Add import-json and export-json commands for importing and exporting fully detailed histories (#271)

client/cmd/export.go

@@ -0,0 +1,76 @@
+package cmd
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"io"
+	"os"
+
+	"github.com/ddworken/hishtory/client/data"
+	"github.com/ddworken/hishtory/client/hctx"
+	"github.com/ddworken/hishtory/client/lib"
+
+	"github.com/spf13/cobra"
+)
+
+var exportJsonCmd = &cobra.Command{
+	Use:   "export-json",
+	Short: "Export history entries formatted in JSON lines format (as accepted by hishtory import-json, and easily parsable by other tools)",
+	Run: func(cmd *cobra.Command, args []string) {
+		ctx := hctx.MakeContext()
+		err := exportToJson(ctx, os.Stdout)
+		lib.CheckFatalError(err)
+	},
+}
+
+func structToMap(entry data.HistoryEntry) (map[string]interface{}, error) {
+	inrec, err := json.Marshal(entry)
+	if err != nil {
+		return nil, err
+	}
+	var m map[string]interface{}
+	err = json.Unmarshal(inrec, &m)
+	return m, err
+}
+
+func exportToJson(ctx context.Context, w io.Writer) error {
+	db := hctx.GetDb(ctx)
+	chunkSize := 1000
+	offset := 0
+	for {
+		entries, err := lib.SearchWithOffset(ctx, db, "", chunkSize, offset)
+		if err != nil {
+			return fmt.Errorf("failed to search for history entries with offset=%d: %w", offset, err)
+		}
+		if len(entries) == 0 {
+			break
+		}
+		for _, entry := range entries {
+			m, err := structToMap(*entry)
+			if err != nil {
+				return err
+			}
+			delete(m, "device_id")
+			delete(m, "entry_id")
+			j, err := json.Marshal(m)
+			if err != nil {
+				return err
+			}
+			_, err = w.Write(j)
+			if err != nil {
+				return err
+			}
+			_, err = w.Write([]byte("\n"))
+			if err != nil {
+				return err
+			}
+		}
+		offset += chunkSize
+	}
+	return nil
+}
+
+func init() {
+	rootCmd.AddCommand(exportJsonCmd)
+}