handles multiple lookup field values (#5112)

handles multiple lookup field values.

**Original `Lookup` list with single value**:
![Lookup-List-Single](https://github.com/alcionai/corso/assets/48874082/6a6b68cf-8fb9-4dfb-985e-702c4d74d3f0)

**Restored `Lookup` list with single value**:
![Restored-Lookup-List](https://github.com/alcionai/corso/assets/48874082/f97ac974-6a3b-4dd2-82c5-9f3596f9adaa)

**Original `Lookup` list with multiple values**:
![Lookup-List-Multi](https://github.com/alcionai/corso/assets/48874082/5f8b1b92-297f-4a66-b0b6-b5007d430690)

**Restored `Lookup` list with multiple values**:
![Restored-Lookup-List-Multi](https://github.com/alcionai/corso/assets/48874082/6c6d79ca-775d-4f50-abee-8090a28f3871)


#### Does this PR need a docs update or release note?

- [ ] ✅ Yes, it's included
- [ ] 🕐 Yes, but in a later PR
- [x] ⛔ No

#### Type of change

<!--- Please check the type of change your PR introduces: --->
- [x] 🌻 Feature
- [ ] 🐛 Bugfix
- [ ] 🗺️ Documentation
- [ ] 🤖 Supportability/Tests
- [ ] 💻 CI/Deployment
- [ ] 🧹 Tech Debt/Cleanup

#### Issue(s)
#5108 
#5084 

#### Test Plan

<!-- How will this be tested prior to merging.-->
- [x] 💪 Manual
- [x] ⚡ Unit test
- [x] 💚 E2E

src/pkg/services/m365/api/lists.go

@@ -23,6 +23,7 @@ type columnDetails struct {
 	createFieldName    string
 	getFieldName       string
 	isPersonColumn     bool
+	isLookupColumn     bool
 	isMultipleEnabled  bool
 	hasDefaultedToText bool
 }
@@ -420,6 +421,16 @@ func setColumnType(
 	case orig.GetNumber() != nil:
 		newColumn.SetNumber(orig.GetNumber())
 	case orig.GetLookup() != nil:
+		colDetails.isLookupColumn = true
+		isMultipleEnabled := ptr.Val(orig.GetLookup().GetAllowMultipleValues())
+		colDetails.isMultipleEnabled = isMultipleEnabled
+		updatedName := colName + LookupIDFieldNamePart
+		colDetails.createFieldName = updatedName
+
+		if !isMultipleEnabled {
+			colDetails.getFieldName = updatedName
+		}
+
 		newColumn.SetLookup(orig.GetLookup())
 	case orig.GetThumbnail() != nil:
 		newColumn.SetThumbnail(orig.GetThumbnail())
@@ -540,7 +551,8 @@ func populateMultipleValues(val any, filteredData map[string]any, colDetails *co
 		return
 	}
 
-	if !colDetails.isPersonColumn {
+	if !colDetails.isPersonColumn &&
+		!colDetails.isLookupColumn {
 		return
 	}
 
@@ -550,11 +562,10 @@ func populateMultipleValues(val any, filteredData map[string]any, colDetails *co
 	}
 
 	lookupIDs := make([]float64, 0)
-	lookupKeys := []string{LookupIDKey, LookupValueKey, PersonEmailKey}
 
 	for _, nestedFields := range multiNestedFields {
 		md, ok := nestedFields.(map[string]any)
-		if !ok || !keys.HasKeys(md, lookupKeys...) {
+		if !ok || !keys.HasKeys(md, checkFields(colDetails)...) {
 			continue
 		}
 
@@ -569,6 +580,17 @@ func populateMultipleValues(val any, filteredData map[string]any, colDetails *co
 	filteredData[colDetails.createFieldName] = lookupIDs
 }
 
+func checkFields(colDetails *columnDetails) []string {
+	switch {
+	case colDetails.isLookupColumn:
+		return []string{LookupIDKey, LookupValueKey}
+	case colDetails.isPersonColumn:
+		return []string{LookupIDKey, LookupValueKey, PersonEmailKey}
+	default:
+		return []string{}
+	}
+}
+
 // when creating list items with multiple values for a single column
 // we let the API know that we are sending a collection.
 // Hence this adds an additional field '<columnName>@@odata.type'
@@ -587,7 +609,7 @@ func specifyODataType(filteredData map[string]any, colDetails *columnDetails, co
 	}
 
 	switch {
-	case colDetails.isPersonColumn:
+	case colDetails.isPersonColumn, colDetails.isLookupColumn:
 		filteredData[colName+ODataTypeFieldNamePart] = ODataTypeFieldNameIntVal
 	default:
 		filteredData[colName+ODataTypeFieldNamePart] = ODataTypeFieldNameStringVal

