/* This Source Code Form is subject to the terms of the Mozilla Public
   License, v. 2.0. If a copy of the MPL was not distributed with this
   file, You can obtain one at http://mozilla.org/MPL/2.0/. */

package org.mozilla.fenix.settings

import android.content.Context
import android.content.res.Resources
import android.graphics.drawable.BitmapDrawable
import android.util.AttributeSet
import android.view.LayoutInflater
import android.view.ViewGroup
import android.widget.CompoundButton
import android.widget.RadioGroup
import androidx.core.content.ContextCompat
import androidx.preference.Preference
import androidx.preference.PreferenceViewHolder
import kotlinx.coroutines.CoroutineScope
import kotlinx.coroutines.Dispatchers
import kotlinx.coroutines.Job
import mozilla.components.browser.search.SearchEngine
import org.mozilla.fenix.DefaultThemeManager
import org.mozilla.fenix.R
import org.mozilla.fenix.ext.components
import org.mozilla.fenix.utils.Settings
import kotlin.coroutines.CoroutineContext

abstract class SearchEngineListPreference : Preference, CoroutineScope {
    private val job = Job()
    override val coroutineContext: CoroutineContext
        get() = job + Dispatchers.Main
    protected var searchEngines: List<SearchEngine> = emptyList()
    protected var searchEngineGroup: RadioGroup? = null

    protected abstract val itemResId: Int

    constructor(context: Context, attrs: AttributeSet) : super(context, attrs) {
        layoutResource = R.layout.preference_search_engine_chooser
    }

    constructor(context: Context, attrs: AttributeSet, defStyleAttr: Int) : super(
        context,
        attrs,
        defStyleAttr
    ) {
        layoutResource = R.layout.preference_search_engine_chooser
    }

    override fun onBindViewHolder(holder: PreferenceViewHolder?) {
        super.onBindViewHolder(holder)
        searchEngineGroup = holder!!.itemView.findViewById(R.id.search_engine_group)
        val context = searchEngineGroup!!.context

        searchEngines = context.components.search.searchEngineManager.getSearchEngines(context)
            .sortedBy { it.name }

        refreshSearchEngineViews(context)
    }

    override fun onDetached() {
        job.cancel()
        super.onDetached()
    }

    protected abstract fun updateDefaultItem(defaultButton: CompoundButton)

    private fun refreshSearchEngineViews(context: Context) {
        if (searchEngineGroup == null) {
            // We want to refresh the search engine list of this preference in onResume,
            // but the first time this preference is created onResume is called before onCreateView
            // so searchEngineGroup is not set yet.
            return
        }

        val defaultSearchEngine =
            context.components.search.searchEngineManager.getDefaultSearchEngine(
                context,
                Settings.getInstance(context).defaultSearchEngineName
            ).identifier

        searchEngineGroup!!.removeAllViews()

        val layoutInflater = LayoutInflater.from(context)
        val layoutParams = ViewGroup.LayoutParams(
            ViewGroup.LayoutParams.MATCH_PARENT,
            ViewGroup.LayoutParams.WRAP_CONTENT
        )

        for (i in searchEngines.indices) {
            val engine = searchEngines[i]
            val engineId = engine.identifier
            val engineItem = makeButtonFromSearchEngine(engine, layoutInflater, context.resources)
            engineItem.id = i
            engineItem.tag = engineId
            if (engineId == defaultSearchEngine) {
                updateDefaultItem(engineItem)
            }
            searchEngineGroup!!.addView(engineItem, layoutParams)
        }
    }

    private fun makeButtonFromSearchEngine(
        engine: SearchEngine,
        layoutInflater: LayoutInflater,
        res: Resources
    ): CompoundButton {
        val buttonItem = layoutInflater.inflate(itemResId, null) as CompoundButton
        buttonItem.text = engine.name
        val iconSize = res.getDimension(R.dimen.preference_icon_drawable_size).toInt()
        val engineIcon = BitmapDrawable(res, engine.icon)
        engineIcon.setBounds(0, 0, iconSize, iconSize)
        val attr =
            DefaultThemeManager.resolveAttribute(android.R.attr.listChoiceIndicatorSingle, context)
        val buttonDrawable = ContextCompat.getDrawable(context, attr)
        buttonDrawable.apply {
            this?.setBounds(0, 0, this.intrinsicWidth, this.intrinsicHeight)
        }
        buttonItem.setCompoundDrawables(engineIcon, null, buttonDrawable, null)
        return buttonItem
    }
}