What is jolt conversion spec for the given input and output

Question

The possible values for applicableOn field are already known but they are not limited to clothes and bags like given in this sample input. Also, there can be multiple elements in purchases array with the same applicableOn type and the sum of all those values should be calculated together.

Input:

{
  "primary": {
    "domainAttributes": {
      "email": "[email protected]",
      "name": "rach",
      "age": "28"
    },
    "meta": {
      "isEntity": true
    },
    "type": "somevalue",
    "purchases": [
      {
        "domainAttributes": {
          "email": "[email protected]",
          "id": "1",
          "age": "28"
        },
        "type": "somevalue",
        "purchaseValue": [
          {
            "domainAttributes": {
              "email": "[email protected]",
              "name": "rach",
              "id": "1",
              "value": "5",
              "applicableOn": "CLOTHES"
            },
            "meta": null,
            "type": "some other value"
          }
        ]
      },
      {
        "domainAttributes": {
          "email": "[email protected]",
          "taxRateEntityId": "2",
          "age": "28"
        },
        "type": "somevalue",
        "purchaseValue": [
          {
            "domainAttributes": {
              "email": "[email protected]",
              "name": "rach",
              "id": "2",
              "value": "7",
              "applicableOn": "BAGS"
            },
            "type": "some other value"
          }
        ]
      }
    ]
  }
}

Expected output:

{
  "email" : "[email protected]",
  "name" : "rach",
  "age" : "28",
  "purchaseSum" : [{"sum":"5", "applicableOn": "CLOTHES"}, {"sum": "7", "applicableOn": "BAGS"}],
  "purchase" : [ {
    "value" : "5",
    "id" : "1",
    "applicableOn" : "CLOTHES"
  }, {
    "value" : "7",
    "id" : "2",
    "applicableOn" : "BAGS"
  } ]
}

I have this spec currently but it calculates the sum of all values in purchaseValues without checking applicableType and also the format of purchase is slightly different than expected:

  [
    {
      "operation": "shift",
      "spec": {
        "primary": {
          "domainAttributes": {
            "email": "email",
            "name": "name",
            "age": "age"
          },
          "purchases": {
            "*": {
              "purchaseValue": {
                "*": {
                  "domainAttributes": {
                    "value": "purchases[].value",
                    "id": "purchases[].id",
                    "applicableOn": "purchases[].applicableOn"
                  }
                }
              }
            }
          }
        }
      }
    },
    {
      "operation": "shift",
      "spec": {
        "email": "email",
        "name": "name",
        "age": "age",
        "purchases": {
          "*": {
            "value": "purchaseSum[]",
            "@": "purchase[]"
          }
        }
      }
    },
    {
      "operation": "modify-overwrite-beta",
      "spec": {
        "purchaseSum": "=intSum(@(1,purchaseSum))"
      }
    },
    {
      "operation": "shift",
      "spec": {
        "email": "email",
        "name": "name",
        "age": "age",
        "purchaseSum": "purchaseSum",
        "purchase": "purchase"
      }
    }
  ]

The current output I'm seeing with the above spec is:

{
  "email" : "[email protected]",
  "name" : "rach",
  "age" : "28",
  "purchaseSum" : 12,
  "purchase" : [ {
    "value" : "5"
  }, {
    "id" : "1"
  }, {
    "applicableOn" : "CLOTHES"
  }, {
    "value" : "7"
  }, {
    "id" : "2"
  }, {
    "applicableOn" : "BAGS"
  } ]
}

Input with single purchase:

{
  "primary": {
    "domainAttributes": {
      "email": "[email protected]",
      "name": "rach",
      "age": "28"
    },
    "meta": {
      "isEntity": true
    },
    "type": "somevalue",
    "purchases": [
      {
        "domainAttributes": {
          "email": "[email protected]",
          "id": "1",
          "age": "28"
        },
        "type": "somevalue",
        "purchaseValue": [
          {
            "domainAttributes": {
              "email": "[email protected]",
              "name": "rach",
              "id": "1",
              "value": "5",
              "applicableOn": "CLOTHES"
            },
            "meta": null,
            "type": "some other value"
          }
        ]
      }
    ]
  }
}

Answer 1

Also since this looks more like querying the data than re structuring it, you can keep it short and sweet using JSLT:

import "http://jslt.schibsted.com/2018/experimental" as exp

    //1- construct the primary info
    let primary = .primary.domainAttributes | {*:. }
    
    //2- construct the purchase list info
    let purchases = .primary.purchases | { "purchase": flatten([ for (.) [for (.purchaseValue) 
                                                    {
                                                      "id":.domainAttributes.id,
                                                      "value": .domainAttributes.value,
                                                      "applicableOn": .domainAttributes.applicableOn
                                                    }
                                                   ]
                                          ])}
    
    //3- group by applicableOn using group by function
    let groupByApplicableOn = exp:group-by($purchases.purchase, .applicableOn, number(.value))
    
    
    //4- merge all sets together in one json object
    $purchases + {"purchaseSum":[for($groupByApplicableOn ) {"Sum":sum(.values),"applicableOn":.key} ] }  + $primary 

Answer 2

The below spec should be dynamic enough to allow any type of applicableOn and any number of items per purchases.

[
  {
    "operation": "shift",
    "spec": {
      "primary": {
        "domainAttributes": {
          "*": "&"
        },
        "purchases": {
          "*": {
            "purchaseValue": {
              "*": {
                "domainAttributes": {
                  "value": "Totals.@(1,applicableOn)[]",
                  "@": "purchase[]"
                }
              }
            }
          }
        }
      }
    }
  },
  {
    "operation": "modify-overwrite-beta",
    "spec": {
      "Totals": {
        "*": "=intSum"
      }
    }
  },

  {
    "operation": "shift",
    "spec": {
      "*": "&",
      "purchase": {
        "*": {
          "id|value|applicableOn": "&2[&1].&"
        }
      },
      "Totals": {
        "*": {
          "@": "purchaseSum[#2].sum",
          "$": "purchaseSum[#2].applicableOn"
        }
      }
    }
  }
]