JOLT moving from LHS to RHS and flattening - json

Question

I am trying to convert the following JSON with JOLT but struggling, any help would be appreciated.
{
"2021-04-14T00:00:00+02:00": {
"249184": {
"SRAD": null,
"T": -50.00000000000001
},
"249185": {
"SRAD": 0.46133333444595337,
"T": null
}
},
"2021-04-14T00:15:00+02:00": {
"249184": {
"SRAD": null,
"T": -50.00000000000001
},
"249185": {
"SRAD": 0.4593333303928375,
"T": null
}
}
}
Desired output: Note here that the timestamps are repeated for each deviceID along with the SRAD and T values.
{
"timestamp": "2021-04-14T00:00:00+02:00",
"deviceID": 249184,
"SRAD":null,
"T":-50.00000000000001
},
{
"timestamp": "2021-04-14T00:00:00+02:00",
"deviceID": 249185,
"SRAD":0.46133333444595337,
"T":null
},
{
"timestamp": "2021-04-14T00:15:00+02:00",
"deviceID": 249184,
"SRAD":null,
"T":-50.00000000000001
},
{
"timestamp": "2021-04-14T00:15:00+02:00",
"deviceID": 249185,
"SRAD": 0.4593333303928375,
"T":null
}
I have tried a bunch of things but keep going in circles.

Answer 1

Here's an alternate spec with 2 shifts that supports any number of fields inside the deviceId object:
[
{
"operation": "shift",
"spec": {
"*": {
"*": {
"$(1)": "a[].timestamp",
"$": "b[].deviceId",
"#": "c[]"
}
}
}
},
{
"operation": "shift",
"spec": {
"a": {
"*": {
"timestamp": "[&1].timestamp",
"#(2,b[&])": "[&1]"
}
},
"b": null,
"c": {
"*": {
"*": "[&1].&"
}
}
}
}
]

Answer 2

[
// Change null as String, as jolt will not
// process null values
{
"operation": "modify-default-beta",
"spec": {
"*": {
"*": {
"SRAD": "null",
"T": "null"
}
}
}
},
{
"operation": "shift",
"spec": {
"*": {
"*": {
"SRAD": "&4.SRAD",
"T": "&4.T",
"$0": "&4.deviceID",
"$1": "&4.timestamp"
}
}
}
}, {
"operation": "shift",
"spec": {
"*": {
"*": {
"*": {
"#": "&"
}
}
}
}
}, {
"operation": "shift",
"spec": {
"*": {
"0": "[&1].deviceID",
"1": "[&1].timestamp",
"2": "[&1].SRAD",
"3": "[&1].T"
}
}
}
]
You cannot process the JSON having null as value, so null is replaced with "null" using modify-default-beta operation.
Input JSON is grouped by timestamp and deviceid, so deconstruct the json by assigning names to the children nodes and then construct the output JSON.