## ----setup, include = FALSE---------------------------------------------------
knitr::opts_chunk$set(
  collapse = TRUE,
  comment  = "#>",
  eval     = FALSE
)

## ----inspect------------------------------------------------------------------
# raw  <- import_steps_data("my_data.sav")
# cols <- detect_steps_columns(raw)
# 
# # See all detected columns
# str(cols[!sapply(cols, is.null)])
# 
# # See what was NOT detected
# names(cols[sapply(cols, is.null)])

## ----convert------------------------------------------------------------------
# # Glucose: mg/dL to mmol/L (divide by 18)
# raw$b5 <- raw$b5 / 18
# 
# # Cholesterol: mg/dL to mmol/L (divide by 38.67)
# raw$b8 <- raw$b8 / 38.67

## ----merge--------------------------------------------------------------------
# step1 <- haven::read_spss("step1_interview.sav")
# step2 <- haven::read_spss("step2_measurements.sav")
# step3 <- haven::read_spss("step3_biochemistry.sav")
# 
# combined <- dplyr::left_join(step1, step2, by = "pid") |>
#   dplyr::left_join(step3, by = "pid")
# 
# # Save combined file
# haven::write_sav(combined, file.path(tempdir(), "steps_combined.sav"))
# 
# # Or import directly
# raw <- combined |> janitor::clean_names()

## ----diagnostic---------------------------------------------------------------
# library(stepssurvey)
# 
# raw  <- import_steps_data("my_data.sav")
# cols <- detect_steps_columns(raw)
# 
# # Summary
# cat("Rows:", nrow(raw), "\n")
# cat("Columns:", ncol(raw), "\n")
# cat("Detected:", sum(!sapply(cols, is.null)), "/", length(cols), "\n")
# 
# # Check key variables
# if (!is.null(cols$age)) {
#   cat("\nAge range:", range(raw[[cols$age]], na.rm = TRUE), "\n")
#   cat("Age NAs:", sum(is.na(raw[[cols$age]])), "\n")
# }
# if (!is.null(cols$sex)) {
#   cat("\nSex distribution:\n")
#   print(table(raw[[cols$sex]], useNA = "ifany"))
# }
# if (!is.null(cols$weight_step1)) {
#   wt <- raw[[cols$weight_step1]]
#   cat("\nWeight range:", round(range(wt, na.rm = TRUE), 3), "\n")
#   cat("Weight NAs:", sum(is.na(wt)), "\n")
# }
# 
# # List undetected variables
# missing <- names(cols[sapply(cols, is.null)])
# cat("\nUndetected variables (", length(missing), "):\n")
# cat(paste(" ", missing, collapse = "\n"), "\n")