mkdat <- function(nsim = 2) {
  d <- do.call(rbind, lapply(seq_len(nsim), function(i)
    data.frame(sim = paste0("T", i),
               Date = as.Date("2016-01-01") + 0:120,
               water = if (i %% 2) "AWD" else "CF",
               wagt = seq(0, 10000, length.out = 121) * i,
               pond = rep(c(0, 50), length.out = 121),
               stringsAsFactors = FALSE)))
  attr(d, "units") <- c(wagt = "kg/ha", pond = "mm")
  d
}

test_that("as_long carries treatment columns through the pivot", {
  l <- as_long(mkdat(), vars = c("wagt", "pond"), keep = "water")
  expect_true("water" %in% names(l))
  expect_equal(sort(unique(l$variable)), c("pond", "wagt"))
})

test_that("secondary axis rescales without changing the drawn range", {
  l <- as_long(mkdat(1), vars = c("wagt", "pond"))
  p <- plot_series(l, vars = c("wagt", "pond"), secondary = "pond")
  b <- ggplot2::ggplot_build(p)
  expect_false(is.null(b$plot$scales$get_scales("y")$sec_name))
  # rescaled secondary must sit inside the primary range, not off the panel
  yr <- range(b$data[[1]]$y, finite = TRUE)
  expect_true(yr[2] <= max(l$value[l$variable == "wagt"]) * 1.001)
})

test_that("a single panel becomes one panel per treatment when faceted", {
  l <- as_long(mkdat(4), vars = "wagt", keep = "water")
  expect_equal(nlevels(ggplot2::ggplot_build(
    suppressMessages(plot_series(l, vars = "wagt")))$data[[1]]$PANEL), 1L)
  expect_equal(nlevels(ggplot2::ggplot_build(
    plot_series(l, vars = "wagt", facet_by = "sim"))$data[[1]]$PANEL), 4L)
  expect_equal(nlevels(ggplot2::ggplot_build(
    plot_series(l, vars = "wagt", facet_by = "water"))$data[[1]]$PANEL), 2L)
})

test_that("stacked layout gives one row per variable", {
  l <- as_long(mkdat(1), vars = c("wagt", "pond"))
  p <- plot_series(l, vars = c("wagt", "pond"), layout = "stacked")
  expect_equal(nlevels(ggplot2::ggplot_build(p)$data[[1]]$PANEL), 2L)
})

test_that("overlaying several treatments in one colour is announced", {
  l <- as_long(mkdat(3), vars = "wagt")
  expect_message(plot_series(l, vars = "wagt"), "treatments overlaid")
  expect_silent(plot_series(l, vars = "wagt", facet_by = "sim"))
})

test_that("observed SD is rescaled as a length, not a position", {
  l <- as_long(mkdat(1), vars = c("wagt", "pond"))
  ob <- data.frame(Date = as.Date("2016-03-01"), variable = "pond",
                   value = 50, obs_sd = 5, stringsAsFactors = FALSE)
  p <- plot_series(l, vars = c("wagt", "pond"), secondary = "pond", obs = ob)
  eb <- Filter(function(x) inherits(x$geom, "GeomErrorbar"), p$layers)[[1]]$data
  # 5 mm on a 0-50 secondary mapped to a 0-10000 primary is 10% of the span
  expect_equal(eb$obs_sd, 5 * 10000 / 50, tolerance = 1e-6)
})

test_that("missing variables are refused rather than silently dropped", {
  l <- as_long(mkdat(1), vars = "wagt")
  expect_error(plot_series(l, vars = "nonexistent"), "None of")
})

obsdat <- function(vars = "wagt", sims = "T1") {
  do.call(rbind, lapply(sims, function(s) do.call(rbind, lapply(vars, function(v)
    data.frame(sim = s, Date = as.Date("2016-03-01") + c(0, 30),
               variable = v, value = c(1000, 3000), obs_sd = c(80, 150),
               stringsAsFactors = FALSE)))))
}

