import asyncio
from loguru import logger
from sqlalchemy.orm import Session

from app.models.database import SessionLocal, ProcessedEmail
from app.services.gmail_servise import (
    get_gmail_service,
    fetch_unread_emails,
    is_no_reply_sender,
    is_job_alert_email,
    send_email,
    save_draft,
    mark_as_read,
)
from app.services.ai_servise import analyze_email, generate_reply
from config import POLL_INTERVAL


def already_processed(db: Session, email_id: str) -> bool:
    return db.query(ProcessedEmail).filter(ProcessedEmail.email_id == email_id).first() is not None


def save_to_db(db: Session, email: dict, analysis: dict, action: str, reply_sent: bool, notes: str = ""):
    record = ProcessedEmail(
        email_id     = email["id"],
        sender       = email["sender"],
        subject      = email["subject"],
        category     = analysis.get("category", "Other"),
        priority     = analysis.get("priority", "Low"),
        action_taken = action,
        reply_sent   = reply_sent,
        notes        = notes,
    )
    db.add(record)
    db.commit()


def decide_and_act(service, db: Session, email: dict):
    """
    Core decision engine:

    SKIP if:
      - already processed
      - Gmail flagged as spam/promo
      - sender is noreply/automated
      - email is a job alert/digest

    ANALYZE with AI:
      - If AI says spam → skip
      - If AI says no reply needed → skip
      - If HIGH priority → auto send reply
      - Otherwise → save as draft
    """
    email_id = email["id"]
    sender   = email["sender"]
    subject  = email["subject"]

    # ── Guard 1: Already processed ────────────────────────────────────────────
    if already_processed(db, email_id):
        logger.debug(f"⏭  Already processed: {subject}")
        return

    # ── Guard 2: Gmail spam/promo label ──────────────────────────────────────
    if email["is_spam"]:
        logger.info(f"🚫 Gmail flagged as spam/promo: {subject}")
        save_to_db(db, email, {"category": "Spam", "priority": "Low"}, "skipped", False, "Gmail spam/promo label")
        mark_as_read(service, email_id)
        return

    # ── Guard 3: No-reply sender ──────────────────────────────────────────────
    if is_no_reply_sender(sender):
        logger.info(f"🚫 No-reply sender detected: {sender}")
        save_to_db(db, email, {"category": "Automated", "priority": "Low"}, "skipped", False, "No-reply sender")
        mark_as_read(service, email_id)
        return

    # ── Guard 4: Job alert / digest ───────────────────────────────────────────
    if is_job_alert_email(sender, subject):
        logger.info(f"📋 Job alert email, skipping reply: {subject}")
        save_to_db(db, email, {"category": "Job Alert", "priority": "Low"}, "skipped", False, "Job alert digest")
        mark_as_read(service, email_id)
        return

    # ── AI Analysis ───────────────────────────────────────────────────────────
    analysis = analyze_email(sender, subject, email["body"])

    if analysis.get("is_spam"):
        logger.info(f"🤖 AI flagged as spam: {subject}")
        save_to_db(db, email, analysis, "skipped", False, "AI detected spam")
        mark_as_read(service, email_id)
        return

    if not analysis.get("requires_reply", False):
        logger.info(f"📭 No reply needed: {subject} ({analysis.get('reason', '')})")
        save_to_db(db, email, analysis, "skipped", False, analysis.get("reason", ""))
        mark_as_read(service, email_id)
        return

    # ── Generate reply ────────────────────────────────────────────────────────
    reply_body = generate_reply(sender, subject, email["body"])
    if not reply_body:
        logger.warning(f"⚠️  Could not generate reply for: {subject}")
        save_to_db(db, email, analysis, "skipped", False, "Reply generation failed")
        return

    # ── HIGH priority → Auto send ─────────────────────────────────────────────
    if analysis.get("priority") == "High":
        sent = send_email(service, sender, subject, reply_body)
        action = "auto_sent" if sent else "send_failed"
        save_to_db(db, email, analysis, action, sent, "Auto-sent: high priority")
        mark_as_read(service, email_id)

    # ── Medium/Low → Save as draft ────────────────────────────────────────────
    else:
        save_draft(service, sender, subject, reply_body)
        save_to_db(db, email, analysis, "draft_saved", False, "Draft saved: medium/low priority")
        mark_as_read(service, email_id)


async def email_loop():
    logger.info("🚀 Email worker started")
    service = get_gmail_service()

    while True:
        try:
            logger.info("📬 Checking Gmail for new emails...")
            db = SessionLocal()
            emails = fetch_unread_emails(service, max_results=10)
            logger.info(f"📩 Found {len(emails)} unread emails")

            for email in emails:
                decide_and_act(service, db, email)

            db.close()

        except Exception as e:
            logger.error(f"💥 Worker error: {e}")

        await asyncio.sleep(POLL_INTERVAL)