#' Make the Civilytics plot theme
#'
#' @param font_size default 14, a number representing the base font for the theme
#' @param font_family default "", a character for the font family to use in the theme
#' @param line_size default 0.5, the line size to use for the theme
#' @param rel_small default 12/14, the scale factor to create a small font from the base font_size
#' @param rel_tiny default 11/14, the scale factor to create a tiny font from the base font_size
#' @param rel_large default 16/14, the scale factor to create a large font from the base font_size
#' @return a ggplot2 theme object suitable for combining with ggplot objects to theme them
#' @export
theme_civilytics <-
  function (font_size = 14,
            font_family = "",
            line_size = 0.5,
            rel_small = 12 / 14,
            rel_tiny = 11 / 14,
            rel_large = 16 / 14) {
    half_line <- font_size / 2
    small_size <- rel_small * font_size
    theme_grey(base_size = font_size, base_family = font_family) %+replace%
      theme(
        line = element_line(
          color = "black",
          linewidth = line_size,
          linetype = 1,
          lineend = "butt"
        ),
        rect = element_rect(
          fill = NA,
          color = NA,
          linewidth = line_size,
          linetype = 1
        ),
        text = element_text(
          family = font_family,
          face = "plain",
          color = "black",
          size = font_size,
          hjust = 0.5,
          vjust = 0.5,
          angle = 0,
          lineheight = 0.9,
          margin = margin(),
          debug = FALSE
        ),
        axis.line = element_line(
          color = "black",
          linewidth = line_size,
          lineend = "square"
        ),
        axis.line.x = NULL,
        axis.line.y = NULL,
        axis.text = element_text(color = "black",
                                 size = small_size),
        axis.text.x = element_text(margin = margin(t = small_size / 4),
                                   vjust = 1),
        axis.text.x.top = element_text(margin = margin(b = small_size / 4),
                                       vjust = 0),
        axis.text.y = element_text(margin = margin(r = small_size / 4),
                                   hjust = 1),
        axis.text.y.right = element_text(margin = margin(l = small_size / 4),
                                         hjust = 0),
        axis.ticks = element_line(color = "black",
                                  linewidth = line_size),
        axis.ticks.length = unit(half_line / 2,
                                 "pt"),
        axis.title.x = element_text(margin = margin(t = half_line / 2),
                                    vjust = 1),
        axis.title.x.top = element_text(margin = margin(b = half_line / 2),
                                        vjust = 0),
        axis.title.y = element_text(
          angle = 90,
          margin = margin(r = half_line /
                            2),
          vjust = 1
        ),
        axis.title.y.right = element_text(
          angle = -90,
          margin = margin(l = half_line / 2),
          vjust = 0
        ),
        legend.background = element_blank(),
        legend.spacing = unit(font_size, "pt"),
        legend.spacing.x = NULL,
        legend.spacing.y = NULL,
        legend.margin = margin(0,
                               0, 0, 0),
        legend.key = element_blank(),
        legend.key.size = unit(1.1 *
                                 font_size, "pt"),
        legend.key.height = NULL,
        legend.key.width = NULL,
        legend.text = element_text(size = rel(rel_small)),
        legend.title = element_text(hjust = 0),
        legend.position = "right",
        legend.direction = NULL,
        legend.justification = c("left",
                                 "center"),
        legend.box = NULL,
        legend.box.margin = margin(0,
                                   0, 0, 0),
        legend.box.background = element_blank(),
        legend.box.spacing = unit(font_size, "pt"),
        panel.background = element_blank(),
        panel.border = element_blank(),
        panel.grid = element_blank(),
        panel.grid.major = NULL,
        panel.grid.minor = NULL,
        panel.grid.major.x = NULL,
        panel.grid.major.y = NULL,
        panel.grid.minor.x = NULL,
        panel.grid.minor.y = NULL,
        panel.spacing = unit(half_line,
                             "pt"),
        panel.spacing.x = NULL,
        panel.spacing.y = NULL,
        panel.ontop = FALSE,
        strip.background = element_rect(fill = "grey80"),
        strip.text = element_text(
          size = rel(rel_small),
          margin = margin(half_line / 2, half_line /
                            2, half_line / 2,
                          half_line / 2)
        ),
        strip.text.x = NULL,
        strip.text.y = element_text(angle = -90),
        strip.placement = "inside",
        strip.placement.x = NULL,
        strip.placement.y = NULL,
        strip.switch.pad.grid = unit(half_line / 2,
                                     "pt"),
        strip.switch.pad.wrap = unit(half_line / 2,
                                     "pt"),
        plot.background = element_blank(),
        plot.title = element_text(
          face = "bold",
          size = rel(rel_large),
          hjust = 0,
          vjust = 1,
          margin = margin(b = half_line)
        ),
        plot.subtitle = element_text(
          size = rel(rel_small),
          hjust = 0,
          vjust = 1,
          margin = margin(b = half_line)
        ),
        plot.caption = element_text(
          size = rel(rel_tiny),
          hjust = 0, # set hjust to 0
          vjust = 1,
          lineheight = 1,
          margin = margin(t = half_line)
        ),
        plot.tag = element_text(
          face = "bold",
          hjust = 0,
          vjust = 0.7
        ),
        plot.tag.position = c(0, 1),
        plot.margin = margin(half_line,
                             half_line, half_line, half_line),
        complete = TRUE
      )
  }