<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission
        android:name="android.permission.MANAGE_EXTERNAL_STORAGE"
        tools:ignore="ScopedStorage" />

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools">
    <application
        android:allowBackup="true"
        android:dataExtractionRules="@xml/data_extraction_rules"
        android:fullBackupContent="@xml/backup_rules"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/Theme.AbstractFunctionDemo"
        tools:targetApi="31">
        <activity
            android:name=".MainActivity"
            android:exported="true">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>
    <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
    <uses-permission
        android:name="android.permission.MANAGE_EXTERNAL_STORAGE"
        tools:ignore="ScopedStorage" />
</manifest>

package com.example.abstractfunctiondemo
import android.os.Bundle
import androidx.activity.enableEdgeToEdge
import androidx.appcompat.app.AppCompatActivity
import androidx.core.view.ViewCompat
import androidx.core.view.WindowInsetsCompat
import android.Manifest
import android.app.Activity
import android.content.ContentUris
import android.content.ContentValues
import android.content.Context
import android.content.Intent
import android.content.pm.PackageManager
import android.provider.Settings
import android.net.Uri
import android.os.Build
import android.os.Environment
import android.provider.DocumentsContract
import android.provider.MediaStore
import android.provider.OpenableColumns
import android.util.Log
import android.widget.Toast
import androidx.activity.result.contract.ActivityResultContracts
import androidx.core.app.ActivityCompat
import androidx.core.content.ContextCompat
import androidx.documentfile.provider.DocumentFile
import com.google.android.material.button.MaterialButton
import java.io.File
import java.io.FileInputStream
import java.io.FileOutputStream
import java.io.OutputStream
class MainActivity : AppCompatActivity() {
    /**
     * 1.定義選擇器的公共變量
     *
     * 定義這個(gè)全局變量是因?yàn)楸仨氃趏nCreate的時(shí)候就注冊(cè)，
     * 不可以現(xiàn)用現(xiàn)注冊(cè)
     */
    private lateinit var filePickerLauncher: androidx.activity.result.ActivityResultLauncher<Intent>
    private var onFilePicked: ((String) -> Unit)? = null
    /**
     * 定義目標(biāo)文件路徑的公共變量
     */
    private var sourceFilePath: String? = null
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        enableEdgeToEdge()
        setContentView(R.layout.activity_main)
        ViewCompat.setOnApplyWindowInsetsListener(findViewById(R.id.main)) { v, insets ->
            val systemBars = insets.getInsets(WindowInsetsCompat.Type.systemBars())
            v.setPadding(systemBars.left, systemBars.top, systemBars.right, systemBars.bottom)
            insets
        }
        /**
         * 5.注冊(cè)文件選擇器
         */
        filePickerLauncher =
            registerForActivityResult(ActivityResultContracts.StartActivityForResult()) { result ->
                if (result.resultCode == Activity.RESULT_OK) {
                    val uri: Uri? = result.data?.data
                    if (uri != null) {
                        Log.e("選取文件", "選擇的文件 URI: $uri")
                        onFilePicked?.invoke(uri.toString()) // ? 直接返回 `Uri`
                        deleteFileByUri(uri) // ? 直接用 `Uri` 刪除
                        Log.e("選取文件", "執(zhí)行結(jié)束")
                    } else {
                        Toast.makeText(this, "無(wú)法獲取文件", Toast.LENGTH_SHORT).show()
                    }
                } else {
                    Toast.makeText(this, "未選擇文件", Toast.LENGTH_SHORT).show()
                }
            }
        val testButton2: MaterialButton = findViewById(R.id.testButton2)
        testButton2.setOnClickListener {
            /**
             * 6.調(diào)用
             */
            if (checkAndRequestPermissions()) {
                pickFile()
            }
        }
    }
    /**
     * 2.定義文件選擇器激活函數(shù)
     */
    private fun pickFile() {
        filePickerLauncher.launch(Intent(Intent.ACTION_OPEN_DOCUMENT).apply {
            addCategory(Intent.CATEGORY_OPENABLE)
            type = "*/*"
        })
    }
    /**
     * 3.定義URI解析函數(shù)
     */
    private fun getFilePathFromUri(uri: Uri): String? {
        val context = applicationContext
        var filePath: String? = null
        if (uri.scheme == "content") {
            val projection = arrayOf(MediaStore.Files.FileColumns.DATA)
            context.contentResolver.query(uri, projection, null, null, null)?.use { cursor ->
                if (cursor.moveToFirst()) {
                    val columnIndex =
                        cursor.getColumnIndexOrThrow(MediaStore.Files.FileColumns.DATA)
                    filePath = cursor.getString(columnIndex)
                }
            }
        }
        return filePath
    }
    /**
     * 4.定義文件刪除函數(shù)
     */
    private fun deleteFileByUri(uri: Uri) {
        try {
            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
                // ? Android 10+ 需要用 `DocumentsContract.deleteDocument()`
                val deleted = DocumentsContract.deleteDocument(contentResolver, uri)
                if (deleted) {
                    Log.e("刪除文件", "文件刪除成功: $uri")
                    Toast.makeText(this, "文件刪除成功", Toast.LENGTH_SHORT).show()
                } else {
                    Log.e("刪除文件", "文件刪除失敗: $uri")
                    Toast.makeText(this, "無(wú)法刪除文件", Toast.LENGTH_SHORT).show()
                }
            } else {
                // ? Android 9 及以下，嘗試轉(zhuǎn)換為文件路徑
                val filePath = getFilePathFromUri(uri)
                if (filePath != null) {
                    val file = File(filePath)
                    if (file.exists() && file.delete()) {
                        Log.e("刪除文件", "文件刪除成功: $filePath")
                        Toast.makeText(this, "文件刪除成功", Toast.LENGTH_SHORT).show()
                    } else {
                        Log.e("刪除文件", "文件刪除失敗: $filePath")
                        Toast.makeText(this, "無(wú)法刪除文件", Toast.LENGTH_SHORT).show()
                    }
                } else {
                    Toast.makeText(this, "無(wú)法獲取文件路徑，嘗試手動(dòng)刪除", Toast.LENGTH_SHORT).show()
                }
            }
        } catch (e: Exception) {
            e.printStackTrace()
            Toast.makeText(this, "刪除文件出錯(cuò): ${e.message}", Toast.LENGTH_SHORT).show()
        }
    }
}