feat(reporting): bill of materials (#275)

* new reporting service

* API route

* code gen

* get tsv export from tools page

* fix naming

backend/internal/core/services/all.go

@@ -1,11 +1,16 @@
 package services
 
-import "github.com/hay-kot/homebox/backend/internal/data/repo"
+import (
+	"github.com/hay-kot/homebox/backend/internal/core/services/reporting"
+	"github.com/hay-kot/homebox/backend/internal/data/repo"
+	"github.com/rs/zerolog/log"
+)
 
 type AllServices struct {
-	User  *UserService
-	Group *GroupService
-	Items *ItemService
+	User      *UserService
+	Group     *GroupService
+	Items     *ItemService
+	Reporting *reporting.ReportingService
 }
 
 type OptionsFunc func(*options)
@@ -40,5 +45,7 @@ func New(repos *repo.AllRepos, opts ...OptionsFunc) *AllServices {
 			repo:                 repos,
 			autoIncrementAssetID: options.autoIncrementAssetID,
 		},
+		// TODO: don't use global logger
+		Reporting: reporting.NewReportingService(repos, &log.Logger),
 	}
 }

backend/internal/core/services/reporting/reporting.go

@@ -0,0 +1,85 @@
+package reporting
+
+import (
+	"context"
+	"encoding/csv"
+	"io"
+	"time"
+
+	"github.com/gocarina/gocsv"
+	"github.com/google/uuid"
+	"github.com/hay-kot/homebox/backend/internal/data/repo"
+	"github.com/rs/zerolog"
+)
+
+type ReportingService struct {
+	repos *repo.AllRepos
+	l     *zerolog.Logger
+}
+
+func NewReportingService(repos *repo.AllRepos, l *zerolog.Logger) *ReportingService {
+	gocsv.SetCSVWriter(func(out io.Writer) *gocsv.SafeCSVWriter {
+		writer := csv.NewWriter(out)
+		writer.Comma = '\t'
+		return gocsv.NewSafeCSVWriter(writer)
+	})
+
+	return &ReportingService{
+		repos: repos,
+		l:     l,
+	}
+}
+
+// =================================================================================================
+
+// NullableTime is a custom type that implements the MarshalCSV interface
+// to allow for nullable time.Time fields in the CSV output to be empty
+// and not "0001-01-01". It also overrides the default CSV output format
+type NullableTime time.Time
+
+func (t NullableTime) MarshalCSV() (string, error) {
+	if time.Time(t).IsZero() {
+		return "", nil
+	}
+	// YYYY-MM-DD
+	return time.Time(t).Format("2006-01-02"), nil
+}
+
+type BillOfMaterialsEntry struct {
+	PurchaseDate NullableTime `csv:"Purchase Date"`
+	Name         string       `csv:"Name"`
+	Description  string       `csv:"Description"`
+	Manufacturer string       `csv:"Manufacturer"`
+	SerialNumber string       `csv:"Serial Number"`
+	ModelNumber  string       `csv:"Model Number"`
+	Quantity     int          `csv:"Quantity"`
+	Price        float64      `csv:"Price"`
+	TotalPrice   float64      `csv:"Total Price"`
+}
+
+// BillOfMaterialsTSV returns a byte slice of the Bill of Materials for a given GID in TSV format
+// See BillOfMaterialsEntry for the format of the output
+func (rs *ReportingService) BillOfMaterialsTSV(ctx context.Context, GID uuid.UUID) ([]byte, error) {
+	entities, err := rs.repos.Items.GetAll(ctx, GID)
+	if err != nil {
+		rs.l.Debug().Err(err).Msg("failed to get all items for BOM Csv Reporting")
+		return nil, err
+	}
+
+	bomEntries := make([]BillOfMaterialsEntry, len(entities))
+	for i, entity := range entities {
+		bomEntries[i] = BillOfMaterialsEntry{
+			PurchaseDate: NullableTime(entity.PurchaseTime),
+			Name:         entity.Name,
+			Description:  entity.Description,
+			Manufacturer: entity.Manufacturer,
+			SerialNumber: entity.SerialNumber,
+			ModelNumber:  entity.ModelNumber,
+			Quantity:     entity.Quantity,
+			Price:        entity.PurchasePrice,
+			TotalPrice:   entity.PurchasePrice * float64(entity.Quantity),
+		}
+	}
+
+	return gocsv.MarshalBytes(&bomEntries)
+}

backend/internal/core/services/service_items_csv_test.go

@@ -12,10 +12,10 @@ import (
 	"github.com/stretchr/testify/assert"
 )
 
-//go:embed testdata/import.csv
+//go:embed .testdata/import.csv
 var CSVData_Comma []byte
 
-//go:embed testdata/import.tsv
+//go:embed .testdata/import.tsv
 var CSVData_Tab []byte
 
 func loadcsv() [][]string {