated already
function gr_set_font(f::Font; halign = f.halign, valign = f.valign,
                              color = f.color, rotation = f.rotation)
    family = lowercase(f.family)
    GR.setcharheight(_gr_point_mult[1] * f.pointsize)
    GR.setcharup(sind(-rotation), cosd(-rotation))
    if haskey(gr_font_family, family)
        GR.settextfontprec(100 + gr_font_family[family], GR.TEXT_PRECISION_STRING)
    end
    gr_set_textcolor(color)
    GR.settextalign(gr_halign[halign], gr_valign[valign])
end

function gr_nans_to_infs!(z)
    for (i,zi) in enumerate(z)
        if zi == NaN
            z[i] = Inf
        end
    end
end

# --------------------------------------------------------------------------------------
# viewport plot area

# this stays constant for a given subplot while displaying that subplot.
# values are [xmin, xmax, ymin, ymax].  they range [0,1].
const viewport_plotarea = zeros(4)

# the size of the current plot in pixels
const gr_plot_size = zeros(2)

function gr_viewport_from_bbox(sp::Subplot{GRBackend}, bb::BoundingBox, w, h, viewport_canvas)
    viewport = zeros(4)
    viewport[1] = viewport_canvas[2] * (left(bb) / w)
    viewport[2] = viewport_canvas[2] * (right(bb) / w)
    viewport[3] = viewport_canvas[4] * (1.0 - bottom(bb) / h)
    viewport[4] = viewport_canvas[4] * (1.0 - top(bb) / h)
    if is3d(sp)
        vp = viewport[:]
        extent = min(vp[2] - vp[1], vp[4] - vp[3])
        viewport[1] = 0.5 * (vp[1] + vp[2] - extent)
        viewport[2] = 0.5 * (vp[1] + vp[2] + extent)
        viewport[3] = 0.5 * (vp[3] + vp[4] - extent)
        viewport[4] = 0.5 * (vp[3] + vp[4] + extent)
    end
    viewport
end

# change so we're focused on the viewport area
function gr_set_viewport_cmap(sp::Subplot)
    GR.setviewport(
        viewport_plotarea[2] + (is3d(sp) ? 0.07 : 0.02),
        viewport_plotarea[2] + (is3d(sp) ? 0.10 : 0.05),
        viewport_plotarea[3],
        viewport_plotarea[4]
    )
end

# reset the viewport to the plot area
function gr_set_viewport_plotarea()
    GR.setviewport(
        viewport_plotarea[1],
        viewport_plotarea[2],
        viewport_plotarea[3],
        viewport_plotarea[4]
    )
end

function gr_set_viewport_polar()
    xmin, xmax, ymin, ymax = viewport_plotarea
    ymax -= 0.05 * (xmax - xmin)
    xcenter = 0.5 * (xmin + xmax)
    ycenter = 0.5 * (ymin + ymax)
    r = 0.5 * NaNMath.min(xmax - xmin, ymax - ymin)
    GR.setviewport(xcenter -r, xcenter + r, ycenter - r, ycenter + r)
    GR.setwindow(-1, 1, -1, 1)
    r
end

# add the colorbar
function gr_colorbar(sp::Subplot)
    if sp[:colorbar] != :none
        gr_set_viewport_cmap(sp)
        GR.colorbar()
        gr_set_viewport_plotarea()
    end
end

gr_view_xcenter() = 0.5 * (viewport_plotarea[1] + viewport_plotarea[2])
gr_view_ycenter() = 0.5 * (viewport_plotarea[3] + viewport_plotarea[4])

function gr_legend_pos(s::Symbol,w,h)
    str = string(s)
    if str == "best"
        str = "topright"
    end
    if contains(str,"right")
        xpos = viewport_plotarea[2] - 0.05 - w
    elseif contains(str,"left")
        xpos = viewport_plotarea[1] + 0.11
    else
        xpos = (viewport_plotarea[2]-viewport_plotarea[1])/2 - w/2 +.04
    end
    if contains(str,"top")
        ypos = viewport_plotarea[4] - 0.06
    elseif contains(str,"bottom")
        ypos = viewport_plotarea[3] + h + 0.06
    else
        ypos = (viewport_plotarea[4]-viewport_plotarea[3])/2 + h/2
    end
    (xpos,ypos)
end

