library("testthat")
library("stream")

stream1 <- DSD_Gaussians(k = 3, d = 2)
stream2 <- DSD_Gaussians(k = 1, d = 2)

rename <- function(x, names) {
  colnames(x) <-  names
  x
}

context("DSF_Func with a DSD")

library(dplyr)

# DSF with stream
dsfs <- list(
  stream1 %>% DSF_Func(func = rename, names = c("x", "y")),
  stream1 %>% DSF_Convolve(kernel = filter_MA(5), dim = 1),
  stream1 %>% DSF_Downsample(factor = 1),
  stream1 %>% DSF_dplyr(func = mutate(Xsum = X1 + X2)) %>% DSF_dplyr(func = select(!X1)),
  stream1 %>% DSF_ExponentialMA(alpha = .7),
  stream1 %>% DSF_Scale()
)

for (stream_dsf in dsfs) {
  if (interactive()) {
    print(stream_dsf)
    cat("\n")
  }

  ps <- get_points(stream_dsf, n = 5)
  ps$weight <- NULL
  expect_equal(dim(ps), c(5L, 3L))

  ps <- get_points(stream_dsf, n = 5, info = FALSE)
  ps$weight <- NULL
  expect_equal(dim(ps), c(5L, 2L))

  ps <- get_points(stream_dsf, n = 0)
  ps$weight <- NULL
  expect_equal(dim(ps), c(0L, 3L))

  ps <- update(stream_dsf, n = 5)
  ps$weight <- NULL
  expect_equal(nrow(ps), 5L)

  ps <- update(stream_dsf, dsd = stream2, n = 5)
  ps$weight <- NULL
  expect_equal(nrow(ps), 5L)
}


context("DSF_Func without a DSD")

expect_error(DSF_Scale())
points <- get_points(stream1, n = 100, info = FALSE)
center <- colMeans(points)
scale <- apply(points, MARGIN = 2, sd)


# DSF without stream
dsfs <- list(
  DSF_Func(func = rename, names = c("x", "y")),
  DSF_Convolve(kernel = filter_MA(5), dim = 1),
  DSF_Downsample(factor = 1),
  DSF_dplyr(func = mutate(Xsum = X1 + X2)) %>% DSF_dplyr(func = select(!X1)),
  DSF_ExponentialMA(alpha = .7),
  DSF_Scale(center = center, scale = scale, dim = c("X1", "X2"))
)

for (dsf in dsfs) {
  if (interactive()) {
    print(stream_dsf)
    cat("\n")
  }

  # no stream
  expect_error(get_points(dsf, n = 5))

  # specify stream
  expect_equal(nrow(update(dsf, dsd = stream2, n = 5)), 5L)

  # use data.frame
  expect_equal(nrow(update(dsf, dsd = get_points(stream2, n = 5))), 5L)
}


# DSF Feature Selection
stream <- DSD_Gaussians(k = 3, d = 3)

stream_2features <- DSF_FeatureSelection(stream, features = c("X1", "X3"))
p <- get_points(stream_2features, n = 3)
expect_equal(dim(p), c(3L, 3L))

p <- get_points(stream_2features, n = 3, info = FALSE)
expect_equal(dim(p), c(3L, 2L))

p <- get_points(stream_2features, n = 0)
expect_equal(dim(p), c(0L, 3L))

p <- get_points(stream_2features, n = 0, info = FALSE)
expect_equal(dim(p), c(0L, 2L))

stream_2features <- DSF_FeatureSelection(stream, features = c("X1", "X4"))
expect_error(get_points(stream_2features, n = 3, info = FALSE))