test_that("plot helper returns ggplot", {
  p <- vb_plot(iris, "Sepal.Length", type = "histogram")
  expect_s3_class(p, "ggplot")
})

test_that("dashboard returns html tags", {
  d <- vb_dashboard(iris)
  expect_true(inherits(d, "shiny.tag.list") || inherits(d, "shiny.tag"))
})

test_that("vb_plot creates all supported plot types", {
  dat <- data.frame(
    group = factor(c("A", "B", "A", "B")),
    x = c(1, 2, 3, 4),
    y = c(2, 4, 3, 5)
  )
  
  p_bar <- vb_plot(dat, "group", type = "bar")
  expect_s3_class(p_bar, "ggplot")
  
  p_hist <- vb_plot(dat, "x", type = "histogram")
  expect_s3_class(p_hist, "ggplot")
  
  p_density <- vb_plot(dat, "x", type = "density")
  expect_s3_class(p_density, "ggplot")
  
  p_scatter <- vb_plot(dat, "x", "y", type = "scatter")
  expect_s3_class(p_scatter, "ggplot")
  
  p_line <- vb_plot(dat, "x", "y", type = "line")
  expect_s3_class(p_line, "ggplot")
  
  p_box <- vb_plot(dat, "group", "y", type = "boxplot")
  expect_s3_class(p_box, "ggplot")
})


test_that("vb_plot validates x and y variables", {
  dat <- data.frame(
    x = 1:4,
    y = 5:8
  )
  
  expect_error(
    vb_plot(dat, "missing", type = "bar"),
    "`x` must name a column in `data`."
  )
  
  expect_error(
    vb_plot(dat, "x", y = "missing", type = "scatter"),
    "`y` must name a column in `data`."
  )
  
  expect_error(
    vb_plot(dat, "x", type = "scatter"),
    "requires `y`"
  )
  
  expect_error(
    vb_plot(dat, "x", type = "line"),
    "requires `y`"
  )
  
  expect_error(
    vb_plot(dat, "x", type = "boxplot"),
    "requires `y`"
  )
})


test_that("vb_plot rejects invalid plot types", {
  dat <- data.frame(x = 1:4)
  
  expect_error(
    vb_plot(dat, "x", type = "invalid"),
    "arg.*should be one of"
  )
})


test_that("autoviz creates an autoviz object", {
  dat <- data.frame(
    group = factor(c("A", "B", "A", "B")),
    x = c(1, 2, 3, 4),
    y = c(2, 4, 3, 5)
  )
  
  result <- autoviz(dat)
  
  expect_s3_class(result, "autoviz")
  expect_equal(result$data, dat)
  expect_true(is.data.frame(result$profile))
  expect_true(is.data.frame(result$summary))
  expect_true(is.data.frame(result$missing))
  expect_true(is.data.frame(result$outliers))
  expect_true(is.data.frame(result$recommendations))
})


test_that("autoviz respects max_plots", {
  dat <- data.frame(
    a = 1:5,
    b = 6:10,
    c = 11:15,
    d = 16:20
  )
  
  result <- autoviz(dat, max_plots = 2)
  
  expect_s3_class(result, "autoviz")
  expect_lte(nrow(result$recommendations), 2)
})


test_that("autoviz validates max_plots", {
  dat <- data.frame(x = 1:4)
  
  expect_error(
    autoviz(dat, max_plots = 0),
    "`max_plots` must be a positive number."
  )
  
  expect_error(
    autoviz(dat, max_plots = -1),
    "`max_plots` must be a positive number."
  )
  
  expect_error(
    autoviz(dat, max_plots = "two"),
    "`max_plots` must be a positive number."
  )
})


test_that("print.autoviz prints a summary", {
  dat <- data.frame(
    group = factor(c("A", "B", "A", "B")),
    x = c(1, 2, 3, 4)
  )
  
  obj <- autoviz(dat)
  
  output <- capture.output(print(obj))
  
  expect_true(any(grepl("<AutoViz>", output)))
  expect_true(any(grepl("Rows:", output)))
  expect_true(any(grepl("Columns:", output)))
  expect_true(any(grepl("Recommended visualizations:", output)))
  
  expect_identical(print(obj), obj)
})

test_that("dashboard renders recommendations table", {
  dat <- data.frame(
    group = factor(c("A", "B", "A", "B")),
    x = c(1, 2, 3, 4),
    y = c(2, 4, 3, 5)
  )
  
  d <- vb_dashboard(dat)
  
  expect_true(inherits(d, "shiny.tag.list") || inherits(d, "shiny.tag"))
  
  html <- as.character(d)
  
  expect_match(html, "Visualization recommendations")
  expect_match(html, "Dataset profile")
  expect_match(html, "Missing values")
  expect_match(html, "Categorical frequency")
})


test_that("dashboard renders missing-value table", {
  dat <- data.frame(
    group = factor(c("A", "B", NA, "A")),
    x = c(1, NA, 3, 4),
    y = c(2, 4, NA, 5)
  )
  
  d <- vb_dashboard(dat)
  
  expect_true(inherits(d, "shiny.tag.list") || inherits(d, "shiny.tag"))
  
  html <- as.character(d)
  
  expect_match(html, "Missing values")
  expect_match(html, "Missing %")
  expect_match(html, "group")
  expect_match(html, "x")
  expect_match(html, "y")
})


test_that("dashboard uses custom title", {
  dat <- data.frame(
    x = 1:4,
    y = 5:8
  )
  
  d <- vb_dashboard(
    dat,
    title = "My Custom Dashboard"
  )
  
  html <- as.character(d)
  
  expect_match(html, "My Custom Dashboard")
  expect_match(html, "AutoViz 1.0.0")
})


test_that("dashboard handles data with no missing values", {
  dat <- data.frame(
    x = 1:4,
    y = 5:8
  )
  
  d <- vb_dashboard(dat)
  
  html <- as.character(d)
  
  expect_match(html, "No missing values detected.")
})