//
//  XMLResponseDecoder.swift
//  FantasyWatch
//
//  Created by Claude Code
//

import Foundation

final class XMLResponseDecoder: NSObject, XMLParserDelegate {
    private var currentElement = ""
    private var currentValue = ""
    private var elementStack: [String] = []
    private var dataDict: [String: Any] = [:]
    private var arrayStack: [[String: Any]] = []

    func decode<T: Decodable>(_ type: T.Type, from data: Data) throws -> T {
        let parser = XMLParser(data: data)
        parser.delegate = self

        guard parser.parse() else {
            throw NetworkError.decodingError(
                NSError(domain: "XMLDecoder", code: -1, userInfo: [NSLocalizedDescriptionKey: "Failed to parse XML"])
            )
        }

        let jsonData = try JSONSerialization.data(withJSONObject: dataDict)
        return try JSONDecoder().decode(T.self, from: jsonData)
    }

    func parser(_ parser: XMLParser, didStartElement elementName: String, namespaceURI: String?, qualifiedName qName: String?, attributes attributeDict: [String : String] = [:]) {
        currentElement = elementName
        elementStack.append(elementName)
        currentValue = ""
    }

    func parser(_ parser: XMLParser, foundCharacters string: String) {
        currentValue += string.trimmingCharacters(in: .whitespacesAndNewlines)
    }

    func parser(_ parser: XMLParser, didEndElement elementName: String, namespaceURI: String?, qualifiedName qName: String?) {
        elementStack.removeLast()

        if !currentValue.isEmpty {
            let path = elementStack.joined(separator: ".")
            dataDict[elementName] = currentValue

            if !path.isEmpty {
                dataDict[path + "." + elementName] = currentValue
            }
        }

        currentValue = ""
    }
}

// NOTE: This is a simplified XML decoder for POC purposes.
// The Yahoo Fantasy API returns complex nested XML structures.
// For production, we would need to implement more sophisticated parsing
// that handles arrays, nested objects, and the specific Yahoo XML schema.
// For now, we will parse the specific endpoints we need with custom logic.