#' @tool_code ST_T_TEST_IND
#' @name 独立样本 T 检验
#' @version 1.0.0
#' @description 比较两组独立样本的均值差异
#' @author SSA-Pro Team

library(glue)
library(ggplot2)
library(base64enc)

# 统一入口函数
run_analysis <- function(input) {
  # ===== 初始化 =====
  logs <- c()
  log_add <- function(msg) { logs <<- c(logs, paste0("[", Sys.time(), "] ", msg)) }
  tmp_files <- c()
  
  # 确保退出时清理临时文件
  on.exit({
    if (length(tmp_files) > 0) {
      unlink(tmp_files)
    }
  }, add = TRUE)
  
  # ===== 数据加载 =====
  log_add("开始加载输入数据")
  df <- tryCatch(
    load_input_data(input),
    error = function(e) {
      log_add(paste("数据加载失败:", e$message))
      return(NULL)
    }
  )
  
  if (is.null(df)) {
    return(make_error(ERROR_CODES$E100_INTERNAL_ERROR, details = "数据加载失败"))
  }
  log_add(glue("数据加载成功: {nrow(df)} 行, {ncol(df)} 列"))
  
  p <- input$params
  guardrails_cfg <- input$guardrails
  
  group_var <- p$group_var
  value_var <- p$value_var
  
  # ===== 参数校验 =====
  if (!(group_var %in% names(df))) {
    return(make_error(ERROR_CODES$E001_COLUMN_NOT_FOUND, col = group_var))
  }
  if (!(value_var %in% names(df))) {
    return(make_error(ERROR_CODES$E001_COLUMN_NOT_FOUND, col = value_var))
  }
  
  # ===== 数据清洗：移除分组变量或数值变量中的缺失值 =====
  original_rows <- nrow(df)
  
  # 处理分组变量：移除 NA、空字符串、纯空白字符
  df <- df[!is.na(df[[group_var]]) & trimws(as.character(df[[group_var]])) != "", ]
  
  # 处理数值变量：移除 NA
  df <- df[!is.na(df[[value_var]]), ]
  
  removed_rows <- original_rows - nrow(df)
  if (removed_rows > 0) {
    log_add(glue("数据清洗: 移除 {removed_rows} 行缺失值 (剩余 {nrow(df)} 行)"))
  }
  
  if (nrow(df) < 6) {
    return(make_error(ERROR_CODES$E004_SAMPLE_TOO_SMALL, 
                      n = nrow(df), min_required = 6))
  }
  
  groups <- unique(df[[group_var]])
  if (length(groups) != 2) {
    return(make_error(ERROR_CODES$E003_INSUFFICIENT_GROUPS, 
                      col = group_var, expected = 2, actual = length(groups)))
  }
  
  # ===== 护栏检查 =====
  guardrail_results <- list()
  method_used <- "t.test"
  warnings_list <- c()
  
  # 样本量检查
  g1_vals <- df[df[[group_var]] == groups[1], value_var]
  g2_vals <- df[df[[group_var]] == groups[2], value_var]
  
  sample_check <- check_sample_size(min(length(g1_vals), length(g2_vals)), 
                                    min_required = 3, 
                                    action = ACTION_BLOCK)
  guardrail_results <- c(guardrail_results, list(sample_check))
  log_add(glue("样本量检查: {sample_check$reason}"))
  
  # 正态性检验
  if (isTRUE(guardrails_cfg$check_normality)) {
    log_add("执行正态性检验")
    
    for (g in groups) {
      vals <- df[df[[group_var]] == g, value_var]
      norm_check <- check_normality(vals, 
                                    alpha = 0.05,
                                    action = ACTION_SWITCH,
                                    action_target = "ST_MANN_WHITNEY")
      guardrail_results <- c(guardrail_results, list(norm_check))
      log_add(glue("组[{g}] 正态性检验: p = {round(norm_check$p_value, 4)}, {norm_check$reason}"))
    }
  }
  
