#!/usr/bin/env Rscript
# Validate local/patches/registry.json: schema, referenced patch files, and
# ambiguous overlaps. Exits 1 on any problem. Used by pre-commit and CI.
#
# Defaults to local/patches/registry.json. To validate a candidate registry
# without touching the real one (e.g. from the patch proposer), set:
#   PATCH_DIR      directory patch-file paths resolve against (default local/patches)
#   REGISTRY_FILE  registry.json to validate       (default <PATCH_DIR>/registry.json)

dir <- Sys.getenv("PATCH_DIR", unset = "local/patches")
registry_file <- Sys.getenv(
  "REGISTRY_FILE",
  unset = file.path(dir, "registry.json")
)
if (!file.exists(registry_file)) {
  cat("No registry.json found; nothing to validate.\n")
  quit(status = 0L)
}

or_q <- function(x) if (is.null(x)) "?" else x

reg <- jsonlite::fromJSON(registry_file, simplifyVector = FALSE)
required <- c("package", "versions", "platforms", "reason")
errs <- character(0L)

for (i in seq_along(reg)) {
  e <- reg[[i]]
  missing <- setdiff(required, names(e))
  if (length(missing) > 0L) {
    errs <- c(
      errs,
      sprintf(
        "entry %d (%s): missing %s",
        i,
        if (is.null(e$package)) "?" else e$package,
        toString(missing)
      )
    )
  }
  if (!is.null(e$patch)) {
    p <- file.path(dir, e$patch)
    if (!file.exists(p)) {
      errs <- c(
        errs,
        sprintf("entry %d (%s): patch file '%s' missing", i, e$package, p)
      )
    }
  }
}

# Ambiguous overlap: two entries for the same package with identical platforms
# and versions.
keys <- vapply(
  reg,
  function(e) {
    sprintf(
      "%s|%s|%s",
      or_q(e$package),
      paste(sort(as.character(unlist(e$platforms))), collapse = ","),
      or_q(e$versions)
    )
  },
  character(1L)
)
dups <- keys[duplicated(keys)]
if (length(dups) > 0L) {
  errs <- c(
    errs,
    sprintf("ambiguous duplicate entries: %s", toString(unique(dups)))
  )
}

if (length(errs) > 0L) {
  cat("Patch registry validation FAILED:\n")
  cat(paste0("  - ", errs, "\n"))
  quit(status = 1L)
}
cat(sprintf(
  "Patch registry OK (%d %s).\n",
  length(reg),
  if (length(reg) == 1L) "entry" else "entries"
))