First pass implementation of an SQLite backing store for fetched opportunities

internal/cli/migrate/down.go

@@ -0,0 +1,77 @@
+package migrate
+
+import (
+	"errors"
+	"fmt"
+	"log/slog"
+
+	"git.avsdev.uk/Go/job-search/internal/cli"
+	"git.avsdev.uk/Go/job-search/internal/store"
+	"github.com/spf13/cobra"
+)
+
+func commandDown(opts *cli.Options) *cobra.Command {
+	cmd := &cobra.Command{
+		Use:   "down",
+		Short: "Migrate SQLite database to a previous version",
+		Long: `Roll back the most recent migrations.
+
+--steps 0 rolls back every migration which deletes all data and must be
+confirmed by providing -yes.`,
+		Args: cobra.NoArgs,
+		PersistentPreRun: func(cmd *cobra.Command, args []string) {
+			slog.Debug("migrate.down.PersistentPreRun")
+		},
+		PersistentPostRun: func(cmd *cobra.Command, args []string) {
+			slog.Debug("migrate.down.PersistentPostRun")
+		},
+		RunE: func(cmd *cobra.Command, args []string) (err error) {
+			slog.Debug("migrate.down.Run")
+
+			yes, _ := cmd.Flags().GetBool("yes")
+			steps, _ := cmd.Flags().GetUint("steps")
+
+			m, db, err := openMigrator(cmd, opts, false, false)
+			if err != nil {
+				return err
+			}
+			defer closeDB(db, &err)
+
+			results, err := store.StepDown(cmd.Context(), m, int(steps), yes)
+
+			if len(results) == 0 && err == nil {
+				fmt.Println("No changes made to database (empty)")
+				return nil
+			}
+			if err == store.ErrWouldEmptyDatabase {
+				return fmt.Errorf(
+					"%w\n\nTo confirm you wish to proceed, pass the --yes flag", err,
+				)
+			}
+
+			if printErr := printResults(cmd.OutOrStdout(), results); printErr != nil {
+				return errors.Join(err, printErr)
+			}
+
+			if err != nil {
+				return failure(cmd.OutOrStdout(), err)
+			}
+
+			return printVersion(cmd.Context(), cmd.OutOrStdout(), m)
+		},
+	}
+	cmd.Flags().Uint(
+		"steps",
+		0,
+		"number of migrations to roll back. 0 = all (deletes all data)",
+	)
+	if err := cmd.MarkFlagRequired("steps"); err != nil {
+		panic(err) // only fails if the flag isn't defined
+	}
+	cmd.Flags().BoolP(
+		"yes", "y",
+		false,
+		"confirm you are intending to roll back every migration",
+	)
+	return cmd
+}