package oppen.tva.ui.gemtext

import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import androidx.recyclerview.widget.RecyclerView
import kotlinx.android.synthetic.main.gemtext_link.view.*
import kotlinx.android.synthetic.main.gemtext_text.view.gemtext_text_textview
import oppen.tva.R
import java.net.URI

class GemtextAdapter(val onLink: (link: URI) -> Unit): RecyclerView.Adapter<GemtextAdapter.ViewHolder>() {

    var lines = mutableListOf<String>()

    val typeText = 0
    val typeH1 = 1
    val typeH2 = 2
    val typeH3 = 3
    val typeListItem = 4
    val typeLink = 5

    sealed class ViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView){
        class Text(itemView: View): ViewHolder(itemView)
        class H1(itemView: View): ViewHolder(itemView)
        class H2(itemView: View): ViewHolder(itemView)
        class H3(itemView: View): ViewHolder(itemView)
        class ListItem(itemView: View): ViewHolder(itemView)
        class Link(itemView: View): ViewHolder(itemView)
    }

    fun render(lines: List<String>){
        this.lines.clear()
        this.lines.addAll(lines)
        notifyDataSetChanged()
    }

    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ViewHolder {
        return when(viewType){
            typeText -> ViewHolder.Text( LayoutInflater.from(parent.context).inflate(R.layout.gemtext_text, parent, false) )
            typeH1 -> ViewHolder.H1( LayoutInflater.from(parent.context).inflate(R.layout.gemtext_h1, parent, false) )
            typeH2 -> ViewHolder.H1( LayoutInflater.from(parent.context).inflate(R.layout.gemtext_h2, parent, false) )
            typeH3 -> ViewHolder.H1( LayoutInflater.from(parent.context).inflate(R.layout.gemtext_h3, parent, false) )
            typeListItem -> ViewHolder.ListItem( LayoutInflater.from(parent.context).inflate(R.layout.gemtext_text, parent, false) )
            typeLink -> ViewHolder.Link( LayoutInflater.from(parent.context).inflate(R.layout.gemtext_link, parent, false) )
            else -> ViewHolder.Text( LayoutInflater.from(parent.context).inflate(R.layout.gemtext_text, parent, false) )
        }
    }

    override fun getItemViewType(position: Int): Int {
        val line = lines[position]
        return when {
            line.startsWith("###") -> typeH3
            line.startsWith("##") -> typeH2
            line.startsWith("#") -> typeH1
            line.startsWith("*") -> typeListItem
            line.startsWith("=>") -> typeLink
            else -> typeText
        }
    }

    override fun getItemCount(): Int = lines.size

    override fun onBindViewHolder(holder: ViewHolder, position: Int) {
        val line = lines[position]

        when(holder){
            is ViewHolder.Text -> holder.itemView.gemtext_text_textview.text = line
            is ViewHolder.H1 -> holder.itemView.gemtext_text_textview.text = line.drop(2).trim()
            is ViewHolder.H2 -> holder.itemView.gemtext_text_textview.text = line.drop(3).trim()
            is ViewHolder.H3 -> holder.itemView.gemtext_text_textview.text = line.drop(4).trim()
            is ViewHolder.ListItem -> holder.itemView.gemtext_text_textview.text = "• ${line.drop(1)}".trim()
            is ViewHolder.Link -> {
                println("Tva: link: $line")
                val linkParts = line.substring(2).trim().split("\\s+".toRegex(), 2)
                var linkName = linkParts[0]
                if(linkParts.size > 1) {
                    linkName = linkParts[1]
                }
                val displayText = linkName
                holder.itemView.gemtext_text_textview.text = displayText
                holder.itemView.gemtext_text_textview.paint.isUnderlineText = true
                holder.itemView.gemtext_link.setOnClickListener {
                    onLink(getUri(lines[holder.adapterPosition]))
                }
            }
        }
    }

    private fun getUri(linkLine: String): URI{
        val linkParts = linkLine.substring(2).trim().split("\\s+".toRegex(), 2)
        return URI.create(linkParts.first())
    }
}