library(tidyverse)
library(sf)
library(glue)
library(janitor)
library(patchwork)

# Home-work commute in France 2019, by commune
# https://www.insee.fr/fr/information/2383337
# https://www.insee.fr/fr/statistiques/6454112
hwc_file <- "base-csv-flux-mobilite-domicile-lieu-travail-2019.zip"

if (!file.exists(hwc_file)) {
  download.file(paste0("https://www.insee.fr/fr/statistiques/fichier/6454112/",
                       hwc_file), 
                hwc_file)
}

hwc <- read_delim(hwc_file,
                  delim = ";",
                  locale = locale(decimal_mark = ".")) |> 
  clean_names() |> 
  filter(str_detect(dclt, "6938[1-9]"),
         !str_detect(codgeo, "6938[1-9]")) |> 
  mutate(across(c(codgeo, dclt), 
                ~ case_when(between(.x, "13201", "13216") ~ "13055",
                            between(.x, "75101", "75120") ~ "75056",
                            between(.x, "69381", "69389") ~ "69123",
                            .default = .x))) |> 
  group_by(codgeo, dclt) |> 
  summarise(nbflux_c19_actocc15p = sum(nbflux_c19_actocc15p),
            .groups = "drop")

# France communes
# See https://r.iresmi.net/posts/2021/simplifying_polygons_layers/ for the data
com <- read_sf("~/data/adminexpress/adminexpress_cog_simpl_000_2022.gpkg", 
               layer = "commune") |> 
  filter(insee_reg > "06") |> 
  st_transform("EPSG:2154")

# France region
reg <- read_sf("~/data/adminexpress/adminexpress_cog_simpl_000_2022.gpkg", 
               layer = "region") |> 
  filter(insee_reg > "06") |> 
  st_transform("EPSG:2154")

# get coordinates for origin points
com_orig <- com |> 
  st_point_on_surface() |> 
  mutate(x = st_coordinates(geom)[, 1],
         y = st_coordinates(geom)[, 2]) |> 
  select(insee_com, x, y)

# we only need one destination point : Lyon
com_dest <- com_orig |> 
  filter(insee_com == "69123")

# Add origine and destination coord to the commute table
flow <- hwc |> 
  left_join(com_orig, 
            join_by(codgeo == insee_com)) |> 
  left_join(com_dest, 
            join_by(dclt == insee_com), 
            suffix = c("_orig", "_dest")) 

ggplot(reg) +
  geom_sf(color = "grey70",
          fill="grey95") +
  geom_curve(data = flow,
             aes(x = x_orig, y = y_orig, xend = x_dest, yend = y_dest,
                 linewidth = nbflux_c19_actocc15p, 
                 alpha = nbflux_c19_actocc15p),
             color = "dodgerblue3",
             curvature = 0.2) +
  scale_linewidth_continuous(labels = scales::label_number(big.mark = " "),
                             trans = "log10",
                             breaks = c(10, 100, 1000, 10000),
                             range = c(0.05, 3)) +
  scale_alpha_continuous(labels = scales::label_number(big.mark = " "),
                         trans = "log10",
                         breaks = c(10, 100, 1000, 10000),
                         range = c(0.05, .4)) +
  labs(title = "Working flow to Lyon",
       subtitle = "2019",
       linewidth = "workers",
       alpha = "workers",
       caption = glue("https://www.iresmi.net {Sys.Date()}
                      Data: INSEE 2019")) +
  theme_void() +
  theme(text = element_text(family = "Courrier New"),
        plot.caption = element_text(size = 7))