---
title: "CMR Snapshot: Provider Metadata Health, Today"
output: rmarkdown::html_vignette
vignette: >
  %\VignetteIndexEntry{CMR Snapshot: Provider Metadata Health, Today}
  %\VignetteEngine{knitr::rmarkdown}
  %\VignetteEncoding{UTF-8}
---

```{r setup, include = FALSE}
knitr::opts_chunk$set(collapse = TRUE, comment = "#>")

online <- tryCatch({
  con <- url("https://cmr.earthdata.nasa.gov/search/collections.json?page_size=1",
             open = "rb")
  close(con)
  TRUE
}, error = function(e) FALSE)

knitr::opts_chunk$set(eval = online)
```

```{r offline-note, echo = FALSE, eval = !online, results = "asis"}
cat(
  "CMR (`cmr.earthdata.nasa.gov`) wasn't reachable when this vignette was ",
  "built, so the live checks below were skipped. Re-build with a network ",
  "connection to see current numbers, or see `vignette(\"cmr-landscape\")` ",
  "for a written-up example run.", sep = ""
)
```

Unlike `vignette("cmr-landscape")` -- a fixed narrative of one
exploration session, kept as a written record -- this article
re-queries CMR **live, every time it's built**, and shows whatever the
catalog looks like right now. Re-render it occasionally to see how
these numbers drift as collections are added, retired, or have their
metadata cleaned up.

```{r libs, message = FALSE}
library(cmrlifecycle)
library(dplyr)
```

```{r timestamp}
Sys.time()
```

## One collection, right now

A quick liveness + declared-coverage check, the way a new user would
use this package day to day:

```{r one-collection}
cmr_collection_liveness("MUR-JPL-L4-GLOB-v4.1")

cmr_find_collections(short_name = "MUR-JPL-L4-GLOB-v4.1") |>
  select(short_name, temporal_start, temporal_end, ends_at_present, granule_count)
```

For contrast, a collection this package found to have *no granules at
all* (see `vignette("cmr-landscape")`) -- still true today?

```{r aadc-collection}
cmr_find_collections(short_name = "AAS_4088_Adelie_occupancy_Mawson_Taylor") |>
  select(short_name, granule_count, temporal_start, temporal_end)
```

## `ends_at_present`, provider by provider, today

This re-runs the PO.DAAC-vs-LAADS comparison from `vignette("cmr-landscape")`
fresh. Each provider costs just two requests (one for collection
metadata, one for granule counts), so this is cheap enough to run on
every build, even though the earlier deep-dive sampling (checking
individual collections' *recent* granule activity to validate the
flag) is not repeated here.

```{r provider-breakdown}
providers <- c("POCLOUD", "LAADS")

breakdown <- lapply(providers, function(p) {
  cols <- cmr_all_collections(provider = p, delay = 0)
  tibble(
    provider = p,
    n_collections = nrow(cols),
    pct_true = round(100 * mean(cols$ends_at_present), 1),
    pct_ambiguous = round(100 * mean(!cols$ends_at_present &
                                        is.na(cols$temporal_end) &
                                        cols$granule_count > 0), 1)
  )
}) |> bind_rows()

breakdown
```

```{r provider-plot, fig.alt = "Bar chart comparing the percentage of collections declaring ends_at_present = TRUE between POCLOUD and LAADS"}
barplot(breakdown$pct_true, names.arg = breakdown$provider,
        ylim = c(0, 100), ylab = "% of collections with ends_at_present = TRUE",
        main = "ends_at_present reliability by provider (live)")
```

As of the `vignette("cmr-landscape")` write-up (2026-08-25), this stood
at 4.5% for POCLOUD and 70.7% for LAADS -- if the bars above look
different, that's the catalog changing, which is exactly the point of
re-running this rather than trusting a single snapshot.

## A small live liveness sample

A tiny, cheap version of the "sample some ambiguous collections and
check if they're really still active" method from the landscape
article -- a handful of PO.DAAC collections that declare
`ends_at_present = FALSE` with no end date, checked directly:

```{r liveness-sample}
sample_check <- cmr_all_collections(provider = "POCLOUD", delay = 0) |>
  filter(!ends_at_present, is.na(temporal_end), granule_count > 0) |>
  slice_sample(n = 5) |>
  cmr_collection_liveness(delay = 0)

sample_check
```

```{r liveness-summary}
sprintf("%d of %d sampled collections were live in the last %d days",
        sum(sample_check$is_live), nrow(sample_check),
        sample_check$lookback_days[1])
```

Small samples like this move around run to run -- see
`vignette("cmr-landscape")` for a fuller (25-collection) version with
more stable percentages.