PlantGuide/Docs/save_shit.md

Plan: Persist PlantCareInfo in Core Data

Overview

Cache Trefle API care info locally so API is only called once per plant. Preserves all timing info (watering frequency, fertilizer schedule) for proper notification scheduling.

Current Problem

• PlantCareInfo is fetched from Trefle API every time PlantDetailView appears
• No local caching - unnecessary API calls and poor offline experience

Solution

Add PlantCareInfoMO Core Data entity with cache-first logic in FetchPlantCareUseCase.

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Implementation Steps

Step 1: Add Value Transformers for Complex Types

File: PlantGuide/Core/Utilities/ValueTransformers.swift

Add JSON-based transformers (following existing IdentificationResultArrayTransformer pattern):

• WateringScheduleTransformer - encodes WateringSchedule struct
• TemperatureRangeTransformer - encodes TemperatureRange struct
• FertilizerScheduleTransformer - encodes FertilizerSchedule struct
• SeasonArrayTransformer - encodes [Season] array

Register all transformers in PlantGuideApp.swift init.

Step 2: Update Core Data Model

File: PlantGuide/Data/DataSources/Local/CoreData/PlantGuideModel.xcdatamodeld

Add new entity PlantCareInfoMO:

Attribute	Type	Notes
id	UUID	Required, unique
scientificName	String	Required
commonName	String	Optional
lightRequirement	String	Enum rawValue
wateringScheduleData	Binary	JSON-encoded WateringSchedule
temperatureRangeData	Binary	JSON-encoded TemperatureRange
fertilizerScheduleData	Binary	Optional, JSON-encoded
humidity	String	Optional, enum rawValue
growthRate	String	Optional, enum rawValue
bloomingSeasonData	Binary	Optional, JSON-encoded [Season]
additionalNotes	String	Optional
sourceURL	URI	Optional
trefleID	Integer 32	Optional
fetchedAt	Date	Required, for cache expiration

Relationships:

• plant → PlantMO (optional, one-to-one, inverse: plantCareInfo)

Update PlantMO:

• Add relationship plantCareInfo → PlantCareInfoMO (optional, cascade delete)

Step 3: Create PlantCareInfoMO Managed Object

File: PlantGuide/Data/DataSources/Local/CoreData/ManagedObjects/PlantCareInfoMO.swift (NEW)

• Define @NSManaged properties
• Add toDomainModel() -> PlantCareInfo? - decodes JSON data to domain structs
• Add static func fromDomainModel(_:context:) -> PlantCareInfoMO? - encodes domain to MO
• Add func update(from:) - updates existing MO

Step 4: Create Repository Protocol and Implementation

File: PlantGuide/Domain/RepositoryInterfaces/PlantCareInfoRepositoryProtocol.swift (NEW)

protocol PlantCareInfoRepositoryProtocol: Sendable {
    func fetch(scientificName: String) async throws -> PlantCareInfo?
    func fetch(trefleID: Int) async throws -> PlantCareInfo?
    func fetch(for plantID: UUID) async throws -> PlantCareInfo?
    func save(_ careInfo: PlantCareInfo, for plantID: UUID?) async throws
    func isCacheStale(scientificName: String, cacheExpiration: TimeInterval) async throws -> Bool
    func delete(for plantID: UUID) async throws
}

File: PlantGuide/Data/DataSources/Local/CoreData/CoreDataPlantCareInfoStorage.swift (NEW)

Implement repository with Core Data queries.

Step 5: Update FetchPlantCareUseCase with Cache-First Logic

File: PlantGuide/Domain/UseCases/PlantCare/FetchPlantCareUseCase.swift

Modify to:

1. Inject PlantCareInfoRepositoryProtocol
2. Check cache first before API call
3. Validate cache freshness (7-day expiration)
4. Save API response to cache after fetch

func execute(scientificName: String) async throws -> PlantCareInfo {
    // 1. Check cache
    if let cached = try await repository.fetch(scientificName: scientificName),
       !(try await repository.isCacheStale(scientificName: scientificName, cacheExpiration: 7 * 24 * 60 * 60)) {
        return cached
    }

    // 2. Fetch from API
    let careInfo = try await fetchFromAPI(scientificName: scientificName)

    // 3. Cache result
    try await repository.save(careInfo, for: nil)

    return careInfo
}

Step 6: Update DIContainer

File: PlantGuide/Core/DI/DIContainer.swift

• Add _plantCareInfoStorage lazy service
• Add plantCareInfoRepository accessor
• Update _fetchPlantCareUseCase to inject repository
• Add to resetAll() method

Step 7: Update PlantMO

File: PlantGuide/Data/DataSources/Local/CoreData/ManagedObjects/PlantMO.swift

Add relationship property:

@NSManaged public var plantCareInfo: PlantCareInfoMO?

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Migration Strategy

Lightweight migration - no custom mapping model needed:

• New entity with no existing data
• New relationship is optional (nil default)
• shouldMigrateStoreAutomatically and shouldInferMappingModelAutomatically already enabled

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Files to Create/Modify

File	Action
Core/Utilities/ValueTransformers.swift	Add 4 transformers
PlantGuideModel.xcdatamodel/contents	Add PlantCareInfoMO entity
ManagedObjects/PlantCareInfoMO.swift	NEW - managed object + mappers
RepositoryInterfaces/PlantCareInfoRepositoryProtocol.swift	NEW - protocol
CoreData/CoreDataPlantCareInfoStorage.swift	NEW - implementation
UseCases/PlantCare/FetchPlantCareUseCase.swift	Add cache-first logic
DI/DIContainer.swift	Register new dependencies
ManagedObjects/PlantMO.swift	Add relationship
App/PlantGuideApp.swift	Register new transformers

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Verification

1. Build verification: xcodebuild -scheme PlantGuide build

2. Test cache behavior:

   • Add a new plant → view details (should call Trefle API)
   • Navigate away and back to details (should NOT call API - use cache)
   • Check console logs for API calls

3. Test timing preservation:

   • Verify watering frequency intervalDays property works after cache retrieval
   • Create care schedule from cached info → verify notifications scheduled correctly

4. Test cache expiration:

   • Manually set fetchedAt to 8 days ago
   • View plant details → should re-fetch from API

5. Run existing tests: xcodebuild test -scheme PlantGuide -destination 'platform=iOS Simulator,name=iPhone 17'