// GoDaddyService.swift
// CxIDE — GoDaddy API integration for domain and DNS management
//
// Supports both OTE (test) and Production environments.
// API docs: https://developer.godaddy.com/doc

import Foundation

// MARK: - GoDaddy Service

final class GoDaddyService: @unchecked Sendable {

    enum Environment: String, CaseIterable, Sendable {
        case ote = "OTE (Test)"
        case production = "Production"

        var baseURL: String {
            switch self {
            case .ote: return "https://api.ote-godaddy.com"
            case .production: return "https://api.godaddy.com"
            }
        }
    }

    private let credentialStore: CredentialStore
    var environment: Environment

    init(credentialStore: CredentialStore = .shared, environment: Environment = .ote) {
        self.credentialStore = credentialStore
        self.environment = environment
    }

    // MARK: - Auth Header

    private var authHeader: String? {
        let key: String?
        let secret: String?
        switch environment {
        case .ote:
            key = credentialStore.godaddyOTEKey
            secret = credentialStore.godaddyOTESecret
        case .production:
            key = credentialStore.godaddyProdKey
            secret = credentialStore.godaddyProdSecret
        }
        guard let k = key, let s = secret, !k.isEmpty, !s.isEmpty else { return nil }
        return "sso-key \(k):\(s)"
    }

    // MARK: - Domain Operations

    /// List all domains in the account
    func listDomains() async throws -> [GoDaddyDomain] {
        let data = try await request(path: "/v1/domains", method: "GET")
        return try JSONDecoder().decode([GoDaddyDomain].self, from: data)
    }

    /// Get domain details
    func getDomain(_ domain: String) async throws -> GoDaddyDomainDetail {
        let data = try await request(path: "/v1/domains/\(domain)", method: "GET")
        return try JSONDecoder().decode(GoDaddyDomainDetail.self, from: data)
    }

    /// Check domain availability
    func checkAvailability(domain: String) async throws -> GoDaddyAvailability {
        let data = try await request(path: "/v1/domains/available?domain=\(domain)", method: "GET")
        return try JSONDecoder().decode(GoDaddyAvailability.self, from: data)
    }

    /// Get suggested domains
    func suggestDomains(query: String, limit: Int = 10) async throws -> [GoDaddySuggestion] {
        let encoded = query.addingPercentEncoding(withAllowedCharacters: .urlQueryAllowed) ?? query
        let data = try await request(
            path: "/v1/domains/suggest?query=\(encoded)&limit=\(limit)",
            method: "GET"
        )
        return try JSONDecoder().decode([GoDaddySuggestion].self, from: data)
    }

    // MARK: - DNS Records

    /// Get all DNS records for a domain
    func getDNSRecords(domain: String) async throws -> [DNSRecord] {
        let data = try await request(path: "/v1/domains/\(domain)/records", method: "GET")
        return try JSONDecoder().decode([DNSRecord].self, from: data)
    }

    /// Get DNS records by type
    func getDNSRecords(domain: String, type: DNSRecordType) async throws -> [DNSRecord] {
        let data = try await request(
            path: "/v1/domains/\(domain)/records/\(type.rawValue)",
            method: "GET"
        )
        return try JSONDecoder().decode([DNSRecord].self, from: data)
    }

    /// Add DNS records
    func addDNSRecords(domain: String, records: [DNSRecord]) async throws {
        let body = try JSONEncoder().encode(records)
        _ = try await request(path: "/v1/domains/\(domain)/records", method: "PATCH", body: body)
    }

    /// Replace all DNS records of a specific type and name
    func replaceDNSRecord(domain: String, type: DNSRecordType, name: String, records: [DNSRecord]) async throws {
        let body = try JSONEncoder().encode(records)
        _ = try await request(
            path: "/v1/domains/\(domain)/records/\(type.rawValue)/\(name)",
            method: "PUT",
            body: body
        )
    }

    /// Delete all DNS records of a specific type and name
    func deleteDNSRecord(domain: String, type: DNSRecordType, name: String) async throws {
        _ = try await request(
            path: "/v1/domains/\(domain)/records/\(type.rawValue)/\(name)",
            method: "DELETE"
        )
    }

    // MARK: - Convenience: Point domain to hosting

    /// Point a domain's A record to an IP address (for hosting)
    func pointDomainToIP(domain: String, ip: String, ttl: Int = 600) async throws {
        let record = DNSRecord(type: .A, name: "@", data: ip, ttl: ttl)
        try await replaceDNSRecord(domain: domain, type: .A, name: "@", records: [record])
    }

    /// Set a CNAME record (e.g., www -> hosting provider)
    func setCNAME(domain: String, name: String, target: String, ttl: Int = 3600) async throws {
        let record = DNSRecord(type: .CNAME, name: name, data: target, ttl: ttl)
        try await replaceDNSRecord(domain: domain, type: .CNAME, name: name, records: [record])
    }

    /// Configure DNS for Netlify hosting
    func configureForNetlify(domain: String, netlifySubdomain: String) async throws {
        // Point @ to Netlify's load balancer
        try await pointDomainToIP(domain: domain, ip: "75.2.60.5")
        // Point www to Netlify subdomain
        try await setCNAME(domain: domain, name: "www", target: "\(netlifySubdomain).netlify.app")
    }

