#' @include RcppExports.R raptr-internal.R

NULL

#' Calculate boundary data for planning units

#'

#' This function calculates boundary length data for

#' [PBSmapping::PolySet()], [sp::SpatialPolygons()], and

#' [sp::SpatialPolygonsDataFrame()] objects. Be aware that this

#' function is designed with performance in mind, and as a consequence, if this

#' function is used improperly then it may crash R. Furthermore, multipart

#' polygons with touching edges will likely result in inaccuracies.

#' If argument set to [sp::SpatialPolygons()] or

#' [sp::SpatialPolygonsDataFrame()], this will be converted to

#' PolySet before processing.

#'

#' @param x [PBSmapping::PolySet()],

#'   [sp::SpatialPolygons()] or

#'   [sp::SpatialPolygonsDataFrame()] object.

#'

#' @param tol `numeric` to specify precision of calculations. In other

#'   words, how far apart vertices have to be to be considered different?

#'

#' @param length.factor `numeric` to scale boundary lengths.

#'

#' @param edge.factor `numeric` to scale boundary lengths for edges that

#'   do not have any neighbors, such as those that occur along the margins.

#'

#' @return `data.frame` with 'id1' (`integer`), 'id2'

#'   (`integer`), and 'amount' (`numeric`) columns.

#'

#' @seealso This function is based on the algorithm in QMARXAN

#'   <https://github.com/tsw-apropos/qmarxan> for calculating boundary

#'   length.

#'

#' @examples

#' # simulate planning units

#' sim_pus <- sim.pus(225L)

#'

#' # calculate boundary data

#' bound.dat <- calcBoundaryData(sim_pus)

#'

#' # print summary of boundary data

#' summary(bound.dat)

#'

#' @export

calcBoundaryData <- function(x, tol, length.factor, edge.factor)

  UseMethod("calcBoundaryData")

#' @rdname calcBoundaryData

#'

#' @method calcBoundaryData PolySet

#'

#' @export

calcBoundaryData.PolySet <- function(x, tol = 0.001, length.factor = 1.0,

                                     edge.factor = 1.0) {

  assertthat::assert_that(inherits(x, "PolySet"), assertthat::is.scalar(tol),

                          assertthat::is.scalar(length.factor),

                          assertthat::is.scalar(edge.factor))

  ret <- rcpp_calcBoundaryDF(x, tolerance = tol, lengthFactor = length.factor,

                             edgeFactor = edge.factor)

  if (length(ret$warnings) != 0) {

    warning(paste0("Invalid geometries detected, see \"warnings\" attribute ",

                   "for more information."))

    attr(ret$bldf, "warnings") <- ret$warnings

  }

  return(ret$bldf)

}

#' @rdname calcBoundaryData

#'

#' @method calcBoundaryData SpatialPolygons

#'

#' @export

calcBoundaryData.SpatialPolygons <- function(x, tol = 0.001,

                                             length.factor = 1.0,

                                             edge.factor = 1.0) {

  return(calcBoundaryData(rcpp_Polygons2PolySet(x@polygons), tol,

                          length.factor, edge.factor))

}