function gr_legend_pos{S<:Real, T<:Real}(v::Tuple{S,T},w,h)
    xpos = v[1] * (viewport_plotarea[2] - viewport_plotarea[1]) + viewport_plotarea[1]
    ypos = v[2] * (viewport_plotarea[4] - viewport_plotarea[3]) + viewport_plotarea[3]
    (xpos,ypos)
end

# --------------------------------------------------------------------------------------

const _gr_gradient_alpha = ones(256)

function gr_set_gradient(c)
    grad = isa(c, ColorGradient) ? c : cgrad()
    for (i,z) in enumerate(linspace(0, 1, 256))
        c = grad[z]
        GR.setcolorrep(999+i, red(c), green(c), blue(c))
        _gr_gradient_alpha[i] = alpha(c)
    end
    grad
end

# this is our new display func... set up the viewport_canvas, compute bounding boxes, and display each subplot
function gr_display(plt::Plot)
    GR.clearws()

    # collect some monitor/display sizes in meters and pixels
    display_width_meters, display_height_meters, display_width_px, display_height_px = GR.inqdspsize()
    display_width_ratio = display_width_meters / display_width_px
    display_height_ratio = display_height_meters / display_height_px

    # compute the viewport_canvas, normalized to the larger dimension
    viewport_canvas = Float64[0,1,0,1]
    w, h = plt[:size]
    gr_plot_size[:] = [w, h]
    if w > h
        ratio = float(h) / w
        msize = display_width_ratio * w
        GR.setwsviewport(0, msize, 0, msize * ratio)
        GR.setwswindow(0, 1, 0, ratio)
        viewport_canvas[3] *= ratio
        viewport_canvas[4] *= ratio
    else
        ratio = float(w) / h
        msize = display_height_ratio * h
        GR.setwsviewport(0, msize * ratio, 0, msize)
        GR.setwswindow(0, ratio, 0, 1)
        viewport_canvas[1] *= ratio
        viewport_canvas[2] *= ratio
    end

    # fill in the viewport_canvas background
    gr_fill_viewport(viewport_canvas, plt[:background_color_outside])

    # update point mult
    px_per_pt = px / pt
    _gr_point_mult[1] = 1.5 * px_per_pt / max(h,w)

    # subplots:
    for sp in plt.subplots
        gr_display(sp, w*px, h*px, viewport_canvas)
    end

    GR.updatews()
end


function _update_min_padding!(sp::Subplot{GRBackend})
    sp.minpad = (10mm,2mm,2mm,8mm)
end


function gr_display(sp::Subplot{GRBackend}, w, h, viewport_canvas)
    # the viewports for this subplot
    viewport_subplot = gr_viewport_from_bbox(sp, bbox(sp), w, h, viewport_canvas)
    viewport_plotarea[:] = gr_viewport_from_bbox(sp, plotarea(sp), w, h, viewport_canvas)
    # get data limits
    data_lims = gr_xy_axislims(sp)
    xy_lims = data_lims

    ratio = sp[:aspect_ratio]
    if ratio != :none
        if ratio == :equal
            ratio = 1
        end
        viewport_ratio = (viewport_plotarea[2] - viewport_plotarea[1]) / (viewport_plotarea[4] - viewport_plotarea[3])
        window_ratio = (data_lims[2] - data_lims[1]) / (data_lims[4] - data_lims[3]) / ratio
        if window_ratio < viewport_ratio
            viewport_center = 0.5 * (viewport_plotarea[1] + viewport_plotarea[2])
            viewport_size = (viewport_plotarea[2] - viewport_plotarea[1]) * window_ratio / viewport_ratio
            viewport_plotarea[1] = viewport_center - 0.5 * viewport_size
            viewport_plotarea[2] = viewport_center + 0.5 * viewport_size
        elseif window_ratio > viewport_ratio
            viewport_center = 0.5 * (viewport_plotarea[3] + viewport_plotarea[4])
            viewport_size = (viewport_plotarea[4] - viewport_plotarea[3]) * viewport_ratio / window_ratio
            viewport_plotarea[3] = viewport_center - 0.5 * viewport_size
            viewport_plotarea[4] = viewport_center + 0.5 * viewport_size
        end
    end

