import Foundation

public struct XMLElement: Codable, Equatable, CustomStringConvertible {
    public let name: String
    public let xmlns: String?
    public let attributes: [String: String]
    public let content: String?
    public let nodes: [XMLElement]
    public var woClose: Bool = false

    public var stringRepresentation: String {
        var result = "<\(name)"
        for (key, value) in attributes {
            let val = value.escaped
            result += " \(key)='\(val)'"
        }
        if let xmlns {
            result += " xmlns='\(xmlns)'"
        }
        if !nodes.isEmpty {
            result += ">"
            for child in nodes {
                result += child.stringRepresentation
            }
            result += "</\(name)>"
        } else {
            if let content = content {
                result += ">"
                result += content
                result += "</\(name)>"
            } else {
                result += woClose ? ">" : "/>"
            }
        }
        return result
    }

    public var description: String {
        stringRepresentation.prettyStr
    }

    var data: Data {
        Data(stringRepresentation.utf8)
    }
}

// I decided to not use mutation functions and just
// make a new element during update
extension XMLElement {
    func updateXmlns(_ new: String?) -> XMLElement {
        XMLElement(
            name: name,
            xmlns: new,
            attributes: attributes,
            content: content,
            nodes: nodes,
            woClose: woClose
        )
    }

    func addNode(_ new: XMLElement) -> XMLElement {
        var nodes = nodes
        nodes.append(new)

        return XMLElement(
            name: name,
            xmlns: xmlns,
            attributes: attributes,
            content: content,
            nodes: nodes,
            woClose: woClose
        )
    }

    func updateContent(_ new: String?) -> XMLElement {
        guard let new else { return self }

        var content = self.content ?? ""
        content += new

        return XMLElement(
            name: name,
            xmlns: xmlns,
            attributes: attributes,
            content: content,
            nodes: nodes,
            woClose: woClose
        )
    }
}

//
extension XMLElement {
    static var randomId: String {
        let letters = "abcdefghijklmnopqrstuvwxyz0123456789"
        return String((0 ..< 8).map { _ in letters.randomElement() ?? "x" })
    }
}