/*
 * Copyright (C) 2025 The Android Open Source Project
 *
 * 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.
 */
package com.android.privatespace

import android.app.ActivityOptions
import android.content.ActivityNotFoundException
import android.content.Intent
import android.content.IntentSender.SendIntentException
import android.content.pm.LauncherApps
import android.net.Uri
import android.os.Bundle
import android.util.Log
import androidx.activity.ComponentActivity
import androidx.activity.compose.setContent
import androidx.activity.result.ActivityResultLauncher
import androidx.activity.result.contract.ActivityResultContracts
import androidx.activity.viewModels
import androidx.compose.material3.Button
import androidx.compose.material3.OutlinedButton
import androidx.compose.material3.Text
import androidx.compose.material3.TextButton
import androidx.compose.runtime.Composable
import androidx.compose.ui.res.stringResource

/**
 * The main activity for the Private Space system app.
 *
 * This activity handles the following actions:
 * - `com.android.privatespace.action.OPEN_MARKET_APP`: Opens the market app (e.g. Play Store) to
 *   allow the user to install apps in the Private Space.
 * - `com.android.privatespace.action.ADD_FILES`: Opens a document picker to select files to add to
 *   the Private Space. When the document picker intent returns the dialog is shown to the user to
 *   choose between moving the files to the Private Space, copying them, or canceling the operation.
 */
class PrivateSpaceActivity : ComponentActivity() {

    private lateinit var documentPickerLauncher: ActivityResultLauncher<Intent>

    private val viewModel: PrivateSpaceViewModel by viewModels()

    companion object {
        private const val TAG = "PrivateSpaceActivity"
        private const val ACTION_ADD_FILES = "com.android.privatespace.action.ADD_FILES"
        private const val ACTION_OPEN_MARKET_APP = "com.android.privatespace.action.OPEN_MARKET_APP"
    }

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)

        documentPickerLauncher =
            registerForActivityResult(ActivityResultContracts.StartActivityForResult()) { result ->
                if (result.resultCode == RESULT_OK) {
                    result.data?.let { handleDocumentSelection(it) }
                } else {
                    Log.w(
                        TAG,
                        "Document picker activity result not OK: resultCode = ${result.resultCode}",
                    )
                    viewModel.finishFlow()
                }
            }

        setContent { PrivateSpaceAppTheme { PrivateSpaceActivityScreen(viewModel = viewModel) } }
        handleIntent(intent)
    }

    private fun handleIntent(intent: Intent) {
        Log.d(TAG, "handleIntent action: ${intent.action}")

        when (intent.action) {
            ACTION_ADD_FILES -> openDocumentPicker()
            ACTION_OPEN_MARKET_APP -> openMarketApp()
            else -> {
                Log.d(TAG, "No known action specified")
                // TODO(b/397383858): default to the Private Space settings screen
                viewModel.finishFlow()
            }
        }
    }

    private fun openDocumentPicker() {
        val intent =
            Intent(Intent.ACTION_OPEN_DOCUMENT).apply {
                type = "*/*"
                addCategory(Intent.CATEGORY_OPENABLE)
                putExtra(Intent.EXTRA_ALLOW_MULTIPLE, true)
            }
        documentPickerLauncher.launch(intent)
    }

    private fun openMarketApp() {
        val launcherApps =
            applicationContext.getSystemService(LauncherApps::class.java)
                ?: run {
                    Log.e(TAG, "Failed to get LauncherApps service")
                    viewModel.finishFlow()
                    return
                }

        try {
            val intentSender =
                launcherApps.getAppMarketActivityIntent(
                    applicationContext.packageName,
                    applicationContext.user,
                )
            intentSender?.let {
                // Satisfy BAL restrictions.
                val fillInIntent = Intent()
                val options =
                    ActivityOptions.makeBasic()
                        .setPendingIntentBackgroundActivityStartMode(
                            ActivityOptions.MODE_BACKGROUND_ACTIVITY_START_ALLOW_IF_VISIBLE
                        )
                        .toBundle()
                startIntentSender(it, fillInIntent, 0, 0, 0, options)
            } ?: run { Log.e(TAG, "Failed to open market app.") }
        } catch (e: Exception) {
            when (e) {
                is NullPointerException,
                is ActivityNotFoundException,
                is SecurityException,
                is SendIntentException -> {
                    Log.e(TAG, "Private Space could not start the market app", e)
                }
                else -> throw e
            }
        } finally {
            viewModel.finishFlow()
        }
    }

    private fun handleDocumentSelection(data: Intent) {
        val uris = buildList {
            // Single URI is passed in data, multiple URIs are passed in clipData
            data.data?.let {
                persistUriPermissions(it)
                add(it)
            }
            data.clipData?.let { clipData ->
                for (i in 0 until clipData.itemCount) {
                    val uri: Uri = clipData.getItemAt(i).uri
                    persistUriPermissions(uri)
                    add(uri)
                }
            }
        }

        viewModel.showMoveFilesDialog(uris)
    }

    @Composable
    fun PrivateSpaceActivityScreen(viewModel: PrivateSpaceViewModel) {
        when (viewModel.uiState) {
            PrivateSpaceUiState.STARTED -> {
                // Show nothing, wait for the results of the document picker.
            }
            PrivateSpaceUiState.SHOW_MOVE_FILES_DIALOG -> {
                ThreeButtonAlertDialog(
                    onDismissRequest = viewModel::finishFlow,
                    title = stringResource(R.string.move_files_dialog_title),
                    message = stringResource(R.string.move_files_dialog_summary),
                    primaryButton = {
                        Button(onClick = { viewModel.moveFiles(applicationContext) }) {
                            Text(stringResource(R.string.move_files_dialog_button_label_move))
                        }
                    },
                    secondaryButton = {
                        OutlinedButton(onClick = { viewModel.copyFiles(applicationContext) }) {
                            Text(stringResource(R.string.move_files_dialog_button_label_copy))
                        }
                    },
                    dismissButton = {
                        TextButton(onClick = viewModel::finishFlow) {
                            Text(stringResource(R.string.move_files_dialog_button_label_cancel))
                        }
                    },
                )
            }
            PrivateSpaceUiState.FINISHED -> {
                finish()
            }
        }
    }

    private fun persistUriPermissions(uri: Uri) {
        applicationContext.contentResolver.takePersistableUriPermission(
            uri,
            Intent.FLAG_GRANT_READ_URI_PERMISSION or Intent.FLAG_GRANT_WRITE_URI_PERMISSION,
        )
    }
}