#!/usr/bin/env Rscript

options(stringsAsFactors = FALSE)

if (!requireNamespace("ggplot2", quietly = TRUE)) {
  stop("Required package not installed: ggplot2")
}
library(ggplot2)

script_args <- commandArgs(trailingOnly = FALSE)
file_arg <- script_args[grepl("^--file=", script_args)][1]
if (length(file_arg) && !is.na(file_arg)) {
  script_path <- normalizePath(sub("^--file=", "", file_arg))
  repo_root <- normalizePath(file.path(dirname(script_path), ".."))
} else if (!exists("repo_root")) {
  repo_root <- normalizePath(".")
}
setwd(repo_root)

panel_file <- file.path("data", "releases", "party_2d_election_year_panel_v0.csv.gz")
output_dir <- file.path("validation", "outputs")
figure_dir <- file.path("validation", "figures")

if (!file.exists(panel_file)) stop("Required input not found: ", panel_file)
dir.create(output_dir, recursive = TRUE, showWarnings = FALSE)
dir.create(figure_dir, recursive = TRUE, showWarnings = FALSE)

panel <- read.csv(panel_file, check.names = FALSE)

trajectory_spec <- data.frame(
  party_id = c(1691, 379, 432),
  series = c("Fidesz", "Danish Social Democrats", "US Democrats"),
  start_year = c(1990, 2007, 1944),
  end_year = c(2022, 2019, 2020)
)

trajectory_rows <- lapply(seq_len(nrow(trajectory_spec)), function(i) {
  spec <- trajectory_spec[i, ]
  d <- panel[
    panel$party_id == spec$party_id &
      panel$year >= spec$start_year & panel$year <= spec$end_year,
  ]
  if (!nrow(d)) stop("No trajectory rows found for PartyFacts ", spec$party_id)
  d$series <- spec$series
  d$display_role <- "trajectory"
  d$is_labelled <- d$year %in% c(spec$start_year, spec$end_year)
  d$label <- ifelse(d$is_labelled, paste(spec$series, d$year), "")
  d[order(d$year), ]
})
trajectories <- do.call(rbind, trajectory_rows)

anchor_spec <- data.frame(
  party_id = c(1545, 1375, 1565, 1567, 433, 809),
  year = c(2021, 2021, 2019, 1979, 2022, 2020),
  label = c(
    "The Left 2021", "CDU 2021", "PiS 2019",
    "UK Conservatives 1979", "French National Front 2022",
    "US Republicans 2020"
  )
)

anchors <- merge(anchor_spec, panel, by = c("party_id", "year"), all.x = TRUE, sort = FALSE)
if (anyNA(anchors$economic_lr) || anyNA(anchors$galtan)) {
  stop("One or more declared scale anchors are absent from the release panel")
}
anchors$series <- "Standalone anchors"
anchors$display_role <- "anchor"
anchors$is_labelled <- TRUE

plot_columns <- c(
  "party_id", "party_name_english", "country", "year", "series",
  "display_role", "is_labelled", "label", "economic_lr",
  "economic_lr_q025", "economic_lr_q975", "galtan", "galtan_q025",
  "galtan_q975", "source_support_class"
)
plot_data <- rbind(trajectories[plot_columns], anchors[plot_columns])
write.csv(
  plot_data,
  file.path(output_dir, "party_scale_example_plot_data.csv"),
  row.names = FALSE,
  na = ""
)

labelled <- plot_data[plot_data$is_labelled, ]
label_positions <- data.frame(
  label = c(
    "Fidesz 1990", "Fidesz 2022",
    "Danish Social Democrats 2007", "Danish Social Democrats 2019",
    "US Democrats 1944", "US Democrats 2020",
    "The Left 2021", "CDU 2021", "PiS 2019",
    "UK Conservatives 1979", "French National Front 2022",
    "US Republicans 2020"
  ),
  plot_label = c(
    "Fidesz\n1990", "Fidesz\n2022",
    "Danish Social Democrats\n2007", "Danish Social Democrats\n2019",
    "US Democrats\n1944", "US Democrats\n2020",
    "The Left\n2021", "CDU\n2021", "PiS\n2019",
    "UK Conservatives\n1979", "French National Front\n2022",
    "US Republicans\n2020"
  ),
  label_x = c(.84, .36, .12, .33, .73, .36, .11, .65, .14, .84, .58, .88),
  label_y = c(.36, .93, .32, .49, .33, .27, .16, .48, .93, .51, .91, .78)
)
labelled <- merge(labelled, label_positions, by = "label", all.x = TRUE, sort = FALSE)
if (anyNA(labelled$label_x) || anyNA(labelled$label_y)) {
  stop("Missing manual label position for a displayed scale example")
}

trajectory_levels <- trajectory_spec$series
trajectories$series <- factor(trajectories$series, levels = trajectory_levels)

p <- ggplot() +
  geom_path(
    data = trajectories,
    aes(x = economic_lr, y = galtan, group = series, linetype = series),
    colour = "grey25", linewidth = .7,
    arrow = grid::arrow(type = "closed", length = grid::unit(.065, "inches"))
  ) +
  geom_point(
    data = trajectories,
    aes(x = economic_lr, y = galtan),
    colour = "grey35", size = 1.1
  ) +
  geom_errorbar(
    data = labelled,
    aes(x = economic_lr, ymin = galtan_q025, ymax = galtan_q975),
    width = 0, colour = "grey45", alpha = .65
  ) +
  geom_errorbar(
    data = labelled,
    aes(y = galtan, xmin = economic_lr_q025, xmax = economic_lr_q975),
    orientation = "y", width = 0, colour = "grey45", alpha = .65
  ) +
  geom_point(
    data = anchors,
    aes(x = economic_lr, y = galtan),
    shape = 21, fill = "white", colour = "black", size = 2.5, stroke = .7
  ) +
  geom_point(
    data = labelled[labelled$display_role == "trajectory", ],
    aes(x = economic_lr, y = galtan),
    shape = 16, colour = "black", size = 2.1
  ) +
  geom_segment(
    data = labelled,
    aes(x = economic_lr, y = galtan, xend = label_x, yend = label_y),
    colour = "grey55", linewidth = .25
  ) +
  geom_text(
    data = labelled,
    aes(x = label_x, y = label_y, label = plot_label),
    size = 2.6, lineheight = .9
  ) +
  scale_linetype_manual(
    values = c("Fidesz" = "solid", "Danish Social Democrats" = "dashed", "US Democrats" = "dotdash")
  ) +
  scale_x_continuous(limits = c(0, 1), breaks = c(0, .25, .5, .75, 1)) +
  scale_y_continuous(limits = c(0, 1), breaks = c(0, .25, .5, .75, 1)) +
  labs(
    x = "Economic: left (0) to right (1)",
    y = "Cultural: cosmopolitan (0) to traditionalist (1)",
    linetype = "Election-year path"
  ) +
  theme_minimal(base_size = 9) +
  theme(
    panel.grid.minor = element_blank(),
    legend.position = "bottom",
    legend.title = element_text(face = "bold"),
    plot.margin = margin(7, 12, 7, 7)
  )

ggsave(
  file.path(figure_dir, "party_scale_examples.pdf"),
  p, width = 8.8, height = 6.0, device = cairo_pdf
)

message("Wrote validation/outputs/party_scale_example_plot_data.csv")
message("Wrote validation/figures/party_scale_examples.pdf")