//
//  NetworkService.swift
//  WatchRunner Watch App
//
//  Created by LittleSheep on 2025/10/29.
//

import Foundation

// MARK: - Network Service

class NetworkService {
    private let session = URLSession.shared
    
    func fetchActivities(filter: String, cursor: String? = nil, token: String, serverUrl: String) async throws -> ActivityResponse {
        guard let baseURL = URL(string: serverUrl) else {
            throw URLError(.badURL)
        }
        var components = URLComponents(url: baseURL.appendingPathComponent("/sphere/activities"), resolvingAgainstBaseURL: false)!
        var queryItems = [URLQueryItem(name: "take", value: "20")]
        if filter.lowercased() != "explore" {
            queryItems.append(URLQueryItem(name: "filter", value: filter.lowercased()))
        }
        if let cursor = cursor {
            queryItems.append(URLQueryItem(name: "cursor", value: cursor))
        }
        components.queryItems = queryItems
        
        var request = URLRequest(url: components.url!)
        request.httpMethod = "GET"
        request.setValue("application/json", forHTTPHeaderField: "Accept")
        
        request.setValue("AtField \(token)", forHTTPHeaderField: "Authorization")
        request.setValue("SolianWatch/1.0", forHTTPHeaderField: "User-Agent")
        
        let (data, _) = try await session.data(for: request)
        
        let decoder = JSONDecoder()
        decoder.dateDecodingStrategy = .iso8601
        decoder.keyDecodingStrategy = .convertFromSnakeCase
        
        let activities = try decoder.decode([SnActivity].self, from: data)
        
        let hasMore = (activities.first?.type ?? "empty") != "empty"
        let nextCursor = activities.isEmpty ? nil : activities.map { $0.createdAt }.min()?.ISO8601Format()
        
        return ActivityResponse(activities: activities, hasMore: hasMore, nextCursor: nextCursor)
    }
    
    func createPost(title: String, content: String, token: String, serverUrl: String) async throws {
        guard let baseURL = URL(string: serverUrl) else {
            throw URLError(.badURL)
        }
        let url = baseURL.appendingPathComponent("/sphere/posts")
        
        var request = URLRequest(url: url)
        request.httpMethod = "POST"
        request.setValue("application/json", forHTTPHeaderField: "Content-Type")
        request.setValue("application/json", forHTTPHeaderField: "Accept")
        request.setValue("AtField \(token)", forHTTPHeaderField: "Authorization")
        request.setValue("SolianWatch/1.0", forHTTPHeaderField: "User-Agent")
        
        let body: [String: Any] = ["title": title, "content": content]
        request.httpBody = try JSONSerialization.data(withJSONObject: body)
        
        let (data, response) = try await session.data(for: request)
        
        if let httpResponse = response as? HTTPURLResponse, httpResponse.statusCode != 201 {
            let responseBody = String(data: data, encoding: .utf8) ?? ""
            print("[watchOS] createPost failed with status code: \(httpResponse.statusCode), body: \(responseBody)")
            throw URLError(URLError.Code(rawValue: httpResponse.statusCode))
        }
    }
    
    func fetchNotifications(offset: Int = 0, take: Int = 20, token: String, serverUrl: String) async throws -> NotificationResponse {
        guard let baseURL = URL(string: serverUrl) else {
            throw URLError(.badURL)
        }
        var components = URLComponents(url: baseURL.appendingPathComponent("/ring/notifications"), resolvingAgainstBaseURL: false)!
        var queryItems = [URLQueryItem(name: "offset", value: String(offset)), URLQueryItem(name: "take", value: String(take))]
        components.queryItems = queryItems
        
        var request = URLRequest(url: components.url!)
        request.httpMethod = "GET"
        request.setValue("application/json", forHTTPHeaderField: "Accept")
        request.setValue("AtField \(token)", forHTTPHeaderField: "Authorization")
        request.setValue("SolianWatch/1.0", forHTTPHeaderField: "User-Agent")
        
        let (data, response) = try await session.data(for: request)
        
        let decoder = JSONDecoder()
        decoder.dateDecodingStrategy = .iso8601
        decoder.keyDecodingStrategy = .convertFromSnakeCase
        
        let notifications = try decoder.decode([SnNotification].self, from: data)
        
