crowd-funder-for-time-pwa/ios/App/App/TimeSafariNativeFetcher.swift

import Foundation
import TimesafariDailyNotificationPlugin

/// Native content fetcher for API-driven New Activity notifications on iOS.
/// Mirrors `TimeSafariNativeFetcher.java` (POST `plansLastUpdatedBetween`, starred plans, JWT pool, pagination).
final class TimeSafariNativeFetcher: NativeNotificationContentFetcher {
    static let shared = TimeSafariNativeFetcher()

    private let endpoint = "/api/v2/report/plansLastUpdatedBetween"
    private let readTimeoutSec: TimeInterval = 15
    private let maxRetries = 3
    private let retryDelayMs = 1_000

    /// Matches plugin `updateStarredPlans` storage (`DailyNotificationPlugin.swift`).
    private let prefsStarredKey = "daily_notification_timesafari.starredPlanIds"
    /// Matches Java `TimeSafariNativeFetcher` prefs namespace `daily_notification_timesafari` + `last_acked_jwt_id`.
    private let prefsLastAckedKey = "daily_notification_timesafari.last_acked_jwt_id"

    private var apiBaseUrl: String?
    private var activeDid: String?
    private var jwtToken: String?
    private var jwtTokenPool: [String]?

    private init() {}

    func configure(apiBaseUrl: String, activeDid: String, jwtToken: String, jwtTokenPool: [String]?) {
        self.apiBaseUrl = apiBaseUrl.trimmingCharacters(in: .whitespacesAndNewlines).replacingOccurrences(
            of: "/$",
            with: "",
            options: .regularExpression
        )
        self.activeDid = activeDid
        self.jwtToken = jwtToken
        self.jwtTokenPool = (jwtTokenPool?.isEmpty == false) ? jwtTokenPool : nil
    }

    func fetchContent(context: FetchContext) async throws -> [NotificationContent] {
        try await fetchContentWithRetry(context: context, retryCount: 0)
    }

    /// One pool entry per UTC day (epoch day mod pool size); else primary `jwtToken` — same as Java.
    private func selectBearerTokenForRequest() -> String? {
        guard let pool = jwtTokenPool, !pool.isEmpty else { return jwtToken }
        let epochDay = Int64(Date().timeIntervalSince1970 * 1000) / (24 * 60 * 60 * 1000)
        let idx = Int(epochDay) % pool.count
        let t = pool[idx]
        if t.isEmpty { return jwtToken }
        return t
    }

    private func fetchContentWithRetry(context: FetchContext, retryCount: Int) async throws -> [NotificationContent] {
        guard let base = apiBaseUrl, !base.isEmpty,
              activeDid != nil,
              let bearer = selectBearerTokenForRequest(), !bearer.isEmpty
        else {
            NSLog("[TimeSafariNativeFetcher] Not configured; call configureNativeFetcher from JS first.")
            return []
        }

        guard let url = URL(string: base + endpoint) else {
            return []
        }

        var request = URLRequest(url: url)
        request.httpMethod = "POST"
        request.setValue("application/json", forHTTPHeaderField: "Content-Type")
        request.setValue("Bearer \(bearer)", forHTTPHeaderField: "Authorization")
        request.timeoutInterval = readTimeoutSec

        let planIds = getStarredPlanIds()
        var afterId = getLastAcknowledgedJwtId() ?? "0"
        if afterId.isEmpty { afterId = "0" }

        let body: [String: Any] = [
            "planIds": planIds,
            "afterId": afterId,
        ]
        request.httpBody = try JSONSerialization.data(withJSONObject: body)

        NSLog(
            "[TimeSafariNativeFetcher] POST \(endpoint) planCount=\(planIds.count) afterId=\(afterId.prefix(12))…"
        )

        let config = URLSessionConfiguration.ephemeral
        config.timeoutIntervalForRequest = readTimeoutSec
        config.timeoutIntervalForResource = readTimeoutSec
        let session = URLSession(configuration: config)

        do {
            let (data, response) = try await session.data(for: request)
            guard let http = response as? HTTPURLResponse else {
                return []
            }

            if http.statusCode == 200 {
                let bodyStr = String(data: data, encoding: .utf8) ?? ""
                let contents = parseApiResponse(responseBody: bodyStr, context: context)
                if !contents.isEmpty {
                    updateLastAckedJwtIdFromResponse(responseBody: bodyStr)
                }
                return contents
            }

            if retryCount < maxRetries && (http.statusCode >= 500 || http.statusCode == 429) {
                let delayMs = retryDelayMs * (1 << retryCount)
                try await Task.sleep(nanoseconds: UInt64(delayMs) * 1_000_000)
                return try await fetchContentWithRetry(context: context, retryCount: retryCount + 1)
            }

