SpecCollection — Import / Update across Collections (#750)

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Operations

Operation	Scope	Notes
Import	Selected device(s) from source → target	Source is read-only. Selecting the collection root imports all devices and additionally includes tags.
Update	Re-sync previously imported device(s) from source	Uses stored cross-collection link; source reopens automatically.

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Data coverage

Table / data	Import	Update	Notes
device	✅	✅	All types (Catalog, Virtual, Storage). Update: source authoritative for all metadata.
catalog	✅	✅	Metadata + file indexes.
file	✅	✅	Full file list per catalog.
folder	✅	✅	Folder structure per catalog.
catalog_filter	✅	✅	Per-catalog exclude folders. Update: replaced from source.
storage (table row)	✅	✅	Imported via Catalog's associated storage. Update: full row replaced via device_external_id → storage_id.
device_mapping (CollectionImport)	✅	—	Created for every imported device (all types, except Physical root id=1); used by Update to locate source.
device_mapping (BackUp)	✅	✅	Existing BackUp mappings carried over.
statistics_device	✅	✅	Per-device statistics.
tag	✅ (collection only)	❌	Tags imported only when the collection root is selected. Not updated.
storage image files	❌	❌	Not yet — storage picture files not transferred.
parameter (exclude dirs)	✅	❌	Import: exclude_directory rows copied, skipping duplicates by path. Update: not covered.
parameter (other: imageFolderPath, …)	❌	❌	Not imported — collection-level settings stay in the target collection.

Source modes: File (.db) and Memory (CSV folder). Hosted source: use export first (see below).

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Source connection

Opened as a separate read-only connection named "importSourceConnection" alongside the active target.

Source mode	Opening strategy
File	QSqlDatabase::addDatabase("QSQLITE", ...)
Memory	In-memory SQLite, schema created via Database::createAllTables(), then CSV + .idx files loaded
Hosted	Not direct — export to File or Memory first, then import from the exported collection

Schema version guard: abort if source and target dbSchemaVersion differ.

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ID remapping (Import only)

device_id_offset  = MAX(device_id)  in target + 1
catalog_id_offset = MAX(catalog_id) in target + 1

Cascading updates: device.device_parent_id, device.device_external_id, catalog.catalog_id, file.file_catalog_id, folder.folder_catalog_id, catalog_filter.filter_catalog_id.

Not needed for Update — device and catalog IDs already exist in the target.

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Cross-collection links (device_mapping)

One mapping_type = 'CollectionImport' row is created per Catalog-type device on Import:

Column	Value
mapping_device_source_id	original device_id in source
mapping_device_target_id	new device_id in target
mapping_source_collection	path to source collection (File path or Memory folder)

mapping_source_collection is NULL for BackUp-type rows. Persisted in device.csv for Memory-mode targets (included in saveMappingTableToFile() / loadMappingFileToTable()).

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Update algorithm (updateDeviceFromExternalCollection)

1. Recursive CTE on target device_mapping to collect all CollectionImport rows for the selected device and its descendants.
2. Auto-open source from stored mapping_source_collection — no user browse needed.
3. For each mapped device, update the device row from source (source authoritative for all metadata), then branch on type:
   • Catalog: delete file/folder/catalog_filter, re-insert from source, update catalog metadata.
   • Storage: UPDATE storage table row via device_external_id → storage_id (both source and target).
   • Virtual and other containers: device row update only.
4. Missing source device: skip with warning, continue remaining.
5. Single transaction; Memory-mode target: call persistImportToFiles() after commit.

Button enabled when selected target device or any descendant has a CollectionImport mapping.

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Name conflicts (Import)

Scope	Default policy
catalog_name (UNIQUE)	Rename: append (2), (3), …
device_name within parent	Rename
Virtual ancestor	Reuse existing if name matches

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Ancestor chain

Importing a sub-device inserts its full ancestor chain as Virtual-type parents. Source device_id = 1 (Physical group) always maps directly to target id = 1 — never re-inserted.

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Memory mode specifics

Source Memory: load CSV + .idx files into "importSourceConnection" via Collection::loadCatalogFilterFileToTable() etc. — including loadParameterFileToTable() first (required for schema version check).

Target Memory: after any write operation, call persistImportToFiles(collection) before loadCollection() to persist device/mapping/filter CSVs. .idx files are written inside insertFileData().

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Export modes (for Hosted source workaround)

Source mode	→ SQLite file	→ Memory mode
Memory	✅ backupMemoryDatabaseToFile()	—
File	—	✅ exportAllToMemoryMode() + exportAllCatalogFiles()
Hosted	✅ exportToSQLiteFile() (table copy)	✅ same as File (temporarily fakes Memory mode)

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Status reporting

StatusBarMessageBuilder in K2 UI. Operation names: tr("COLLECTION IMPORT") / tr("COLLECTION UPDATE"). Progress driven by importProgress(int current, int total, QString itemName) signal. Errors: .setOperation(...).setStatus(tr("Error")).setCurrentItem(message).

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Key decisions

#	Decision
1	Partial import: full ancestor chain as Virtual parents; reuse by name match
2	Hosted source: not direct — export first
3	Schema mismatch: strict abort
4	Update scope: full sub-tree under selected device; respects device type (Catalog, Storage, Virtual)
5	Update ID remapping: none needed (IDs already in target)
6	Update — device row: source authoritative for all metadata
7	catalog_filter on Update: Replace from source
8	Update source: auto-opens from stored path; no manual browse
9	Manual mapping of existing devices (no prior Import): backlog
10	CollectionImport mappings saved in mapping CSV (not excluded) for Memory-mode persistence
11	Tags: imported only at collection-root level; not updated
12	parameter exclude dirs: imported (INSERT with duplicate check by path); other parameter rows (imageFolderPath, …) not imported — they are collection-level settings that belong to the target

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Known bugs fixed

Bug	Root cause	Fix
catalog_filter not imported	insertCatalogFilter() used filter_path instead of filter_value	Column name corrected; INSERT OR IGNORE added
CollectionImport mappings lost on reload (Memory target)	saveMappingTableToFile() excluded CollectionImport rows; source_collection column missing from CSV	Filter removed; column added to save/load cycle
Schema version check failed (Memory source)	loadParameterFileToTable() not called during openSource()	Added as first load step
Import completed but device lost (Memory target)	loadCollection() wiped in-memory tables before CSV was saved	persistImportToFiles() called before every loadCollection()
Physical group duplicated on import	ensureAncestors() tried to re-insert source device_id = 1	Early-exit: map source id=1 → target id=1 directly
Catalog path warning / wrong file deleted after import	loadCatalogFilesToTable() inserted into wrong connection	setConnectionName() called before insert; insertFileData() does full SELECT before saveCatalogToFile()