新增 Android 版（Kotlin + Compose，CLI-only 工具鏈）

CLAUDE.md

@@ -6,6 +6,8 @@ This file provides guidance to Claude Code (claude.ai/code) when working with co
 
 抓取台灣銀行 CSV 匯率並即時換算成台幣的跨平台 GUI 小工具。目標是「使用者雙擊即跑、零 runtime 依賴」，所以主程式是 Rust（`bot_rates_rs/src/main.rs`）；根目錄下的 `bot_rates.py` / `bot_rates_gui.py` / `build.bat` 是已被取代的早期 Python 版本，修改時請以 Rust 版為準。
 
+Android 版獨立在 `android/`（Kotlin + Jetpack Compose），用純 CLI（`gradle` + `sdkmanager`）建置，不依賴 Android Studio。核心邏輯（CSV col 13、TARGETS）與 Rust 版對齊，改動時兩邊要同步。詳細見 `android/README.md`。
+
 ## 常用指令
 
 所有 cargo 指令都要在 `bot_rates_rs/` 下執行，並帶 `RUST_MIN_STACK=16777216`（少了這個 LLVM 在 release 優化 `eframe` 依賴時會堆疊溢位 SIGSEGV）。

android/.gitignore

@@ -0,0 +1,7 @@
+.gradle/
+build/
+local.properties
+*.iml
+.idea/
+.kotlin/
+captures/

android/README.md

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+# Android 版（Kotlin + Jetpack Compose，不需要 Android Studio）
+
+用 CLI（`sdkmanager` + `gradle`）從零到 APK 全程在 terminal 完成。編輯用任何 editor / Claude Code 即可。
+
+## 一次性環境設定
+
+### 1. JDK 17 與 Gradle
+
+```bash
+brew install openjdk@17 gradle
+
+# 讓系統找得到 openjdk@17
+sudo ln -sfn "$(brew --prefix)/opt/openjdk@17/libexec/openjdk.jdk" \
+  /Library/Java/JavaVirtualMachines/openjdk-17.jdk
+
+# 加到 ~/.zshrc
+export JAVA_HOME="$(/usr/libexec/java_home -v 17)"
+```
+
+### 2. Android SDK（只裝 cmdline-tools / platform-tools / build-tools，不裝 IDE）
+
+```bash
+brew install --cask android-commandlinetools
+
+# 加到 ~/.zshrc
+export ANDROID_HOME="/opt/homebrew/share/android-commandlinetools"  # Apple Silicon
+# 若是 Intel Mac：export ANDROID_HOME="/usr/local/share/android-commandlinetools"
+export PATH="$PATH:$ANDROID_HOME/cmdline-tools/latest/bin:$ANDROID_HOME/platform-tools"
+
+# 裝必要元件
+sdkmanager --install "platform-tools" "platforms;android-34" "build-tools;34.0.0"
+yes | sdkmanager --licenses
+```
+
+確認路徑被 Gradle 看得到，在 `android/` 下建一個 `local.properties`：
+
+```
+sdk.dir=/opt/homebrew/share/android-commandlinetools
+```
+
+（或讓 `ANDROID_HOME` 環境變數生效也行，Gradle 會自己找。）
+
+### 3. 產生 Gradle wrapper（只要做一次，之後就都用 `./gradlew`）
+
+```bash
+cd android
+gradle wrapper --gradle-version 8.9 --distribution-type bin
+```
+
+## 編譯
+
+```bash
+cd android
+./gradlew assembleDebug
+# 產物：app/build/outputs/apk/debug/app-debug.apk
+```
+
+Release build（未簽章，只能自己用）：
+
+```bash
+./gradlew assembleRelease
+# 產物：app/build/outputs/apk/release/app-release-unsigned.apk
+```
+
+## 安裝到手機
+
+```bash
+# 1. 手機開「開發人員選項」→「USB 偵錯」
+# 2. USB 接上
+adb devices                   # 應列出裝置
+adb install -r app/build/outputs/apk/debug/app-debug.apk
+```
+
+## 程式結構
+
+單一 Activity + Compose，所有邏輯在 `app/src/main/java/tw/local/botrates/MainActivity.kt`：
+
+- `fetchRates()`：`HttpURLConnection` 抓台銀 CSV，同樣用欄位索引 13（即期賣出）解析
+- `App()`：Compose UI，每個幣別一列：幣別+匯率 / 金額輸入 / TWD 結果 / 複製鈕
+- 複製用 `ClipboardManager.setPrimaryClip`，Toast 提示「已複製」
+
+### 想改的地方
+
+| 改什麼 | 位置 |
+|--------|------|
+| 新增幣別 | `MainActivity.kt` 頂端 `TARGETS` |
+| 買入／賣出 | `fetchRates()` 內的 `cols[13]`（見根 `QUICKSTART.md` 的欄位表） |
+| 視覺配色 | `RateRow()` 裡的 `Color(0xFF...)` 常數 |
+| applicationId / 版本 | `app/build.gradle.kts` 的 `defaultConfig` |
+
+## 為什麼不用 Android Studio
+
+AS 整包 2GB+，但實際需要的只有 JDK + Android SDK platform + build-tools（加起來 300MB 左右）。Gradle 本身也是 CLI 工具。Compose 的開發體驗在純 editor 下唯一損失的是即時 Preview，但寫完 `./gradlew installDebug` 直接跑在手機上看也沒差多少。

