feat(dedup): implement two-stage duplicate detection and content rewriter

This commit is contained in:
mamad
2026-08-27 19:53:34 +03:30
parent 4e6b3eca6f
commit d823a3749a
4 changed files with 286 additions and 0 deletions
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import hashlib
import re
from typing import Optional
def normalize_text(text: Optional[str]) -> str:
"""Normalize text by removing URLs, telegram handles, hashtags, excessive punctuation/whitespace, and lowercasing."""
if not text:
return ""
# Remove URLs
text = re.sub(r'https?://\S+|www\.\S+', '', text)
# Remove Telegram @mentions / hashtags
text = re.sub(r'[@#]\w+', '', text)
# Normalize punctuation and whitespace
text = re.sub(r'[^\w\s]', ' ', text)
text = re.sub(r'\s+', ' ', text)
return text.strip().lower()
def compute_content_hash(text: Optional[str], media_hash: Optional[str] = None) -> Optional[str]:
"""Generate SHA256 hash from normalized text and/or media hash."""
norm_text = normalize_text(text)
if not norm_text and not media_hash:
return None
raw_key = f"{norm_text}|{media_hash or ''}"
return hashlib.sha256(raw_key.encode('utf-8')).hexdigest()
def compute_file_hash(file_path: str) -> Optional[str]:
"""Generate SHA256 hash of a media file."""
try:
hasher = hashlib.sha256()
with open(file_path, 'rb') as f:
while chunk := f.read(65536):
hasher.update(chunk)
return hasher.hexdigest()
except Exception:
return None
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import os
import json
import time
import httpx
import logging
from typing import Dict, Any, Optional
from core.metrics import AI_REQUESTS_TOTAL, AI_LATENCY_SECONDS
logger = logging.getLogger(__name__)
class LLMClient:
def __init__(
self,
provider: Optional[str] = None,
api_key: Optional[str] = None,
model: Optional[str] = None,
base_url: Optional[str] = None,
):
self.provider = provider or os.getenv("AI_PROVIDER", "gemini").lower()
self.api_key = api_key or os.getenv("AI_API_KEY", "")
self.model = model or os.getenv("AI_MODEL", "gemini-1.5-flash" if self.provider == "gemini" else "gpt-4o-mini")
self.base_url = base_url or os.getenv("AI_BASE_URL")
async def generate_json(self, prompt: str, system_prompt: Optional[str] = None, action_name: str = "general") -> Dict[str, Any]:
"""Send prompt to LLM and parse JSON response."""
start_time = time.time()
status = "error"
try:
if self.provider == "gemini":
result = await self._call_gemini(prompt, system_prompt)
else:
result = await self._call_openai(prompt, system_prompt)
status = "success"
return result
except Exception as e:
logger.error(f"LLM generation failed ({self.provider}/{self.model}): {e}")
raise
finally:
duration = time.time() - start_time
AI_LATENCY_SECONDS.labels(action=action_name).observe(duration)
AI_REQUESTS_TOTAL.labels(action=action_name, status=status).inc()
async def _call_gemini(self, prompt: str, system_prompt: Optional[str] = None) -> Dict[str, Any]:
url = f"https://generativelanguage.googleapis.com/v1beta/models/{self.model}:generateContent?key={self.api_key}"
payload: Dict[str, Any] = {
"contents": [
{
"parts": [{"text": prompt}]
}
],
"generationConfig": {
"responseMimeType": "application/json",
"temperature": 0.2,
}
}
if system_prompt:
payload["systemInstruction"] = {
"parts": [{"text": system_prompt}]
}
async with httpx.AsyncClient(timeout=60.0) as client:
resp = await client.post(url, json=payload)
resp.raise_for_status()
data = resp.json()
raw_text = data["candidates"][0]["content"]["parts"][0]["text"]
return json.loads(raw_text)
async def _call_openai(self, prompt: str, system_prompt: Optional[str] = None) -> Dict[str, Any]:
url = self.base_url or "https://api.openai.com/v1/chat/completions"
headers = {
"Authorization": f"Bearer {self.api_key}",
"Content-Type": "application/json"
}
messages = []
if system_prompt:
messages.append({"role": "system", "content": system_prompt})
messages.append({"role": "user", "content": prompt})
payload = {
"model": self.model,
"messages": messages,
"response_format": {"type": "json_object"},
"temperature": 0.2,
}
async with httpx.AsyncClient(timeout=60.0) as client:
resp = await client.post(url, headers=headers, json=payload)
resp.raise_for_status()
data = resp.json()
content = data["choices"][0]["message"]["content"]
return json.loads(content)
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import logging
from typing import List, Optional, Dict, Any
from db.models import Post, TargetChannel
from db.repository import Repository
from core.llm import LLMClient
from core.dedup import compute_content_hash
from core.metrics import DUPLICATES_DETECTED_TOTAL
logger = logging.getLogger(__name__)
TAG_EXTRACTION_SYSTEM_PROMPT = """
You are an AI news analyst and classifier.
Given a social media/channel post, extract:
1. "subject": A brief, specific headline/subject (3-8 words).
2. "tags": A JSON array of 3 to 6 lowercase keywords/topics/entities (e.g. ["ai", "nvidia", "gpus", "hardware"]).
Respond ONLY in JSON format:
{
"subject": "...",
"tags": ["tag1", "tag2", "tag3"]
}
"""
DUPLICATE_CHECK_SYSTEM_PROMPT = """
You are an expert news editor checking for duplicate news stories.
