#' Title
#'
#' @param path
#' @param add
#' @param upscale
#'
#' @return
#' @export
#' @importFrom jpeg readJPEG
#' @importFrom graphics rasterImage
#' @examples
#' img <- readJPEG(system.file("img","Rlogo.jpg",package="jpeg"))
plot_jpeg <- function(path, add=FALSE, upscale = TRUE)
{
  require('jpeg')
  jpg = readJPEG(path, native=T) # read the file
  res = dim(jpg)[2:1] # get the resolution, [x, y]
  if (upscale){
    res <- res * 3
  }
  if (!add) # initialize an empty plot area if add==FALSE
    plot(1,1,xlim=c(1,res[1]),ylim=c(1,res[2]),asp=1,type='n',xaxs='i',yaxs='i',
         xaxt='n',yaxt='n',xlab='',ylab='',bty='n',  oma=c(0,0,1,1), mar=c(0,0,1,1)
    )
  rasterImage(jpg,1,1,res[1],res[2],interpolate=TRUE)
}


#' Title
#'
#' @param filename
#'
#' @return
#' @export
#' @importFrom png readPNG
#' @importFrom grid rasterGrob
#'
#' @examples
get_png <- function(filename) {
  grid::rasterGrob(png::readPNG(filename), interpolate = TRUE)
}


#' Title
#'
#' @param plot
#' @param logo
#' @param margin_param
#'
#' @return
#' @importFrom ggplot2 theme
#' @importFrom gridExtra arrangeGrob
#' @export
#'
#' @examples
add_logo <- function(plot, logo, margin_param = NULL) {
  if(has_caption(plot)) {
    # convert the caption size to a negative number and on the "pt" scale
    # p1$theme$plot.caption$size * 1.1
    # Count the number of lines, which is this + 1
    # For each line, we can add a certain negative space to align the logo
    cap_lines <- measure_caption(plot)
    if (!is.null(margin_param)) {
      plot <- plot + theme(plot.margin = unit(c(7, 7, margin_param, 7), "pt"))
    } else {
      plot <- plot + theme(plot.margin = unit(c(7, 7, cap_lines * -52, 7), "pt"))
    }
  } else {
    plot <- plot + theme(plot.margin = unit(c(7, 7, -14, 7), "pt"))
  }

  arrangeGrob(plot, logo, heights = c(0.93, 0.1),
              padding = unit(0.1, "line"))
}

#' Title
#'
#' @param gg
#'
#' @return
#' @importFrom stringr str_count
#' @export
#'
#' @examples
measure_caption <- function(gg) {
  if (has_caption(gg)) {
    stringr::str_count(gg$labels$caption, pattern = "\n") + 1
  } else {
    1
  }
}


#' Title
#'
#' @param gg
#'
#' @return
#' @export
#'
#' @examples
has_caption <- function(gg) {
  any(names(gg$labels) == "caption")
}

#' Title
#'
#' @param plot_list
#' @param logo
#' @param nrow
#' @param widths
#' @param margin_param
#'
#' @return
#' @importFrom gridExtra arrangeGrob
#' @importFrom ggplot2 theme
#' @export
#'
#' @examples
add_logo_ga <- function(plot_list, logo, nrow = 1, widths = NULL, margin_param = NULL) {
  # Change position of logo depending on if plot has a caption
  if (!is.null(margin_param)) {
    margin <- theme(plot.margin = unit(c(7, 7, margin_param, 7), "pt"))
  } else if (any(unlist(lapply(plot_list, has_caption)))) {
    cap_lines <- measure_caption(plot_list[[1]]) # measure caption in first plot
    margin <- theme(plot.margin = unit(c(7, 7, -7 * sqrt(cap_lines), 7), "pt"))
  } else {
    margin <- theme(plot.margin = unit(c(7, 7, 7, 7), "pt"))
  }
  if (nrow > 1) {
    len <- length(plot_list)
    plot_list[[len]] <- plot_list[[len]] + margin
  } else {
    plot_list <- lapply(plot_list, "+", margin)
  }

  if (nrow != 1) {
    hold <- arrangeGrob(grobs = plot_list, nrow = nrow, ncol = 1, widths = widths)
  } else {
    hold <- arrangeGrob(grobs = plot_list, nrow = 1, ncol = 2, widths = widths)
  }

  arrangeGrob(hold, logo, heights = c(0.93, .07))
}


#' Get a Civilytics Logo grob
#'
#' @return
#' @export
#'
#' @examples
make_logo_grob <- function() {
  logo_grob <- ggplot(mapping = aes(x = 0:1, y = 1)) +
    theme_void() +
    annotation_custom(get_png(system.file("img", "civilytics_logo.png",
                                          package="civilytics")), xmin = 0.825, xmax = 1)
  logo_grob
}