test_that("illustrative budget builds reproducible PAM accounts", {
  budget <- agri_pam_example("budget")
  expect_s3_class(budget, "data.frame")
  expect_equal(nrow(budget), 28)

  x <- agri_pam_example()
  expect_s3_class(x, "agri_pam")
  expect_equal(pam_values(x)$id, c("Paddy", "Wheat", "Chickpea", "Mustard"))
  paddy <- pam_values(x)[1, ]
  expect_equal(paddy$private_revenue, 123400)
  expect_equal(paddy$private_tradable_inputs, 28300)
  expect_equal(paddy$private_domestic_factors, 67500)
  expect_equal(paddy$private_profit, 27600)
  expect_equal(paddy$social_revenue, 127100)
  expect_equal(paddy$social_profit, 25520)
})

test_that("budget category aliases and grouping work", {
  budget <- data.frame(
    farm = c("A", "A", "A", "B", "B", "B"),
    category = c(
      "Revenue", "Tradable Inputs", "Domestic Factors",
      "output", "tradable", "domestic"
    ),
    quantity = 1,
    pp = c(100, 25, 45, 120, 30, 50),
    sp = c(110, 30, 40, 125, 35, 45)
  )
  x <- pam_from_budget(
    budget, "quantity", "pp", "sp", "category", id = "farm"
  )
  expect_equal(pam_values(x)$private_profit, c(30, 40))
  expect_equal(pam_values(x)$social_profit, c(40, 45))

  expect_error(
    pam_from_budget(
      transform(budget, category = "unknown"),
      "quantity", "pp", "sp", "category", id = "farm"
    ),
    "Unrecognised"
  )
})

test_that("parity prices implement import and export adjustments", {
  expect_equal(
    parity_price(300, 83, transport = 1200, handling = 300, direction = "import"),
    26400
  )
  expect_equal(
    parity_price(300, 83, transport = 1200, handling = 300, direction = "export"),
    23400
  )
  expect_equal(parity_price(c(10, 20), 2), c(20, 40))
  expect_error(parity_price(1, exchange_rate = 0), "strictly positive")
  expect_error(
    parity_price(1, exchange_rate = 1, transport = 2, direction = "export"),
    "negative"
  )
})