LeStorage/LeStorage/PendingOperationManager.swift

//
//  PendingOperationManager.swift
//  LeStorage
//
//  Created by Laurent Morvillier on 01/04/2025.
//

import Foundation

class PendingOperationManager<T: Storable> {
    
    fileprivate(set) var items: [PendingOperation<T>] = []

    fileprivate var _fileName: String = "pending_\(T.resourceName())"
    
    fileprivate var _inMemory: Bool = false
    
    init(store: Store, inMemory: Bool) {
        self._inMemory = inMemory
        if !inMemory {
            do {
                let url = try store.fileURL(fileName: self._fileName)
                if FileManager.default.fileExists(atPath: url.path()) {
                    let jsonString = try FileUtils.readDocumentFile(fileName: self._fileName)
                    if let decoded: [PendingOperation<T>] = try jsonString.decode() {
                        self.items = decoded
                    }
                }
            } catch {
                Logger.error(error)
            }
        }
    }
    
    func addPendingOperation(method: StorageMethod, instance: T, actionOption: ActionOption) {
        Logger.log("addPendingOperation: \(method), \(instance)")
        
        let operation = PendingOperation<T>(method: method, data: instance, actionOption: actionOption)
        self.items.append(operation)
        
        self._writeIfNecessary()
    }
    
    func reset() {
        self.items.removeAll()
        self._writeIfNecessary()
    }
    
    fileprivate func _writeIfNecessary() {
        guard !self._inMemory else { return }
        
        Task(priority: .background) {
            do {
                let jsonString: String = try self.items.jsonString()
                let _ = try FileUtils.writeToDocumentDirectory(content: jsonString, fileName: self._fileName)
            } catch {
                Logger.error(error)
            }
        }
    }
    
}