  # 执行护栏链
  guardrail_status <- run_guardrail_chain(guardrail_results)
  
  if (guardrail_status$status == "blocked") {
    return(list(
      status = "blocked",
      message = guardrail_status$reason,
      trace_log = logs
    ))
  }
  
  if (guardrail_status$status == "switch") {
    log_add(glue("触发方法切换: {guardrail_status$reason} -> {guardrail_status$target_tool}"))
    # TODO: 调用备选方法
    # 目前先继续执行 T 检验，但添加警告
    warnings_list <- c(warnings_list, guardrail_status$reason)
  }
  
  if (length(guardrail_status$warnings) > 0) {
    warnings_list <- c(warnings_list, guardrail_status$warnings)
  }
  
  # ===== 核心计算 =====
  log_add("执行 T 检验")
  result <- t.test(g1_vals, g2_vals, var.equal = FALSE)
  
  # ===== 生成图表 =====
  log_add("生成箱线图")
  plot_base64 <- tryCatch({
    generate_boxplot(df, group_var, value_var, tmp_files)
  }, error = function(e) {
    log_add(paste("图表生成失败:", e$message))
    NULL
  })
  
  # ===== 生成可复现代码 =====
  # 获取原始文件名（如果未提供则使用默认值）
  original_filename <- if (!is.null(input$original_filename) && nchar(input$original_filename) > 0) {
    input$original_filename
  } else {
    "data.csv"
  }
  
  reproducible_code <- glue('
# SSA-Pro 自动生成代码
# 工具: 独立样本 T 检验
# 时间: {Sys.time()}
# ================================

# 自动安装依赖
required_packages <- c("ggplot2")
new_packages <- required_packages[!(required_packages %in% installed.packages()[,"Package"])]
if(length(new_packages)) install.packages(new_packages, repos = "https://cloud.r-project.org")

library(ggplot2)

# 数据准备
df <- read.csv("{original_filename}")
group_var <- "{group_var}"
value_var <- "{value_var}"

# 独立样本 T 检验 (Welch)
g1_vals <- df[df[[group_var]] == "{groups[1]}", value_var]
g2_vals <- df[df[[group_var]] == "{groups[2]}", value_var]
result <- t.test(g1_vals, g2_vals, var.equal = FALSE)
print(result)

# 可视化
ggplot(df, aes(x = .data[[group_var]], y = .data[[value_var]])) +
  geom_boxplot(fill = "#3b82f6", alpha = 0.6) +
  theme_minimal() +
  labs(title = paste("Distribution of", value_var, "by", group_var))
')
  
  # ===== 返回结果 =====
  log_add("分析完成")
  
  return(list(
    status = "success",
    message = "分析完成",
    warnings = if (length(warnings_list) > 0) warnings_list else NULL,
    results = list(
      method = result$method,
      statistic = jsonlite::unbox(as.numeric(result$statistic)),
      df = jsonlite::unbox(as.numeric(result$parameter)),
      p_value = jsonlite::unbox(as.numeric(result$p.value)),
      p_value_fmt = format_p_value(result$p.value),
      conf_int = as.numeric(result$conf.int),
      estimate = as.numeric(result$estimate),
      group_stats = list(
        list(group = as.character(groups[1]), n = length(g1_vals), mean = mean(g1_vals), sd = sd(g1_vals)),
        list(group = as.character(groups[2]), n = length(g2_vals), mean = mean(g2_vals), sd = sd(g2_vals))
      )
    ),
    plots = if (!is.null(plot_base64)) list(plot_base64) else list(),
    trace_log = logs,
    reproducible_code = as.character(reproducible_code)
  ))
}

# 辅助函数：生成箱线图
generate_boxplot <- function(df, group_var, value_var, tmp_files_ref) {
  p <- ggplot(df, aes(x = .data[[group_var]], y = .data[[value_var]])) +
    geom_boxplot(fill = "#3b82f6", alpha = 0.6) +
    theme_minimal() +
    labs(title = paste("Distribution of", value_var, "by", group_var))
  
  tmp_file <- tempfile(fileext = ".png")
  
  ggsave(tmp_file, p, width = 6, height = 4, dpi = 100)
  
  base64_str <- base64encode(tmp_file)
  unlink(tmp_file)
  
  return(paste0("data:image/png;base64,", base64_str))
}