//
//  RenderingBlock.swift
//  GeminiRenderer
//
//  Created by Shadowfacts on 7/12/20.
//

import Foundation
import GeminiFormat

enum RenderingBlock: Equatable {
    case text(String)
    case link(URL, text: String?)
    case preformatted(String, alt: String?)
    case heading(String, level: Document.HeadingLevel)
    case unorderedListItem(String)
    case quote(String)
}

extension Document {
    var renderingBlocks: [RenderingBlock] {
        var blocks = [RenderingBlock]()
        
        var currentPreformatted: (text: String, alt: String?)?
        
        for line in self.lines {
            switch line {
            case let .preformattedToggle(alt: alt):
                if let (text, alt) = currentPreformatted {
                    // drop last trailing newline
                    let realText = String(text.dropLast(1))
                    blocks.append(.preformatted(realText, alt: alt))
                    currentPreformatted = nil
                } else {
                    currentPreformatted = ("", alt: alt)
                }
            case let .preformattedText(text):
                currentPreformatted!.text += text
                currentPreformatted!.text += "\n"
            case let .text(text):
                blocks.append(.text(text))
            case let .link(url, text: text):
                blocks.append(.link(url, text: text))
            case let .heading(text, level: level):
                blocks.append(.heading(text, level: level))
            case let .unorderedListItem(text):
                blocks.append(.unorderedListItem(text))
            case let .quote(text):
                blocks.append(.quote(text))
            }
        }
        
        
        return blocks
    }
}