# tests/testthat/test-dose_response.R

make_dose_resp <- function(seed = 10) {
  set.seed(seed)
  doses <- rep(c(0, 10, 30, 100, 300, 1000, 3000), each = 4)
  resp  <- 100 / (1 + exp(-(-1.8) * (log(pmax(doses, 0.01)) - log(80)))) +
           rnorm(length(doses), 0, 3)
  resp  <- pmin(pmax(resp, 0), 100)
  data.frame(dose_g_ha = doses, weed_control_pct = resp)
}

dat_dr <- make_dose_resp()

# ---- fit_dose_response ----------------------------------------------------
test_that("fit_dose_response LL.4 returns agriDRC", {
  skip_if_not_installed("drc")
  m <- fit_dose_response(dat_dr, "dose_g_ha", "weed_control_pct", fct = "LL.4")
  expect_s3_class(m, "agriDRC")
  expect_equal(m$fct, "LL.4")
})

test_that("fit_dose_response LL.5 returns agriDRC", {
  skip_if_not_installed("drc")
  m <- fit_dose_response(dat_dr, "dose_g_ha", "weed_control_pct", fct = "LL.5")
  expect_s3_class(m, "agriDRC")
})

test_that("fit_dose_response stores dose and resp column names", {
  skip_if_not_installed("drc")
  m <- fit_dose_response(dat_dr, "dose_g_ha", "weed_control_pct")
  expect_equal(m$dose_col, "dose_g_ha")
  expect_equal(m$resp_col, "weed_control_pct")
})

test_that("fit_dose_response errors on missing column", {
  skip_if_not_installed("drc")
  expect_error(fit_dose_response(dat_dr, "missing_col", "weed_control_pct"))
})

# ---- ed_estimates ---------------------------------------------------------
test_that("ed_estimates returns matrix with ED50 row", {
  skip_if_not_installed("drc")
  m  <- fit_dose_response(dat_dr, "dose_g_ha", "weed_control_pct")
  ed <- ed_estimates(m, respLev = c(50))
  expect_true(is.matrix(ed) || is.data.frame(ed))
})

test_that("ed_estimates ED50 is in plausible range", {
  skip_if_not_installed("drc")
  m   <- fit_dose_response(dat_dr, "dose_g_ha", "weed_control_pct")
  ed  <- ed_estimates(m, respLev = 50, interval = "none")
  # True ED50 is ~80 g/ha; allow a wide margin for small simulated dataset
  expect_true(ed[1, 1] > 10 && ed[1, 1] < 500)
})

# ---- print / summary ------------------------------------------------------
test_that("print.agriDRC outputs agriReg header", {
  skip_if_not_installed("drc")
  m <- fit_dose_response(dat_dr, "dose_g_ha", "weed_control_pct")
  expect_output(print(m), "agriReg")
})

test_that("summary.agriDRC prints without error", {
  skip_if_not_installed("drc")
  m <- fit_dose_response(dat_dr, "dose_g_ha", "weed_control_pct")
  expect_output(summary(m), "Dose-Response")
})

# ---- plot -----------------------------------------------------------------
test_that("plot.agriDRC returns ggplot", {
  skip_if_not_installed("drc")
  skip_if_not_installed("ggplot2")
  m <- fit_dose_response(dat_dr, "dose_g_ha", "weed_control_pct")
  p <- plot(m)
  expect_s3_class(p, "gg")
})

test_that("plot.agriDRC linear scale returns ggplot", {
  skip_if_not_installed("drc")
  skip_if_not_installed("ggplot2")
  m <- fit_dose_response(dat_dr, "dose_g_ha", "weed_control_pct")
  p <- plot(m, log_dose = FALSE)
  expect_s3_class(p, "gg")
})