Given a NEW POST and a list of PREVIOUS POSTS, determine if the NEW POST is covering the same exact event, news item, or story as any of the previous posts.
Respond ONLY in JSON format:
{
"is_duplicate": true/false,
"duplicate_of_id": <id of matched previous post or null>,
"similarity_reason": "<short explanation of why it is or is not a duplicate>"
}
"""
POST_REWRITE_SYSTEM_PROMPT = """
You are an expert Telegram content creator and copywriter.
Rewrite the provided post to make it engaging, well-formatted, professional, and clear.
Use appropriate emojis, clear paragraphs, and markdown formatting.
Remove any original promotional links, author credits, or watermarks.
Respond ONLY in JSON format:
{
"ai_text": "...",
"suggested_target_id": <optional id of best matching target channel or null>
}
"""
class AIProcessor:
def __init__(self, repo: Repository, llm: Optional[LLMClient] = None):
self.repo = repo
self.llm = llm or LLMClient()
async def process_post(self, post_id: int) -> Optional[Post]:
post = await self.repo.get_post_by_id(post_id)
if not post or not post.raw_text:
return post
raw_text = post.raw_text
is_dup = False
dup_of_id = None
sim_reason = None
# 1. Exact hash duplicate check
content_hash = post.content_hash or compute_content_hash(raw_text)
if content_hash:
exact_dup = await self.repo.find_duplicate_post_by_hash(content_hash)
if exact_dup and exact_dup.id != post.id:
is_dup = True
dup_of_id = exact_dup.id
sim_reason = "Exact match on normalized text/media hash"
DUPLICATES_DETECTED_TOTAL.labels(method="hash").inc()
# 2. Extract Tags and Subject via AI
tags = []
subject = "General News"
try:
tag_res = await self.llm.generate_json(
prompt=f"Post content:\n\n{raw_text}",
system_prompt=TAG_EXTRACTION_SYSTEM_PROMPT,
action_name="extract_tags"
)
subject = tag_res.get("subject", subject)
tags = [t.lower().strip() for t in tag_res.get("tags", []) if isinstance(t, str)]
await self.repo.update_post_tags(post.id, tags, subject)
except Exception as e:
logger.error(f"Tag extraction failed for post {post.id}: {e}")
# 3. Candidate search & Semantic AI Deduplication check (if not already exact dup)
if not is_dup and tags:
candidates = await self.repo.find_candidate_posts_by_tags(tags, exclude_post_id=post.id, hours_lookback=72, limit=5)
if candidates:
cand_texts = "\n---\n".join([f"ID {c.id} (Subject: {c.subject}):\n{c.raw_text}" for c in candidates if c.raw_text])
prompt = f"NEW POST:\n{raw_text}\n\nPREVIOUS CANDIDATE POSTS:\n{cand_texts}"
try:
dup_res = await self.llm.generate_json(
prompt=prompt,
system_prompt=DUPLICATE_CHECK_SYSTEM_PROMPT,
action_name="check_duplicate"
)
if dup_res.get("is_duplicate"):
is_dup = True
dup_of_id = dup_res.get("duplicate_of_id")
sim_reason = dup_res.get("similarity_reason", "AI detected duplicate news topic")
DUPLICATES_DETECTED_TOTAL.labels(method="ai_semantic").inc()
except Exception as e:
logger.error(f"Semantic duplicate check failed for post {post.id}: {e}")
# 4. Rewrite post for our channels
ai_text = raw_text
suggested_target_id = None
targets = await self.repo.get_active_targets()
target_info = "\n".join([f"Target ID {t.id}: {t.title} (@{t.username or 'none'})" for t in targets])
rewrite_prompt = f"TARGET CHANNELS AVAILABLE:\n{target_info or 'None'}\n\nORIGINAL POST:\n{raw_text}"
try:
rewrite_res = await self.llm.generate_json(
prompt=rewrite_prompt,
system_prompt=POST_REWRITE_SYSTEM_PROMPT,
action_name="rewrite_post"
)
ai_text = rewrite_res.get("ai_text", raw_text)
suggested_target_id = rewrite_res.get("suggested_target_id")
except Exception as e:
logger.error(f"Post rewrite failed for post {post.id}: {e}")
# 5. Save AI results into database
await self.repo.update_ai_result(
post_id=post.id,
subject=subject,
ai_text=ai_text,
tags=tags,
suggested_target_id=suggested_target_id,
is_duplicate=is_dup,
duplicate_of_id=dup_of_id,
similarity_reason=sim_reason,
)
return await self.repo.get_post_by_id(post.id)
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from core.dedup import normalize_text, compute_content_hash
def test_normalize_text():
raw = " Check out this link: https://t.me/example! @admin #tech news... "
norm = normalize_text(raw)
assert "https" not in norm
assert "admin" not in norm
assert "tech" not in norm
assert norm == "check out this link news"
def test_content_hash():
text1 = "Breaking News: Bitcoin hits $100k! Check https://example.com"
text2 = "Breaking News: Bitcoin hits $100k! Check https://other.com"
hash1 = compute_content_hash(text1)
hash2 = compute_content_hash(text2)
# Both normalize to the same text after link removal
assert hash1 == hash2
if __name__ == "__main__":
test_normalize_text()
test_content_hash()
print("All deduplication unit tests passed!")