        let httpResponse = response as? HTTPURLResponse
        let total = Int(httpResponse?.value(forHTTPHeaderField: "X-Total") ?? "0") ?? 0
        let hasMore = offset + notifications.count < total
        
        return NotificationResponse(notifications: notifications, total: total, hasMore: hasMore)
    }
    
    func fetchUserProfile(token: String, serverUrl: String) async throws -> SnAccount {
        guard let baseURL = URL(string: serverUrl) else {
            throw URLError(.badURL)
        }
        let url = baseURL.appendingPathComponent("/pass/accounts/me")
        
        var request = URLRequest(url: url)
        request.httpMethod = "GET"
        request.setValue("application/json", forHTTPHeaderField: "Accept")
        request.setValue("AtField \(token)", forHTTPHeaderField: "Authorization")
        request.setValue("SolianWatch/1.0", forHTTPHeaderField: "User-Agent")
        
        let (data, _) = try await session.data(for: request)
        
        let decoder = JSONDecoder()
        decoder.dateDecodingStrategy = .iso8601
        decoder.keyDecodingStrategy = .convertFromSnakeCase
        
        return try decoder.decode(SnAccount.self, from: data)
    }
    
    func fetchAccountStatus(token: String, serverUrl: String) async throws -> SnAccountStatus? {
        guard let baseURL = URL(string: serverUrl) else {
            throw URLError(.badURL)
        }
        let url = baseURL.appendingPathComponent("/pass/accounts/me/statuses")
        
        var request = URLRequest(url: url)
        request.httpMethod = "GET"
        request.setValue("application/json", forHTTPHeaderField: "Accept")
        request.setValue("AtField \(token)", forHTTPHeaderField: "Authorization")
        request.setValue("SolianWatch/1.0", forHTTPHeaderField: "User-Agent")
        
        let (data, response) = try await session.data(for: request)
        
        if let httpResponse = response as? HTTPURLResponse, httpResponse.statusCode == 404 {
            return nil
        }
        
        let decoder = JSONDecoder()
        decoder.dateDecodingStrategy = .iso8601
        decoder.keyDecodingStrategy = .convertFromSnakeCase
        
        return try decoder.decode(SnAccountStatus.self, from: data)
    }
    
    func createOrUpdateStatus(attitude: Int, isInvisible: Bool, isNotDisturb: Bool, label: String?, token: String, serverUrl: String) async throws -> SnAccountStatus {
        // Check if there's already a customized status
        let existingStatus = try? await fetchAccountStatus(token: token, serverUrl: serverUrl)
        let method = (existingStatus?.isCustomized == true) ? "PATCH" : "POST"
        
        guard let baseURL = URL(string: serverUrl) else {
            throw URLError(.badURL)
        }
        let url = baseURL.appendingPathComponent("/pass/accounts/me/statuses")
        
        var request = URLRequest(url: url)
        request.httpMethod = method
        request.setValue("application/json", forHTTPHeaderField: "Content-Type")
        request.setValue("application/json", forHTTPHeaderField: "Accept")
        request.setValue("AtField \(token)", forHTTPHeaderField: "Authorization")
        request.setValue("SolianWatch/1.0", forHTTPHeaderField: "User-Agent")
        
        var body: [String: Any] = [
            "attitude": attitude,
            "is_invisible": isInvisible,
            "is_not_disturb": isNotDisturb
        ]
        
        if let label = label, !label.isEmpty {
            body["label"] = label
        }
        
        request.httpBody = try JSONSerialization.data(withJSONObject: body)
        
        let (data, response) = try await session.data(for: request)
        
        if let httpResponse = response as? HTTPURLResponse, httpResponse.statusCode != 201 && httpResponse.statusCode != 200 {
            let responseBody = String(data: data, encoding: .utf8) ?? ""
            print("[watchOS] createOrUpdateStatus failed with status code: \(httpResponse.statusCode), body: \(responseBody)")
            throw URLError(URLError.Code(rawValue: httpResponse.statusCode))
        }
        
        let decoder = JSONDecoder()
        decoder.dateDecodingStrategy = .iso8601
        decoder.keyDecodingStrategy = .convertFromSnakeCase
        
        return try decoder.decode(SnAccountStatus.self, from: data)
    }
    
    func clearStatus(token: String, serverUrl: String) async throws {
        guard let baseURL = URL(string: serverUrl) else {
            throw URLError(.badURL)
        }
        let url = baseURL.appendingPathComponent("/pass/accounts/me/statuses")
        
