import asyncio
import json
import os
from contextlib import suppress
from typing import List

from fastapi import BackgroundTasks, Depends, FastAPI, HTTPException, Request
from fastapi.responses import HTMLResponse, RedirectResponse
from fastapi.staticfiles import StaticFiles
from fastapi.templating import Jinja2Templates
from sqlalchemy.orm import Session

from ai import analyze_thread
from alerts import process_alerts
from database import (
    Message,
    SessionLocal,
    Thread,
    create_db_tables,
    get_thread_messages,
    ingest_emails,
)
from zoho_client import ZohoClient


def get_db():
    db = SessionLocal()
    try:
        yield db
    finally:
        db.close()


create_db_tables()
app = FastAPI(title="Email Alerts UI")

# Static and templates
os.makedirs("templates", exist_ok=True)
os.makedirs("static", exist_ok=True)
templates = Jinja2Templates(directory="templates")
app.mount("/static", StaticFiles(directory="static"), name="static")


@app.get("/", response_class=HTMLResponse)
def home(request: Request, db: Session = Depends(get_db), account: str | None = None):
    q = db.query(Thread).order_by(Thread.updated_at.desc())
    if account:
        q = q.filter(Thread.account_email == account.lower())
    threads = q.limit(100).all()
    return templates.TemplateResponse(
        "threads.html",
        {
            "request": request,
            "threads": threads,
            "account": account or "",
            "status": _status_for_templates(),
        },
    )


@app.get("/thread/{thread_id}", response_class=HTMLResponse)
def show_thread(thread_id: int, request: Request, db: Session = Depends(get_db)):
    thread = db.query(Thread).filter(Thread.id == thread_id).one_or_none()
    if not thread:
        raise HTTPException(status_code=404, detail="Thread not found")
    messages: List[Message] = get_thread_messages(db, thread_id)
    # Convert for AI analyzer and template
    msg_dicts = [
        {
            "id": m.id,
            "date_sent": m.date_sent,
            "subject": m.subject,
            "from_email": m.from_email,
            "to_email": m.to_email,
            "body": m.body,
            "is_incoming": m.is_incoming,
        }
        for m in messages
    ]
    ai = analyze_thread(thread.subject or "", msg_dicts)
    # Save AI info on the thread for listing and downstream alerts
    try:
        from datetime import datetime, timezone

        thread.actionable = bool(ai.get("actionable", False))
        thread.ai_summary = ai.get("summary")
        thread.ai_confidence = ai.get("confidence")
        thread.last_analyzed_at = datetime.now(timezone.utc)
        db.commit()
    except Exception:
        pass
    return templates.TemplateResponse(
        "thread_detail.html",
        {
            "request": request,
            "thread": thread,
            "messages": messages,
            "ai": ai,
            "status": _status_for_templates(),
        },
    )


@app.get("/health")
def health():
    return {"status": "ok"}


# ---------------------
# Config editor routes
# ---------------------

CONFIG_PATH = os.path.join(os.path.dirname(__file__), "config.json")


def load_config() -> dict:
    if not os.path.exists(CONFIG_PATH):
        return {
            "email_address": "",
            "time_frames": [
                {"name": "1-24 hours", "hours": 24, "alert_level": 1},
                {"name": "24-48 hours", "hours": 48, "alert_level": 2},
                {"name": "48+ hours", "hours": 72, "alert_level": 3},
            ],
            "email_days_back": 7,
            "agency_domains": [],
            "zoho_email": "",
            "zoho_app_password": "",
            "whatsapp_to": "",
            "auto_process": False,
            "auto_process_interval": 30,
            # Sync status
            "sync_in_progress": False,
            "last_sync_at": None,
            "last_sync_count": 0,
            "last_sync_status": "idle",
            "last_sync_error": None,
        }
    with open(CONFIG_PATH, "r", encoding="utf-8") as f:
        return json.load(f)


def save_config(cfg: dict) -> None:
    with open(CONFIG_PATH, "w", encoding="utf-8") as f:
        json.dump(cfg, f, indent=2, ensure_ascii=False)


