test_that("dataset_df() works", {
  expect_s3_class(dataset_df(mtcars), "dataset_df")
  expect_true(is.dataset_df(dataset_df(mtcars)))
  expect_false(is.dataset_df(mtcars))
  expect_equal(get_bibentry(dataset_df(mtcars))$author, person("Author", "Unknown"))
  expect_equal(
    dataset_df(mtcars, identifier = c(mt = "http:/mtcars.com/dataset#"))$rowid,
    defined(paste0("mt:", seq_along(mtcars$mpg)),
      namespace = c(mt = "http:/mtcars.com/dataset#")
    )
  )
  my_dataset <- dataset_df(
    country_name = defined(
      c("AD", "LI"),
      concept = "http://data.europa.eu/bna/c_6c2bb82d",
      namespace = "https://www.geonames.org/countries/$1/"
    ),
    gdp = defined(
      c(3897, 7365),
      label = "Gross Domestic Product",
      unit = "million dollars",
      concept = "http://data.europa.eu/83i/aa/GDP"
    )
  )
  expect_equal(var_label(my_dataset$gdp), "Gross Domestic Product")
})

test_that("dataset_df() works", {
  orange_bibentry <- dublincore(
    title = "Growth of Orange Trees",
    creator = c(
      person(
        given = "N.R.",
        family = "Draper",
        role = "cre",
        comment = c(VIAF = "http://viaf.org/viaf/84585260")
      ),
      person(
        given = "H",
        family = "Smith",
        role = "cre"
      )
    ),
    contributor = person(
      given = "Antal",
      family = "Daniel",
      role = "dtm"
    ), # Add data manager
    identifier = "https://doi.org/10.5281/zenodo.10396807", #
    publisher = "Wiley",
    datasource = "https://isbnsearch.org/isbn/9780471170822",
    dataset_date = 1998,
    language = "en",
    description = "The Orange data frame has 35 rows and 3 columns of records of the growth of orange trees."
  )
  orange_df <- dataset_df(
    rowid = defined(paste0("orange:", row.names(Orange)),
      label = "ID in the Orange dataset",
      namespace = c("orange" = "datasets::Orange")
    ),
    tree = defined(Orange$Tree,
      label = "The number of the tree"
    ),
    age = defined(Orange$age,
      label = "The age of the tree",
      unit = "days since 1968/12/31"
    ),
    circumference = defined(Orange$circumference,
      label = "circumference at breast height",
      unit = "milimeter",
      concept = "https://www.wikidata.org/wiki/Property:P2043"
    ),
    dataset_bibentry = orange_bibentry
  )
  expect_equal(dataset_title(orange_df), "Growth of Orange Trees")
  expect_equal(creator(orange_df), c(c(
    person(
      given = "N.R.",
      family = "Draper",
      role = "cre",
      comment = c(VIAF = "http://viaf.org/viaf/84585260")
    ),
    person(
      given = "H",
      family = "Smith",
      role = "cre"
    )
  )))
})

test_that("dataset_df() works", {
  test_dataset <- dataset_df(
    a = 3,
    dataset_bibentry = datacite(
      Title = "Hello",
      Creator = person("Jane", "Doe"),
      PublicationYear = 2025
    )
  )
  expect_equal(get_bibentry(test_dataset)$author,
               person("Jane", "Doe"))
  expect_true(is.subject(subject(test_dataset)))
})

test_that("subsetting works", {
  expect_equal(ncol(iris_dataset[, 1]), 1)
  expect_equal(nrow(iris_dataset[1, 2]), 1)
  expect_equal(iris$Sepal.Length[1], as_numeric(iris_dataset[[1, 2]]))
})

test_that("new_dataset() works", {
  myiris <- new_dataset(x = iris, identifier = "example")
  expect_error(new_dataset(2))
  expect_equal(class(new_dataset(iris, identifier = "example")),
               c("dataset_df", "tbl_df", "tbl", "data.frame"))
  expect_output(print(provenance(myiris)), "<http://example.com/dataset#>")
})

test_that("is.dataset_df() works", {
  expect_true(is.dataset_df(iris_dataset))
  expect_false(is.dataset_df(mtcars))
})

test_that("rbind works", {
  iris_dataset1 <- iris_dataset
  iris_dataset2 <- iris_dataset
  expect_equal(nrow(rbind(iris_dataset1, iris_dataset2)), 300)
})

