AzureCommunicationUI/sdk/AzureCommunicationUICalling/Sources/Data/CallHistoryRepository.swift

//
//  Copyright (c) Microsoft Corporation. All rights reserved.
//  Licensed under the MIT License.
//

import Foundation

class CallHistoryRepository {
    private let numberOfDaysToKeepHistoryRecords: Int = 31
    private let storageKey: String = "com.azure.ios.communication.ui.calling.CallHistory"
    private let logger: Logger
    private let userDefaults: UserDefaults

    init(logger: Logger, userDefaults: UserDefaults = .standard) {
        self.logger = logger
        self.userDefaults = userDefaults
    }

    func insert(callStartedOn: Date, callId: String) async -> Error? {
        await withCheckedContinuation { continuation in
            var historyRecords = self.getAllAsDictionary()
            if var existingCalls = historyRecords[callStartedOn] {
                existingCalls.append(callId)
                historyRecords[callStartedOn] = existingCalls
            } else {
                historyRecords[callStartedOn] = [callId]
            }
            do {
                let encoder = JSONEncoder()
                let data = try encoder.encode(historyRecords)
                self.userDefaults.set(data, forKey: self.storageKey)
                continuation.resume(returning: nil)
            } catch let error {
                self.logger.error("Failed to save call history, reason: \(error.localizedDescription)")
                continuation.resume(returning: error)
            }
        }
    }

    func getAll() -> [CallHistoryRecord] {
        getAllAsDictionary().map(CallHistoryRecord.init(callStartedOn:callIds:))
    }

    private func filterExpiredRecords(_ historyRecords: [Date: [String]]) -> [Date: [String]] {
        guard let thresholdDate = Calendar.current.date(
            byAdding: DateComponents(day: -numberOfDaysToKeepHistoryRecords), to: Date()) else {
            return historyRecords
        }

        return historyRecords.filter { callHistoryRecord in
            callHistoryRecord.key >= thresholdDate
        }
    }

    private func getAllAsDictionary() -> [Date: [String]] {
        if let data = userDefaults.data(forKey: storageKey) {
            do {
                let decoder = JSONDecoder()
                return try filterExpiredRecords(decoder.decode([Date: [String]].self, from: data))
            } catch {
                return [:]
            }
        }
        return [:]
    }
}