    # fill in the plot area background
    bg = plot_color(sp[:background_color_inside])
    gr_fill_viewport(viewport_plotarea, bg)

    # reduced from before... set some flags based on the series in this subplot
    # TODO: can these be generic flags?
    outside_ticks = false
    cmap = false
    draw_axes = true
    # axes_2d = true
    for series in series_list(sp)
        st = series[:seriestype]
        if st in (:contour, :surface, :heatmap) || series[:marker_z] != nothing
            cmap = true
        end
        if st == :pie
            draw_axes = false
        end
        if st == :heatmap
            outside_ticks = true
            x, y = heatmap_edges(series[:x], sp[:xaxis][:scale]), heatmap_edges(series[:y], sp[:yaxis][:scale])
            xy_lims = x[1], x[end], y[1], y[end]
            expand_extrema!(sp[:xaxis], x)
            expand_extrema!(sp[:yaxis], y)
            data_lims = gr_xy_axislims(sp)
        end
    end

    if cmap && sp[:colorbar] != :none
        # note: add extra midpadding on the right for the colorbar
        viewport_plotarea[2] -= 0.1
    end

    # set our plot area view
    gr_set_viewport_plotarea()

    # these are the Axis objects, which hold scale, lims, etc
    xaxis = sp[:xaxis]
    yaxis = sp[:yaxis]
    zaxis = sp[:zaxis]

    # set the scale flags and window
    xmin, xmax, ymin, ymax = data_lims
    scaleop = 0
    xtick, ytick = 1, 1
    if xmax > xmin && ymax > ymin
        # NOTE: for log axes, the major_x and major_y - if non-zero (omit labels) - control the minor grid lines (1 = draw 9 minor grid lines, 2 = no minor grid lines)
        # NOTE: for log axes, the x_tick and y_tick - if non-zero (omit axes) - only affect the output appearance (1 = nomal, 2 = scientiic notation)
        xaxis[:scale] == :log10 && (scaleop |= GR.OPTION_X_LOG)
        yaxis[:scale] == :log10 && (scaleop |= GR.OPTION_Y_LOG)
        xaxis[:flip]            && (scaleop |= GR.OPTION_FLIP_X)
        yaxis[:flip]            && (scaleop |= GR.OPTION_FLIP_Y)
        if scaleop & GR.OPTION_X_LOG == 0
            majorx = 1 #5
            xtick = GR.tick(xmin, xmax) / majorx
        else
            # log axis
            xtick = 2  # scientific notation
            majorx = 2 # no minor grid lines
        end
        if scaleop & GR.OPTION_Y_LOG == 0
            majory = 1 #5
            ytick = GR.tick(ymin, ymax) / majory
        else
            # log axis
            ytick = 2  # scientific notation
            majory = 2 # no minor grid lines
        end

        # NOTE: setwindow sets the "data coordinate" limits of the current "viewport"
        GR.setwindow(xmin, xmax, ymin, ymax)
        GR.setscale(scaleop)
    end

    # draw the axes
    gr_set_font(xaxis[:tickfont])
    gr_set_textcolor(xaxis[:foreground_color_text])
    GR.setlinewidth(1)

    if is3d(sp)
        zmin, zmax = gr_lims(zaxis, true)
        clims = sp[:clims]
        if is_2tuple(clims)
            isfinite(clims[1]) && (zmin = clims[1])
            isfinite(clims[2]) && (zmax = clims[2])
        end
        GR.setspace(zmin, zmax, 40, 70)
        xtick = GR.tick(xmin, xmax) / 2
        ytick = GR.tick(ymin, ymax) / 2
        ztick = GR.tick(zmin, zmax) / 2
        ticksize = 0.01 * (viewport_plotarea[2] - viewport_plotarea[1])

