import os
import logging
from datetime import datetime, timedelta, timezone
import aiosqlite
import httpx
from db import DB_PATH

log = logging.getLogger(__name__)

API_KEY = os.environ.get("ANTHROPIC_API_KEY", "")
BASE_URL = os.environ.get("ANTHROPIC_BASE_URL", "https://www.bytecatcode.org")
MODEL = "claude-haiku-4-5-20251001"
CST = timezone(timedelta(hours=8))

PROMPT = """You are a chat group digest assistant. Summarize the following chat messages into a concise daily digest.

Rules:
- Group by topic/theme, not by chat group
- Highlight key decisions, shared links, and action items
- Skip greetings, small talk, and low-value chatter
- Use markdown formatting
- Write in the same language as the messages (likely Chinese)
- Be concise

Messages:
{messages}"""

async def summarize(date_str: str = None):
    now = datetime.now(CST)
    if not date_str:
        date_str = now.strftime("%Y-%m-%d")

    start = datetime.strptime(date_str, "%Y-%m-%d").replace(tzinfo=CST)
    end = start + timedelta(days=1)

    async with aiosqlite.connect(DB_PATH) as db:
        cursor = await db.execute(
            "SELECT group_name, sender_name, text, timestamp FROM messages WHERE timestamp >= ? AND timestamp < ? ORDER BY timestamp",
            (start.isoformat(), end.isoformat())
        )
        rows = await cursor.fetchall()

    if not rows:
        log.info("No messages for %s, skipping summary", date_str)
        return None

    # Format messages for the prompt
    formatted = []
    for group_name, sender, text, ts in rows:
        formatted.append(f"[{group_name}] {sender}: {text}")
    messages_text = "\n".join(formatted)

    # Call Claude API
    async with httpx.AsyncClient(timeout=120) as client:
        resp = await client.post(
            f"{BASE_URL}/v1/messages",
            headers={"x-api-key": API_KEY, "anthropic-version": "2023-06-01", "content-type": "application/json"},
            json={
                "model": MODEL,
                "max_tokens": 4096,
                "messages": [{"role": "user", "content": PROMPT.format(messages=messages_text)}]
            }
        )
        resp.raise_for_status()
        data = resp.json()
        summary = data["content"][0]["text"]

    # Store summary
    async with aiosqlite.connect(DB_PATH) as db:
        await db.execute(
            "INSERT OR REPLACE INTO summaries (date, content, created_at) VALUES (?,?,?)",
            (date_str, summary, now.isoformat())
        )
        await db.commit()

    log.info("Generated summary for %s (%d messages)", date_str, len(rows))
    return summary