rsat_preview.R

#' @importFrom leaflet addProviderTiles addLayersControl addPolygons
#' @importFrom leaflet providerTileOptions layersControlOptions
createMap <- function() {
  theMap<-leaflet::leaflet()
  theMap<-addProviderTiles(theMap,"OpenStreetMap",
                           group = "OpenStreetMap",
                           options = providerTileOptions(zIndex = 0))
  theMap<-addProviderTiles(theMap,"Esri.WorldImagery",
                           group = "Esri.WorldImagery",
                           options = providerTileOptions(zIndex = 0))
  theMap<-addProviderTiles(theMap,"CartoDB.Positron",
                           group = "CartoDB.Positron",
                           options = providerTileOptions(zIndex = 0))
  theMap<-addProviderTiles(theMap,"CartoDB.DarkMatter",
                           group = "CartoDB.DarkMatter",
                           options = providerTileOptions(zIndex = 0))
  addLayersControl(theMap,
    baseGroups = c(
      "OpenStreetMap",
      "Esri.WorldImagery",
      "CartoDB.Positron",
      "CartoDB.DarkMatter"
    ),
    position = "topleft",
    options = layersControlOptions(autoZIndex = FALSE)
  )
}

updateLayersControl <- function(map,
                                addBaseGroups = NULL,
                                addOverlayGroups = NULL) {
  for (i in seq_len(length(map$x$calls))) {
    if (map$x$calls[[i]]$method == "addLayersControl") {
      map$x$calls[[i]][[2]][[1]] <- c(map$x$calls[[i]][[2]][[1]],
                                      addBaseGroups)
      map$x$calls[[i]][[2]][[2]] <- c(map$x$calls[[i]][[2]][[2]],
                                      addOverlayGroups)
    }
  }
  return(map)
}

#' @importFrom leafem updateLayersControl addRasterRGB
#' @importFrom stars st_as_stars
addMapRasterRGB <- function(img, lname, lpos, project = project) {
  nmap <- getPreviewMap() #%>%
    # addRasterRGB(subset(img,lpos), group=lname) #%>%
  nmap <- addRasterRGB(nmap,
                       img[,,,lpos],
                 group = lname,
                 project = project)
  # addHomeButton(st_bbox(transform_multiple_proj(img,
  # proj4=st_crs(4326))),
  # group = lname,
  # position = "bottomright",
  # add = TRUE)
  # updateLayersControl(addOverlayGroups = lname)
  setPreviewMap(updateLayersControl(nmap, addOverlayGroups = lname))
}

#' @importFrom leaflet addPolygons
#' @importFrom leafem addHomeButton addFeatures
#' @importFrom sf st_bbox st_crs
addMapFeature <- function(sfobj, lname) {
  nmap <- getPreviewMap()
  if (!any(unlist(lapply(nmap$x$calls, function(x) {
    if (x$method == "addPolygons") {
      if (x$args[[3]] == lname) {
        return(TRUE)
      }
    }
    return(FALSE)
  }), recursive = TRUE))) {
    nmap <- addFeatures(nmap,
                  sfobj,
                  group = lname,
                  label = lname,
                  color = "#3f8dfc",
                  fillOpacity = 0.2)
    nmap <- addHomeButton(nmap,
                          st_bbox(transform_multiple_proj(sfobj,
                                                    proj4 = st_crs(4326))),
                    group = lname,
                    position = "bottomright",
                    add = TRUE)
    setPreviewMap(nmap)
  }
}

previewmap <- new.env()
assign("map",
       NULL,
       env = previewmap)

getPreviewMap <- function() {
  if(is.null(get("map", envir = previewmap)))
    return(createMap())
  else
    return(get("map", envir = previewmap))
}
setPreviewMap <- function(map) {
  assign("map", map, envir = previewmap)
}

#' Preview a \code{records} or an \code{rtoi} object
#'
#' @param x a \code{records} or an \code{rtoi} object.
#' @param lpos vector argument. Defines the position of the red-green-blue
#' layers to enable a false color visualization.
#' @param add.layer logical argument. If \code{TRUE}, the function plots the
#' image on an existing map.
#' @param verbose logical argument. If \code{TRUE}, the function prints the
#' running steps and warnings.
#' @param tmp_dir character argument. The directory where preview images
#' are located.
#' @param get.map logical argument. If \code{TRUE}, the function
#' return the leaflet map.
#' @param n the date expressed as the temporal index in the time series.
#' @param ... additional arguments
#' @return nothing. Previews the region in the viewer.
#' @include rtoi.R records.R
#' @export
#' @examples
#' \dontrun{
#' library(rsat)
#'
#' # load example rtoi
#' file.copy(from=system.file("ex/Navarre",package="rsat"),
#'          to=tempdir(),
#'          recursive = TRUE)
#'
#' navarre <- read_rtoi(file.path(tempdir(),"Navarre"))
#'
#' set_credentials("username", "password")
#' set_database(file.path(tempdir(), "DATABASE"))
#'
#' # by default the first date in rtoi is previewed
#' rsat_preview(navarre)
#'
#'
#' preview.dates <- dates(navarre)
#' # use add.layer to preview images of several days
#' rsat_preview(navarre,preview.dates[2],add.layer = TRUE)
#'
#' # you can also preview records
#' rcrds <- records(navarre)
#' rsat_preview(rcrds, n = 1)
#' }
#' @export
setGeneric("rsat_preview", function(x, n, ...) {
  standardGeneric("rsat_preview")
})
#' @rdname rsat_preview
#' @aliases rsat_preview,rtoi,date
setMethod(
  f = "rsat_preview",
  signature = c("rtoi", "Date"),
  function(x,
           n,
           lpos = c(3, 2, 1),
           add.layer = FALSE,
           verbose = FALSE,
           ...) {
    # plot the rgb files
    rsat_preview(records(x),
            n,
            lpos,
            tmp_dir = get_database(x),
            add.layer=add.layer,
            verbose=verbose,
            get.map = FALSE,
            ...)
    # plot sf
    addMapFeature(region(x), names(x))
    return(getPreviewMap())
  }
)

