/* 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.library.bookmarks

import android.graphics.PorterDuff
import android.graphics.PorterDuffColorFilter
import android.view.LayoutInflater
import android.view.ViewGroup
import android.widget.ImageButton
import android.widget.LinearLayout
import androidx.appcompat.app.AppCompatActivity
import androidx.appcompat.view.menu.ActionMenuItemView
import androidx.appcompat.widget.ActionMenuView
import androidx.appcompat.widget.Toolbar
import androidx.core.content.ContextCompat
import io.reactivex.Observable
import io.reactivex.Observer
import io.reactivex.functions.Consumer
import kotlinx.android.synthetic.main.component_bookmark.view.*
import mozilla.appservices.places.BookmarkRoot
import mozilla.components.concept.storage.BookmarkNode
import mozilla.components.support.base.feature.BackHandler
import org.mozilla.fenix.R
import org.mozilla.fenix.ext.asActivity
import org.mozilla.fenix.ext.getColorIntFromAttr
import org.mozilla.fenix.mvi.UIView

class BookmarkUIView(
    container: ViewGroup,
    actionEmitter: Observer<BookmarkAction>,
    changesObservable: Observable<BookmarkChange>
) :
    UIView<BookmarkState, BookmarkAction, BookmarkChange>(container, actionEmitter, changesObservable),
    BackHandler {

    var mode: BookmarkState.Mode = BookmarkState.Mode.Normal
        private set
    var tree: BookmarkNode? = null
        private set

    private var canGoBack = false

    override val view: LinearLayout = LayoutInflater.from(container.context)
        .inflate(R.layout.component_bookmark, container, true) as LinearLayout

    private val bookmarkAdapter: BookmarkAdapter
    private val context = container.context
    private val activity = context?.asActivity()

    init {
        view.bookmark_list.apply {
            bookmarkAdapter = BookmarkAdapter(view.bookmarks_empty_view, actionEmitter)
            adapter = bookmarkAdapter
        }
    }

    override fun updateView() = Consumer<BookmarkState> {
        canGoBack = !(listOf(null, BookmarkRoot.Root.id).contains(it.tree?.guid))
        if (it.tree != tree) {
            tree = it.tree
        }
        if (it.mode != mode) {
            mode = it.mode
            actionEmitter.onNext(BookmarkAction.ModeChanged)
        }
        bookmarkAdapter.updateData(it.tree, it.mode)
        when (val modeCopy = mode) {
            is BookmarkState.Mode.Normal -> setUIForNormalMode(it.tree)
            is BookmarkState.Mode.Selecting -> setUIForSelectingMode(modeCopy)
        }
    }

    override fun onBackPressed(): Boolean {
        return when {
            mode is BookmarkState.Mode.Selecting -> {
                mode = BookmarkState.Mode.Normal
                bookmarkAdapter.updateData(tree, mode)
                setUIForNormalMode(tree)
                actionEmitter.onNext(BookmarkAction.ModeChanged)
                true
            }
            canGoBack -> {
                actionEmitter.onNext(BookmarkAction.BackPressed)
                true
            }
            else -> false
        }
    }

    fun getSelected(): Set<BookmarkNode> = bookmarkAdapter.selected

    private fun setToolbarColors(foreground: Int, background: Int) {
        val toolbar = activity?.findViewById<Toolbar>(R.id.navigationToolbar)
        val colorFilter = PorterDuffColorFilter(
            ContextCompat.getColor(context, foreground), PorterDuff.Mode.SRC_IN
        )
        toolbar?.run {
            setBackgroundColor(ContextCompat.getColor(context, background))
            setTitleTextColor(ContextCompat.getColor(context, foreground))
            themeToolbar(
                toolbar, foreground,
                background, colorFilter
            )
        }
    }

    private fun setUIForSelectingMode(
        mode: BookmarkState.Mode.Selecting
    ) {
        activity?.title =
            context.getString(R.string.bookmarks_multi_select_title, mode.selectedItems.size)
        setToolbarColors(
            R.color.white_color,
            R.attr.accentBright.getColorIntFromAttr(context!!)
        )
    }

    private fun setUIForNormalMode(root: BookmarkNode?) {
        setTitle(root)
        setToolbarColors(
            R.attr.primaryText.getColorIntFromAttr(context!!),
            R.attr.foundation.getColorIntFromAttr(context)
        )
    }

    private fun setTitle(root: BookmarkNode?) {
        (activity as? AppCompatActivity)?.title =
            if (root?.guid in setOf(
                    BookmarkRoot.Mobile.id,
                    BookmarkRoot.Root.id,
                    null
                )
            ) context.getString(R.string.library_bookmarks) else root!!.title
    }

    private fun themeToolbar(
        toolbar: Toolbar,
        textColor: Int,
        backgroundColor: Int,
        colorFilter: PorterDuffColorFilter? = null
    ) {
        toolbar.setTitleTextColor(ContextCompat.getColor(context!!, textColor))
        toolbar.setBackgroundColor(ContextCompat.getColor(context, backgroundColor))

        if (colorFilter == null) {
            return
        }

        toolbar.overflowIcon?.colorFilter = colorFilter
        (0 until toolbar.childCount).forEach {
            when (val item = toolbar.getChildAt(it)) {
                is ImageButton -> item.drawable.colorFilter = colorFilter
                is ActionMenuView -> themeActionMenuView(item, colorFilter)
            }
        }
    }

    private fun themeActionMenuView(
        item: ActionMenuView,
        colorFilter: PorterDuffColorFilter
    ) {
        (0 until item.childCount).forEach {
            val innerChild = item.getChildAt(it)
            if (innerChild is ActionMenuItemView) {
                themeChildren(innerChild, item, colorFilter)
            }
        }
    }

    private fun themeChildren(
        innerChild: ActionMenuItemView,
        item: ActionMenuView,
        colorFilter: PorterDuffColorFilter
    ) {
        val drawables = innerChild.compoundDrawables
        for (k in drawables.indices) {
            drawables[k]?.let {
                item.post { innerChild.compoundDrawables[k].colorFilter = colorFilter }
            }
        }
    }
}