migrate from github

internal/repository/document_repo/move_subtree.go

@@ -0,0 +1,78 @@
+package document_repo
+
+import (
+	"github.com/XingfenD/yoresee_doc/internal/model"
+	"gorm.io/gorm"
+)
+
+type DocumentMoveSubtreeOperation struct {
+	repo        *DocumentRepository
+	docID       int64
+	newParentID int64
+	tx          *gorm.DB
+}
+
+func (r *DocumentRepository) MoveSubtree(docID, newParentID int64) *DocumentMoveSubtreeOperation {
+	return &DocumentMoveSubtreeOperation{
+		repo:        r,
+		docID:       docID,
+		newParentID: newParentID,
+	}
+}
+
+func (op *DocumentMoveSubtreeOperation) WithTx(tx *gorm.DB) *DocumentMoveSubtreeOperation {
+	op.tx = tx
+	return op
+}
+
+func (op *DocumentMoveSubtreeOperation) Exec() error {
+	if op.tx == nil {
+		op.tx = op.repo.db
+	}
+
+	type pathDepth struct {
+		Path  string
+		Depth int
+	}
+	var old pathDepth
+	if err := op.tx.Model(&model.Document{}).
+		Select("path, depth").
+		Where("id = ? AND deleted_at IS NULL", op.docID).
+		Take(&old).Error; err != nil {
+		return err
+	}
+
+	var newPath string
+	var newDepth int
+	if op.newParentID == 0 {
+		newDepth = 0
+	} else {
+		var parent pathDepth
+		if err := op.tx.Model(&model.Document{}).
+			Select("path, depth").
+			Where("id = ? AND deleted_at IS NULL", op.newParentID).
+			Take(&parent).Error; err != nil {
+			return err
+		}
+		newPath = parent.Path
+		newDepth = parent.Depth + 1
+	}
+
+	depthDelta := newDepth - old.Depth
+
+	if op.newParentID == 0 {
+		return op.tx.Exec(`
+			UPDATE document_metas
+			SET path = (?::text)::ltree || COALESCE(subpath(path, nlevel(?::ltree)), ''::ltree),
+				depth = depth + ?
+			WHERE path <@ ?::ltree AND deleted_at IS NULL
+		`, op.docID, old.Path, depthDelta, old.Path).Error
+	}
+
+	return op.tx.Exec(`
+		UPDATE document_metas
+		SET path = (?::ltree) || (?::text)::ltree || COALESCE(subpath(path, nlevel(?::ltree)), ''::ltree),
+			depth = depth + ?
+		WHERE path <@ ?::ltree AND deleted_at IS NULL
+	`, newPath, op.docID, old.Path, depthDelta, old.Path).Error
+}