语言漂移治理: 长句拆段≤140字段级编号一次生成再拼回(治简→繁→异语中途掉线)、目标语健全检查(ja须假名/zh须简体/en无CJK)、漂移带温度0.3重试一次、提示词注入目标语硬约束、MISS langdrift/seg-drift日志

app/src/main/java/com/k2fsa/sherpa/onnx/MainActivity.kt

@@ -1946,6 +1946,8 @@ class MainActivity : AppCompatActivity() {
                             Log.i(TAG, "MISS sid=" + s2.id + " reason=seg-empty")
                         isEcho(s2.text, tr, echoJaccardTh(s2.text)) ->
                             Log.i(TAG, "MISS sid=" + s2.id + " reason=seg-echo")
+                        !targetLangOk(tr) ->
+                            Log.i(TAG, "MISS sid=" + s2.id + " reason=seg-drift")
                         else -> if (s2.trans != tr) {
                             s2.trans = tr
                             s2.line?.let { touched.add(it) }
@@ -2020,99 +2022,145 @@ class MainActivity : AppCompatActivity() {
         if (initialPending.isEmpty() || translateDisabled) return
         val batch = ArrayList(initialPending)
         initialPending.clear()
-        translateHandler.post {
-            val map = translateNumbered(batch.map {
-                Pair(it.first.toString(), it.second)
-            })
+        translateHandler.post { runTranslateBatch(batch, 0f) }
+    }
+
+    // 翻译线程执行:直出/编号批 → 逐条质检(空/复读/语言漂移)→ 主线程应用。
+    // 生成失败或语言漂移 → 带温度重试一次(每句仅一次,retriedSids 全部在本线程读写)。
+    private fun runTranslateBatch(batch: List<Pair<Long, String>>, temp: Float) {
+        val map = translateNumbered(
+            batch.map { Pair(it.first.toString(), it.second) }, temp
+        )
         if (map == null || !plausibleTranslations(map.values)) {
             Log.i(TAG, "MISS reason=genfail sids=" +
                     batch.joinToString(",") { it.first.toString() })
-                // 失败自动重试一次(仅一次;判重在主线程做,避免竞态)
-                uiHandler.post {
+            if (temp == 0f) {
                 val retry = batch.filter { retriedSids.add(it.first) }
-                    if (retry.isNotEmpty()) {
-                        initialPending.addAll(retry)
-                        flushInitialBatch()
+                if (retry.isNotEmpty()) translateHandler.post {
+                    runTranslateBatch(retry, 0.3f)
                 }
             }
-                return@post
+            return
         }
-            uiHandler.post {
-                val touched = HashSet<SubtitleLine>()
-                batch.forEach { (sid, src) ->
+        val good = HashMap<Long, String>()
+        val drift = ArrayList<Pair<Long, String>>()
+        for ((sid, src) in batch) {
             val tr = map[sid.toString()]
             when {
                 tr == null || tr.isBlank() ->
-                            Log.i(TAG, "MISS sid=$sid reason=empty")
+                    Log.i(TAG, "MISS sid=" + sid + " reason=empty")
                 isEcho(src, tr, echoJaccardTh(src)) ->
-                            Log.i(TAG, "MISS sid=$sid reason=echo")
-                        else -> findSentence(sid)?.let { s2 ->
+                    Log.i(TAG, "MISS sid=" + sid + " reason=echo")
+                !targetLangOk(tr) -> {
+                    Log.i(TAG, "MISS sid=" + sid + " reason=langdrift")
+                    if (temp == 0f && retriedSids.add(sid)) drift.add(Pair(sid, src))
+                }
+                else -> good[sid] = tr
+            }
+        }
+        uiHandler.post {
+            val touched = HashSet<SubtitleLine>()
+            good.forEach { (sid, tr) ->
+                findSentence(sid)?.let { s2 ->
                     if (s2.trans != tr) {
                         s2.trans = tr
                         s2.line?.let { touched.add(it) }
                     }
                 }
             }
-                }
             touched.forEach { notifyLine(it) }
         }
+        if (drift.isNotEmpty()) translateHandler.post {
+            runTranslateBatch(drift, 0.3f)
         }
     }
 
