libnovel/backend/migrations/20260414000003_visibility.go

// Migration 3 — add visibility + submitted_by fields to books.
//
// visibility:   "public" | "admin_only"
//               All existing (scraped) books are backfilled to "admin_only".
//               New author-submitted books are created with "public".
//
// submitted_by: optional app_users ID for books submitted by a registered author.
//               Empty for scraped books.
//
// The backfill iterates books in pages of 200.  It is idempotent: books whose
// visibility is already set are skipped.
package migrations

import (
	"github.com/pocketbase/pocketbase/core"
	m "github.com/pocketbase/pocketbase/migrations"
)

func init() {
	m.Register(func(app core.App) error {
		coll, err := app.FindCollectionByNameOrId("books")
		if err != nil {
			return err
		}

		changed := false
		if coll.Fields.GetByName("visibility") == nil {
			coll.Fields.Add(&core.TextField{Name: "visibility"})
			changed = true
		}
		if coll.Fields.GetByName("submitted_by") == nil {
			coll.Fields.Add(&core.TextField{Name: "submitted_by"})
			changed = true
		}
		if changed {
			if err := app.Save(coll); err != nil {
				return err
			}
		}

		// Backfill: mark all existing books as admin_only where visibility is empty.
		// These are scraped books that pre-date this migration.
		const perPage = 200
		for page := 1; ; page++ {
			records, err := app.FindRecordsByFilter(
				"books", `visibility=""`, "+id", perPage, (page-1)*perPage, nil,
			)
			if err != nil || len(records) == 0 {
				break
			}
			for _, rec := range records {
				rec.Set("visibility", "admin_only")
				// Best-effort: ignore individual save errors (don't abort migration).
				_ = app.Save(rec)
			}
			if len(records) < perPage {
				break
			}
		}
		return nil
	}, func(app core.App) error {
		coll, err := app.FindCollectionByNameOrId("books")
		if err != nil {
			return nil
		}
		for _, name := range []string{"visibility", "submitted_by"} {
			f := coll.Fields.GetByName(name)
			if f == nil {
				continue
			}
			coll.Fields.RemoveById(f.GetId())
		}
		return app.Save(coll)
	})
}