const path = require('path');
const { readJson, writeJson, defaultMemoryPath } = require('../../core/memory-store');

const DEFAULT_MEMORY_FILE = 'douyin-trend-memory.json';

function cleanList(values) {
  return [...new Set((values || [])
    .flatMap(value => Array.isArray(value) ? value : String(value || '').split(/[,，、\n\r]+|以及|与|和/))
    .map(value => String(value || '').trim())
    .filter(Boolean))];
}

function appendNote(notes, note) {
  const text = String(note || '').trim();
  if (!text) return (notes || []).slice(-20);
  const next = [...(notes || []).filter(Boolean), text];
  return [...new Set(next)].slice(-20);
}

function defaultTrendMemory() {
  return {
    version: '0.3.12',
    preferredDirections: [],
    blockedDirections: [],
    focusModes: [],
    notes: [],
    updatedAt: ''
  };
}

function trendMemoryPath(input = {}) {
  return path.resolve(input.memory || input.memoryPath || defaultMemoryPath(DEFAULT_MEMORY_FILE));
}

function readTrendMemory(memoryPath) {
  return {
    ...defaultTrendMemory(),
    ...readJson(memoryPath, {})
  };
}

function extractAfter(text, pattern) {
  const match = String(text || '').match(pattern);
  return match ? match[1] : '';
}

function inferPreferenceFromMessage(message) {
  const text = String(message || '').trim();
  const preferred = cleanList([
    extractAfter(text, /(?:保留|多给|继续给|更喜欢|适合)(.+?)(?:。|；|;|，但|但是|不要|少给|降权|$)/)
  ]);
  const blocked = cleanList([
    extractAfter(text, /(?:不要|少给|降权|过滤|不适合|避开)(.+?)(?:。|；|;|，|$)/)
  ]);
  const focus = cleanList([
    extractAfter(text, /(?:更偏|侧重|多看|下一版更偏)(.+?)(?:。|；|;|，|$)/)
  ]);
  return { preferred, blocked, focus };
}

function updateTrendMemory(input = {}) {
  const memoryPath = trendMemoryPath(input);
  const memory = readTrendMemory(memoryPath);
  const inferred = inferPreferenceFromMessage(input.message || input.feedback || '');
  const preferredDirections = cleanList([
    ...memory.preferredDirections,
    ...inferred.preferred,
    ...(input.preferredDirections || [])
  ]);
  const blockedDirections = cleanList([
    ...memory.blockedDirections,
    ...inferred.blocked,
    ...(input.blockedDirections || [])
  ]);
  const focusModes = cleanList([
    ...memory.focusModes,
    ...inferred.focus,
    ...(input.focusModes || [])
  ]);
  const note = String(input.message || input.feedback || '').trim();
  const notes = appendNote(memory.notes, note);
  const next = {
    ...memory,
    version: defaultTrendMemory().version,
    preferredDirections,
    blockedDirections,
    focusModes,
    notes,
    updatedAt: new Date().toISOString()
  };
  writeJson(memoryPath, next);
  return { memoryPath, memory: next };
}

function topicMatches(topic, terms) {
  const text = `${topic.title || ''} ${topic.angle || ''} ${topic.evidence || ''}`;
  const domainTerms = ['抖音', '视频', '评论', '口播', '开头', '脚本', '账号', '表达', '钩子', '转化', '选题', '流量'];
  const candidates = cleanList(terms).flatMap(term => {
    const trimmed = String(term || '').replace(/(方向|选题|内容|话术|场景|趋势)$/u, '');
    return cleanList([
      term,
      trimmed,
      ...domainTerms.filter(domainTerm => String(term || '').includes(domainTerm))
    ]);
  });
  return candidates.some(term => text.includes(term));
}

function rankTopicsWithMemory(topics, memory) {
  const preferred = cleanList(memory.preferredDirections);
  const blocked = cleanList(memory.blockedDirections);
  return [...topics]
    .map((topic, originalIndex) => {
      let score = topics.length - originalIndex;
      if (topicMatches(topic, preferred)) score += 20;
      if (topicMatches(topic, blocked)) score -= 50;
      return { topic, score };
    })
    .sort((a, b) => b.score - a.score)
    .map(item => item.topic);
}

module.exports = {
  DEFAULT_MEMORY_FILE,
  trendMemoryPath,
  readTrendMemory,
  updateTrendMemory,
  rankTopicsWithMemory,
  cleanList
};