    /// Configure DNS for GitHub Pages
    func configureForGitHubPages(domain: String, githubUsername: String) async throws {
        // GitHub Pages IPs
        let githubIPs = ["185.199.108.153", "185.199.109.153", "185.199.110.153", "185.199.111.153"]
        let records = githubIPs.map { DNSRecord(type: .A, name: "@", data: $0, ttl: 600) }
        try await replaceDNSRecord(domain: domain, type: .A, name: "@", records: records)
        try await setCNAME(domain: domain, name: "www", target: "\(githubUsername).github.io")
    }

    /// Configure DNS for Vercel hosting
    func configureForVercel(domain: String) async throws {
        try await pointDomainToIP(domain: domain, ip: "76.76.21.21")
        try await setCNAME(domain: domain, name: "www", target: "cname.vercel-dns.com")
    }

    /// Configure DNS for Cloudflare Pages
    func configureForCloudflare(domain: String, projectName: String) async throws {
        try await setCNAME(domain: domain, name: "@", target: "\(projectName).pages.dev")
        try await setCNAME(domain: domain, name: "www", target: "\(projectName).pages.dev")
    }

    // MARK: - HTTP Client

    private func request(path: String, method: String, body: Data? = nil) async throws -> Data {
        guard let auth = authHeader else {
            throw GoDaddyError.notAuthenticated
        }

        let urlString = environment.baseURL + path
        guard let url = URL(string: urlString) else {
            throw GoDaddyError.invalidURL(urlString)
        }

        var req = URLRequest(url: url)
        req.httpMethod = method
        req.setValue(auth, forHTTPHeaderField: "Authorization")
        req.setValue("application/json", forHTTPHeaderField: "Content-Type")
        req.setValue("application/json", forHTTPHeaderField: "Accept")
        req.timeoutInterval = 30

        if let body = body {
            req.httpBody = body
        }

        let (data, response) = try await URLSession.shared.data(for: req)

        guard let httpResponse = response as? HTTPURLResponse else {
            throw GoDaddyError.invalidResponse
        }

        switch httpResponse.statusCode {
        case 200...299:
            return data
        case 401:
            throw GoDaddyError.unauthorized
        case 403:
            throw GoDaddyError.forbidden
        case 404:
            throw GoDaddyError.notFound(path)
        case 422:
            let msg = String(data: data, encoding: .utf8) ?? "Validation error"
            throw GoDaddyError.validationError(msg)
        case 429:
            throw GoDaddyError.rateLimited
        default:
            let msg = String(data: data, encoding: .utf8) ?? "HTTP \(httpResponse.statusCode)"
            throw GoDaddyError.apiError(httpResponse.statusCode, msg)
        }
    }
}

// MARK: - Models

struct GoDaddyDomain: Codable, Sendable {
    let domain: String
    let status: String?
    let expires: String?
    let expirationProtected: Bool?
    let holdRegistrar: Bool?
    let locked: Bool?
    let privacy: Bool?
    let renewAuto: Bool?
    let renewable: Bool?
    let transferProtected: Bool?
}

struct GoDaddyDomainDetail: Codable, Sendable {
    let domain: String
    let domainId: Int?
    let status: String?
    let expires: String?
    let nameServers: [String]?
    let locked: Bool?
    let privacy: Bool?
    let renewAuto: Bool?
    let contactAdmin: GoDaddyContact?
    let contactRegistrant: GoDaddyContact?
}

struct GoDaddyContact: Codable, Sendable {
    let email: String?
    let nameFirst: String?
    let nameLast: String?
    let organization: String?
    let phone: String?
}

struct GoDaddyAvailability: Codable, Sendable {
    let available: Bool
    let domain: String
    let definitive: Bool?
    let price: Int?
    let currency: String?
    let period: Int?
}

struct GoDaddySuggestion: Codable, Sendable {
    let domain: String
}

enum DNSRecordType: String, Codable, Sendable, CaseIterable {
    case A, AAAA, CNAME, MX, NS, SOA, SRV, TXT, CAA
}

struct DNSRecord: Codable, Sendable {
    let type: DNSRecordType
    let name: String
    let data: String
    var ttl: Int?
    var priority: Int?
    var port: Int?
    var weight: Int?
    var service: String?
    var `protocol`: String?

    init(type: DNSRecordType, name: String, data: String, ttl: Int? = nil, priority: Int? = nil) {
        self.type = type
        self.name = name
        self.data = data
        self.ttl = ttl
        self.priority = priority
    }
}

// MARK: - Errors

enum GoDaddyError: LocalizedError {
    case notAuthenticated
    case unauthorized
    case forbidden
    case notFound(String)
    case invalidURL(String)
    case invalidResponse
    case validationError(String)
    case rateLimited
    case apiError(Int, String)

    var errorDescription: String? {
        switch self {
        case .notAuthenticated: return "GoDaddy API credentials not configured"
        case .unauthorized: return "Invalid GoDaddy API credentials"
        case .forbidden: return "Access forbidden — check API key permissions"
        case .notFound(let path): return "Resource not found: \(path)"
        case .invalidURL(let url): return "Invalid URL: \(url)"
        case .invalidResponse: return "Invalid response from GoDaddy API"
        case .validationError(let msg): return "Validation error: \(msg)"
        case .rateLimited: return "GoDaddy API rate limit exceeded"
        case .apiError(let code, let msg): return "GoDaddy API error (\(code)): \(msg)"
        }
    }
}