def _status_for_templates() -> dict:
    cfg = load_config()
    return {
        "auto_process": bool(cfg.get("auto_process")),
        "interval": int(cfg.get("auto_process_interval", 30) or 30),
        "sync_in_progress": bool(cfg.get("sync_in_progress")),
        "last_sync_at": cfg.get("last_sync_at"),
        "last_sync_status": cfg.get("last_sync_status", "idle"),
        "last_sync_count": int(cfg.get("last_sync_count") or 0),
        "last_sync_error": cfg.get("last_sync_error"),
    }


@app.get("/config", response_class=HTMLResponse)
def config_form(request: Request, saved: int | None = None):
    cfg = load_config()
    # Render up to existing frames or at least 3 rows
    frames = cfg.get("time_frames") or []
    min_rows = max(len(frames), 3)
    return templates.TemplateResponse(
        "config.html",
        {
            "request": request,
            "cfg": cfg,
            "rows": list(range(min_rows)),
            "saved": bool(saved),
            "status": _status_for_templates(),
        },
    )


@app.post("/config")
async def config_save(request: Request):
    form = await request.form()
    cfg = load_config()

    # Basic fields
    cfg["email_address"] = (form.get("email_address") or "").strip()
    # email_days_back
    try:
        cfg["email_days_back"] = int(
            form.get("email_days_back") or cfg.get("email_days_back", 7)
        )
    except Exception:
        cfg["email_days_back"] = 7
    # agency domains (comma or newline separated)
    domains_raw = (form.get("agency_domains") or "").replace("\r", "")
    parts = [p.strip() for p in domains_raw.replace(",", "\n").split("\n") if p.strip()]
    cfg["agency_domains"] = parts
    # auto_process
    cfg["auto_process"] = form.get("auto_process") == "on"
    # auto_process_interval
    try:
        cfg["auto_process_interval"] = int(
            form.get("auto_process_interval") or cfg.get("auto_process_interval", 30)
        )
    except Exception:
        cfg["auto_process_interval"] = 30

    # Zoho (optional - note: current client reads env vars)
    cfg["zoho_email"] = (form.get("zoho_email") or cfg.get("zoho_email", "")).strip()
    cfg["zoho_app_password"] = (
        form.get("zoho_app_password") or cfg.get("zoho_app_password", "")
    ).strip()
    # WhatsApp destination
    cfg["whatsapp_to"] = (form.get("whatsapp_to") or cfg.get("whatsapp_to", "")).strip()

    # Time frames: collect indexed rows
    frames: list[dict] = []
    # find indices present
    indices = set()
    for k in form.keys():
        if k.startswith("time_name_"):
            try:
                indices.add(int(k.split("_")[-1]))
            except Exception:
                pass
    for i in sorted(indices):
        name = (form.get(f"time_name_{i}") or "").strip()
        hrs_raw = form.get(f"time_hours_{i}") or ""
        lvl_raw = form.get(f"time_alert_{i}") or ""
        if not name and not hrs_raw and not lvl_raw:
            continue
        try:
            hours = int(hrs_raw)
        except Exception:
            hours = 0
        try:
            level = int(lvl_raw)
        except Exception:
            level = 0
        if name:
            frames.append({"name": name, "hours": hours, "alert_level": level})
    if frames:
        cfg["time_frames"] = frames

    save_config(cfg)
    return RedirectResponse(url="/config?saved=1", status_code=303)


@app.post("/process")
def process(db: Session = Depends(get_db)):
    cfg = load_config()
    alerted = process_alerts(db, cfg)
    return {"alerted_threads": alerted}


def _sync_emails_once(cfg: dict) -> int:
    """Fetch INBOX and Sent from Zoho and ingest into DB. Returns threads requiring reply count."""
    from datetime import datetime, timezone