     // 一批 = 一个全新引擎(nativeGenerate 不清 KV 的 workaround)。
     // items: key(通常是 sid 字符串) × 原文;返回 key × 译文,失败 null。
-    private fun translateNumbered(items: List<Pair<String, String>>): Map<String, String>? {
+    private fun translateNumbered(
+        items: List<Pair<String, String>>, temp: Float = 0f,
+    ): Map<String, String>? {
         if (items.isEmpty()) return emptyMap()
         val targetName = when (uiLanguage()) {
             "ja" -> "日本語"; "en" -> "English"; else -> "简体中文"
         }
+        val langHint = when (uiLanguage()) {
+            "ja" -> "译文必须是日语(须含假名,不要输出中文或繁体)"
+            "zh" -> "译文必须是简体中文(不得用繁体字,不要输出日语或英语)"
+            else -> "The translation must be English only (no CJK characters)"
+        }
         translateEngine?.let { runCatching { it.release() } }
         translateEngine = null
         val engine = ensureTranslateEngine()
             ?: run { translateDisabled = true; return null }
-        // 动态预算:按原文总长给输出额度(译文常比原文长,原 160/句 会把
-        // 长句截断成残缺 JSON,整批被静默丢弃——"第一句不翻"的直接死因)
-        val budget = (items.sumOf { it.second.length } * 2 + 96)
+        // 长句拆段:小模型对短输入才稳定;长句译到中途会"掉语言"
+        // (简体→繁体→别的语言)。拆 ≤140 字段一次 generate,段序拼回。
+        val segKeys = ArrayList<Pair<String, String>>()
+        val segCount = HashMap<String, Int>()
+        for ((key, t) in items) {
+            val segs = splitSegments(t)
+            if (segs.size > 1) segCount[key] = segs.size
+            segs.forEachIndexed { i, sg ->
+                val sk = if (segs.size == 1) key else key + "#s" + i
+                segKeys.add(sk to sg)
+            }
+        }
+        val budget = (segKeys.sumOf { it.second.length } * 2 + 96)
             .coerceAtMost(1200)
-        // 单句 = 直出模式:不套 JSON 包装,无格式可坏,截断也仍是有效译文
-        if (items.size == 1) {
+        val got = HashMap<String, String>()
+        if (segKeys.size == 1) {
             val one = try {
                 engine.generate(
                     systemPrompt = "你是专业翻译。把给出的句子翻译成" + targetName +
-                            "。只输出译文本身,不要解释、不要引号、不要抄写原文。",
-                    userPrompt = items[0].second,
-                    maxNewTokens = budget, temperature = 0f,
+                            "。只输出译文本身,不要解释、不要引号、不要抄写原文。" +
+                            langHint + "。",
+                    userPrompt = segKeys[0].second,
+                    maxNewTokens = budget, temperature = temp,
                 )
             } catch (t: Throwable) {
-                Log.w(TAG, "TRANSLATE single failed: ${t.message}"); null
+                Log.w(TAG, "TRANSLATE single failed: " + t.message); null
             }
             val tr = one?.trim()?.lines()?.firstOrNull { it.isNotBlank() }?.trim()
-            return if (tr.isNullOrEmpty()) null
-            else mapOf(items[0].first to tr)
-        }
-        val numbered = items.mapIndexed { i, (_, t) -> "${i + 1}. $t" }
-                .joinToString("\n")
+            if (!tr.isNullOrEmpty()) got[segKeys[0].first] = tr
+            if (got.isEmpty()) return null
+        } else {
+            val numbered = segKeys.mapIndexed { i, st ->
+                (i + 1).toString() + ". " + st.second
+            }.joinToString("\n")
             val out = try {
                 engine.generate(
-                systemPrompt = "你是专业翻译。逐句翻译下面编号句子为" + targetName +
-                        "。各句相互独立,必须逐句对应翻译,不得合并、不得重复、不得解释。" +
+                    systemPrompt = "你是专业翻译。逐段翻译下面编号文本为" + targetName +
+                            "。各段相互独立,逐段对应,不得合并、不得重复、不得解释。" +
                             "只输出JSON对象,键是编号字符串,值是译文," +
                             "例如 {\"1\":\"…\",\"2\":\"…\"}。不得增删编号。" +
-                        "严禁把原句原样作为译文输出;确实无法翻译的句子," +
-                        "值输出空字符串。",
-                userPrompt = "【句子】\n$numbered",
-                maxNewTokens = budget,
-                temperature = 0f,
+                            "严禁把原文照抄为译文;无法翻译的段值输出空字符串。" +
+                            langHint + "。",
+                    userPrompt = "【文本】\n" + numbered,
+                    maxNewTokens = budget, temperature = temp,
                 )
             } catch (t: Throwable) {
-            Log.w(TAG, "TRANSLATE batch failed: ${t.message}"); null
+                Log.w(TAG, "TRANSLATE batch failed: " + t.message); null
             }
             val byIdx = extractNumberedPairs(out) ?: return null
-        val res = HashMap<String, String>()
-        items.forEachIndexed { i, (key, _) ->
-            byIdx[(i + 1).toString()]?.let { res[key] = it }
+            segKeys.forEachIndexed { i, st ->
+                byIdx[(i + 1).toString()]?.takeIf { it.isNotBlank() }
+                    ?.let { got[st.first] = it }
             }
-        return res
+            if (got.isEmpty()) return null
+        }
+        val res = HashMap<String, String>()
+        for ((key, _) in items) {
+            val n = segCount[key]
+            if (n == null) got[key]?.let { res[key] = it }
+            else {
+                val sb = StringBuilder()
+                for (i in 0 until n) {
+                    got[key + "#s" + i]?.let { sb.append(it) }
+                }
+                if (sb.isNotEmpty()) res[key] = sb.toString()
+            }
+        }
+        return if (res.isEmpty()) null else res
     }
 
