Add Reddit monitoring bot — backend, frontend, and Docker config

Python/FastAPI backend with PostgreSQL for collecting Reddit data via
public .json endpoints. React/Vite dashboard for analytics. Docker Compose
setup with API and worker services connecting to shared PostgreSQL.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

backend/services/post_service.py

@@ -0,0 +1,102 @@
+from datetime import datetime
+from sqlalchemy import select, func
+from sqlalchemy.ext.asyncio import AsyncSession
+from sqlalchemy.orm import joinedload
+
+from backend.models.post import Post
+from backend.models.subreddit import MonitoredSubreddit
+from backend.models.author import Author
+from backend.models.comment import Comment
+
+
+async def list_posts(
+    db: AsyncSession,
+    subreddit_id: int | None = None,
+    author: str | None = None,
+    flair: str | None = None,
+    sort_by: str = "created_utc",
+    sort_order: str = "desc",
+    since: datetime | None = None,
+    until: datetime | None = None,
+    page: int = 1,
+    per_page: int = 25,
+) -> tuple[list[dict], int]:
+    base = select(Post, MonitoredSubreddit.name, Author.username).join(
+        MonitoredSubreddit
+    ).outerjoin(Author)
+
+    filters = []
+    if subreddit_id:
+        filters.append(Post.subreddit_id == subreddit_id)
+    if flair:
+        filters.append(Post.flair == flair)
+    if since:
+        filters.append(Post.created_utc >= since)
+    if until:
+        filters.append(Post.created_utc <= until)
+    if author:
+        filters.append(Author.username == author)
+
+    if filters:
+        base = base.where(*filters)
+
+    # Count
+    count_stmt = select(func.count()).select_from(base.subquery())
+    total = (await db.execute(count_stmt)).scalar() or 0
+
+    # Sort
+    sort_col = getattr(Post, sort_by, Post.created_utc)
+    if sort_order == "asc":
+        base = base.order_by(sort_col.asc())
+    else:
+        base = base.order_by(sort_col.desc())
+
+    # Paginate
+    base = base.offset((page - 1) * per_page).limit(per_page)
+
+    result = await db.execute(base)
+    rows = result.all()
+
+    posts = []
+    for post, sub_name, author_name in rows:
+        data = {c.name: getattr(post, c.name) for c in post.__table__.columns}
+        data["subreddit_name"] = sub_name
+        data["author_name"] = author_name
+        posts.append(data)
+
+    return posts, total
+
+
+async def get_post(db: AsyncSession, post_id: int) -> dict | None:
+    stmt = (
+        select(Post, MonitoredSubreddit.name, Author.username)
+        .join(MonitoredSubreddit)
+        .outerjoin(Author)
+        .where(Post.id == post_id)
+    )
+    result = await db.execute(stmt)
+    row = result.first()
+    if not row:
+        return None
+
+    post, sub_name, author_name = row
+    data = {c.name: getattr(post, c.name) for c in post.__table__.columns}
+    data["subreddit_name"] = sub_name
+    data["author_name"] = author_name
+
+    # Get comments
+    comment_stmt = (
+        select(Comment, Author.username)
+        .outerjoin(Author)
+        .where(Comment.post_id == post_id)
+        .order_by(Comment.created_utc.asc())
+    )
+    comment_result = await db.execute(comment_stmt)
+    comments = []
+    for comment, c_author in comment_result.all():
+        c_data = {c.name: getattr(comment, c.name) for c in comment.__table__.columns}
+        c_data["author_name"] = c_author
+        comments.append(c_data)
+
+    data["comments"] = comments
+    return data