hacking rstac queries

[mdsumner]

mgrs_codes <- c("MGRS-20LKP", "MGRS-04QGH")
# Query all 136 estinel tiles at once (or in batches)
stac("https://earth-search.aws.element84.com/v1") %>%
  stac_search(
    collections = "sentinel-2-c1-l2a",
    datetime = "2025-01-01T00:00:00Z/2025-12-31T23:59:59Z"
  ) %>%
  ext_query(`grid:code` %in% mgrs_codes) %>%
  post_request() %>%
  items_fetch()  # get all pages

So the body is just a list that gets JSON-encoded. You can build that directly:

rbody <- list(
  collections = list("sentinel-2-c1-l2a"),
  datetime = "2025-01-01T00:00:00Z/2025-12-31T23:59:59Z",
  limit = 300,
  query = list(
    `grid:code` = list(`in` = c("MGRS-20LKP", "MGRS-04QGH"))
  )
)

# As JSON
jsonlite::toJSON(body, auto_unbox = TRUE, pretty = TRUE)
And POST it yourself:
rhttr::POST(
  "https://earth-search.aws.element84.com/v1/search",
  body = body,
  encode = "json"
) %>% httr::content()

For a GET-style URL (if sds::stacit needs that), the query param encoding would be:

rquery_param <- list(`grid:code` = list(`in` = c("MGRS-20LKP", "MGRS-04QGH")))
query_json <- jsonlite::toJSON(query_param, auto_unbox = TRUE)

url <- paste0(

"https://earth-search.aws.element84.com/v1/search",
  "?collections=sentinel-2-c1-l2a",
  "&datetime=2025-01-01T00:00:00Z/2025-12-31T23:59:59Z",
  "&limit=300",
  "&query=", URLencode(query_json, reserved = TRUE)
)

[mdsumner]

here's the full workflow from spatial_window (better check antimerdian again with the new split logic)

mgrs_make_ll <- function(spatial_window) {
  tl <- with(spatial_window, cbind(lonmin, latmax))
  bl <- with(spatial_window, cbind(lonmin, latmin))
  tr <- with(spatial_window, cbind(lonmax, latmax))
  br <- with(spatial_window, cbind(lonmax, latmin))
  
  geographiclib::mgrs_fwd(rbind(tl, bl, tr, br), 0L)
}
mgrs_make <- function(assets) {
  paste0(sprintf("%02i", assets[["mgrs_utm_zone"]]), assets[["mgrs_latitude_band"]], assets[["mgrs_grid_square"]] )
}
codes <- sort(unique(mgrs_make_ll(spatial_window))) 
query_json <- '{"grid:code":{"in":["MGRS-20LKP","MGRS-04QGH"]}}'
query_param <- list(`grid:code` = list(`in` = sprintf("MGRS-%s", codes)))
query_json <- jsonlite::toJSON(query_param, auto_unbox = TRUE)

## this is limited to ~80 codes
url <- paste0(
  
  "https://earth-search.aws.element84.com/v1/search",
  "?collections=sentinel-2-c1-l2a",
  "&datetime=2025-01-01T00:00:00Z/2025-12-31T23:59:59Z",
  "&limit=300",
  "&query=", URLencode(query_json, reserved = TRUE)
)
#a <- starc:::get_assets_from_urls(url)




body <- list(
  collections = list("sentinel-2-c1-l2a"),
  datetime = "2025-01-01T00:00:00Z/2025-12-31T23:59:59Z",
  limit = 300,
  query = list(
    `grid:code` = list(`in` = sprintf("MGRS-%s", codes))
  )
)


# As JSON

text <- httr::POST(
    "https://earth-search.aws.element84.com/v1/search",
    body = body,
    encode = "json"
  ) %>% httr::content(as = "text", encoding = "UTF-8")
js <- jsonlite::fromJSON(text)

fetch_all_post <- function(base_body) {
  all_features <- list()
  body <- base_body
  nn <- 0
  repeat {
    #body$limit <- 300  # force it each time
    
    resp <- httr::POST(
      "https://earth-search.aws.element84.com/v1/search",
      body = body,
      encode = "json"
    ) %>% httr::content(as = "text", encoding = "UTF-8") %>% 
      jsonlite::fromJSON()
    
    all_features <- c(all_features, list(resp$features))
    nn <-nn + nrow(resp$features)
    message(sprintf("Fetched %d / %d", nn, resp$numberMatched))
    
    next_token <- resp$links$body$`next`[1]
    if (is.null(next_token) || is.na(next_token)) break
    
    body$`next` <- next_token
  }
  # this is wrong for nowbut hey 
  do.call(rbind, all_features)
}
x <- fetch_all_post(body)