        var request = URLRequest(url: url)
        request.httpMethod = "DELETE"
        request.setValue("application/json", forHTTPHeaderField: "Accept")
        request.setValue("AtField \(token)", forHTTPHeaderField: "Authorization")
        request.setValue("SolianWatch/1.0", forHTTPHeaderField: "User-Agent")
        
        let (data, response) = try await session.data(for: request)
        
        if let httpResponse = response as? HTTPURLResponse, httpResponse.statusCode != 204 {
            let responseBody = String(data: data, encoding: .utf8) ?? ""
            print("[watchOS] clearStatus failed with status code: \(httpResponse.statusCode), body: \(responseBody)")
            throw URLError(URLError.Code(rawValue: httpResponse.statusCode))
        }
    }
    
    // MARK: - Chat API Methods
    
    func fetchChatRooms(token: String, serverUrl: String) async throws -> ChatRoomsResponse {
        guard let baseURL = URL(string: serverUrl) else {
            throw URLError(.badURL)
        }
        let url = baseURL.appendingPathComponent("/sphere/chat")
        
        var request = URLRequest(url: url)
        request.httpMethod = "GET"
        request.setValue("application/json", forHTTPHeaderField: "Accept")
        request.setValue("AtField \(token)", forHTTPHeaderField: "Authorization")
        request.setValue("SolianWatch/1.0", forHTTPHeaderField: "User-Agent")
        
        let (data, _) = try await session.data(for: request)
        
        let decoder = JSONDecoder()
        decoder.dateDecodingStrategy = .iso8601
        decoder.keyDecodingStrategy = .convertFromSnakeCase
        
        let rooms = try decoder.decode([SnChatRoom].self, from: data)
        return ChatRoomsResponse(rooms: rooms)
    }
    
    func fetchChatRoom(identifier: String, token: String, serverUrl: String) async throws -> SnChatRoom {
        guard let baseURL = URL(string: serverUrl) else {
            throw URLError(.badURL)
        }
        let url = baseURL.appendingPathComponent("/sphere/chat/\(identifier)")
        
        var request = URLRequest(url: url)
        request.httpMethod = "GET"
        request.setValue("application/json", forHTTPHeaderField: "Accept")
        request.setValue("AtField \(token)", forHTTPHeaderField: "Authorization")
        request.setValue("SolianWatch/1.0", forHTTPHeaderField: "User-Agent")
        
        let (data, response) = try await session.data(for: request)
        
        if let httpResponse = response as? HTTPURLResponse, httpResponse.statusCode == 404 {
            throw URLError(.resourceUnavailable)
        }
        
        let decoder = JSONDecoder()
        decoder.dateDecodingStrategy = .iso8601
        decoder.keyDecodingStrategy = .convertFromSnakeCase
        
        return try decoder.decode(SnChatRoom.self, from: data)
    }
    
    func fetchChatInvites(token: String, serverUrl: String) async throws -> ChatInvitesResponse {
        guard let baseURL = URL(string: serverUrl) else {
            throw URLError(.badURL)
        }
        let url = baseURL.appendingPathComponent("/sphere/chat/invites")
        
        var request = URLRequest(url: url)
        request.httpMethod = "GET"
        request.setValue("application/json", forHTTPHeaderField: "Accept")
        request.setValue("AtField \(token)", forHTTPHeaderField: "Authorization")
        request.setValue("SolianWatch/1.0", forHTTPHeaderField: "User-Agent")
        
        let (data, _) = try await session.data(for: request)
        
        let decoder = JSONDecoder()
        decoder.dateDecodingStrategy = .iso8601
        decoder.keyDecodingStrategy = .convertFromSnakeCase
        
        let invites = try decoder.decode([SnChatMember].self, from: data)
        return ChatInvitesResponse(invites: invites)
    }
    
    func acceptChatInvite(chatRoomId: String, token: String, serverUrl: String) async throws {
        guard let baseURL = URL(string: serverUrl) else {
            throw URLError(.badURL)
        }
        let url = baseURL.appendingPathComponent("/sphere/chat/invites/\(chatRoomId)/accept")
        
        var request = URLRequest(url: url)
        request.httpMethod = "POST"
        request.setValue("application/json", forHTTPHeaderField: "Accept")
        request.setValue("AtField \(token)", forHTTPHeaderField: "Authorization")
        request.setValue("SolianWatch/1.0", forHTTPHeaderField: "User-Agent")
        
