Plots.jl/src/backends/unicodeplots.jl

# https://github.com/Evizero/UnicodePlots.jl

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


# do all the magic here... build it all at once, since we need to know about all the series at the very beginning
function rebuildUnicodePlot!(plt::Plot)

  # figure out the plotting area xlim = [xmin, xmax] and ylim = [ymin, ymax]
  sargs = plt.seriesargs
  iargs = plt.plotargs

  # get the x/y limits
  if get(iargs, :xlims, :auto) == :auto
    xlim = [Inf, -Inf]
    for d in sargs
      _expand_limits(xlim, d[:x])
    end
  else
    xmin, xmax = iargs[:xlims]
    xlim = [xmin, xmax]
  end

  if get(iargs, :ylims, :auto) == :auto
    ylim = [Inf, -Inf]
    for d in sargs
      _expand_limits(ylim, d[:y])
    end
  else
    ymin, ymax = iargs[:ylims]
    ylim = [ymin, ymax]
  end

  # we set x/y to have a single point, since we need to create the plot with some data.
  # since this point is at the bottom left corner of the plot, it shouldn't actually be shown
  x = Float64[xlim[1]]
  y = Float64[ylim[1]]

  # create a plot window with xlim/ylim set, but the X/Y vectors are outside the bounds
  width, height = iargs[:size]
  o = UnicodePlots.Plot(x, y; width = width,
                                height = height,
                                title = iargs[:title],
                                # labels = iargs[:legend],
                                xlim = xlim,
                                ylim = ylim)

  # set the axis labels
  UnicodePlots.xlabel!(o, iargs[:xlabel])
  UnicodePlots.ylabel!(o, iargs[:ylabel])

  # now use the ! functions to add to the plot
  for d in sargs
    addUnicodeSeries!(o, d, iargs[:legend], xlim, ylim)
  end

  # save the object
  plt.o = o
end


# add a single series
function addUnicodeSeries!(o, d::Dict, addlegend::Bool, xlim, ylim)

  # get the function, or special handling for step/bar/hist
  lt = d[:linetype]

  # handle hline/vline separately
  if lt in (:hline,:vline)
    for yi in d[:y]
      if lt == :hline
        UnicodePlots.lineplot!(o, xlim, [yi,yi])
      else
        UnicodePlots.lineplot!(o, [yi,yi], ylim)
      end
    end
    return
  end

  stepstyle = :post
  if lt == :path
    func = UnicodePlots.lineplot!
  elseif lt == :scatter || d[:markershape] != :none
    func = UnicodePlots.scatterplot!
  elseif lt == :steppost
    func = UnicodePlots.stairs!
  elseif lt == :steppre
    func = UnicodePlots.stairs!
    stepstyle = :pre
  else
    error("Linestyle $lt not supported by UnicodePlots")
  end

  # get the series data and label
  x, y = [collect(float(d[s])) for s in (:x, :y)]
  label = addlegend ? d[:label] : ""

  # if we happen to pass in allowed color symbols, great... otherwise let UnicodePlots decide
  color = d[:linecolor] in UnicodePlots.color_cycle ? d[:linecolor] : :auto

  # add the series
  func(o, x, y; color = color, name = label, style = stepstyle)
end


function handlePlotColors(::UnicodePlotsPackage, d::Dict)
  # TODO: something special for unicodeplots, since it doesn't take kindly to people messing with its color palette
  d[:color_palette] = [RGB(0,0,0)]
end

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


function _create_plot(pkg::UnicodePlotsPackage; kw...)
  plt = Plot(nothing, pkg, 0, Dict(kw), Dict[])

  # do we want to give a new default size?
  if !haskey(plt.plotargs, :size) || plt.plotargs[:size] == _plotDefaults[:size]
    plt.plotargs[:size] = (60,20)
  end

  plt
end

function _add_series(::UnicodePlotsPackage, plt::Plot; kw...)
  d = Dict(kw)
  if d[:linetype] in (:sticks, :bar)
    d = barHack(; d...)
  elseif d[:linetype] == :hist
    d = barHack(; histogramHack(; d...)...)
  end
  push!(plt.seriesargs, d)
  plt
end


function _update_plot(plt::Plot{UnicodePlotsPackage}, d::Dict)
  for k in (:title, :xlabel, :ylabel, :xlims, :ylims)
    if haskey(d, k)
      plt.plotargs[k] = d[k]
    end
  end
end


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

# since this is such a hack, it's only callable using `png`... should error during normal `writemime`
function png(plt::PlottingObject{UnicodePlotsPackage}, fn::@compat(AbstractString))
  fn = addExtension(fn, "png")

  # make some whitespace and show the plot
  println("\n\n\n\n\n\n")
  gui(plt)

  @osx_only begin
    # BEGIN HACK

    # wait while the plot gets drawn
    sleep(0.5)

    # use osx screen capture when my terminal is maximized and cursor starts at the bottom (I know, right?)
    # TODO: compute size of plot to adjust these numbers (or maybe implement something good??)
    run(`screencapture -R50,600,700,420 $fn`)

    # END HACK (phew)
    return
  end

  error("Can only savepng on osx with UnicodePlots (though even then I wouldn't do it)")
end

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

# we don't do very much for subplots... just stack them vertically

function _create_subplot(subplt::Subplot{UnicodePlotsPackage}, isbefore::Bool)
  isbefore && return false
  true
end


function Base.display(::PlotsDisplay, plt::Plot{UnicodePlotsPackage})
  rebuildUnicodePlot!(plt)
  show(plt.o)
end



function Base.display(::PlotsDisplay, subplt::Subplot{UnicodePlotsPackage})
  for plt in subplt.plts
    gui(plt)
  end
end