test_that("sens_anova shares sum to 100", {
  set.seed(1)
  d <- expand.grid(A = c("a1","a2"), B = c("b1","b2","b3"), year = 1:10)
  d$y <- 10 + 3*(d$A=="a2") + 5*(d$B=="b3") + rnorm(nrow(d))
  s <- sens_anova(d, "y", c("A","B"), order = 2)
  expect_equal(sum(s$si), 100, tolerance = 1e-6)
  expect_true(s$term[1] %in% c("A","B"))
  expect_true(all(c("main","interaction","residual") %in% s$kind))
})

test_that("sens_oat elasticity is signed correctly", {
  d <- data.frame(N = rep(c("0","100"), each = 5), y = c(rep(50,5), rep(100,5)),
                  year = rep(1:5, 2), stringsAsFactors = FALSE)
  s <- sens_oat(d, "y", "N", baseline = list(N = "0"))
  expect_equal(s$pct, 100)
  expect_true(is.na(s$elasticity))   # baseline of 0 gives no percent change in x
})

test_that("split_phase assigns both phases by date", {
  d <- data.frame(Date = as.Date("2000-01-01") + c(0, 100, 200, 300),
                  obs = 1:4, pred = 1:4)
  p <- split_phase(d, "date", at = "2000-05-01")
  expect_equal(levels(p$phase), c("Calibration","Validation"))
  expect_equal(as.integer(table(p$phase)), c(2L, 2L))
})

test_that("split_phase by fraction respects date order", {
  d <- data.frame(Date = as.Date("2000-01-01") + (10:1),
                  obs = 1:10, pred = 1:10)
  p <- split_phase(d, "fraction", at = 0.6)
  expect_equal(sum(p$phase == "Calibration"), 6)
  expect_true(max(p$Date[p$phase == "Calibration"]) <=
              min(p$Date[p$phase == "Validation"]))
})

test_that("suggest_cutoff falls between the calibration and validation seasons", {
  d <- data.frame(Date = as.Date(c("2016-08-01","2016-10-01",
                                   "2017-08-01","2017-10-01")))
  cut <- suggest_cutoff(d)
  expect_true(cut > as.Date("2016-10-01"))
  expect_true(cut < as.Date("2017-08-01"))
  expect_equal(sum(d$Date <= cut), 2L)
})

test_that("suggest_cutoff honours a multi-season calibration", {
  d <- data.frame(Date = as.Date(paste0(2016:2020, "-10-01")))
  expect_equal(sum(d$Date <= suggest_cutoff(d, seasons = 3)), 3L)
})

test_that("a cutoff outside the range leaves the series unsplit", {
  sim <- data.frame(Date = as.Date("2016-01-01") + 0:100, value = 1:101)
  p <- plot_ts(sim, cutoff = as.Date("2030-01-01"))
  # no phase band means no fill layer was added
  expect_false(any(vapply(p$layers, function(l)
    inherits(l$geom, "GeomRect"), logical(1))))
})

test_that("plot_ts keeps one panel when a cutoff is given", {
  sim <- data.frame(Date = as.Date("2016-01-01") + 0:400, value = 1:401)
  obs <- sim[c(50, 300), ]
  p <- plot_ts(sim, obs = obs, cutoff = as.Date("2016-08-01"))
  expect_equal(nlevels(ggplot2::ggplot_build(p)$data[[1]]$PANEL), 1L)
  expect_true(any(vapply(p$layers, function(l)
    inherits(l$geom, "GeomVline"), logical(1))))
})

test_that("colour mode changes the palette and restores", {
  old <- colour_mode()
  on.exit(set_colour_mode(old))
  set_colour_mode("colour")
  set_palette(c(a = "#0072B2", b = "#D55E00"))
  expect_equal(unname(get_pal(c("a","b"))), c("#0072B2","#D55E00"))
  set_colour_mode("grey")
  expect_true(all(grepl("^#([0-9A-F]{2})\\1\\1$", get_pal(c("a","b")), ignore.case = TRUE)))
  set_colour_mode("mono")
  expect_equal(unname(get_pal(c("a","b"), "colour")), c("black","black"))
  # fills still vary, since fill is the only channel a bar has
  expect_equal(length(unique(get_pal(c("a","b"), "fill"))), 2L)
})

test_that("mono keeps lines darker than fills", {
  old <- colour_mode(); on.exit(set_colour_mode(old))
  set_colour_mode("grey")
  lum <- function(x) mean(col2rgb(x))
  expect_lt(mean(vapply(get_pal(letters[1:3], "colour"), lum, numeric(1))),
            mean(vapply(get_pal(letters[1:3], "fill"), lum, numeric(1))))
})

test_that("accent and heat colours follow the mode", {
  old <- colour_mode(); on.exit(set_colour_mode(old))
  set_colour_mode("colour"); expect_equal(accent_col(), "#0072B2")
  set_colour_mode("grey");   expect_equal(accent_col(), "black")
  expect_false(grepl("#B2182B", heat_cols()$low))
})