#===============================================================================
# Test: map_column()
# File: test-map_column.R
# Description: Unit tests for the map_column() function
#===============================================================================

#------------------------------------------------------------------------------
# Basic functionality
#------------------------------------------------------------------------------
test_that("map_column() creates a new column correctly", {
  df <- data.frame(id = c("A", "B", "C"))
  label_map <- c("A" = "Apple", "C" = "Cherry")

  result <- map_column(df, by = "id", map = label_map, to = "fruit", preview = FALSE)
  expect_s3_class(result, "data.frame")
  expect_named(result, c("id", "fruit"))
  expect_equal(result$fruit, c("Apple", "unknown", "Cherry"))
})

test_that("map_column() overwrites the existing column when overwrite = TRUE", {
  df <- data.frame(id = c("A", "B", "C"))
  label_map <- c("A" = "Apple", "B" = "Banana")

  result <- map_column(df, by = "id", map = label_map, overwrite = TRUE, preview = FALSE)
  expect_s3_class(result, "data.frame")
  expect_named(result, "id")
  expect_equal(result$id, c("Apple", "Banana", "unknown"))
})

test_that("map_column() handles list input as map", {
  df <- data.frame(group = c("G1", "G2", "G3"))
  group_map <- list("G1" = "Control", "G3" = "Treatment")

  result <- map_column(df, by = "group", map = group_map, to = "condition", preview = FALSE)
  expect_equal(result$condition, c("Control", "unknown", "Treatment"))
})

#------------------------------------------------------------------------------
# Parameter variants
#------------------------------------------------------------------------------
test_that("map_column() maps unmatched to default='unknown'", {
  df <- data.frame(id = c("A", "X"))
  m <- c("A" = "Apple")
  result <- map_column(df, by = "id", map = m, to = "label", preview = FALSE)
  expect_equal(result$label, c("Apple", "unknown"))
})

#------------------------------------------------------------------------------
# Error & edge handling
#------------------------------------------------------------------------------
test_that("map_column() throws error on invalid inputs", {
  df <- data.frame(x = c("A", "B"))
  expect_error(map_column(123, by = "x", map = c("A" = "a"), preview = FALSE),
               "'query' must be a data.frame")
  expect_error(map_column(df, by = NA_character_, map = c("A" = "a"), preview = FALSE),
               "'by' must be a non-empty single string")
  expect_error(map_column(df, by = "", map = c("A" = "a"), preview = FALSE),
               "'by' must be a non-empty single string")
  expect_error(map_column(df, by = "y", map = c("A" = "a"), preview = FALSE),
               "Column 'y' not found")
  expect_error(map_column(df, by = "x", map = c("A", "B"), preview = FALSE),
               "'map' must have names")
})