/**
 * Noise Filter
 * Filters out low-quality memories (meta-questions, agent denials, session boilerplate)
 * Inspired by openclaw-plugin-continuity's noise filtering approach.
 */

import { logInfo } from "./stderr-log.js";
import { redactForLog } from "./pii-detector.js";

// Agent-side denial patterns
const DENIAL_PATTERNS = [
  /i don'?t have (any )?(information|data|memory|record)/i,
  /i'?m not sure about/i,
  /i don'?t recall/i,
  /i don'?t remember/i,
  /it looks like i don'?t/i,
  /i wasn'?t able to find/i,
  /no (relevant )?memories found/i,
  /i don'?t have access to/i,
  // Chinese denial patterns (synced from upstream)
  /我没有(任何)?(相关)?(信息|数据|记忆|记录)/,
  /我不(太)?确定/,
  /我不记得/,
  /我想不起来/,
  /我没(有)?找到/,
  /找不到(相关)?记忆/,
  /没有(相关)?记忆/,
  /我无法(访问|获取)/,
];

// User-side meta-question patterns (about memory itself, not content)
const META_QUESTION_PATTERNS = [
  /\bdo you (remember|recall|know about)\b/i,
  /\bcan you (remember|recall)\b/i,
  /\bdid i (tell|mention|say|share)\b/i,
  /\bhave i (told|mentioned|said)\b/i,
  /\bwhat did i (tell|say|mention)\b/i,
  // Chinese meta-question patterns (synced from upstream)
  /你(还)?记得吗/,
  /你(还)?记不记得/,
  /你知道我(说过|提过|告诉|提到).*吗/,
  /我(有没有|是不是)(说过|提过|告诉|提到)/,
  /我之前(说过|提过|提到|告诉)/,
  /我(跟你)?说过.*吗/,
];

// Session boilerplate (anchored to prevent false positives on real content)
const BOILERPLATE_PATTERNS = [
  /^(hi|hello|hey|good morning|good evening|greetings)\b/i,
  /^fresh session/i,
  /^new session/i,
  /^HEARTBEAT/i,
  /^你好[!！\s,.，。]?$/,
  /^(早上好|早安|午安|晚上好|晚安)[!！\s,.，。]?$/,
  /^(嗨|哈[喽啰]|哈[喽啰]呀)[!！\s,.，。]?$/,
  /^(嗯|哦|噢|呃)[!！\s,.，。]?$/,
  /^新(会话|对话|聊天)/,
];

// Short boilerplate: only noise when total text is very short
// "好的" alone = noise, "好的方案是使用Redis" = real content
const SHORT_BOILERPLATE_PATTERNS = [
  /^(好的|好吧|行|可以|没问题|OK|ok|收到|明白|了解|知道了)/i,
  /^(谢谢|感谢|多谢|谢啦|3Q|thx)/i,
];
const BOILERPLATE_MAX_LENGTH = 10;

// OpenClaw v3.2+ injected metadata headers (backport from v1.0.29)
const METADATA_HEADER_PATTERNS = [
  /^Conversation info \(untrusted metadata\)/i,
  /^---\s*\n\s*\{[\s\S]*?\}\s*\n\s*---/m, // YAML-like JSON blocks
  /^\[?\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}[^\]]*\]?\s*$/m, // bare timestamps
];

// Diagnostic artifact patterns (synced from upstream v1.1.0-beta.3)
// Extractor validation outputs that leak into memory store
const DIAGNOSTIC_ARTIFACT_PATTERNS = [
  /^query\s*->\s*none$/i,
  /^no explicit solution$/i,
  /^如果你知道.+只回复/i,
  /^如果不知道.+只回复\s*none/i,
  /^只回复精确代号/i,
];

// CC bridge injected agent prompts: the Telegram bridge writes CC's own system
// prompts (reply / self-decision templates) as `user` turns, which transcript
// ingest then mis-extracts as profile/preferences. They are never user content.
const AGENT_PROMPT_PATTERNS = [
  /^#{1,3}\s*CC\s+(Reply|Self-Decision)\s+Prompt\b/im,
  /你不是\s*Alice\s*的数字分身/,
  /你是\s*CC[。.]?\s*(Alice\s*刚给你发了消息|现在你周期性醒来)/,
  // Fixed sections of the bridge prompt that survive ingest as standalone chunks
  // (the long prompt turn gets split, so the title/persona lines may be absent).
  /你的输出\s*[\r\n]+\s*直接回复\s*Alice/,
  /节奏要求[：:]\s*[\r\n]+\s*[-*]\s*短话题/,
];

