#! /usr/local/bin/Rscript

Sys.unsetenv("R_HOME")

rec <-
c("MASS", "Matrix", "boot", "class", "cluster", "lattice", "mgcv",
  "nlme", "nnet", "rpart", "spatial", "survival")

args <- commandArgs(TRUE)
.libPaths(args[1])
old <- readRDS(args[2])
old <- as.data.frame(old, stringsAsFactors = FALSE)
new <- installed.packages(args[1])[, c("Package", "Version")]
new <- as.data.frame(new, stringsAsFactors = FALSE)
both <- merge(old, new, by = "Package")
updated <- with(both, Package[Version.x != Version.y])
## new packages might be in Suggests
added <- setdiff(row.names(new), row.names(old))
## and removed packages might have (a few) dependents
removed <- setdiff(row.names(old), row.names(new))
if(!length(c(updated, added, removed))) {
    message("no changed packages")
    q("no")
}
cur <- gsub("[.]out", "", dir(dirname(args[2]), patt = "[.]out"))
foo <- reinst <- character()
changed <- c(updated, added, removed)
for (u in changed) {
    foo0 <- tools::dependsOnPkgs(u, , TRUE)
    foo00 <- intersect(foo0, cur)
    if(length(foo00) <= 250L) reinst <- c(reinst, foo00)
    else {
        foo1 <- tools::dependsOnPkgs(u, , FALSE)
        foo1 <- intersect(foo1, cur)
	if(length(foo1) <= 250L) {
	    reinst <- c(reinst, foo1)
            message(sprintf("re-installing %d/%d revdeps of %s",
                            length(foo1), length(foo0), sQuote(u)))
	} else
            message(sprintf("not re-installing %d revdeps of %s",
                            length(foo0), sQuote(u)))
    }
    foo2 <- c(foo0, tools::dependsOnPkgs(c(u, foo0), 'all', FALSE))
    foo2 <- intersect(foo2, cur)
    if(length(foo2) <= 250L) foo <- c(foo, foo2)
    else {
        foo1 <- tools::dependsOnPkgs(u, 'all', FALSE)
        foo1 <- intersect(foo1, cur)
	if(length(foo1) <= 250L) {
	    foo <- c(foo, foo1)
            message(sprintf("re-checking %d/%d revdeps of %s",
                            length(foo1), length(foo2), sQuote(u)))
	} else
            message(sprintf("not re-checking %d revdeps of %s",
                            length(foo2), sQuote(u)))
    }
}
reinst <- sort(unique(reinst))
reinst <- setdiff(reinst, c(changed, rec))
foo <- sort(unique(foo))
foo <- setdiff(foo, rec)

if(length(reinst)) {
    message ("re-installing ", paste(sQuote(reinst), collapse =" "))
    unlink(file.path(dirname(args[2]), paste0(reinst, ".log")))
    if(length(reinst) > 20L) system("make installn")
    else system("make install")
}
if(length(foo)) {
    message ("re-checking ", paste(sQuote(foo), collapse =" "))
    unlink(file.path(dirname(args[2]), paste0(foo, ".out")))
} else
   message("no re-checking needed")