        # GR.setlinetype(GR.LINETYPE_DOTTED)
        if sp[:grid]
            GR.grid3d(xtick, 0, ztick, xmin, ymax, zmin, 2, 0, 2)
            GR.grid3d(0, ytick, 0, xmin, ymax, zmin, 0, 2, 0)
        end
        GR.axes3d(xtick, 0, ztick, xmin, ymin, zmin, 2, 0, 2, -ticksize)
        GR.axes3d(0, ytick, 0, xmax, ymin, zmin, 0, 2, 0, ticksize)

    elseif ispolar(sp)
        r = gr_set_viewport_polar()
        rmin, rmax = GR.adjustrange(ignorenan_minimum(r), ignorenan_maximum(r))
        # rmin, rmax = axis_limits(sp[:yaxis])
        gr_polaraxes(rmin, rmax)

    elseif draw_axes
        if xmax > xmin && ymax > ymin
            GR.setwindow(xmin, xmax, ymin, ymax)
        end

        xticks, yticks, spine_segs, grid_segs = axis_drawing_info(sp)
        # @show xticks yticks #spine_segs grid_segs

        # draw the grid lines
        if sp[:grid]
            # gr_set_linecolor(sp[:foreground_color_grid])
            # GR.grid(xtick, ytick, 0, 0, majorx, majory)
            gr_set_line(1, :dot, sp[:foreground_color_grid])
            GR.settransparency(0.5)
            gr_polyline(coords(grid_segs)...)
        end
        GR.settransparency(1.0)

        # spine (border) and tick marks
        gr_set_line(1, :solid, sp[:xaxis][:foreground_color_axis])
        GR.setclip(0)
        gr_polyline(coords(spine_segs)...)
        GR.setclip(1)

        if !(xticks in (nothing, false))
            # x labels
            flip = sp[:yaxis][:flip]
            mirror = sp[:xaxis][:mirror]
            gr_set_font(sp[:xaxis][:tickfont],
                        halign = (:left, :hcenter, :right)[sign(sp[:xaxis][:rotation]) + 2],
                        valign = (mirror ? :bottom : :top),
                        color = sp[:xaxis][:foreground_color_axis],
                        rotation = sp[:xaxis][:rotation])
            for (cv, dv) in zip(xticks...)
                # use xor ($) to get the right y coords
                xi, yi = GR.wctondc(cv, xor(flip, mirror) ? ymax : ymin)
                # @show cv dv ymin xi yi flip mirror (flip $ mirror)
                gr_text(xi, yi + (mirror ? 1 : -1) * 5e-3, string(dv))
            end
        end

        if !(yticks in (nothing, false))
            # y labels
            flip = sp[:xaxis][:flip]
            mirror = sp[:yaxis][:mirror]
            gr_set_font(sp[:yaxis][:tickfont],
                        halign = (mirror ? :left : :right),
                        valign = (:top, :vcenter, :bottom)[sign(sp[:yaxis][:rotation]) + 2],
                        color = sp[:yaxis][:foreground_color_axis],
                        rotation = sp[:yaxis][:rotation])
            for (cv, dv) in zip(yticks...)
                # use xor ($) to get the right y coords
                xi, yi = GR.wctondc(xor(flip, mirror) ? xmax : xmin, cv)
                # @show cv dv xmin xi yi
                gr_text(xi + (mirror ? 1 : -1) * 1e-2, yi, string(dv))
            end
        end
    end
    # end

