Replace txtplot with an internal text plotting function for cal objects

And drop it as a dependency.

DESCRIPTION

@@ -32,7 +32,6 @@ Imports:
     fs,
     glue,
     cli,
-    txtplot,
     rlang,
     stringr,
     tidyr,

R/cal.R

@@ -83,7 +83,7 @@ new_cal <- function(x = data.frame(year = integer(0), p = numeric(0)), ...) {
 # }
 
 
-# S3 Methods ------------------------------------------------------------------
+# Print methods --------------------------------------------------------------
 
 #' @rdname cal
 #' @export
@@ -101,7 +101,7 @@ print.cal <- function(x, ...) {
 
   cli::cli_text("# Calibrated probability distribution from {start} to {end} {era}")
   cli::cat_line()
-  txtplot::txtplot(x$year, x$p, height = 10)
+  cal_txtplot(x)
   cli::cat_line()
   # TODO: Messy – should probably refactor into its own function
   if(!is.null(metadata$lab_id)) {
@@ -122,6 +122,68 @@ print.cal <- function(x, ...) {
   invisible(x)
 }
 
+cal_txtplot <- function(x, height = 8, margin = 2) {
+  width <- cli::console_width()
+  if (width > 80) width <- 80
+
+  # Plot geometries
+  geom_area <- cal_txtplot_geom_area(x, width - margin, height - 2)
+
+  # Axis & labels
+  # TODO: Detect direction of year
+  nbreaks <- floor((width - margin) / (max(nchar(round(x$year))) * 3))
+  breaks <- pretty(x$year, nbreaks - 1)
+  while (sum(nchar(breaks)) >= (width - margin)) {
+    nbreaks <- nbreaks - 1
+    breaks <- pretty(x$year, nbreaks - 1)
+  }
+  xaxis <- cal_txtplot_scale(x$year, breaks, width - margin)
+  labels <- cal_txtplot_labels(x$year, breaks, width - margin)
+
+  # Print
+  cli::cat_line(stringr::str_pad(geom_area, width, side = "left"))
+  cli::cat_line(stringr::str_pad(xaxis, width, side = "left"))
+  cli::cat_line(stringr::str_pad(labels, width, side = "left"))
+}
+
+cal_txtplot_geom_area <- function(x, width, height) {
+  k <- stats::ksmooth(x$year, x$p,
+                      bandwidth = abs(max(x$year) - min(x$year)) / width,
+                      n.points = width)
+  k$y[is.na(k$y)] <- 0
+  k$y <- round((k$y / max(k$y)) * height)
+
+  stringr::str_dup("#", k$y) %>%
+    stringr::str_pad(height, side = "left") %>%
+    stringr::str_split(pattern = "", simplify = TRUE) %>%
+    apply(2, paste0, collapse = "")
+}
+
+cal_txtplot_scale <- function(x, breaks, width) {
+  breakpoints <- cal_txtplot_breakpoints(x, breaks, width)
+
+  axis <- rep("-", width)
+  axis[breakpoints] <- "|"
+  paste(axis, collapse = "")
+}
+
+cal_txtplot_labels <- function(x, breaks, width) {
+  breakpoints <- cal_txtplot_breakpoints(x, breaks, width)
+
+  labels <- stringr::str_pad(breaks[-1], c(diff(breakpoints)), side = "left")
+  paste(labels, collapse = "")
+}
+
+cal_txtplot_breakpoints <- function(x, breaks, width) {
+  if (x[1] > x[length(x)]) {
+    x <- -x
+    breaks <- -breaks
+  }
+  sort(round(findInterval(breaks, x) / length(x) * width))
+}
+
+# S3 Methods ------------------------------------------------------------------
+
 #' @export
 min.cal <- function(...) {
   cals <- rlang::list2(...)