Start and end dates are now the contract's, with a new closing date

Find a Tender never sends tender.tenderPeriod.startDate, so an
opportunity's start date was always empty, and its end date was the
bid deadline. Start and end are now the contract period: from the
contracts' periods, else the awards' contract periods, else the lots'
contract periods, each date on its own, taking the earliest start and
the latest end of several.

The bid deadline (tenderPeriod.endDate) moves to a new closing_date
column (migration 00009), in the API as closing_date. EU Supply's
pages give no contract period, so its start and end are left empty
and its response deadline is the closing date.

internal/store/migrations/00009_add_opportunity_closing_date.sql

@@ -0,0 +1,11 @@
+-- +goose Up
+-- +goose StatementBegin
+-- When bids must be in by (the tender period's end). start_date and
+-- end_date are the contract period.
+ALTER TABLE "opportunities" ADD COLUMN "closing_date" DATETIME;
+-- +goose StatementEnd
+
+-- +goose Down
+-- +goose StatementBegin
+ALTER TABLE "opportunities" DROP COLUMN "closing_date";
+-- +goose StatementEnd

internal/store/queries.go

@@ -42,13 +42,13 @@ const upsertOpportunity = `
 INSERT INTO opportunities (
 	uuid, uuid_type, title, status, description, buyer_name, buyer_id,
 	main_category, procurement_method, multi_lot, sme_suitable,
-	vcse_suitable, start_date, end_date, gross_value, has_documents, source,
-	latest_release_date
+	vcse_suitable, start_date, end_date, closing_date, gross_value,
+	has_documents, source, latest_release_date
 ) VALUES (
 	:uuid, :uuid_type, :title, :status, :description, :buyer_name, :buyer_id,
 	:main_category, :procurement_method, :multi_lot, :sme_suitable,
-	:vcse_suitable, :start_date, :end_date, :gross_value, :has_documents,
-	:source, :latest_release_date
+	:vcse_suitable, :start_date, :end_date, :closing_date, :gross_value,
+	:has_documents, :source, :latest_release_date
 )
 ON CONFLICT (uuid) DO UPDATE SET
 	uuid_type = excluded.uuid_type,
@@ -64,6 +64,7 @@ ON CONFLICT (uuid) DO UPDATE SET
 	vcse_suitable = excluded.vcse_suitable,
 	start_date = excluded.start_date,
 	end_date = excluded.end_date,
+	closing_date = excluded.closing_date,
 	gross_value = excluded.gross_value,
 	has_documents = excluded.has_documents,
 	source = excluded.source,

internal/store/store.go

@@ -192,6 +192,7 @@ func prepareOpportunity(opportunity *types.Opportunity) error {
 	opportunity.LatestReleaseDate = latest.UTC()
 	opportunity.StartDate = utcPtr(opportunity.StartDate)
 	opportunity.EndDate = utcPtr(opportunity.EndDate)
+	opportunity.ClosingDate = utcPtr(opportunity.ClosingDate)
 
 	return nil
 }

internal/store/store_test.go

@@ -37,7 +37,7 @@ func opportunity(
 	releaseDay int,
 	releaseIDs ...string,
 ) *types.Opportunity {
-	start, end := day(20), day(28)
+	start, end, closing := day(20), day(28), day(15)
 	t := &types.Opportunity{
 		UUID:              uuid,
 		UUIDType:          "ocid",
@@ -52,6 +52,7 @@ func opportunity(
 		SMESuitable:       true,
 		StartDate:         &start,
 		EndDate:           &end,
+		ClosingDate:       &closing,
 		GrossValue:        125000.50,
 		HasDocuments:      true,
 		Source:            "FindATender",
@@ -144,8 +145,11 @@ func TestSaveAndGetRoundTrip(t *testing.T) {
 		t.Errorf("opportunity fields differ:\n got %+v\nwant %+v", got, in)
 	}
 	if got.StartDate == nil || !got.StartDate.Equal(day(20)) ||
-		got.EndDate == nil || !got.EndDate.Equal(day(28)) {
-		t.Errorf("dates: got %v / %v", got.StartDate, got.EndDate)
+		got.EndDate == nil || !got.EndDate.Equal(day(28)) ||
+		got.ClosingDate == nil || !got.ClosingDate.Equal(day(15)) {
+		t.Errorf(
+			"dates: got %v / %v / %v", got.StartDate, got.EndDate, got.ClosingDate,
+		)
 	}
 	if want := day(1).Add(time.Minute); !got.LatestReleaseDate.Equal(want) {
 		t.Errorf("LatestReleaseDate = %v, want %v", got.LatestReleaseDate, want)
@@ -188,11 +192,14 @@ func TestSaveAndGetRoundTrip(t *testing.T) {
 func TestStartAndEndDateMayBeNil(t *testing.T) {
 	s := openStore(t)
 	in := opportunity("ocds-1", "No dates", 1, "r1")
-	in.StartDate, in.EndDate = nil, nil
+	in.StartDate, in.EndDate, in.ClosingDate = nil, nil, nil
 	mustSave(t, s, in)
 	got := mustGet(t, s, "ocds-1")
-	if got.StartDate != nil || got.EndDate != nil {
-		t.Errorf("got %v / %v, want nil", got.StartDate, got.EndDate)
+	if got.StartDate != nil || got.EndDate != nil || got.ClosingDate != nil {
+		t.Errorf(
+			"got %v / %v / %v, want nil",
+			got.StartDate, got.EndDate, got.ClosingDate,
+		)
 	}
 }