## Testing citations ---------------------------------------
# Utility to capture output of print
capture_output_lines <- function(expr) {
  output <- capture.output(expr)
  output[1]  # Return the APA-style citation line
}

test_that("APA header prints correctly for two personal authors", {
  bib <- dublincore(
    title = "Growth of Orange Trees",
    creator = list(
      person(given = "N.R.", family = "Draper", role = "cre"),
      person(given = "H.", family = "Smith", role = "cre")
    ),
    publisher = "Wiley",
    identifier = "https://doi.org/10.5281/zenodo.14917851",
    dataset_date = 1998,
    description = "Orange tree growth data"
  )

  df <- orange_df
  attr(df, "data_bibentry") <- bib
  class(df) <- c("dataset_df", class(df))

  expect_equal(
    capture_output_lines(print(df)),
    "Draper-Smith (1998): Growth of Orange Trees [dataset], https://doi.org/10.5281/zenodo.14917851"
  )
})

test_that("APA header prints correctly for institutional author", {
  bib <- dublincore(
    title = "GDP Statistics",
    creator = list(person(family = "Eurostat")),
    publisher = "Eurostat",
    identifier = "https://doi.org/10.2908/TEINA011",
    dataset_date = 2025,
    description = "Nominal GDP data"
  )

  df2 <- orange_df
  set_bibentry(df2) <- bib

  expect_equal(
    capture_output_lines(print(df2)),
    "Eurostat (2025): GDP Statistics [dataset], https://doi.org/10.2908/TEINA011"
  )
})

test_that("APA header prints correctly for more than two authors", {
  bib3 <- dublincore(
    title = "Extended Orange Tree Growth Study",
    creator = list(
      person(given = "A.", family = "Miller", role = "cre"),
      person(given = "B.", family = "Nguyen", role = "cre"),
      person(given = "C.", family = "Zhang", role = "cre")
    ),
    publisher = "Springer",
    identifier = "https://doi.org/10.9999/multiple.authors",
    dataset_date = 2020,
    description = "Extended data on orange trees"
  )

  df3 <- orange_df
  set_bibentry(df3) <- bib3

  expect_equal(
    capture_output_lines(print(df3)),
    "Miller et al. (2020): Extended Orange Tree Growth Study [dataset], https://doi.org/10.9999/multiple.authors"
  )
})

## Test as_dataset_df ---------------------------------------------
test_that("as_dataset_df() works", {
  expect_s3_class(as_dataset_df(iris), "dataset_df")
  expect_false(is.dataset_df(mtcars))
})


test_that("summary.dataset_df() works", {
  test_dataset <- dataset_df(
    a = 3,
    dataset_bibentry = datacite(
      Title = "Hello",
      Creator = person("Jane", "Doe"),
      PublicationYear = 2024
    )
  )
  expect_output(summary(test_dataset), "Hello",
                ignore.case = FALSE)
  expect_output(summary(test_dataset), "Doe \\(2024\\)",
                ignore.case = FALSE)
})


test_that("names.dataset_df() works", {
  expect_output(print(names(iris_dataset)), "rowid",
                ignore.case = FALSE)
  expect_output(print(names(iris_dataset)), "Sepal.Length",
                ignore.case = FALSE)
  expect_length(names(iris_dataset), 6)
  expect_equal(names(iris_dataset)[1], "rowid")
})

test_that("Subsetting preserves dataset_df class and attributes", {
  df_sub <- orange_df[1:3, ]
  expect_s3_class(df_sub, "dataset_df")
  expect_true(!is.null(attr(df_sub, "dataset_bibentry")))
})