            NSLog("[TimeSafariNativeFetcher] API error \(http.statusCode)")
            return []
        } catch {
            NSLog("[TimeSafariNativeFetcher] Fetch failed: \(error.localizedDescription)")
            if retryCount < maxRetries {
                let delayMs = retryDelayMs * (1 << retryCount)
                try await Task.sleep(nanoseconds: UInt64(delayMs) * 1_000_000)
                return try await fetchContentWithRetry(context: context, retryCount: retryCount + 1)
            }
            return []
        }
    }

    private func getStarredPlanIds() -> [String] {
        guard let jsonStr = UserDefaults.standard.string(forKey: prefsStarredKey),
              !jsonStr.isEmpty, jsonStr != "[]",
              let data = jsonStr.data(using: .utf8),
              let arr = try? JSONSerialization.jsonObject(with: data) as? [Any]
        else {
            return []
        }
        return arr.compactMap { $0 as? String }
    }

    private func getLastAcknowledgedJwtId() -> String? {
        let s = UserDefaults.standard.string(forKey: prefsLastAckedKey)
        return (s?.isEmpty == false) ? s : nil
    }

    private func updateLastAckedJwtIdFromResponse(responseBody: String) {
        guard let data = responseBody.data(using: .utf8),
              let root = try? JSONSerialization.jsonObject(with: data) as? [String: Any],
              let dataArray = root["data"] as? [[String: Any]], !dataArray.isEmpty
        else { return }

        let lastItem = dataArray[dataArray.count - 1]
        var jwtId: String?
        if let j = lastItem["jwtId"] as? String {
            jwtId = j
        } else if let plan = lastItem["plan"] as? [String: Any], let j = plan["jwtId"] as? String {
            jwtId = j
        }
        if let jwtId = jwtId, !jwtId.isEmpty {
            UserDefaults.standard.set(jwtId, forKey: prefsLastAckedKey)
        }
    }

    private func extractProjectDisplayTitle(_ item: [String: Any]) -> String {
        if let plan = item["plan"] as? [String: Any],
           let name = plan["name"] as? String,
           !name.trimmingCharacters(in: .whitespacesAndNewlines).isEmpty {
            return name.trimmingCharacters(in: .whitespacesAndNewlines)
        }
        return "Unnamed Project"
    }

    private func extractJwtIdFromItem(_ item: [String: Any]) -> String? {
        if let plan = item["plan"] as? [String: Any], let j = plan["jwtId"] as? String, !j.isEmpty {
            return j
        }
        if let j = item["jwtId"] as? String, !j.isEmpty { return j }
        return nil
    }

    private func parseApiResponse(responseBody: String, context: FetchContext) -> [NotificationContent] {
        guard let data = responseBody.data(using: .utf8),
              let root = try? JSONSerialization.jsonObject(with: data) as? [String: Any],
              let dataArray = root["data"] as? [[String: Any]], !dataArray.isEmpty
        else {
            return []
        }

        let firstItem = dataArray[0]
        let firstTitle = extractProjectDisplayTitle(firstItem)
        let jwtId = extractJwtIdFromItem(firstItem)
        let nowMs = Int64(Date().timeIntervalSince1970 * 1000)
        let scheduledMs: Int64 = context.scheduledTimeMillis ?? (nowMs + 3_600_000)

        let n = dataArray.count
        let quotedFirst = "\u{201C}\(firstTitle)\u{201D}"
        let title: String
        let body: String
        if n == 1 {
            title = "Starred Project Update"
            body = "\(quotedFirst) has been updated."
        } else {
            title = "Starred Project Updates"
            let more = n - 1
            body = "\(quotedFirst) + \(more) more have been updated."
        }

        let id = "endorser_\(jwtId ?? "batch_\(nowMs)")"
        return [
            NotificationContent(
                id: id,
                title: title,
                body: body,
                scheduledTime: scheduledMs,
                fetchedAt: nowMs,
                url: apiBaseUrl,
                payload: nil,
                etag: nil
            ),
        ]
    }
}