#!/usr/bin/env Rscript
# Diff tool for comparing the objects in two R data files
#
# Author: Johannes Ranke <johannes.ranke@jrwb.de>
# ULR: https://github.com/jranke/dotfiles/bin/rda_diff
# Last Change: Fri May 12, 2023 at 04:36 PM +0200

# Load required packages {{{1
suppressMessages({
  if (!require(docopt)) {
    stop("Please install the 'docopt' package")
  }
  if (!require(waldo)) {
    stop("Please install the 'waldo' package")
  }
})

# Define usage in docopt syntax {{{1
doc <- "Usage: rda_diff.R [-m --max-diffs] <reference_file> <test_file>

Options:
 -m --max-diffs MAXDIFFS  Maximum number of differences shown [default: 10]"

# Load and process options {{{1
opt <- try(docopt(doc), silent = TRUE)
if (inherits(opt, "try-error")) {
  stop(doc)
}

# Load and compare objects {{{1
# Create environments to load object into
env_ref <- new.env()
env_test <- new.env()

# Load objects into environments and get their names
o_ref <- load(opt$reference_file, env_ref)
o_test <- load(opt$test_file, env_test)

# Report new and deleted objects
if (length(o_new <- setdiff(o_ref, o_test)) > 0) {
  cat("New objects in", opt$test_file, ":\n")
  cat(paste(o_new, collapse = ", "))
  cat("\n")
}
if (length(o_del <- setdiff(o_test, o_ref)) > 0) {
  cat("Objects missing in", opt$test_file, ":\n")
  cat(paste(o_del, collapse = ", "))
  cat("\n")
}

# Compare objects present in both files
for (o in intersect(o_ref, o_test)) {
  ref <- get(o, env_ref)
  test <- get(o, env_test)
  if (!identical(ref, test)) {
    cat("\nChanges in object", o, ":\n")
    print(waldo::compare(ref, test, max_diffs = as.numeric(opt$m)))
  }
}
# vim: set ft=r ts=2 sw=2 expandtab foldmethod=marker: