test_that(
  "amr_alert returns the expected structure",
  {

    x <- c(
      0.10,
      0.12,
      0.11,
      0.13,
      0.15,
      0.20,
      0.30,
      0.40
    )

    result <- amr_alert(x)

    expect_s3_class(
      result,
      "data.frame"
    )

    expect_equal(
      nrow(result),
      length(x)
    )

    expect_true(
      all(
        c(
          "observation",
          "observed",
          "ewma",
          "ewma_alert",
          "cusum",
          "cusum_alert",
          "overall_alert"
        ) %in% names(result)
      )
    )
  }
)


test_that(
  "amr_alert preserves observed values",
  {

    x <- c(
      0.10,
      0.20,
      0.30,
      0.40,
      0.50
    )

    result <- amr_alert(x)

    expect_equal(
      result$observed,
      x
    )

    expect_equal(
      result$observation,
      seq_along(x)
    )
  }
)


test_that(
  "amr_alert combines EWMA and CUSUM alerts",
  {

    x <- c(
      0.10,
      0.10,
      0.10,
      0.10,
      0.50,
      0.60,
      0.70,
      0.80
    )

    result <- amr_alert(
      x,
      lambda = 0.2,
      L = 3,
      h = 5
    )

    expect_equal(
      result$overall_alert,
      result$ewma_alert | result$cusum_alert
    )
  }
)


test_that(
  "amr_alert accepts custom parameters",
  {

    x <- c(
      0.10,
      0.12,
      0.15,
      0.20,
      0.25,
      0.30
    )

    result <- amr_alert(
      x,
      lambda = 0.3,
      L = 2,
      h = 3
    )

    expect_equal(
      nrow(result),
      length(x)
    )
  }
)