/* 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.focus.settings

import android.os.Bundle
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import androidx.compose.foundation.background
import androidx.compose.foundation.layout.Column
import androidx.compose.foundation.layout.padding
import androidx.compose.foundation.layout.systemBarsPadding
import androidx.compose.material3.ExperimentalMaterial3Api
import androidx.compose.material3.Icon
import androidx.compose.material3.Scaffold
import androidx.compose.material3.Text
import androidx.compose.material3.TopAppBar
import androidx.compose.material3.TopAppBarDefaults
import androidx.compose.runtime.Composable
import androidx.compose.ui.Modifier
import androidx.compose.ui.platform.ComposeView
import androidx.compose.ui.platform.ViewCompositionStrategy
import androidx.compose.ui.res.colorResource
import androidx.compose.ui.res.painterResource
import androidx.compose.ui.res.stringResource
import androidx.core.content.ContextCompat
import androidx.fragment.app.Fragment
import mozilla.components.compose.base.button.IconButton
import org.mozilla.focus.R
import org.mozilla.focus.ext.hideToolbar
import org.mozilla.focus.ui.theme.FocusTheme
import org.mozilla.focus.ui.theme.focusColors
import mozilla.components.ui.icons.R as iconsR

/**
 * Fragment acting as a wrapper over a [Composable] which will be shown below a [TopAppBar].
 *
 * Useful for Fragments shown in otherwise fullscreen Activities such that they would be shown
 * beneath the status bar not below it.
 *
 * Classes extending this are expected to provide the [Composable] content and toolbar title.
 */
abstract class BaseComposeFragment : Fragment() {
    /**
     * Screen title shown in toolbar.
     */
    open val titleRes: Int? = null

    open val titleText: String? = null

    open val backgroundColorResource: Int = R.color.settings_background

    private lateinit var composeView: ComposeView

    /**
     * Callback for the up navigation button shown in toolbar.
     */
    open fun onNavigateUp(): () -> Unit = {
        activity?.onBackPressedDispatcher?.onBackPressed()
    }

    /**
     * content of the screen in compose. That will be shown below Toolbar
     */
    @Composable
    abstract fun Content()

    override fun onCreateView(
        inflater: LayoutInflater,
        container: ViewGroup?,
        savedInstanceState: Bundle?,
    ): View {
        return ComposeView(requireContext()).apply {
            composeView = this
            setViewCompositionStrategy(ViewCompositionStrategy.DisposeOnViewTreeLifecycleDestroyed)
            isTransitionGroup = true
            setBackgroundColor(
                ContextCompat.getColor(
                    requireContext(),
                    backgroundColorResource,
                ),
            )
        }
    }

    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
        super.onViewCreated(view, savedInstanceState)
        hideToolbar()
        val title = getTitle()
        composeView.setContent {
            FocusTheme {
                Scaffold(
                    modifier = Modifier.systemBarsPadding(),
                    topBar = {
                        FocusTopAppBar(
                            title = title,
                            modifier = Modifier,
                            onNavigateUpClick = onNavigateUp(),
                        )
                    },
                ) { paddingValues ->
                    Column(
                        modifier = Modifier
                            .background(colorResource(id = backgroundColorResource))
                            .padding(paddingValues),
                    ) {
                        this@BaseComposeFragment.Content()
                    }
                }
            }
        }
    }

    private fun getTitle(): String {
        var title = ""
        titleRes?.let { title = getString(it) }
        titleText?.let { title = it }
        return title
    }
}

@OptIn(ExperimentalMaterial3Api::class)
@Composable
private fun FocusTopAppBar(
    title: String,
    modifier: Modifier = Modifier,
    onNavigateUpClick: () -> Unit,
) {
    TopAppBar(
        title = {
            Text(
                text = title,
            )
        },
        modifier = modifier,
        navigationIcon = {
            IconButton(
                onClick = onNavigateUpClick,
                contentDescription = stringResource(R.string.go_back),
            ) {
                Icon(
                    painter = painterResource(id = iconsR.drawable.mozac_ic_back_24),
                    contentDescription = null,
                )
            }
        },
        colors = TopAppBarDefaults.topAppBarColors(
            containerColor = colorResource(R.color.settings_background),
            scrolledContainerColor = colorResource(R.color.settings_background),
            navigationIconContentColor = focusColors.toolbarColor,
            titleContentColor = focusColors.toolbarColor,
        ),
    )
}
