from __future__ import annotations

from sanic import response
from sqlalchemy import select
from datetime import datetime

from app.core.models.content_v3 import ContentIndexItem
from app.core.logger import make_log


async def s_api_v1_content_index(request):
    rows = (await request.ctx.db_session.execute(select(ContentIndexItem))).scalars().all()
    items = [{**r.payload, "encrypted_cid": r.encrypted_cid, "sig": r.sig, "_updated_at": (r.updated_at.isoformat() + 'Z') if r.updated_at else None} for r in rows]
    # ETag by max updated_at + count
    max_ts = max((it.get("_updated_at") for it in items if it.get("_updated_at")), default="1970-01-01T00:00:00Z")
    etag = f'W/"{max_ts}.{len(items)}"'
    inm = request.headers.get('If-None-Match')
    if inm and inm == etag:
        resp = response.empty(status=304)
        resp.headers['ETag'] = etag
        return resp
    for it in items:
        it.pop("_updated_at", None)
    make_log("content.index", f"items={len(items)} etag={etag}")
    resp = response.json({"items": items, "schema": "my-network/index@1"})
    resp.headers['ETag'] = etag
    return resp


async def s_api_v1_content_delta(request):
    since = request.args.get('since')
    if not since:
        # No since provided → act as full index
        return await s_api_v1_content_index(request)
    try:
        # basic parse
        _ = datetime.fromisoformat(since.replace('Z', '+00:00'))
    except Exception:
        return response.json({"error": "BAD_SINCE"}, status=400)

    rows = (await request.ctx.db_session.execute(select(ContentIndexItem))).scalars().all()
    out = []
    max_ts = since
    for r in rows:
        upd = (r.updated_at.isoformat() + 'Z') if r.updated_at else None
        if upd and upd > since:
            out.append({**r.payload, "encrypted_cid": r.encrypted_cid, "sig": r.sig})
            if upd > max_ts:
                max_ts = upd
    resp = response.json({"items": out, "next_since": max_ts, "schema": "my-network/index@1"})
    # Weak ETag for delta response
    resp.headers['ETag'] = f'W/"{max_ts}.{len(out)}"'
    return resp