src/pkg/services/m365/api/lists_test.go

@@ -288,6 +288,41 @@ func (suite *ListsUnitSuite) TestColumnDefinitionable_ColumnType() {
 					colNames["pg-col"].createFieldName == "pg-colLookupId"
 			},
 		},
+		{
+			name: "lookup column, single value",
+			getOrig: func() models.ColumnDefinitionable {
+				lookupColumn := models.NewLookupColumn()
+
+				cd := models.NewColumnDefinition()
+				cd.SetLookup(lookupColumn)
+				cd.SetName(ptr.To("refer-col"))
+
+				return cd
+			},
+			checkFn: func(cd models.ColumnDefinitionable, colNames map[string]*columnDetails) bool {
+				return cd.GetLookup() != nil &&
+					colNames["refer-col"].getFieldName == "refer-colLookupId" &&
+					colNames["refer-col"].createFieldName == "refer-colLookupId"
+			},
+		},
+		{
+			name: "lookup column, multiple value",
+			getOrig: func() models.ColumnDefinitionable {
+				lookupColumn := models.NewLookupColumn()
+				lookupColumn.SetAllowMultipleValues(ptr.To(true))
+
+				cd := models.NewColumnDefinition()
+				cd.SetLookup(lookupColumn)
+				cd.SetName(ptr.To("refer-col"))
+
+				return cd
+			},
+			checkFn: func(cd models.ColumnDefinitionable, colNames map[string]*columnDetails) bool {
+				return cd.GetLookup() != nil &&
+					colNames["refer-col"].getFieldName == "refer-col" &&
+					colNames["refer-col"].createFieldName == "refer-colLookupId"
+			},
+		},
 		{
 			name: "defaulted to text column",
 			getOrig: func() models.ColumnDefinitionable {
@@ -848,6 +883,51 @@ func (suite *ListsUnitSuite) TestSetAdditionalDataByColumnNames() {
 				"PersonsLookupId@odata.type": "Collection(Edm.Int32)",
 			},
 		},
+		{
+			name: "lookup column, single value",
+			additionalData: map[string]any{
+				"ReferLookupId": ptr.To(10),
+			},
+			colDetails: map[string]*columnDetails{
+				"Refer": {
+					isLookupColumn:  true,
+					getFieldName:    "ReferLookupId",
+					createFieldName: "ReferLookupId",
+				},
+			},
+			assertFn: assert.False,
+			expectedResult: map[string]any{
+				"ReferLookupId": ptr.To(10),
+			},
+		},
+		{
+			name: "lookup column, multiple values",
+			additionalData: map[string]any{
+				"Refers": []any{
+					map[string]any{
+						"LookupId":    ptr.To(float64(10)),
+						"LookupValue": ptr.To("item-1"),
+					},
+					map[string]any{
+						"LookupId":    ptr.To(float64(11)),
+						"LookupValue": ptr.To("item-1"),
+					},
+				},
+			},
+			colDetails: map[string]*columnDetails{
+				"Refers": {
+					isLookupColumn:    true,
+					isMultipleEnabled: true,
+					getFieldName:      "Refers",
+					createFieldName:   "RefersLookupId",
+				},
+			},
+			assertFn: assert.True,
+			expectedResult: map[string]any{
+				"RefersLookupId":            []float64{10, 11},
+				"RefersLookupId@odata.type": "Collection(Edm.Int32)",
+			},
+		},
 	}
 
 	for _, test := range tests {
@@ -861,6 +941,34 @@ func (suite *ListsUnitSuite) TestSetAdditionalDataByColumnNames() {
 	}
 }
 
+func (suite *ListsUnitSuite) TestCheckFields() {
+	t := suite.T()
+
+	tests := []struct {
+		name         string
+		colDetails   *columnDetails
+		expectedKeys []string
+	}{
+		{
+			name:         "lookup column",
+			colDetails:   &columnDetails{isLookupColumn: true},
+			expectedKeys: []string{LookupIDKey, LookupValueKey},
+		},
+		{
+			name:         "person column",
+			colDetails:   &columnDetails{isPersonColumn: true},
+			expectedKeys: []string{LookupIDKey, LookupValueKey, PersonEmailKey},
+		},
+	}
+
+	for _, test := range tests {
+		suite.Run(test.name, func() {
+			res := checkFields(test.colDetails)
+			assert.Equal(t, test.expectedKeys, res)
+		})
+	}
+}
+
 type ListsAPIIntgSuite struct {
 	tester.Suite
 	its intgTesterSetup