############################################
##  Homogeneity of variance test - ui
############################################

## 1. 翻译标签
hv_method <- c("levene", "bartlett", "fligner")
names(hv_method) <- c(i18n$t("Levene"),
                      i18n$t("Bartlett"),
                      i18n$t("Fligner"))

hv_plots <- c("hist", "density", "boxplot")
names(hv_plots) <- c(i18n$t("Histogram"),
                     i18n$t("Density"),
                     i18n$t("Boxplot"))

## 2. 函数形参
hv_args <- as.list(formals(homo_variance_test))

## 3. 收集输入
hv_inputs <- reactive({
  hv_args$data_filter <- if (input$show_filter) input$data_filter else ""
  hv_args$dataset     <- input$dataset
  hv_args$method      <- input$hv_method
  # 确保正确收集分组变量和数值变量
  for (i in r_drop(names(hv_args))) {
    hv_args[[i]] <- input[[paste0("hv_", i)]]
  }
  hv_args
})

## 4. 数值变量选择
output$ui_hv_var <- renderUI({
  req(input$dataset)
  current_data <- get_data(input$dataset, envir = r_data)
  isNum <- sapply(current_data, function(col) is.numeric(col) || is.ts(col))
  num_vars <- names(isNum)[isNum]
  if (length(num_vars) == 0) {
    return(div(class = "alert alert-warning", i18n$t("No numeric variables in dataset.")))
  }
  vars <- c("None" = "", num_vars)
  selectInput(
    inputId = "hv_var", 
    label = i18n$t("Variable (select one):"),
    choices = vars, 
    selected = state_single("hv_var", vars), 
    multiple = FALSE
  )
})

## 5. 分组变量选择
output$ui_hv_group <- renderUI({
  req(input$dataset)
  current_data <- get_data(input$dataset, envir = r_data)
  # 仅保留因子/字符型变量
  group_candidates <- names(which(sapply(current_data, function(col) 
    is.factor(col) || is.character(col)
  )))
  # 筛选有效水平≥2的分组变量
  valid_groups <- character(0)
  for (grp in group_candidates) {
    grp_vals <- current_data[[grp]]
    valid_levels <- length(unique(grp_vals[!is.na(grp_vals)]))
    if (valid_levels >= 2) {
      valid_groups <- c(valid_groups, grp)
    }
  }
  if (length(valid_groups) == 0) {
    return(div(class = "alert alert-warning", i18n$t("No valid grouping variables (need ≥2 levels).")))
  }
  selectInput(
    inputId = "hv_group", 
    label = i18n$t("Grouping variable:"),
    choices = valid_groups, 
    selected = state_single("hv_group", valid_groups), 
    multiple = FALSE
  )
})

## 6. 主UI
output$ui_homo_variance_test <- renderUI({
  req(input$dataset)
  tagList(
    wellPanel(
      conditionalPanel(
        condition = "input.tabs_homo_variance_test == 'Summary'",
        uiOutput("ui_hv_var"),
        uiOutput("ui_hv_group"),
        selectizeInput(
          inputId = "hv_method", 
          label = i18n$t("Test method:"),
          choices = hv_method,
          selected = state_multiple("hv_method", hv_method, "levene"),
          multiple = TRUE,
          options = list(placeholder = i18n$t("Select methods"),
                         plugins = list("remove_button", "drag_drop"))
        )
      ),
      conditionalPanel(
        condition = "input.tabs_homo_variance_test == 'Plot'",
        selectizeInput(
          inputId = "hv_plots", 
          label = i18n$t("Select plots:"),
          choices = hv_plots,
          selected = state_multiple("hv_plots", hv_plots, "boxplot"),
          multiple = TRUE,
          options = list(placeholder = i18n$t("Select plots"),
                         plugins = list("remove_button", "drag_drop"))
        )
      )
    ),
    help_and_report(
      modal_title = i18n$t("Homogeneity of variance test"),
      fun_name = "homo_variance_test",
      help_file = inclMD(file.path(getOption("radiant.path.basics"),
                                   "app/tools/help/homo_variance_test.md"))
    )
  )
})

## 7. 画图尺寸
hv_plot <- reactive({
  list(plot_width = 650,
       plot_height = 400 * max(length(input$hv_plots), 1))
})
hv_plot_width  <- function() hv_plot()$plot_width
hv_plot_height <- function() hv_plot()$plot_height

## 8. 输出面板
output$homo_variance_test <- renderUI({
  register_print_output("summary_homo_variance_test", ".summary_homo_variance_test")
  register_plot_output("plot_homo_variance_test", ".plot_homo_variance_test",
                       height_fun = "hv_plot_height")
  
  hv_output_panels <- tabsetPanel(
    id = "tabs_homo_variance_test",
    tabPanel(title = i18n$t("Summary"), value = "Summary", verbatimTextOutput("summary_homo_variance_test")),
    tabPanel(title = i18n$t("Plot"), value = "Plot", download_link("dlp_homo_variance_test"),
             plotOutput("plot_homo_variance_test", height = "100%"))
  )
  
  stat_tab_panel(
    menu = i18n$t("Basics > Homogeneity"),
    tool = i18n$t("Homogeneity of variance test"),
    tool_ui = "ui_homo_variance_test",
    output_panels = hv_output_panels
  )
})

## 9. 可用性检查（强化变量存在性校验）
hv_available <- reactive({
  req(input$dataset)
  current_data <- get_data(input$dataset, envir = r_data)
  
  # 校验数值变量
  if (not_available(input$hv_var) || !input$hv_var %in% colnames(current_data)) {
    return(i18n$t("Please select a valid numeric variable."))
  }
  
  # 校验分组变量
  if (not_available(input$hv_group) || !input$hv_group %in% colnames(current_data)) {
    return(i18n$t("Please select a valid grouping variable."))
  }
  
  # 校验分组变量水平
  group_vals <- current_data[[input$hv_group]]
  valid_levels <- length(unique(group_vals[!is.na(group_vals)]))
  if (valid_levels < 2) {
    return(i18n$t("Grouping variable has <2 valid levels. Choose another."))
  }
  
  "available"
})

## 10. 计算核心
.homo_variance_test <- reactive({
  req(hv_available() == "available")  # 确保通过可用性检查
  hvi <- hv_inputs()
  hvi$envir <- r_data
  do.call(homo_variance_test, hvi)
})

.summary_homo_variance_test <- reactive({
  if (hv_available() != "available") return(hv_available())
  summary(.homo_variance_test())
})

.plot_homo_variance_test <- reactive({
  if (hv_available() != "available") return(hv_available())
  validate(need(input$hv_plots, i18n$t("Select plot types first")))
  withProgress(message = i18n$t("Generating plots"), value = 1,
               plot(.homo_variance_test(), plots = input$hv_plots, shiny = TRUE))
})

## 11. 下载 & 截图
download_handler(
  id = "dlp_homo_variance_test",
  fun = download_handler_plot,
  fn = function() paste0(input$dataset, "_homo_variance_test"),
  type = "png",
  caption = i18n$t("Save plot"),
  plot = .plot_homo_variance_test,
  width = hv_plot_width,
  height = hv_plot_height
)

observeEvent(input$homo_variance_test_report, {
  r_info[["latest_screenshot"]] <- NULL
  homo_variance_test_report()
})

observeEvent(input$homo_variance_test_screenshot, {
  r_info[["latest_screenshot"]] <- NULL
  radiant_screenshot_modal("modal_homo_variance_test_screenshot")
})

observeEvent(input$modal_homo_variance_test_screenshot, {
  homo_variance_test_report()
  removeModal()
})