LibreTube/app/src/main/java/com/github/libretube/util/LinkHandler.kt

package com.github.libretube.util

import android.text.Editable
import android.text.Spanned
import android.text.TextPaint
import android.text.style.ClickableSpan
import android.util.Log
import android.view.View
import com.github.libretube.util.HtmlParser.Companion.getValue
import org.xml.sax.Attributes

class LinkHandler(private val clickCallback: ((String) -> Unit)?) : HtmlParser.TagHandler {
    private var linkTagStartIndex = -1
    private var link: String? = null
    override fun handleTag(opening: Boolean, tag: String?, output: Editable?, attributes: Attributes?): Boolean {
        if (output != null) {
            if ("a" == tag) {
                if (opening && attributes != null) {
                    linkTagStartIndex = output.length
                    link = getValue(attributes, "href")
                } else {
                    val refTagEndIndex = output.length
                    setLinkSpans(output, linkTagStartIndex, refTagEndIndex, link)
                }
                return true
            }
        }
        return false
    }

    private fun setLinkSpans(output: Editable, start: Int, end: Int, link: String?) {
        output.setSpan(object : ClickableSpan() {
            override fun onClick(widget: View) {
                if (clickCallback != null && link != null) {
                    clickCallback.invoke(link)
                }
            }

            override fun updateDrawState(ds: TextPaint) {
                super.updateDrawState(ds)
                ds.isUnderlineText = false
            }
        }, start, end, Spanned.SPAN_EXCLUSIVE_EXCLUSIVE)
    }
}