import Foundation
import SwiftSoup

public enum AToZParser {
    public static let baseSelector = "section.FilterComics_filterComics__9VGXB"
    static let cardSelector = "a[data-analytics-type=\"feature_card\"]"
    static let titleSelector = "h3"
    static let bylineSelector = "h4"
    static let imageSelector = "img"
    static let updatedSelector = "span"

    public static func parse(content: String) throws -> [Feature] {
        let document = try SwiftSoup.parse(content)
        let content = try element(from: document, selector: baseSelector)
        let links = try content.select(cardSelector)
        let features = try links.compactMap { card in
            let identifier = try card.attr("href")
            let title = try element(from: card, selector: titleSelector).text()
            let byline = try element(from: card, selector: bylineSelector).text()
            let image = try card.select(imageSelector).first().map { try $0.attr("src") }.flatMap { URL(string: $0) }
            let span = try card.select(updatedSelector).first()
            return Feature(identifier: identifier, title: title, byline: byline, imageURL: image, isUpdated: span != nil)
        }
        return features
    }

    static func element(from document: SwiftSoup.Element, selector: String) throws -> SwiftSoup.Element {
        guard let result = try document.select(selector).first() else {
            throw ParserError.missingElement(selector)
        }
        return result
    }
}