/**
 * Pure detectors for recognizing AI assistant action proposals and user
 * short replies (affirmative / negative). Used by the chat UI to render
 * a quick action confirmation bar instead of requiring the user to type.
 *
 * Detectors are intentionally narrow:
 * - A "proposal" requires both a first-person/asking phrase AND an
 *   actionable intent verb (execute query, fetch data, investigate, etc.)
 * - Affirmative / negative detectors only match short replies (the user
 *   typing a couple of words). Long replies fall through.
 *
 * Side-effect free. Safe to import from anywhere.
 */

/** Trim whitespace, leading/trailing punctuation (CJK + ASCII) for short-reply matching. */
function stripOuterPunctuation(input: string): string {
  return input
    .replace(/^[\s　]+/, "")
    .replace(/[\s　]+$/, "")
    .replace(/^[!?.,;:！？。，；：]+/, "")
    .replace(/[!?.,;:！？。，；：]+$/, "");
}

/** Returns the last non-empty line/sentence-ish chunk of the assistant message. */
function lastNonEmptyLine(content: string): string {
  const lines = content.split(/\r?\n/);
  for (let i = lines.length - 1; i >= 0; i--) {
    const trimmed = lines[i].trim();
    if (trimmed) return trimmed;
  }
  return "";
}

/** True when the string contains at least one CJK ideograph. */
export function containsChinese(input: string): boolean {
  return /[一-鿿]/.test(input);
}

// Phrases that indicate the assistant is asking permission to take an action.
const ZH_ASK_PHRASES = [
  /需要我/, // "do you need me to"
  /要不要我/, // "shall I"
  /是否需要/, // "is it needed"
  /帮我?(?:你)?/, // "shall I help" (loose)
  /我来/, // "let me"
  /我帮你/, // "let me help you"
  /我现在/, // "shall I now"
  /我可以/, // "may I"
  /我去/, // "shall I go"
  /我能/, // "may I"
];

const EN_ASK_PHRASES = [/\bshould\s+i\b/i, /\bdo\s+you\s+want\s+me\s+to\b/i, /\bwould\s+you\s+like\s+me\s+to\b/i, /\bwant\s+me\s+to\b/i, /\bshall\s+i\b/i, /\bcan\s+i\b/i, /\blet\s+me\s+know\s+if\s+you\s+want\s+me\s+to\b/i];

// Actionable intent verbs/phrases. Must co-occur with an ask phrase to count.
const ZH_ACTION_PHRASES = [
  /执行/, // execute
  /运行/, // run
  /查询/, // query
  /查看/, // view
  /看看/,
  /查一下/, // check
  /拉取/, // fetch
  /获取/, // get/fetch
  /读取/, // read
  /取出?/, // take out / extract
  /取数据/,
  /看看数据/,
  /看一下/,
  /分析/, // analyze
  /统计/, // count/aggregate
  /排查/, // investigate
  /调查/, // investigate
  /生成/, // generate
  /创建/, // create
  /列出/, // list
  /对比/, // compare
];

const EN_ACTION_PHRASES = [
  /\bexecute\b/i,
  /\brun\b/i,
  /\bquery\b/i,
  /\bfetch\b/i,
  /\bpull\b/i,
  /\bretrieve\b/i,
  /\bread\b/i,
  /\bget\s+(?:the\s+)?(?:data|rows|sample|columns|results)\b/i,
  /\banalyze\b/i,
  /\binvestigate\b/i,
  /\bcheck\b/i,
  /\binspect\b/i,
  /\bgenerate\b/i,
  /\bcreate\b/i,
  /\blist\b/i,
  /\bcompare\b/i,
  /\bcount\b/i,
  /\bsample\b/i,
];

/**
 * Detect whether the assistant message ends with a proposal-style question
 * such as "Should I execute this query?" / "需要我拉取这两个表的数据吗？".
 *
 * Heuristic:
 * - Looks at the last non-empty line.
 * - Must end with a question mark (Chinese ？ or English ?).
 * - Must contain BOTH a first-person ask phrase AND an actionable intent.
 *
 * Returns false for generic clarifying questions (no actionable verb).
 */
export function looksLikeActionProposal(content: string): boolean {
  if (!content) return false;
  const lastLine = lastNonEmptyLine(content);
  if (!lastLine) return false;

  // Must be a question.
  if (!/[?？]\s*$/.test(lastLine)) return false;

  const isZh = containsChinese(lastLine);
  const askPhrases = isZh ? ZH_ASK_PHRASES : EN_ASK_PHRASES;
  const actionPhrases = isZh ? ZH_ACTION_PHRASES : EN_ACTION_PHRASES;

  const hasAsk = askPhrases.some((re) => re.test(lastLine));
  if (!hasAsk) return false;

  const hasAction = actionPhrases.some((re) => re.test(lastLine));
  return hasAction;
}

// Short affirmative words/phrases. Must match (after stripping punctuation /
// whitespace) the entire reply for it to count — long replies fall through.
const ZH_AFFIRMATIVE = [/^需要$/, /^需要的$/, /^要$/, /^要的$/, /^好$/, /^好的$/, /^可以$/, /^行$/, /^是$/, /^是的$/, /^对$/, /^对的$/, /^嗯$/, /^嗯嗯$/, /^OK$/i, /^OKK*$/i, /^没问题$/, /^请$/, /^麻烦了$/, /^来吧$/, /^继续$/];

const EN_AFFIRMATIVE = [/^yes$/i, /^yeah$/i, /^yep$/i, /^y$/i, /^ok$/i, /^okay$/i, /^k$/i, /^sure$/i, /^go$/i, /^go\s+ahead$/i, /^do\s+it$/i, /^please\s+do$/i, /^please$/i, /^proceed$/i, /^continue$/i, /^confirm(?:ed)?$/i];

const ZH_NEGATIVE = [/^不$/, /^不用$/, /^不用了$/, /^不需要$/, /^不要$/, /^别$/, /^先不$/, /^先不(?:用|要)$/, /^算了$/, /^不必$/, /^取消$/, /^停$/, /^先别$/];

const EN_NEGATIVE = [/^no$/i, /^nope$/i, /^nah$/i, /^n$/i, /^don'?t$/i, /^do\s+not$/i, /^not\s+needed$/i, /^skip$/i, /^cancel$/i, /^stop$/i, /^never\s*mind$/i, /^nvm$/i, /^hold\s+off$/i, /^not\s+now$/i];

/**
 * Detect "short affirmative" user replies like 需要 / 好 / 可以 / 是 / 对 /
 * 嗯 / yes / ok / sure / go ahead / do it.
 *
 * Long messages (multiple sentences, or words mixed with extra context)
 * intentionally do NOT match — those should be sent to the LLM normally.
 */
export function isShortAffirmative(content: string): boolean {
  const cleaned = stripOuterPunctuation(content);
  if (!cleaned) return false;
  // Reject when the reply has multiple words/lines unless still very short
  // and matches a known phrase (e.g. "go ahead" / "do it" / "好的").
  if (cleaned.length > 24) return false;
  const all = [...ZH_AFFIRMATIVE, ...EN_AFFIRMATIVE];
  return all.some((re) => re.test(cleaned));
}

/**
 * Detect "short negative" user replies like 不用 / 不需要 / 不要 / no /
 * nope / don't / not needed.
 */
export function isShortNegative(content: string): boolean {
  const cleaned = stripOuterPunctuation(content);
  if (!cleaned) return false;
  if (cleaned.length > 24) return false;
  const all = [...ZH_NEGATIVE, ...EN_NEGATIVE];
  return all.some((re) => re.test(cleaned));
}