Gemini/GeminiRenderer/RenderingBlockView.swift

//
//  RenderingBlockView.swift
//  GeminiRenderer
//
//  Created by Shadowfacts on 7/13/20.
//

import SwiftUI
import GeminiFormat

struct RenderingBlockView: View {
    let block: RenderingBlock
    let changeURL: ((URL) -> Void)?
    
    init(block: RenderingBlock, changeURL: ((URL) -> Void)? = nil) {
        self.block = block
        self.changeURL = changeURL
    }
    
    @ViewBuilder
    var body: some View {
        switch block {
        case let .text(text):
            Text(verbatim: text)
                .font(.documentBody)
                .frame(maxWidth: .infinity, alignment: .leading)
        case let .link(url, text: linkText):
            let text = linkText ?? url.absoluteString
            Button {
                self.changeURL?(url)
            } label: {
                Text(verbatim: text)
                    .font(.documentBody)
                    .foregroundColor(.blue)
                    .underline()
                    .frame(maxWidth: .infinity, alignment: .leading)
            }.buttonStyle(LinkButtonStyle())
        case let .preformatted(text, alt: _):
            ScrollView(.horizontal) {
                Text(verbatim: text)
                    .font(.documentBodyPreformatted)
                    .frame(maxWidth: .infinity, alignment: .leading)
            }
        case let .heading(text, level: level):
            Text(verbatim: text)
                .font(level.font)
                .frame(maxWidth: .infinity, alignment: .leading)
        case let .unorderedListItem(text):
            // todo: should this be .firstTextBaseline?
            HStack(alignment: .top, spacing: 4) {
                Text(verbatim: "\u{2022}")
                Text(verbatim: text)
                    .font(.documentBody)
                Spacer()
            }.frame(maxWidth: .infinity, alignment: .leading)
        case let .quote(text):
            HStack(spacing: 4) {
                Color.gray
                    .frame(width: 4)
                Text(verbatim: text)
                    .font(Font.documentBody.italic())
                    .foregroundColor(.gray)
                Spacer()
            }.frame(maxWidth: .infinity, alignment: .leading)
        }
    }
}

struct RenderingBlockView_Previews: PreviewProvider {
    static var previews: some View {
        Group {
            RenderingBlockView(block: .text("Some Text"))
            RenderingBlockView(block: .quote("A Quote"))
        }
    }
}