android/app/build.gradle.kts

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+plugins {
+    id("com.android.application")
+    id("org.jetbrains.kotlin.android")
+    id("org.jetbrains.kotlin.plugin.compose")
+}
+
+android {
+    namespace = "tw.local.botrates"
+    compileSdk = 34
+
+    defaultConfig {
+        applicationId = "tw.local.botrates"
+        minSdk = 26
+        targetSdk = 34
+        versionCode = 1
+        versionName = "1.0"
+    }
+
+    compileOptions {
+        sourceCompatibility = JavaVersion.VERSION_17
+        targetCompatibility = JavaVersion.VERSION_17
+    }
+
+    kotlinOptions {
+        jvmTarget = "17"
+    }
+
+    buildFeatures {
+        compose = true
+    }
+
+    buildTypes {
+        release {
+            isMinifyEnabled = false
+            proguardFiles(
+                getDefaultProguardFile("proguard-android-optimize.txt"),
+                "proguard-rules.pro"
+            )
+        }
+    }
+
+    packaging {
+        resources {
+            excludes += "/META-INF/{AL2.0,LGPL2.1}"
+        }
+    }
+}
+
+dependencies {
+    implementation("androidx.core:core-ktx:1.13.1")
+    implementation("androidx.activity:activity-compose:1.9.2")
+    implementation(platform("androidx.compose:compose-bom:2024.09.02"))
+    implementation("androidx.compose.ui:ui")
+    implementation("androidx.compose.ui:ui-tooling-preview")
+    implementation("androidx.compose.material3:material3")
+    implementation("androidx.lifecycle:lifecycle-runtime-ktx:2.8.6")
+    implementation("androidx.lifecycle:lifecycle-viewmodel-compose:2.8.6")
+}

android/app/proguard-rules.pro

@@ -0,0 +1,2 @@
+# Keep Kotlin metadata for reflection (if any future libs need it)
+-keepattributes *Annotation*

android/app/src/main/AndroidManifest.xml

@@ -0,0 +1,21 @@
+<?xml version="1.0" encoding="utf-8"?>
+<manifest xmlns:android="http://schemas.android.com/apk/res/android">
+
+    <uses-permission android:name="android.permission.INTERNET" />
+
+    <application
+        android:allowBackup="true"
+        android:label="@string/app_name"
+        android:supportsRtl="true"
+        android:theme="@android:style/Theme.Material.Light.NoActionBar">
+        <activity
+            android:name=".MainActivity"
+            android:exported="true"
+            android:label="@string/app_name">
+            <intent-filter>
+                <action android:name="android.intent.action.MAIN" />
+                <category android:name="android.intent.category.LAUNCHER" />
+            </intent-filter>
+        </activity>
+    </application>
+</manifest>