    # add the guides
    GR.savestate()
    if sp[:title] != ""
        gr_set_font(sp[:titlefont])
        GR.settextalign(GR.TEXT_HALIGN_CENTER, GR.TEXT_VALIGN_TOP)
        gr_set_textcolor(sp[:foreground_color_title])
        gr_text(gr_view_xcenter(), viewport_subplot[4], sp[:title])
    end

    if xaxis[:guide] != ""
        gr_set_font(xaxis[:guidefont])
        GR.settextalign(GR.TEXT_HALIGN_CENTER, GR.TEXT_VALIGN_BOTTOM)
        gr_set_textcolor(xaxis[:foreground_color_guide])
        gr_text(gr_view_xcenter(), viewport_subplot[3], xaxis[:guide])
    end

    if yaxis[:guide] != ""
        gr_set_font(yaxis[:guidefont])
        GR.settextalign(GR.TEXT_HALIGN_CENTER, GR.TEXT_VALIGN_TOP)
        GR.setcharup(-1, 0)
        gr_set_textcolor(yaxis[:foreground_color_guide])
        gr_text(viewport_subplot[1], gr_view_ycenter(), yaxis[:guide])
    end
    GR.restorestate()

    gr_set_font(xaxis[:tickfont])

    # this needs to be here to point the colormap to the right indices
    GR.setcolormap(1000 + GR.COLORMAP_COOLWARM)

    for (idx, series) in enumerate(series_list(sp))
        st = series[:seriestype]

        # update the current stored gradient
        if st in (:contour, :surface, :wireframe, :heatmap)
            gr_set_gradient(series[:fillcolor]) #, series[:fillalpha])
        elseif series[:marker_z] != nothing
            series[:markercolor] = gr_set_gradient(series[:markercolor])
        end

        GR.savestate()


        # update the bounding window
        if ispolar(sp)
            gr_set_viewport_polar()
        else
            xmin, xmax, ymin, ymax = data_lims
            if xmax > xmin && ymax > ymin
                GR.setwindow(xmin, xmax, ymin, ymax)
            end
        end

        x, y, z = series[:x], series[:y], series[:z]
        frng = series[:fillrange]

        # add custom frame shapes to markershape?
        series_annotations_shapes!(series)
        # -------------------------------------------------------

        # recompute data
        if typeof(z) <: Surface
            z = vec(transpose_z(series, z.surf, false))
        elseif ispolar(sp)
            if frng != nothing
                _, frng = convert_to_polar(x, frng, (rmin, rmax))
            end
            x, y = convert_to_polar(x, y, (rmin, rmax))
        end

        if st in (:path, :scatter)
            if length(x) > 1
                # do area fill
                if frng != nothing
                    GR.setfillintstyle(GR.INTSTYLE_SOLID)
                    fr_from, fr_to = (is_2tuple(frng) ? frng : (y, frng))
                    for (i,rng) in enumerate(iter_segments(series[:x], series[:y]))
                        if length(rng) > 1
                            gr_set_fillcolor(_cycle(series[:fillcolor], i))
                            fx = _cycle(x, vcat(rng, reverse(rng)))
                            fy = vcat(_cycle(fr_from,rng), _cycle(fr_to,reverse(rng)))
                            # @show i rng fx fy
                            GR.fillarea(fx, fy)
                        end
                    end
                end

                # draw the line(s)
                if st == :path
                    gr_set_line(series[:linewidth], series[:linestyle], series[:linecolor]) #, series[:linealpha])
                    arrowside = isa(series[:arrow], Arrow) ? series[:arrow].side : :none
                    gr_polyline(x, y; arrowside = arrowside)
                end
            end

            if series[:markershape] != :none
                gr_draw_markers(series, x, y)
            end

        elseif st == :contour
            zmin, zmax = gr_lims(zaxis, false)
            clims = sp[:clims]
            if is_2tuple(clims)
                isfinite(clims[1]) && (zmin = clims[1])
                isfinite(clims[2]) && (zmax = clims[2])
            end
            GR.setspace(zmin, zmax, 0, 90)
            if typeof(series[:levels]) <: Array
                h = series[:levels]
            else
                h = linspace(zmin, zmax, series[:levels])
            end
            if series[:fillrange] != nothing
                GR.surface(x, y, z, GR.OPTION_CELL_ARRAY)
            else
                GR.contour(x, y, h, z, 1000)
            end

