# Tests for visualization functions
# Test file: tests/testthat/test-visualization.R

# Skip if ggplot2 not available
skip_if_not_installed("ggplot2")

# Helper function
generate_test_data <- function(n = 200, changepoints = 100, means = c(0, 3), sd = 1) {
  c(rnorm(changepoints, means[1], sd), 
    rnorm(n - changepoints, means[2], sd))
}

# =============================================================================
# Basic Plot Tests
# =============================================================================

test_that("plot.regime_result returns ggplot object", {
  set.seed(123)
  data <- generate_test_data()
  result <- detect_regimes(data)
  
  p <- plot(result)
  
  expect_s3_class(p, "ggplot")
})

test_that("plot type 'data' works", {
  set.seed(123)
  data <- generate_test_data()
  result <- detect_regimes(data)
  
  p <- plot(result, type = "data")
  
  expect_s3_class(p, "ggplot")
})

test_that("plot type 'segments' works", {
  set.seed(123)
  data <- generate_test_data()
  result <- detect_regimes(data)
  
  p <- plot(result, type = "segments")
  
  expect_s3_class(p, "ggplot")
})

test_that("plot type 'posterior' works for Bayesian methods", {
  set.seed(123)
  data <- generate_test_data()
  result <- detect_regimes(data, method = "bocpd")
  
  p <- plot(result, type = "posterior")
  
  expect_s3_class(p, "ggplot")
})

test_that("plot type 'diagnostic' works for CUSUM", {
  set.seed(123)
  data <- generate_test_data()
  result <- detect_regimes(data, method = "cusum")
  
  p <- plot(result, type = "diagnostic")
  
  expect_s3_class(p, "ggplot")
})

# =============================================================================
# Plot Options Tests
# =============================================================================

test_that("show_ci option works", {
  set.seed(123)
  data <- generate_test_data()
  result <- detect_regimes(data, uncertainty = TRUE, bootstrap_reps = 20)
  
  p <- plot(result, show_ci = TRUE)
  
  expect_s3_class(p, "ggplot")
})

test_that("show_segments option works", {
  set.seed(123)
  data <- generate_test_data()
  result <- detect_regimes(data)
  
  p <- plot(result, show_segments = TRUE)
  
  expect_s3_class(p, "ggplot")
})

test_that("custom title works", {
  set.seed(123)
  data <- generate_test_data()
  result <- detect_regimes(data)
  
  p <- plot(result, title = "Custom Title")
  
  expect_s3_class(p, "ggplot")
  # Check title is in the plot
  expect_true(grepl("Custom", p$labels$title))
})

# =============================================================================
# Run Length Plot Tests
# =============================================================================

test_that("plot type 'runlength' works for BOCPD", {
  set.seed(123)
  data <- generate_test_data()
  result <- detect_regimes(data, method = "bocpd")
  
  p <- plot(result, type = "runlength")
  
  expect_s3_class(p, "ggplot")
})

# =============================================================================
# Summary Plot Tests
# =============================================================================

test_that("plot_summary creates multi-panel plot", {
  skip_if_not_installed("patchwork")
  
  set.seed(123)
  data <- generate_test_data()
  result <- detect_regimes(data, method = "bocpd")
  
  p <- plot_summary(result)
  
  expect_s3_class(p, c("patchwork", "ggplot"))
})

# =============================================================================
# Comparison Plot Tests
# =============================================================================

test_that("plot_compare works", {
  set.seed(123)
  data <- generate_test_data()
  
  result1 <- detect_regimes(data, method = "pelt")
  result2 <- detect_regimes(data, method = "binseg")
  
  p <- plot_compare(list(pelt = result1, binseg = result2))
  
  expect_s3_class(p, "ggplot")
})

# =============================================================================
# Interactive Plot Tests
# =============================================================================

test_that("plot_interactive returns plotly object", {
  skip_if_not_installed("plotly")
  
  set.seed(123)
  data <- generate_test_data()
  result <- detect_regimes(data)
  
  p <- plot_interactive(result)
  
  expect_s3_class(p, "plotly")
})

# =============================================================================
# Edge Cases
# =============================================================================

test_that("plot handles no changepoints", {
  set.seed(123)
  data <- rnorm(100)
  result <- detect_regimes(data, method = "pelt", penalty = 100)
  
  # Should not error even with no changepoints
  p <- plot(result)
  
  expect_s3_class(p, "ggplot")
})

test_that("plot handles single changepoint", {
  set.seed(123)
  data <- generate_test_data()
  result <- detect_regimes(data)
  
  p <- plot(result)
  
  expect_s3_class(p, "ggplot")
})

test_that("plot handles many changepoints", {
  set.seed(123)
  # Data with many changepoints
  n_segments <- 10
  segment_length <- 30
  data <- unlist(lapply(1:n_segments, function(i) {
    rnorm(segment_length, mean = ifelse(i %% 2 == 0, 0, 3))
  }))
  
  result <- detect_regimes(data, method = "pelt", min_segment = 10)
  
  p <- plot(result)
  
  expect_s3_class(p, "ggplot")
})

# =============================================================================
# Theme and Aesthetics Tests
# =============================================================================

test_that("plot respects ggplot2 theme additions", {
  set.seed(123)
  data <- generate_test_data()
  result <- detect_regimes(data)
  
  p <- plot(result) + ggplot2::theme_minimal()
  
  expect_s3_class(p, "ggplot")
})

test_that("plot can be modified with ggplot2 layers", {
  set.seed(123)
  data <- generate_test_data()
  result <- detect_regimes(data)
  
  p <- plot(result) + 
    ggplot2::labs(x = "Time Index", y = "Value")
  
  expect_s3_class(p, "ggplot")
})

# =============================================================================
# Data Visualization Helper Tests
# =============================================================================

test_that("segment coloring is correct", {
  set.seed(123)
  data <- generate_test_data()
  result <- detect_regimes(data)
  
  p <- plot(result, type = "segments")
  
  # Check that plot has segment information
  expect_s3_class(p, "ggplot")
})

test_that("changepoint lines are added", {
  set.seed(123)
  data <- generate_test_data()
  result <- detect_regimes(data)
  
  p <- plot(result, type = "data")
  
  # Plot should have vertical line geoms if changepoints detected
  if (length(result$changepoints) > 0) {
    layer_classes <- sapply(p$layers, function(l) class(l$geom)[1])
    expect_true("GeomVline" %in% layer_classes || 
                any(grepl("line", tolower(layer_classes))))
  }
})