#' @rdname rsat_preview
#' @aliases rsat_preview,rtoi,missing
setMethod(
  f = "rsat_preview",
  signature = c("rtoi", "missing"),
  function(x,
           n,
           lpos = c(3, 2, 1),
           add.layer = FALSE,
           verbose = FALSE,
           ...) {
    # plot the rgb files
    rsat_preview(records(x),
            dates(x)[1],
            lpos,
            tmp_dir = get_database(x),
            add.layer= add.layer,
            verbose = verbose,
            get.map = FALSE,
            ...)
    # plot sf
    addMapFeature(region(x), names(x))
    return(getPreviewMap())
  }
)
#' @rdname rsat_preview
#' @aliases rsat_preview,records,date
setMethod(
  f = "rsat_preview",
  signature = c("records", "Date"),
  function(x,
           n,
           lpos = c(3, 2, 1),
           tmp_dir = file.path(tempdir()),
           add.layer = FALSE,
           verbose = FALSE,
           get.map = TRUE,
           ...) {
    if (!add.layer) setPreviewMap(createMap())
    r <- x[dates(x) %in% n]
    for (n in seq_len(length(r))) {
      rsat_preview(r,
              n,
              lpos,
              tmp_dir,
              add.layer = TRUE,
              verbose=verbose,
              get.map = FALSE)
    }
    if (get.map) {
      return(getPreviewMap())
    }
  }
)
#' @importFrom terra rast
#' @rdname rsat_preview
#' @aliases rsat_preview,rtoi,numeric
setMethod(
  f = "rsat_preview",
  signature = c("records", "numeric"),
  function(x,
           n,
           lpos = c(3, 2, 1),
           tmp_dir = file.path(tempdir()),
           add.layer = FALSE,
           verbose = FALSE,
           get.map = TRUE,
           ...) {
    if (length(x) >= n & n > 0) {
      r <- x[n]
      dir.create(get_preview_path(r, tmp_dir),
                 showWarnings = FALSE,
                 recursive = TRUE)
      proj_file <- get_preview_proj(r, tmp_dir)
      if (!file.exists(proj_file)) {
        download_preview(r, tmp_dir, verbose = verbose, ...)
      }
      if (!add.layer) setPreviewMap(createMap())
      img <- read_stars(proj_file)
      # lname<-paste0(sat_name(r),"_",dates(r))
      lname <- names(r)
      addMapRasterRGB(img,
                      lname,
                      lpos,
                      project = FALSE)
      if (get.map) {
        return(getPreviewMap())
      }
    } else {
      if (verbose) {
        if (length(x) == 0) {
          message("No records for previewing.")
        }
        message("Cannot load new map.")
      }
      if (get.map) {
        return(getPreviewMap())
      }
    }
  }
)

get_preview_path <- function(r, tmp_dir) {
  return(file.path(tmp_dir, get_dir(r), "rgt_preview"))
}
get_preview_file <- function(r, tmp_dir) {
  return(file.path(get_preview_path(r, tmp_dir), names(r)))
}
get_preview_proj <- function(r, tmp_dir) {
  return(paste0(get_preview_file(r, tmp_dir), "_proj.tif"))
}
#' @importFrom terra writeRaster ext ext<- crs<-
#' @importFrom raster extent extent<- stack
#' @importFrom sf gdal_utils st_crs
download_preview <- function(r, tmp_dir, verbose = FALSE, ...) {
  pre.file <- get_preview_file(r, tmp_dir)
  if (verbose) message(paste0("Preview file download file: ",
                              pre.file))
  if (!file.exists(pre.file)) {
    p.url <- get_preview(r)
    con <- connection$getApi(get_api_name(r))
    con$file_download(p.url, pre.file)
  }
  suppressWarnings(img <- rast(pre.file))


  # check if we have projection from search result
  if (any(is.na(as.vector(extent(r))))) {
    # plotRGB(img)
    warning("Image without projection, cannot mosaick")
    return(NULL)
  } else {

    ext(img) <- ext(r)
    crs(img) <- st_crs(crs(r))$proj4string
    tmp.img <- paste0(pre.file, "_tmp.tif")

    writeRaster(img, tmp.img, overwrite = TRUE)
    gdal_utils(
      util = "warp",
      source = tmp.img,
      destination = get_preview_proj(r, tmp_dir),
      options = c("-t_srs", st_crs(4326)$proj4string)
    )
    rm(img)
    gc()
    file.remove(tmp.img)
  }
}