android/app/src/main/java/tw/local/botrates/MainActivity.kt

@@ -0,0 +1,263 @@
+package tw.local.botrates
+
+import android.content.ClipData
+import android.content.ClipboardManager
+import android.content.Context
+import android.os.Bundle
+import android.widget.Toast
+import androidx.activity.ComponentActivity
+import androidx.activity.compose.setContent
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.PaddingValues
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.height
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.width
+import androidx.compose.foundation.text.KeyboardOptions
+import androidx.compose.material3.Button
+import androidx.compose.material3.ExperimentalMaterial3Api
+import androidx.compose.material3.HorizontalDivider
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.OutlinedTextField
+import androidx.compose.material3.Scaffold
+import androidx.compose.material3.Text
+import androidx.compose.material3.TopAppBar
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.LaunchedEffect
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateMapOf
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.rememberCoroutineScope
+import androidx.compose.runtime.setValue
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.platform.LocalContext
+import androidx.compose.ui.text.TextStyle
+import androidx.compose.ui.text.font.FontFamily
+import androidx.compose.ui.text.font.FontWeight
+import androidx.compose.ui.text.input.KeyboardType
+import androidx.compose.ui.unit.dp
+import androidx.compose.ui.unit.sp
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.launch
+import kotlinx.coroutines.withContext
+import java.net.HttpURLConnection
+import java.net.URL
+import java.text.SimpleDateFormat
+import java.util.Date
+import java.util.Locale
+
+private const val URL_CSV = "https://rate.bot.com.tw/xrt/flcsv/0/day"
+private val TARGETS = listOf("USD" to "美元", "JPY" to "日幣", "EUR" to "歐元")
+
+data class Rate(val code: String, val name: String, val rate: Double)
+
+private fun fetchRates(): List<Rate> {
+    val conn = (URL(URL_CSV).openConnection() as HttpURLConnection).apply {
+        connectTimeout = 10_000
+        readTimeout = 10_000
+        setRequestProperty("User-Agent", "Mozilla/5.0 bot_rates")
+    }
+    val body = conn.inputStream.bufferedReader().use { it.readText() }
+        .trimStart('\uFEFF')
+
+    val out = mutableListOf<Rate>()
+    body.lines().drop(1).forEach { line ->
+        val cols = line.split(",")
+        if (cols.size < 14) return@forEach
+        val code = cols[0].trim()
+        val pair = TARGETS.firstOrNull { it.first == code } ?: return@forEach
+        val v = cols[13].trim().toDoubleOrNull() ?: return@forEach
+        out.add(Rate(code, pair.second, v))
+    }
+    return out.sortedBy { r -> TARGETS.indexOfFirst { it.first == r.code } }
+}
+
+private fun parseAmount(s: String): Double? =
+    s.filter { it != ',' && !it.isWhitespace() }.takeIf { it.isNotEmpty() }?.toDoubleOrNull()
+
+private fun formatTwd(v: Double): String {
+    val rounded = kotlin.math.round(v * 100.0) / 100.0
+    return "%,.2f".format(rounded)
+}
+
+private fun formatTwdRaw(v: Double): String =
+    "%.2f".format(kotlin.math.round(v * 100.0) / 100.0)
+
+class MainActivity : ComponentActivity() {
+    override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+        setContent {
+            MaterialTheme {
+                App()
+            }
+        }
+    }
+}
+
+@OptIn(ExperimentalMaterial3Api::class)
+@Composable
+private fun App() {
+    val scope = rememberCoroutineScope()
+    val context = LocalContext.current
+
+    var rates by remember { mutableStateOf<List<Rate>>(emptyList()) }
+    val amounts = remember {
+        mutableStateMapOf<String, String>().apply {
+            TARGETS.forEach { put(it.first, "100") }
+        }
+    }
+    var loading by remember { mutableStateOf(false) }
+    var error by remember { mutableStateOf<String?>(null) }
+    var fetchedAt by remember { mutableStateOf<String?>(null) }
+
+    fun load() {
+        if (loading) return
+        loading = true
+        error = null
+        scope.launch {
+            try {
+                val r = withContext(Dispatchers.IO) { fetchRates() }
+                if (r.isEmpty()) {
+                    error = "解析結果為空"
+                } else {
+                    rates = r
+                    fetchedAt = SimpleDateFormat("yyyy-MM-dd HH:mm:ss", Locale.US)
+                        .format(Date())
+                }
+            } catch (e: Exception) {
+                error = e.message ?: "載入失敗"
+            } finally {
+                loading = false
+            }
+        }
+    }
+
+    LaunchedEffect(Unit) { load() }
+
+    Scaffold(
+        topBar = { TopAppBar(title = { Text("台銀 即期賣出") }) }
+    ) { padding ->
+        Column(
+            modifier = Modifier
+                .padding(padding)
+                .padding(16.dp)
+                .fillMaxSize()
+        ) {
+            Text(
+                "輸入外幣金額，下方顯示台幣換算",
+                fontSize = 12.sp,
+                color = Color.Gray
+            )
+            Spacer(Modifier.height(12.dp))
+
+            val display = rates.ifEmpty {
+                TARGETS.map { Rate(it.first, it.second, Double.NaN) }
+            }
+
+            display.forEachIndexed { idx, r ->
+                if (idx > 0) {
+                    HorizontalDivider(Modifier.padding(vertical = 8.dp))
+                }
+                RateRow(
+                    rate = r,
+                    amount = amounts[r.code] ?: "",
+                    onAmountChange = { amounts[r.code] = it },
+                    onCopy = { raw ->
+                        val cm = context.getSystemService(Context.CLIPBOARD_SERVICE)
+                            as ClipboardManager
+                        cm.setPrimaryClip(ClipData.newPlainText("TWD", raw))
+                        Toast.makeText(context, "已複製 $raw", Toast.LENGTH_SHORT).show()
+                    }
+                )
+            }
+
+            Spacer(Modifier.height(16.dp))
+            Row(verticalAlignment = Alignment.CenterVertically) {
+                val status = when {
+                    error != null -> "載入失敗：$error"
+                    loading -> "載入中…"
+                    fetchedAt != null -> "更新時間：$fetchedAt"
+                    else -> ""
+                }
+                Text(
+                    status,
+                    fontSize = 11.sp,
+                    color = if (error != null) Color(0xFFB91C1C) else Color.Gray,
+                    modifier = Modifier.weight(1f)
+                )
+                Button(onClick = { load() }, enabled = !loading) {
+                    Text("重新整理")
+                }
+            }
+        }
+    }
+}
+
+@Composable
+private fun RateRow(
+    rate: Rate,
+    amount: String,
+    onAmountChange: (String) -> Unit,
+    onCopy: (String) -> Unit
+) {
+    val rateText = if (rate.rate.isNaN()) "--" else "%.4f".format(rate.rate)
+    val parsed = parseAmount(amount)
+    val twd = if (parsed != null && !rate.rate.isNaN()) parsed * rate.rate else null
+    val twdText = twd?.let { "NT$ ${formatTwd(it)}" } ?: "NT$ --"
+
+    Column(modifier = Modifier.fillMaxWidth()) {
+        Row(verticalAlignment = Alignment.CenterVertically) {
+            Column(Modifier.width(110.dp)) {
+                Text(
+                    "${rate.name} ${rate.code}",
+                    fontWeight = FontWeight.Bold,
+                    fontSize = 14.sp
+                )
+                Text(
+                    rateText,
+                    fontSize = 12.sp,
+                    fontFamily = FontFamily.Monospace,
+                    color = Color(0xFF0F766E)
+                )
+            }
+            Spacer(Modifier.width(8.dp))
+            OutlinedTextField(
+                value = amount,
+                onValueChange = onAmountChange,
+                keyboardOptions = KeyboardOptions(keyboardType = KeyboardType.Number),
+                singleLine = true,
+                modifier = Modifier.fillMaxWidth(),
+                textStyle = TextStyle(fontFamily = FontFamily.Monospace)
+            )
+        }
+        Spacer(Modifier.height(6.dp))
+        Row(
+            verticalAlignment = Alignment.CenterVertically,
+            horizontalArrangement = Arrangement.End,
+            modifier = Modifier.fillMaxWidth()
+        ) {
+            Text(
+                twdText,
+                modifier = Modifier.weight(1f),
+                fontWeight = FontWeight.Bold,
+                fontSize = 16.sp,
+                color = Color(0xFFB45309),
+                fontFamily = FontFamily.Monospace
+            )
+            Button(
+                onClick = { twd?.let { onCopy(formatTwdRaw(it)) } },
+                enabled = twd != null,
+                contentPadding = PaddingValues(horizontal = 14.dp, vertical = 4.dp)
+            ) {
+                Text("複製", fontSize = 12.sp)
+            }
+        }
+    }
+}

