suppressPackageStartupMessages({
  library(argparse)
  library(ggplot2)
  library(dplyr)
  library(tidyr)
  library(readr)
  library(scales)
  library(tikzDevice)
})

SOLUTION_ORDER <- c("tso", "tso-pacing", "cake")

SOLUTION_LABELS <- c(
  "no-tso"      = "TSO Off",
  "tso"         = "TSO On",
  "tso-pacing"  = "TSO Pacing",
  "cake"        = "Cake"
)

SOLUTION_COLORS <- c(
  "no-tso"      = "#009E73",
  "tso"         = "#E69F00",
  "tso-pacing"  = "#0072B2",
  "cake"        = "#CC79A7"
)

SOLUTION_LINETYPES <- c(
  "no-tso"      = "longdash",
  "tso"         = "dashed",
  "tso-pacing"  = "solid",
  "cake"        = "twodash"
)

# Global figure size and font size, overridable via env vars
# (Makefile exports FIG_WIDTH / FIG_HEIGHT / FIG_FONTSIZE).
.env_num <- function(var, default) {
  v <- Sys.getenv(var)
  if (nchar(v) == 0) default else as.numeric(v)
}
DEFAULT_WIDTH    <- .env_num("FIG_WIDTH",    3.33)
DEFAULT_HEIGHT   <- .env_num("FIG_HEIGHT",   2.4)
DEFAULT_FONTSIZE <- .env_num("FIG_FONTSIZE", 10)

theme_paper <- function(base_size = DEFAULT_FONTSIZE) {
  theme_bw(base_size = base_size) +
    theme(
      legend.position = "bottom",
      legend.title = element_blank(),
      legend.margin = margin(t = -4, l = -20),
      legend.text = element_text(size = base_size - 1),
      legend.key.size = unit(base_size, "pt"),
      axis.text = element_text(size = base_size - 1),
      strip.background = element_rect(fill = "grey90"),
      panel.grid.minor = element_blank(),
      plot.margin = margin(2, 4, 2, 2)
    )
}

prepare_solution <- function(df) {
  df %>%
    filter(solution %in% SOLUTION_ORDER) %>%
    mutate(solution = factor(solution, levels = SOLUTION_ORDER,
                             labels = SOLUTION_LABELS[SOLUTION_ORDER]))
}

LABEL_COLORS    <- setNames(SOLUTION_COLORS[SOLUTION_ORDER],    SOLUTION_LABELS[SOLUTION_ORDER])
LABEL_LINETYPES <- setNames(SOLUTION_LINETYPES[SOLUTION_ORDER], SOLUTION_LABELS[SOLUTION_ORDER])

COL_WIDTH <- 3.33
TEXT_WIDTH <- 7.0

# ACM page-fraction presets, in inches.
HALF_WIDTH  <- 3.3      # two figures side-by-side under one \begin{figure}
THIRD_WIDTH <- 2.2      # three figures side-by-side

label_pct <- function() percent_format(accuracy = 1)
label_us  <- function() "µs"
pct_sign  <- function() "%"

fig_parser <- function(default_width = DEFAULT_WIDTH, default_height = DEFAULT_HEIGHT,
                       description = "Generate figure") {
  p <- ArgumentParser(description = description)
  p$add_argument("--data", required = TRUE, help = "derived CSV directory")
  p$add_argument("--pdf",  help = "write PDF to this path")
  p$add_argument("--tikz", help = "write tikz .tex to this path")
  p$add_argument("--width", type = "double", default = default_width)
  p$add_argument("--height", type = "double", default = default_height)
  p$add_argument("--zoom", action = "store_true", help = "use zoomed axis limits")
  p$add_argument("--debug-margins", action = "store_true",
                 help = "color plot.background / panel.background / panel.border to visualise layout")
  p
}

# Optional theme overlay that colors the plot canvas, plot panel, and panel
# border so layout / whitespace can be inspected. Returns NULL when off
# (adding NULL to a ggplot is a no-op).
theme_debug_margins <- function(args) {
  if (!isTRUE(args$debug_margins)) return(NULL)
  theme(
    plot.background  = element_rect(fill = "#FFF7B3", colour = "black"),
    panel.background = element_rect(fill = "#CCE5FF", colour = NA),
    panel.border     = element_rect(colour = "red", fill = NA, linewidth = 0.6)
  )
}

save_figure <- function(plot, args) {
  if (is.null(args$pdf) && is.null(args$tikz)) {
    stop("save_figure: pass --pdf and/or --tikz")
  }
  if (!is.null(args$pdf)) {
    dir.create(dirname(args$pdf), showWarnings = FALSE, recursive = TRUE)
    ggsave(args$pdf, plot, width = args$width, height = args$height, device = "pdf")
    message("wrote ", args$pdf)
  }
  if (!is.null(args$tikz)) {
    dir.create(dirname(args$tikz), showWarnings = FALSE, recursive = TRUE)
    old <- options(
      tikzSanitizeCharacters    = c(getOption("tikzSanitizeCharacters"),    "µ"),
      tikzReplacementCharacters = c(getOption("tikzReplacementCharacters"), "$\\mu$")
    )
    on.exit(options(old), add = TRUE)
    tikz(args$tikz, width = args$width, height = args$height,
         standAlone = FALSE, sanitize = TRUE)
    print(plot)
    dev.off()
    message("wrote ", args$tikz)
  }
}