            # create the colorbar of contour levels
            if sp[:colorbar] != :none
                gr_set_viewport_cmap(sp)
                l = round(Int32, 1000 + (h - ignorenan_minimum(h)) / (ignorenan_maximum(h) - ignorenan_minimum(h)) * 255)
                GR.setwindow(xmin, xmax, zmin, zmax)
                GR.cellarray(xmin, xmax, zmax, zmin, 1, length(l), l)
                ztick = 0.5 * GR.tick(zmin, zmax)
                GR.axes(0, ztick, xmax, zmin, 0, 1, 0.005)
                gr_set_viewport_plotarea()
            end

        elseif st in [:surface, :wireframe]
            if st == :surface
                if length(x) == length(y) == length(z)
                    GR.trisurface(x, y, z)
                else
                    GR.gr3.surface(x, y, z, GR.OPTION_COLORED_MESH)
                end
            else
                GR.setfillcolorind(0)
                GR.surface(x, y, z, GR.OPTION_FILLED_MESH)
            end
            cmap && gr_colorbar(sp)

        elseif st == :heatmap
            xmin, xmax, ymin, ymax = xy_lims
            zmin, zmax = gr_lims(zaxis, true)
            clims = sp[:clims]
            if is_2tuple(clims)
                isfinite(clims[1]) && (zmin = clims[1])
                isfinite(clims[2]) && (zmax = clims[2])
            end
            GR.setspace(zmin, zmax, 0, 90)
            grad = isa(series[:fillcolor], ColorGradient) ? series[:fillcolor] : cgrad()
            colors = [grad[clamp((zi-zmin) / (zmax-zmin), 0, 1)] for zi=z]
            rgba = map(c -> UInt32( round(Int, alpha(c) * 255) << 24 +
                                    round(Int,  blue(c) * 255) << 16 +
                                    round(Int, green(c) * 255) << 8  +
                                    round(Int,   red(c) * 255) ), colors)
            w, h = length(x), length(y)
            GR.drawimage(xmin, xmax, ymax, ymin, w, h, rgba)
            cmap && gr_colorbar(sp)

        elseif st in (:path3d, :scatter3d)
            # draw path
            if st == :path3d
                if length(x) > 1
                    gr_set_line(series[:linewidth], series[:linestyle], series[:linecolor]) #, series[:linealpha])
                    GR.polyline3d(x, y, z)
                end
            end

            # draw markers
            if st == :scatter3d || series[:markershape] != :none
                x2, y2 = unzip(map(GR.wc3towc, x, y, z))
                gr_draw_markers(series, x2, y2)
            end

        # TODO: replace with pie recipe
        elseif st == :pie
            GR.selntran(0)
            GR.setfillintstyle(GR.INTSTYLE_SOLID)
            xmin, xmax, ymin, ymax = viewport_plotarea
            ymax -= 0.1 * (xmax - xmin)
            xcenter = 0.5 * (xmin + xmax)
            ycenter = 0.5 * (ymin + ymax)
            if xmax - xmin > ymax - ymin
                r = 0.5 * (ymax - ymin)
                xmin, xmax = xcenter - r, xcenter + r
            else
                r = 0.5 * (xmax - xmin)
                ymin, ymax = ycenter - r, ycenter + r
            end
            labels = pie_labels(sp, series)
            slices = series[:y]
            numslices = length(slices)
            total = sum(slices)
            a1 = 0
            x = zeros(3)
            y = zeros(3)
            for i in 1:numslices
                a2 = round(Int, a1 + (slices[i] / total) * 360.0)
                GR.setfillcolorind(980 + (i-1) % 20)
                GR.fillarc(xmin, xmax, ymin, ymax, a1, a2)
                α = 0.5 * (a1 + a2)
                cosf = r * cos(α * pi / 180)
                sinf = r * sin(α * pi / 180)
                x[1] = xcenter + cosf
                y[1] = ycenter + sinf
                x[2] = x[1] + 0.1 * cosf
                y[2] = y[1] + 0.1 * sinf
                y[3] = y[2]
                if 90 <= α < 270
                    x[3] = x[2] - 0.05
                    GR.settextalign(GR.TEXT_HALIGN_RIGHT, GR.TEXT_VALIGN_HALF)
                    gr_text(x[3] - 0.01, y[3], string(labels[i]))
                else
                    x[3] = x[2] + 0.05
                    GR.settextalign(GR.TEXT_HALIGN_LEFT, GR.TEXT_VALIGN_HALF)
                    gr_text(x[3] + 0.01, y[3], string(labels[i]))
                end
                gr_polyline(x, y)
                a1 = a2
            end
            GR.selntran(1)

