day26_transport.R

library(mapgl)
library(sf)
library(stringr)
library(dplyr)
library(readr)
library(lubridate)
library(tidyr)

# read in data and tidy up
locations <- read_csv("./data/afghanistan.csv") |> 
  st_as_sf(coords = c("lon", "lat"), crs = 4326)
locations <- bind_cols(
  unite(data = locations,                     # data source
        col = "FlowMonitoringPoint",          # new col name
        sep = " - ",                          # joiner
        c(name, other),                       # vector of cols to unite
        na.rm = TRUE,                         # deal with NAs
        remove = FALSE))                      # perserve other cols
locations <- locations |>
  mutate(FlowMonitoringPoint = ifelse(
    FlowMonitoringPoint == "Dak - DAK", "DAK", FlowMonitoringPoint
  ))

people <- read_csv(paste0("./data/",
                          "afghanistan-flow-monitoring-counting-data-",
                          "10jan2024to22nov2025.csv"))
people <- people |> mutate(
  ReportingDate = dmy(ReportingDate),
  ReportingMonth = month(ReportingDate),
  ReportingYear = year(ReportingDate),
  FlowMonitoringPoint = str_squish(FlowMonitoringPoint)
  ) |> 
  rename_all(\(x) str_replace_all(x, " ", ""))

# try making a map
p_all1 <- p_all |> filter(ReportingMonth == 10,
                          ReportingYear == 2025)
p1 <- locations |> left_join(p_all1)
# if NA
p1 <- p1 |> filter(!is.na(Direction))
# combine same
p1 <- p1 |> group_by(FlowMonitoringPoint, Direction, rotate) |> summarise(n = sum(TotalHeadcount), .groups = "drop")


maplibre(style = carto_style("positron")) |> 
  fit_bounds(locations) |> 
  add_image("direction",
            url = "./images/gx_arrow.png") |> 
  add_symbol_layer(
    id = "direction_in",
    source = p1,
    icon_image = "direction",
    icon_offset = c(0, 20), # rotation affects offset!
    icon_size = 0.5,
    icon_allow_overlap = TRUE,
    icon_ignore_placement = TRUE,
    icon_rotate = match_expr(
      column = "rotate",
      values = c("ew", "we", "sn"),
      stops = c(90, 270, 180),
      default = 0
    ),
    filter = list(
      "==", "Direction", "Inflow" # ie Direction == "Inflow"
    ),
    text_field = concat("in:",get_column("n")),
    text_allow_overlap = TRUE,
    text_offset = c(0, -1)
  ) |> 
  add_symbol_layer(
    id = "direction_out",
    source = p1,
    icon_image = "direction",
    icon_offset = c(0, 20), # rotation affects offset!
    icon_size = 0.5,
    icon_allow_overlap = TRUE,
    icon_ignore_placement = TRUE,
    icon_rotate = match_expr(
      column = "rotate",
      values = c("ew", "we", "sn"),
      stops = c(270, 90, 0),
      default = 0
    ),
    filter = list(
      "==", "Direction", "Outflow"
    ),
    text_field = concat("out:",get_column("n")),
    text_allow_overlap = TRUE,
    text_offset = c(0, 1)
  ) |>
  add_control("<div style='padding:5px'>
              <b>Cross-border mobility</b><br />
              between Afghanistan and its neighbours<br />
              aggregated for October 2025<br />
              Data: <a href='https://data.humdata.org/'>The Humanitarian Data Exchange</a><br />
              macka szechno<br />26 November 2025
              </div>")