// CC bridge self-decision / RecallNest distill payloads embed structured JSON
// (decision logs, conversation history, interaction stats). Long prompts get
// split by transcript chunking, orphaning JSON field-lines that lost their
// enclosing braces — these survive ingest looking like preferences. We match
// the severed-fragment SHAPE, not JSON in general: a complete { } object is left
// alone (it may be real discussion); only orphaned field-lines (start as "key":
// with no brace) and dangling structural tokens (leading , } ]) qualify.
const CONTEXT_JSON_FRAGMENT_PATTERNS = [
  // bridge/distill proprietary schema keys — ANCHORED to line start (^). These
  // keys are also RecallNest's own schema fields, so a real memory may MENTION
  // them inline (e.g. 我们讨论 "distilled_at": 要不要保留); anchoring ensures only
  // an orphaned line that LEADS with the key is filtered, not such discussion.
  /^"?(?:next_check_hint|alice_interaction_stats(?:_7d)?|alice_last_cc_hours_ago|engagement_rate|seen_no_reply|distilled_at)"\s*:/,
  // orphan field-line: whole chunk starts as  "key": <scalar>  with no { wrapper.
  // SCALAR values only (string/number/bool/null). A `{` or `[` value is left
  // alone so real config / package.json chunks like `"scripts": {` survive.
  /^"?[A-Za-z_][\w]*"\s*:\s*(?:"|\d|true\b|false\b|null\b)/,
  // severed JSON array/object element: a dangling , } ] then a NEWLINE into a
  // brace/quoted-key. Requiring the newline-then-JSON shape avoids real code
  // fragments like `} catch (e) {` or `});` (close-token followed by code on
  // the same line, never a newline into a JSON key).
  /^[,}\]]+[ \t]*\r?\n\s*[{[]?\s*"[A-Za-z_]/,
];

export interface NoiseFilterOptions {
  /** Filter agent denial responses (default: true) */
  filterDenials?: boolean;
  /** Filter meta-questions about memory (default: true) */
  filterMetaQuestions?: boolean;
  /** Filter session boilerplate (default: true) */
  filterBoilerplate?: boolean;
  /** Filter CC bridge injected agent prompts (default: true) */
  filterAgentPrompts?: boolean;
}

const DEFAULT_OPTIONS: Required<NoiseFilterOptions> = {
  filterDenials: true,
  filterMetaQuestions: true,
  filterBoilerplate: true,
  filterAgentPrompts: true,
};

/**
 * Check if a memory text is noise that should be filtered out.
 * Returns true if the text is noise.
 */
export function isNoise(text: string, options: NoiseFilterOptions = {}): boolean {
  const opts = { ...DEFAULT_OPTIONS, ...options };
  const trimmed = text.trim();

  if (trimmed.length < 5) {
    logInfo(`[INFO] noise-filter: skipped short text (${trimmed.length} chars)`);
    return true;
  }

  if (opts.filterDenials && DENIAL_PATTERNS.some(p => p.test(trimmed))) {
    logInfo(`[INFO] noise-filter: denial pattern matched: "${redactForLog(trimmed)}..."`);
    return true;
  }
  if (opts.filterMetaQuestions && META_QUESTION_PATTERNS.some(p => p.test(trimmed))) {
    logInfo(`[INFO] noise-filter: meta-question filtered: "${redactForLog(trimmed)}..."`);
    return true;
  }
  if (opts.filterBoilerplate) {
    if (BOILERPLATE_PATTERNS.some(p => p.test(trimmed))) {
      logInfo(`[INFO] noise-filter: boilerplate filtered: "${redactForLog(trimmed)}..."`);
      return true;
    }
    if (trimmed.length <= BOILERPLATE_MAX_LENGTH &&
        SHORT_BOILERPLATE_PATTERNS.some(p => p.test(trimmed))) {
      logInfo(`[INFO] noise-filter: short boilerplate filtered: "${redactForLog(trimmed)}"`);
      return true;
    }
  }
  // OpenClaw v3.2+ metadata noise (backport from v1.0.29)
  if (METADATA_HEADER_PATTERNS.some(p => p.test(trimmed))) {
    logInfo(`[INFO] noise-filter: metadata header filtered`);
    return true;
  }
  // Diagnostic artifact noise (synced from upstream v1.1.0-beta.3)
  if (DIAGNOSTIC_ARTIFACT_PATTERNS.some(p => p.test(trimmed))) {
    logInfo(`[INFO] noise-filter: diagnostic artifact filtered: "${redactForLog(trimmed)}..."`);
    return true;
  }
  // CC bridge injected agent prompts (reply/self-decision templates leaked as user turns)
  if (opts.filterAgentPrompts && AGENT_PROMPT_PATTERNS.some(p => p.test(trimmed))) {
    logInfo(`[INFO] noise-filter: agent prompt filtered: "${redactForLog(trimmed)}..."`);
    return true;
  }
  // Severed bridge/distill context-JSON fragments (orphaned field-lines from chunking)
  if (opts.filterAgentPrompts && CONTEXT_JSON_FRAGMENT_PATTERNS.some(p => p.test(trimmed))) {
    logInfo(`[INFO] noise-filter: context JSON fragment filtered: "${redactForLog(trimmed)}..."`);
    return true;
  }

  return false;
}

/**
 * Filter an array of items, removing noise entries.
 */
export function filterNoise<T>(
  items: T[],
  getText: (item: T) => string,
  options?: NoiseFilterOptions
): T[] {
  const opts = { ...DEFAULT_OPTIONS, ...options };
  return items.filter(item => !isNoise(getText(item), opts));
}