How to flip lines and change keys in JQ - json

Question

I'm creating a interactive map of my campus, the ideia is to replicate what I did on uMaps, in this link. The geojson was downloaded from UMap and I'm using the coordinates that came with it.
My first issue is my coordinates in the json, originally were a GeoJson, are sorted wrongly, my long came first then lat, thus when parse Google Maps can't read properly.
Json:
{
"type": "FeatureCollection",
"features": [
{
"type": "Feature",
"properties": {
"name": "Almoxarifado / Patrimônio"
},
"geometry": {
"type": "Polygon",
"coordinates": [
[
[
-52.163317,
-32.075462
],
[
-52.163884,
-32.075467
],
[
-52.163883,
-32.075336
],
[
-52.163321,
-32.075332
],
[
-52.163317,
-32.075462
]
]
]
}
},
{
...
},
{
...
},
...
]
}
So, I have to flip the coordinates lines to proper put in my Google Maps Api.
And my second issue is chaging the "type" key to "layer", for a better sepation layers in my app.
I've tried:
.features[] | .["type"] |= .["new value"]
How ever that changes the value and only accepts float values
Any help, advice or guidance would be greatly appreciated.

Answer 1

Part 1
flip the coordinates lines
For clarity and ease of testing, let's define a helper function:
# input: a JSON object with a coordinates array of arrays of pairs
def flip: .coordinates |= map(map(reverse)) ;
or even better - before invoking reverse, check the array has the expected length, e.g.:
def flip:
.coordinates
|= map(map(if length == 2 then reverse
else error("incorrect length: \(length)")
end)) ;
To flip the coordinates, we can now simply write:
.features[].geometry |= flip
Part 2
change the "type" key to "layer"
{layer: .type} + .
| del(.type)
Putting it together
{layer:.type} + .
| del(.type)
| .features[].geometry |= flip