 #=============================================================================#
 # Copyright (c) 2009, 2018 Stephan Wahlbrink and others.
 # 
 # This program and the accompanying materials are made available under the
 # terms of the Eclipse Public License 2.0 which is available at
 # https://www.eclipse.org/legal/epl-2.0, or the Apache License, Version 2.0
 # which is available at https://www.apache.org/licenses/LICENSE-2.0.
 # 
 # SPDX-License-Identifier: EPL-2.0 OR Apache-2.0
 # 
 # Contributors:
 #     Stephan Wahlbrink <sw@wahlbrink.eu> - initial API and implementation
 #=============================================================================#


## RJ init

.rj.config <- new.env()
.rj.config$isDebug <- FALSE

#' Initializes the package
.onLoad <- function(libname, pkgname) {
	utilsEnv <- getNamespace("utils")
	assign("help", envir = .rj.originals, value = get("help", envir = utilsEnv))
	assign("help.start", envir = .rj.originals, value = get("help.start", envir = utilsEnv))
	
	return (invisible(TRUE))
}

.rj.originals <- new.env()


## Tmp

#' Environment for temporary R objects
.rj.tmp <- new.env()

#' Returns the next available id (a element name with the specified prefix)
#' 
#' @param prefix prefix of the element name, usually a key for a element type
#' @param envir optional environment, default is \code{.rj.tmp}
#' @return the id
#' @returnType char
tmp.createId <- function(prefix, envir = .rj.tmp) {
	i <- 1L; 
	repeat {
		name <- paste(prefix, i, sep= "")
		if (!exists(name, envir = envir, inherits = FALSE)) {
			assign(name, NULL, envir= envir)
			return(name); 
		}
		i <- i + 1L; 
	}
}

tmp.set <- function(name, value, envir = .rj.tmp) {
	assign(name, value, envir= envir)
	return (invisible())
}

tmp.remove <- function(name, envir = .rj.tmp) {
	if (exists(name, envir= envir, inherits= FALSE)) {
		rm(list= name, envir= envir, inherits= FALSE)
	}
	return (invisible())
}

tmp.removeAll <- function(id, envir = .rj.tmp) {
	names <- ls(envir= envir, pattern= paste0("^\\Q", id, "\\E"))
	if (length(names)) {
		rm(list= names, envir= envir, inherits= FALSE)
	}
	return (invisible())
}

tmp.setReverseIndex <- function(name, index, len = NA, envir = .rj.tmp) {
	index = get(index, envir= envir, inherits= FALSE)
	if (is.na(len)) {
		len <- length(index)
	}
	index.r <- rep.int(NA_integer_, len)
	index.r[index] <- 1L:length(index)
	assign(name, index.r, envir= envir)
	return (invisible())
}

tmp.setWhichIndex <- function(name, filter, envir = .rj.tmp) {
	filter <- get(filter, envir= envir, inherits= FALSE)
	filter <- which(filter)
	assign(name, filter, envir= envir)
	return (invisible())
}

tmp.setFilteredIndex <- function(name, filter, index, envir = .rj.tmp) {
	filter <- get(filter, envir= envir, inherits= FALSE)
	index <- get(index, envir= envir, inherits= FALSE)
	if (length(dim(index)) > 1L) {
		idx <- index[,1L]
		index <- index[filter[idx],]
	}
	else {
		index <- index[filter[index]]
	}
	assign(name, index, envir= envir)
	return (invisible())
}

tmp.getFilteredCount <- function(index, filter, envir = .rj.tmp) {
	filter <- get(filter, envir= envir, inherits= FALSE)
	if (missing(index)) {
		return (sum(filter))
	}
	index <- get(index, envir= envir, inherits= FALSE)
	if (length(dim(index)) > 1L) {
		index <- index[,1L]
	}
	return (sum(filter[index]))
}

tmp.clear <- function(envir = .rj.tmp) {
	toRemove <- ls(envir= envir)
	toRemove <- toRemove[toRemove != "help"] # TODO Remove in RJ-1.2
	rm(list= toRemove, envir= envir)
}


## Internal utils

.rj.errorHandler <- function(e) {
	if (.rj.config$isDebug) {
		print(e)
	}
}

patchPackage <- function(name, value, envir, ns = TRUE) {
	if (exists(name, envir)) {
		unlockBinding(name, envir)
		on.exit(lockBinding(name, envir), add= TRUE)
		assign(name, value, envir)
	}
	if (ns && getRversion() < "2.15.0") {
		envName <- environmentName(envir)
		if (envName == "base") {
			ns <- "base"
		}
		else if (!is.null(envName) && substring(envName, 1L, 8L) == "package:") {
			ns <- asNamespace(substring(envName, 9L))
		}
		else {
			ns <- NULL
		}
		if (!is.null(ns)) {
			assignInNamespace(name, value, ns= ns)
		}
	}
	return (invisible(TRUE))
}

resolveVisible <- function(result) {
	if (result$visible) {
		return (result$value)
	}
	else {
		return (invisible(result$value))
	}
}