     // 复读/退化检测:一半以上译文雷同 → 判退化,保留旧译文
@@ -2134,6 +2182,45 @@ class MainActivity : AppCompatActivity() {
         return if ((d == "ja" || d == "zh") && (t == "ja" || t == "zh")) 0.88 else 0.72
     }
 
+    // 长文按句读切成 ≤140 字的段(优先在句末标点断开,兜底硬切)
+    private fun splitSegments(t: String, max: Int = 140): List<String> {
+        if (t.length <= max) return listOf(t)
+        val parts = ArrayList<String>()
+        val cur = StringBuilder()
+        for (ch in t) {
+            cur.append(ch)
+            if (cur.length >= max * 3 / 4 && (ch == '。' || ch == '！' ||
+                    ch == '？' || ch == '!' || ch == '?' ||
+                    ch == '；' || ch == ';' || ch == '\n')
+            ) {
+                parts.add(cur.toString()); cur.setLength(0)
+            }
+        }
+        if (cur.isNotBlank()) parts.add(cur.toString())
+        val out = ArrayList<String>()
+        for (raw in parts) {
+            var x = raw
+            while (x.length > max) {
+                out.add(x.substring(0, max)); x = x.substring(max)
+            }
+            if (x.isNotBlank()) out.add(x)
+        }
+        return if (out.isEmpty()) listOf(t) else out
+    }
+
+    // 目标语健全检查(治"译着译着变繁体/变第三种语言"):
+    // ja 必须含足量假名;zh 不得有假名且繁体专用字 ≤1;en 不得含 CJK。
+    private val tradOnlyChars = "們這來說對學體豐華讓裡國變顯點單據觀"
+    private fun targetLangOk(tr: String): Boolean {
+        if (tr.length < 12) return true
+        return when (uiLanguage()) {
+            "ja" -> tr.count { it.code in 0x3040..0x30FF } * 25 >= tr.length
+            "zh" -> tr.none { it.code in 0x3040..0x30FF } &&
+                    tr.count { c -> tradOnlyChars.contains(c) } <= 1
+            else -> tr.none { it.code >= 0x2E80 }
+        }
+    }
+
     private fun isEcho(src: String, tr: String, th: Double = 0.72): Boolean {
         val a = normalizeForEcho(src)
         val b = normalizeForEcho(tr)