        let (data, response) = try await session.data(for: request)
        
        if let httpResponse = response as? HTTPURLResponse, httpResponse.statusCode != 200 {
            let responseBody = String(data: data, encoding: .utf8) ?? ""
            print("[watchOS] acceptChatInvite failed with status code: \(httpResponse.statusCode), body: \(responseBody)")
            throw URLError(URLError.Code(rawValue: httpResponse.statusCode))
        }
    }
    
    func declineChatInvite(chatRoomId: String, token: String, serverUrl: String) async throws {
        guard let baseURL = URL(string: serverUrl) else {
            throw URLError(.badURL)
        }
        let url = baseURL.appendingPathComponent("/sphere/chat/invites/\(chatRoomId)/decline")
        
        var request = URLRequest(url: url)
        request.httpMethod = "POST"
        request.setValue("application/json", forHTTPHeaderField: "Accept")
        request.setValue("AtField \(token)", forHTTPHeaderField: "Authorization")
        request.setValue("SolianWatch/1.0", forHTTPHeaderField: "User-Agent")
        
        let (data, response) = try await session.data(for: request)
        
        if let httpResponse = response as? HTTPURLResponse, httpResponse.statusCode != 200 {
            let responseBody = String(data: data, encoding: .utf8) ?? ""
            print("[watchOS] declineChatInvite failed with status code: \(httpResponse.statusCode), body: \(responseBody)")
            throw URLError(URLError.Code(rawValue: httpResponse.statusCode))
        }
    }
    
    // MARK: - Message API Methods
    
    func fetchChatMessages(chatRoomId: String, token: String, serverUrl: String, before: Date? = nil, take: Int = 50) async throws -> [SnChatMessage] {
        guard let baseURL = URL(string: serverUrl) else {
            throw URLError(.badURL)
        }
        
        // Try a different pattern: /sphere/chat/messages with roomId as query param
        var components = URLComponents(
            url: baseURL.appendingPathComponent("/sphere/chat/\(chatRoomId)/messages"),
            resolvingAgainstBaseURL: false
        )!
        var queryItems = [
            URLQueryItem(name: "take", value: String(take))
        ]
        if let before = before {
            queryItems.append(URLQueryItem(name: "before", value: ISO8601DateFormatter().string(from: before)))
        }
        components.queryItems = queryItems
        
        var request = URLRequest(url: components.url!)
        request.httpMethod = "GET"
        request.setValue("application/json", forHTTPHeaderField: "Accept")
        request.setValue("AtField \(token)", forHTTPHeaderField: "Authorization")
        request.setValue("SolianWatch/1.0", forHTTPHeaderField: "User-Agent")
        
        let (data, response) = try await session.data(for: request)

        if let httpResponse = response as? HTTPURLResponse {
            _ = String(data: data, encoding: .utf8) ?? "Unable to decode response body"

            if httpResponse.statusCode != 200 {
                print("[watchOS] fetchChatMessages failed with status \(httpResponse.statusCode)")
                throw URLError(URLError.Code(rawValue: httpResponse.statusCode))
            }
        }

        // Check if data is empty
        if data.isEmpty {
            print("[watchOS] fetchChatMessages received empty response data")
            return []
        }

        let decoder = JSONDecoder()
        decoder.dateDecodingStrategy = .iso8601
        decoder.keyDecodingStrategy = .convertFromSnakeCase

        do {
            let messages = try decoder.decode([SnChatMessage].self, from: data)
            print("[watchOS] fetchChatMessages successfully decoded \(messages.count) messages")
            return messages
        } catch DecodingError.dataCorrupted(let context) {
            print(context)
            return []
        } catch DecodingError.keyNotFound(let key, let context) {
            print("Key '\(key)' not found:", context.debugDescription)
            print("codingPath:", context.codingPath)
            return []
        } catch DecodingError.valueNotFound(let value, let context) {
            print("Value '\(value)' not found:", context.debugDescription)
            print("codingPath:", context.codingPath)
            return []
        } catch DecodingError.typeMismatch(let type, let context) {
            print("Type '\(type)' mismatch:", context.debugDescription)
            print("codingPath:", context.codingPath)
            return []
        } catch {
            print("error: ", error)
            throw error
        }
    }
}