        elseif st == :shape
            for (i,rng) in enumerate(iter_segments(series[:x], series[:y]))
                if length(rng) > 1
                    # connect to the beginning
                    rng = vcat(rng, rng[1])

                    # get the segments
                    x, y = series[:x][rng], series[:y][rng]

                    # draw the interior
                    gr_set_fill(_cycle(series[:fillcolor], i))
                    GR.fillarea(x, y)

                    # draw the shapes
                    gr_set_line(series[:linewidth], :solid, _cycle(series[:linecolor], i))
                    GR.polyline(x, y)
                end
            end


        elseif st == :image
            z = transpose_z(series, series[:z].surf, true)'
            w, h = size(z)
            if eltype(z) <: Colors.AbstractGray
                grey = round(UInt8, float(z) * 255)
                rgba = map(c -> UInt32( 0xff000000 + Int(c)<<16 + Int(c)<<8 + Int(c) ), grey)
            else
                rgba = map(c -> UInt32( round(Int, alpha(c) * 255) << 24 +
                                        round(Int,  blue(c) * 255) << 16 +
                                        round(Int, green(c) * 255) << 8  +
                                        round(Int,   red(c) * 255) ), z)
            end
            GR.drawimage(xmin, xmax, ymax, ymin, w, h, rgba)
        end

        # this is all we need to add the series_annotations text
        anns = series[:series_annotations]
        for (xi,yi,str,fnt) in EachAnn(anns, x, y)
            gr_set_font(fnt)
            gr_text(GR.wctondc(xi, yi)..., str)
        end

        GR.restorestate()
    end


    # add the legend
    if sp[:legend] != :none
        GR.savestate()
        GR.selntran(0)
        GR.setscale(0)
        gr_set_font(sp[:legendfont])
        w = 0
        i = 0
        n = 0
        if sp[:legendtitle] != nothing
            tbx, tby = gr_inqtext(0, 0, string(sp[:legendtitle]))
            w = tbx[3] - tbx[1]
            n += 1
        end
        for series in series_list(sp)
            should_add_to_legend(series) || continue
            n += 1
            if typeof(series[:label]) <: Array
                i += 1
                lab = series[:label][i]
            else
                lab = series[:label]
            end
            tbx, tby = gr_inqtext(0, 0, lab)
            w = max(w, tbx[3] - tbx[1])
        end
        if w > 0
            dy = _gr_point_mult[1] * sp[:legendfont].pointsize * 1.75
            h = dy*n
            (xpos,ypos) = gr_legend_pos(sp[:legend],w,h)
            GR.setfillintstyle(GR.INTSTYLE_SOLID)
            gr_set_fillcolor(sp[:background_color_legend])
            GR.fillrect(xpos - 0.08, xpos + w + 0.02, ypos + dy, ypos - dy * n)
            GR.setlinetype(1)
            GR.setlinewidth(1)
            GR.drawrect(xpos - 0.08, xpos + w + 0.02, ypos + dy, ypos - dy * n)
            i = 0
            if sp[:legendtitle] != nothing
                GR.settextalign(GR.TEXT_HALIGN_CENTER, GR.TEXT_VALIGN_HALF)
                gr_set_textcolor(sp[:foreground_color_legend])
                gr_text(xpos - 0.03 + 0.5*w, ypos, string(sp[:legendtitle]))
                ypos -= dy
            end
            for series in series_list(sp)
                should_add_to_legend(series) || continue
                st = series[:seriestype]
                gr_set_line(series[:linewidth], series[:linestyle], series[:linecolor]) #, series[:linealpha])
                if st == :path && series[:fillrange] == nothing
                    GR.polyline([xpos - 0.07, xpos - 0.01], [ypos, ypos])
                elseif st == :shape || series[:fillrange] != nothing
                    gr_set_fill(series[:fillcolor]) #, series[:fillalpha])
                    l, r = xpos-0.07, xpos-0.01
                    b, t = ypos-0.4dy, ypos+0.4dy
                    x = [l, r, r, l, l]
                    y = [b, b, t, t, b]
                    gr_polyline(x, y, GR.fillarea)
                    gr_polyline(x, y)
                end

