import Alamofire
import Foundation
import LilithAgentCore
import LilithLogging
import MacSyncShared
import SwiftyJSON

private let log = AppLogger.logger(for: "ICal.API")

// MARK: - Payload Types

public struct SyncCalendarPayload {
    public let calendarIdentifier: String
    public let title: String
    public let calendarType: String
    public let color: String
    public let source: String

    var dictionary: [String: Any?] {
        [
            "calendarIdentifier": calendarIdentifier,
            "title": title,
            "calendarType": calendarType,
            "color": color,
            "source": source,
        ]
    }
}

public struct SyncEventPayload {
    public let eventIdentifier: String
    public let calendarIdentifier: String
    public let title: String
    public let notes: String?
    public let location: String?
    public let url: String?
    public let isAllDay: Bool
    public let startDate: String
    public let endDate: String
    public let createdAt: String?
    public let modifiedAt: String?
    public let status: String
    public let availability: String
    public let isDetached: Bool
    public let hasAlarms: Bool
    public let hasRecurrenceRules: Bool
    public let recurrenceRule: String?
    public let organizerEmail: String?
    public let organizerName: String?
    public let attendeeCount: Int

    var dictionary: [String: Any?] {
        [
            "eventIdentifier": eventIdentifier,
            "calendarIdentifier": calendarIdentifier,
            "title": title,
            "notes": notes,
            "location": location,
            "url": url,
            "isAllDay": isAllDay,
            "startDate": startDate,
            "endDate": endDate,
            "createdAt": createdAt,
            "modifiedAt": modifiedAt,
            "status": status,
            "availability": availability,
            "isDetached": isDetached,
            "hasAlarms": hasAlarms,
            "hasRecurrenceRules": hasRecurrenceRules,
            "recurrenceRule": recurrenceRule,
            "organizerEmail": organizerEmail,
            "organizerName": organizerName,
            "attendeeCount": attendeeCount,
        ]
    }
}

public struct ICalStatsResponse {
    public let totalCalendars: Int
    public let totalEvents: Int
    public let lastSyncAt: Date?
}

// MARK: - Protocol

public protocol ICalAPIClientProtocol: AnyObject, Sendable {
    var isAuthenticated: Bool { get }
    func syncCalendars(_ payloads: [SyncCalendarPayload]) async throws -> Int
    func syncEvents(_ payloads: [SyncEventPayload]) async throws -> Int
    func getStats() async throws -> ICalStatsResponse
    func getPendingSends() async throws -> [PendingCalendarSend]
    func reportSendResult(id: String, status: String, error: String?) async throws
}

// MARK: - APIClient

public final class APIClient: BaseAPIClient, ICalAPIClientProtocol, @unchecked Sendable {
    public static let shared: APIClient = {
        APIClient(baseURL: macSyncResolveServerURL(), keychain: macSyncSharedKeychain)
    }()

    public var isAuthenticated: Bool {
        (try? getAuthToken()) != nil
    }

    public func syncCalendars(_ payloads: [SyncCalendarPayload]) async throws -> Int {
        let params: [String: Any] = ["calendars": payloads.map { $0.dictionary }]
        let data = try await authenticatedRequest("/client/ical/calendars", method: .post, parameters: params)
        let json = JSON(data)
        guard json["success"].boolValue else {
            let msg = json["error"]["message"].stringValue
            throw APIError.serverError(statusCode: json["statusCode"].intValue,
                                       message: msg.isEmpty ? "Server error" : msg)
        }
        let synced = json["data"]["synced"].intValue
        log.info("syncCalendars synced=\(synced)")
        return synced
    }

    public func syncEvents(_ payloads: [SyncEventPayload]) async throws -> Int {
        let params: [String: Any] = ["events": payloads.map { $0.dictionary }]
        let data = try await authenticatedRequest("/client/ical/events", method: .post, parameters: params)
        let json = JSON(data)
        guard json["success"].boolValue else {
            let msg = json["error"]["message"].stringValue
            throw APIError.serverError(statusCode: json["statusCode"].intValue,
                                       message: msg.isEmpty ? "Server error" : msg)
        }
        let synced = json["data"]["synced"].intValue
        log.info("syncEvents synced=\(synced)")
        return synced
    }

    // MARK: - Send Queue

    public func getPendingSends() async throws -> [PendingCalendarSend] {
        let data = try await authenticatedRequest("/client/ical/send-queue/pending", method: .get)
        let json = JSON(data)
        guard json["success"].boolValue else {
            throw APIError.serverError(statusCode: 0, message: json["error"]["message"].stringValue)
        }
        return json["data"]["items"].arrayValue.map { item in
            PendingCalendarSend(
                id: item["id"].stringValue,
                action: item["action"].stringValue,
                payload: CalendarSendPayload(
                    eventIdentifier: item["payload"]["eventIdentifier"].string,
                    calendarIdentifier: item["payload"]["calendarIdentifier"].string,
                    title: item["payload"]["title"].string,
                    notes: item["payload"]["notes"].string,
                    location: item["payload"]["location"].string,
                    startDate: item["payload"]["startDate"].string,
                    endDate: item["payload"]["endDate"].string,
                    isAllDay: item["payload"]["isAllDay"].bool,
                    url: item["payload"]["url"].string
                ),
                createdAt: item["createdAt"].stringValue
            )
        }
    }

    public func reportSendResult(id: String, status: String, error: String?) async throws {
        var params: [String: Any] = ["status": status]
        if let err = error { params["error"] = err }
        let data = try await authenticatedRequest("/client/ical/send-queue/\(id)/result", method: .post, parameters: params)
        let json = JSON(data)
        guard json["success"].boolValue else {
            throw APIError.serverError(statusCode: 0, message: json["error"]["message"].stringValue)
        }
    }

    public func getStats() async throws -> ICalStatsResponse {
        let data = try await authenticatedRequest("/client/ical/stats", method: .get)
        let json = JSON(data)
        guard json["success"].boolValue else {
            throw APIError.serverError(statusCode: 0, message: json["error"]["message"].stringValue)
        }
        return ICalStatsResponse(
            totalCalendars: json["data"]["totalCalendars"].intValue,
            totalEvents: json["data"]["totalEvents"].intValue,
            lastSyncAt: json["data"]["lastSyncAt"].string.flatMap { ISO8601DateFormatter().date(from: $0) }
        )
    }
}