/*
 * Copyright 2016 JetBrains s.r.o.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

@file:Suppress("unused")

package org.jetbrains.anko

import android.app.Activity
import android.content.Context
import android.content.ContextWrapper
import android.view.View
import android.view.ViewGroup
import android.view.ViewManager
import androidx.fragment.app.Fragment
import org.jetbrains.anko.internals.AnkoInternals.createAnkoContext

@DslMarker
private annotation class AnkoContextDslMarker

@AnkoContextDslMarker
interface AnkoContext<out T> : ViewManager {
    val ctx: Context
    val owner: T
    val view: View

    override fun updateViewLayout(view: View, params: ViewGroup.LayoutParams) {
        throw UnsupportedOperationException()
    }

    override fun removeView(view: View) {
        throw UnsupportedOperationException()
    }

    companion object {
        fun create(ctx: Context, setContentView: Boolean = false): AnkoContext<Context> =
            AnkoContextImpl(ctx, ctx, setContentView)

        fun createReusable(ctx: Context, setContentView: Boolean = false): AnkoContext<Context> =
            ReusableAnkoContext(ctx, ctx, setContentView)

        fun <T> create(ctx: Context, owner: T, setContentView: Boolean = false): AnkoContext<T> =
            AnkoContextImpl(ctx, owner, setContentView)

        fun <T> createReusable(
            ctx: Context,
            owner: T,
            setContentView: Boolean = false,
        ): AnkoContext<T> = ReusableAnkoContext(ctx, owner, setContentView)

        fun <T : ViewGroup> createDelegate(owner: T): AnkoContext<T> = DelegatingAnkoContext(owner)
    }
}

internal class DelegatingAnkoContext<T : ViewGroup>(override val owner: T) : AnkoContext<T> {
    override val ctx: Context = owner.context
    override val view: View = owner

    override fun addView(view: View?, params: ViewGroup.LayoutParams?) {
        if (view == null) return

        if (params == null) {
            owner.addView(view)
        } else {
            owner.addView(view, params)
        }
    }
}

internal class ReusableAnkoContext<T>(
    override val ctx: Context,
    override val owner: T,
    setContentView: Boolean,
) : AnkoContextImpl<T>(ctx, owner, setContentView) {
    override fun alreadyHasView() {}
}

open class AnkoContextImpl<T>(
    override val ctx: Context,
    override val owner: T,
    private val setContentView: Boolean,
) : AnkoContext<T> {
    private var myView: View? = null

    override val view: View
        get() = myView ?: throw IllegalStateException("View was not set previously")

    override fun addView(view: View?, params: ViewGroup.LayoutParams?) {
        if (view == null) return

        if (myView != null) {
            alreadyHasView()
        }

        this.myView = view

        if (setContentView) {
            doAddView(ctx, view)
        }
    }

    private fun doAddView(context: Context, view: View) {
        when (context) {
            is Activity -> context.setContentView(view)
            is ContextWrapper -> doAddView(context.baseContext, view)
            else -> throw IllegalStateException("Context is not an Activity, can't set content view")
        }
    }

    protected open fun alreadyHasView(): Unit =
        throw IllegalStateException("View is already set: $myView")
}

@Suppress("FunctionNaming")
inline fun Context.UI(
    setContentView: Boolean,
    init: AnkoContext<Context>.() -> Unit,
): AnkoContext<Context> =
    createAnkoContext(this, init, setContentView)

@Suppress("FunctionNaming")
inline fun Context.UI(init: AnkoContext<Context>.() -> Unit): AnkoContext<Context> =
    createAnkoContext(this, init)

@Suppress("FunctionNaming")
inline fun Fragment.UI(init: AnkoContext<Fragment>.() -> Unit): AnkoContext<Fragment> =
    createAnkoContext(requireContext(), init)

interface AnkoComponent<in T> {
    fun createView(ui: AnkoContext<T>): View
}

fun <T : Activity> AnkoComponent<T>.setContentView(activity: T): View =
    createView(AnkoContextImpl(activity, activity, true))