test_that("variables without observed data are reported, not fatal", {
  l <- as_long(mkdat(1), vars = c("wagt", "pond"))
  expect_message(plot_series(l, vars = c("wagt", "pond"), obs = obsdat("wagt")),
                 "No observed data for: pond")
  p <- suppressMessages(
    plot_series(l, vars = c("wagt", "pond"), obs = obsdat("wagt")))
  pt <- Filter(function(x) inherits(x$geom, "GeomPoint"), p$layers)[[1]]
  expect_equal(nrow(pt$data), 2L)
  expect_equal(as.character(unique(pt$data$variable)), "wagt")
})

test_that("the observed legend lists only variables that have observations", {
  l <- as_long(mkdat(1), vars = c("wagt", "pond"))
  p <- suppressMessages(plot_series(l, vars = c("wagt", "pond"),
                                    secondary = "pond", obs = obsdat("wagt")))
  pt <- Filter(function(x) inherits(x$geom, "GeomPoint"), p$layers)[[1]]
  expect_equal(nlevels(pt$data$.series), 1L)
})

test_that("observed points reach their panel when the facet column is derivable", {
  l <- as_long(mkdat(2), vars = "wagt", keep = "water")
  ob <- obsdat("wagt", c("T1", "T2"))          # has sim, but no water column
  p <- suppressMessages(plot_series(l, vars = "wagt", facet_by = "water", obs = ob))
  pt <- Filter(function(x) inherits(x$geom, "GeomPoint"), p$layers)[[1]]
  expect_true("water" %in% names(pt$data))
  expect_equal(nrow(pt$data), 4L)
  expect_equal(sort(unique(as.character(pt$data$water))), c("AWD", "CF"))
})

test_that("unplaceable observed records are dropped with a message", {
  l <- as_long(mkdat(2), vars = "wagt", keep = "water")
  ob <- obsdat("wagt", "T99")                  # matches no simulation
  msgs <- character(0)
  withCallingHandlers(
    plot_series(l, vars = "wagt", facet_by = "water", obs = ob),
    message = function(m) {
      msgs <<- c(msgs, conditionMessage(m)); invokeRestart("muffleMessage")
    })
  expect_true(any(grepl("could not be placed", msgs)))
})

test_that("error bars follow each variable to its own axis and panel", {
  l <- as_long(mkdat(1), vars = c("wagt", "pond"))
  ob <- rbind(obsdat("wagt"), obsdat("pond"))
  p <- plot_series(l, vars = c("wagt", "pond"), secondary = "pond", obs = ob)
  eb <- Filter(function(x) inherits(x$geom, "GeomErrorbar"), p$layers)[[1]]$data
  expect_equal(nrow(eb), 4L)
  # the pond SD is rescaled, the wagt SD is not
  expect_equal(eb$obs_sd[eb$variable == "wagt"], c(80, 150))
  expect_false(isTRUE(all.equal(eb$obs_sd[eb$variable == "pond"], c(80, 150))))
})

test_that("unplottable observed records are dropped with a message, not a warning", {
  sim <- data.frame(sim = "T1", Date = as.Date("2016-01-01") + 0:120,
                    variable = "wagt", value = seq(0, 10000, length.out = 121),
                    unit = "kg/ha", stringsAsFactors = FALSE)
  obs <- data.frame(sim = "T1", Date = as.Date(c("2016-02-01", "2016-03-01")),
                    variable = "wagt", value = c(2000, NA),
                    stringsAsFactors = FALSE)
  msgs <- character(0)
  p <- withCallingHandlers(plot_series(sim, vars = "wagt", obs = obs),
    message = function(m) {
      msgs <<- c(msgs, conditionMessage(m)); invokeRestart("muffleMessage") })
  expect_true(any(grepl("omitted", msgs)))
  pt <- Filter(function(x) inherits(x$geom, "GeomPoint"), p$layers)[[1]]
  expect_equal(nrow(pt$data), 1L)
  expect_silent(ggplot2::ggplot_build(p))
})

test_that("plot_ts drops unplottable observed records too", {
  sim <- data.frame(Date = as.Date("2016-01-01") + 0:100, value = 1:101)
  obs <- data.frame(Date = as.Date(c("2016-02-01", "2016-03-01")),
                    value = c(32, NA))
  p <- suppressMessages(plot_ts(sim, obs = obs))
  expect_silent(ggplot2::ggplot_build(p))
})