# ==============================================================================
# The package's plotting style module (R/plot_style.R)
# ==============================================================================
#
# These helpers are the reference implementation the other panels will be
# restyled onto, so what is tested here is the contract they offer rather than
# the appearance they produce: the constants a caller reads, the geometry of
# an offset axis, the arithmetic of a wheel, and the placement rule of an
# annotation block.
# ==============================================================================

test_that("bgms_panel_par sets the style and hands back the old settings", {
  path = withr::local_tempfile(fileext = ".pdf")
  grDevices::pdf(path)
  on.exit(grDevices::dev.off(), add = TRUE)

  before = graphics::par(no.readonly = TRUE)
  style = bgms_panel_par()
  on.exit(graphics::par(style$old_par), add = TRUE, after = FALSE)

  # No box, axis labels running horizontally, and type larger than R's default
  # of 1 -- the three conventions a reader would notice first.
  expect_equal(graphics::par("bty"), "n")
  expect_equal(graphics::par("las"), 1L)
  expect_gt(graphics::par("cex.axis"), 1)
  expect_equal(graphics::par("mar"), style$mar)

  # The caller can restore exactly what was there.
  expect_equal(style$old_par$bty, before$bty)
  expect_equal(style$old_par$mar, before$mar)
})

test_that("bgms_panel_par takes a margin override", {
  path = withr::local_tempfile(fileext = ".pdf")
  grDevices::pdf(path)
  on.exit(grDevices::dev.off(), add = TRUE)

  style = bgms_panel_par(mar = c(1, 2, 3, 4))
  on.exit(graphics::par(style$old_par), add = TRUE, after = FALSE)
  expect_equal(graphics::par("mar"), c(1, 2, 3, 4))
  expect_equal(style$mar, c(1, 2, 3, 4))
})

test_that("an offset axis stops short of the data range on both sides", {
  axis = bgms_axis_range(c(-0.3, 0.9))

  # The ticks are pretty numbers covering the values...
  expect_true(min(axis$at) <= -0.3)
  expect_true(max(axis$at) >= 0.9)
  # ...and the data region overshoots them, which is what opens the gap at the
  # corner. An axis drawn at these ticks cannot close into a box.
  expect_lt(axis$lim[1], min(axis$at))
  expect_gt(axis$lim[2], max(axis$at))

  eps = bgms_style()$eps
  span = diff(range(axis$at))
  expect_equal(axis$lim, range(axis$at) + c(-1, 1) * eps * span)
})

test_that("a density axis starts its ticks at zero and drops below it", {
  # The lowest tick is the density baseline; the data region reaches under it,
  # which is what lifts the curve off the x axis line.
  axis = bgms_axis_range(c(0, 12))
  expect_equal(min(axis$at), 0)
  expect_lt(axis$lim[1], 0)
  expect_gt(axis$lim[2], 12)
})

test_that("a constant value still yields a drawable axis", {
  axis = bgms_axis_range(c(2, 2))
  expect_true(all(is.finite(axis$lim)))
  expect_lt(axis$lim[1], axis$lim[2])
})

test_that("the probability wheel fills the share it is given", {
  path = withr::local_tempfile(fileext = ".pdf")
  grDevices::pdf(path)
  on.exit(grDevices::dev.off(), add = TRUE)
  graphics::plot(NA, NA, xlim = c(0, 1), ylim = c(0, 1), axes = FALSE)

  wheel = probability_wheel(0.5, 0.5, 0.25, radius = 0.2)
  expect_equal(wheel$x, 0.5)
  expect_equal(wheel$y, 0.5)
  # The radius is given in inches and converted per axis, so the wheel is round
  # on the device rather than in user units.
  expect_gt(wheel$dx, 0)
  expect_gt(wheel$dy, 0)