                if series[:markershape] != :none
                    gr_draw_markers(series, xpos - .035, ypos, 6, nothing)
                end

                if typeof(series[:label]) <: Array
                    i += 1
                    lab = series[:label][i]
                else
                    lab = series[:label]
                end
                GR.settextalign(GR.TEXT_HALIGN_LEFT, GR.TEXT_VALIGN_HALF)
                gr_set_textcolor(sp[:foreground_color_legend])
                gr_text(xpos, ypos, lab)
                ypos -= dy
            end
        end
        GR.selntran(1)
        GR.restorestate()
    end

    # add annotations
    GR.savestate()
    # update the bounding window
    if ispolar(sp)
        gr_set_viewport_polar()
    else
        xmin, xmax, ymin, ymax = data_lims
        if xmax > xmin && ymax > ymin
            GR.setwindow(xmin, xmax, ymin, ymax)
        end
    end
    for ann in sp[:annotations]
        x, y, val = ann
        x, y = if is3d(sp)
            # GR.wc3towc(x, y, z)
        else
            GR.wctondc(x, y)
        end
        gr_set_font(val.font)
        gr_text(x, y, val.str)
    end
    GR.restorestate()
end


# ----------------------------------------------------------------

const _gr_mimeformats = Dict(
    "application/pdf"         => "pdf",
    "image/png"               => "png",
    "application/postscript"  => "ps",
    "image/svg+xml"           => "svg",
)

const _gr_wstype_default = @static if is_linux()
    "x11"
    # "cairox11"
elseif is_apple()
    "quartz"
else
    "use_default"
end

const _gr_wstype = Ref(get(ENV, "GKSwstype", _gr_wstype_default))
gr_set_output(wstype::String) = (_gr_wstype[] = wstype)

for (mime, fmt) in _gr_mimeformats
    @eval function _show(io::IO, ::MIME{Symbol($mime)}, plt::Plot{GRBackend})
        GR.emergencyclosegks()
        filepath = tempname() * "." * $fmt
        ENV["GKSwstype"] = $fmt
        ENV["GKS_FILEPATH"] = filepath
        gr_display(plt)
        GR.emergencyclosegks()
        write(io, readstring(filepath))
        rm(filepath)
    end
end

function _display(plt::Plot{GRBackend})
    if plt[:display_type] == :inline
        GR.emergencyclosegks()
        filepath = tempname() * ".pdf"
        ENV["GKSwstype"] = "pdf"
        ENV["GKS_FILEPATH"] = filepath
        gr_display(plt)
        GR.emergencyclosegks()
        content = string("\033]1337;File=inline=1;preserveAspectRatio=0:", base64encode(open(read, filepath)), "\a")
        println(content)
        rm(filepath)
    else
        ENV["GKS_DOUBLE_BUF"] = true
        if _gr_wstype[] != "use_default"
            ENV["GKSwstype"] = _gr_wstype[]
        end
        gr_display(plt)
    end
end

closeall(::GRBackend) = GR.emergencyclosegks()