    # Mark status
    cfg["sync_in_progress"] = True
    cfg["last_sync_status"] = "running"
    cfg["last_sync_error"] = None
    save_config(cfg)

    account_email = cfg.get("email_address") or cfg.get("zoho_email") or ""
    if not account_email:
        cfg.update(
            {
                "last_sync_status": "error",
                "last_sync_error": "Configure email_address or zoho_email in /config",
                "sync_in_progress": False,
            }
        )
        save_config(cfg)
        raise HTTPException(
            status_code=400, detail="Configure email_address or zoho_email in /config"
        )

    # Incremental lookback by last_sync_at
    days_back = int(cfg.get("email_days_back", 7) or 7)
    last_sync_at = cfg.get("last_sync_at")
    if last_sync_at:
        try:
            last_dt = datetime.fromisoformat(last_sync_at)
            now = datetime.now(timezone.utc)
            delta_days = int(((now - last_dt).total_seconds() + 86399) // 86400)
            days_back = max(1, delta_days)
        except Exception:
            pass
    max_results = 100
    client = ZohoClient(
        email=cfg.get("zoho_email") or account_email,
        app_password=cfg.get("zoho_app_password"),
    )
    try:
        inbox = client.fetch_folder_emails(
            folder="INBOX", max_results=max_results, days_back=days_back
        )
        sent = client.fetch_folder_emails(
            folder="Sent", max_results=max_results, days_back=days_back
        )
    finally:
        client.close()

    db = SessionLocal()
    try:
        ingest_emails(
            db, account_email=account_email, emails=inbox, default_folder="INBOX"
        )
        ingest_emails(
            db, account_email=account_email, emails=sent, default_folder="Sent"
        )
        # Update sync completion status and metrics
        cfg.update(
            {
                "last_sync_at": datetime.now(timezone.utc).isoformat(),
                "last_sync_status": "ok",
                "last_sync_error": None,
                "last_sync_count": int(
                    (len(inbox) if inbox else 0) + (len(sent) if sent else 0)
                ),
                "sync_in_progress": False,
            }
        )
        save_config(cfg)
        return count
    except Exception as e:
        # Update error status
        cfg.update(
            {
                "last_sync_status": "error",
                "last_sync_error": str(e),
                "sync_in_progress": False,
            }
        )
        save_config(cfg)
        raise
    finally:
        db.close()


@app.post("/sync_emails")
def sync_emails(background_tasks: BackgroundTasks):
    cfg = load_config()
    if cfg.get("sync_in_progress"):
        return RedirectResponse(url="/?sync=busy", status_code=303)

    def _background_sync():
        try:
            _sync_emails_once(load_config())
        except Exception:
            # Error handling is done inside _sync_emails_once
            pass

    # Mark as starting and add background task
    cfg["sync_in_progress"] = True
    cfg["last_sync_status"] = "running"
    cfg["last_sync_error"] = None
    save_config(cfg)

    background_tasks.add_task(_background_sync)
    return RedirectResponse(url="/?sync=started", status_code=303)


# ---------------------
# Auto-processing loop
# ---------------------
_auto_task = None
_stop_event = asyncio.Event()


async def _auto_runner():
    # Delay a bit on startup
    await asyncio.sleep(2)
    while not _stop_event.is_set():
        cfg = load_config()
        interval_min = int(cfg.get("auto_process_interval", 30) or 30)
        if cfg.get("auto_process"):
            # Sync emails then run alerts
            try:
                if not cfg.get("sync_in_progress"):
                    _sync_emails_once(cfg)
            except Exception:
                # keep loop alive
                pass
            db = SessionLocal()
            try:
                process_alerts(db, cfg)
            finally:
                db.close()
        try:
            await asyncio.wait_for(
                _stop_event.wait(), timeout=max(5, interval_min * 60)
            )
        except asyncio.TimeoutError:
            continue


@app.on_event("startup")
async def on_startup():
    global _auto_task
    _stop_event.clear()
    _auto_task = asyncio.create_task(_auto_runner())


@app.on_event("shutdown")
async def on_shutdown():
    if _auto_task:
        _stop_event.set()
        with suppress(Exception):
            await _auto_task