  # The ends are drawn rather than refused, and a probability that was never
  # estimated draws an empty wheel instead of failing.
  expect_silent(probability_wheel(0.5, 0.5, 0, radius = 0.1))
  expect_silent(probability_wheel(0.5, 0.5, 1, radius = 0.1))
  expect_silent(probability_wheel(0.5, 0.5, NaN, radius = 0.1))
  expect_silent(probability_wheel(0.5, 0.5, NA_real_, radius = 0.1))
  # Out-of-range input is clamped, not wrapped around the circle.
  expect_silent(probability_wheel(0.5, 0.5, 1.4, radius = 0.1))
  expect_silent(probability_wheel(0.5, 0.5, -0.2, radius = 0.1))
})

test_that("an annotation block stacks downward from its anchor", {
  path = withr::local_tempfile(fileext = ".pdf")
  grDevices::pdf(path)
  on.exit(grDevices::dev.off(), add = TRUE)
  graphics::plot(NA, NA, xlim = c(0, 1), ylim = c(0, 1), axes = FALSE)

  last = annotation_block(0.1, 0.9, c("median = 0.31", "95% CI [0.12, 0.48]"))
  expect_lt(last, 0.9)

  # One line ends where it starts, and nothing to say draws nothing.
  expect_equal(annotation_block(0.1, 0.9, "one"), 0.9)
  expect_equal(annotation_block(0.1, 0.9, character(0)), 0.9)
  expect_equal(annotation_block(0.1, 0.9, NA_character_), 0.9)
})

test_that("a probability prints with its relation, as a log Bayes factor does", {
  expect_equal(format_probability(0.786), "= .786")
  expect_equal(format_probability(0.5), "= .500")
  # The ends get an inequality: a run that never saw the edge absent has not
  # established that the probability is exactly one.
  expect_equal(format_probability(1), "> .999")
  expect_equal(format_probability(0.9999), "> .999")
  expect_equal(format_probability(0), "< .001")
  expect_equal(format_probability(0.0001), "< .001")
  expect_equal(format_probability(NaN), "= NA")

  # Three decimals is the style's, not the call site's: the cut-offs and the
  # strings printed past them follow the constant rather than being written
  # out beside it.
  expect_equal(format_probability(0.786, digits = 2), "= .79")
  expect_equal(format_probability(1, digits = 2), "> .99")
  expect_equal(format_probability(0, digits = 2), "< .01")
  expect_equal(bgms_style()$prob_digits, 3L)

  # The caller composes the inclusion label + this, exactly as it composes
  # "log BF" + format_log_bf(), so the two evidence lines of a panel read
  # alike -- and the label itself comes from the style, so no two figures can
  # name the quantity differently.
  expect_equal(format_inclusion(0.786), "P(included) = .786")
  expect_equal(format_inclusion(1), "P(included) > .999")
  expect_equal(bgms_style()$label_inclusion, "P(included)")
})

test_that("a margin is measured for the text it has to hold", {
  path = withr::local_tempfile(fileext = ".pdf")
  grDevices::pdf(path, width = 7, height = 7)
  on.exit(grDevices::dev.off(), add = TRUE)
  graphics::plot(NA, NA, xlim = c(0, 1), ylim = c(0, 1), axes = FALSE)

  narrow = margin_lines_for("ab", cex = 0.75)
  wide = margin_lines_for(c("ab", strrep("m", 40)), cex = 0.75)
  # A longer label needs a wider margin; nothing to hold needs only the pad.
  expect_gt(wide, narrow)
  expect_equal(margin_lines_for(character(0), pad = 0.5), 0.5)
  expect_equal(margin_lines_for(NA_character_, pad = 0.5), 0.5)

  # The answer is in lines of the device's own text height, so the reserved
  # margin holds the string at any device size.
  expect_equal(
    wide,
    max(graphics::strwidth(c("ab", strrep("m", 40)),
      units = "inches", cex = 0.75
    )) / graphics::par("csi") + 0.5
  )
})

test_that("the style scales as one, so a small multiple is not a second style", {
  base = bgms_style()
  small = bgms_style(scale = 0.6)
  expect_equal(small$cex_axis, 0.6 * base$cex_axis)
  expect_equal(small$cex_caption, 0.6 * base$cex_caption)
  expect_equal(small$wheel_radius, 0.6 * base$wheel_radius)
  # Colours and geometry fractions are not sizes and do not scale.
  expect_equal(small$accent, base$accent)
  expect_equal(small$eps, base$eps)
})