android/app/src/main/res/values/strings.xml

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+<?xml version="1.0" encoding="utf-8"?>
+<resources>
+    <string name="app_name">台銀即期賣出</string>
+</resources>

android/build.gradle.kts

@@ -0,0 +1,5 @@
+plugins {
+    id("com.android.application") version "8.5.2" apply false
+    id("org.jetbrains.kotlin.android") version "2.0.20" apply false
+    id("org.jetbrains.kotlin.plugin.compose") version "2.0.20" apply false
+}

android/gradle.properties

@@ -0,0 +1,6 @@
+org.gradle.jvmargs=-Xmx2048m -Dfile.encoding=UTF-8
+org.gradle.parallel=true
+org.gradle.caching=true
+android.useAndroidX=true
+android.nonTransitiveRClass=true
+kotlin.code.style=official

android/settings.gradle.kts

@@ -0,0 +1,18 @@
+pluginManagement {
+    repositories {
+        google()
+        mavenCentral()
+        gradlePluginPortal()
+    }
+}
+
+dependencyResolutionManagement {
+    repositoriesMode.set(RepositoriesMode.FAIL_ON_PROJECT_REPOS)
+    repositories {
+        google()
+        mavenCentral()
+    }
+}
+
+rootProject.name = "BotRates"
+include(":app")