"""
appointment_tracker.py — CRUD + lifecycle for appointments.json
Each record is scoped to a care profile via profile_id.
"""
from __future__ import annotations
import json, os, uuid
from datetime import date, datetime, timedelta
from typing import Any, Dict, List, Optional

from config import APPOINTMENTS_JSON


def _default_recurrence() -> Dict[str, Any]:
    return {"frequency": "none", "interval": 1,
            "end_type": "never", "end_after": 1, "end_date": ""}


def _migrate(appt: Dict[str, Any]) -> Dict[str, Any]:
    if "recurrence" not in appt:
        rec = _default_recurrence()
        if appt.get("is_recurring"):
            rec["frequency"] = "weekly"
        appt["recurrence"] = rec
    if "status" not in appt:
        appt["status"] = "scheduled"
    if "completed_at" not in appt:
        appt["completed_at"] = ""
    return appt


def _load() -> List[Dict[str, Any]]:
    if APPOINTMENTS_JSON.exists():
        try:
            with open(APPOINTMENTS_JSON, "r", encoding="utf-8") as f:
                return [_migrate(a) for a in json.load(f)]
        except Exception:
            return []
    return []


def _save(appts: List[Dict[str, Any]]):
    APPOINTMENTS_JSON.parent.mkdir(parents=True, exist_ok=True)
    with open(APPOINTMENTS_JSON, "w", encoding="utf-8") as f:
        json.dump(appts, f, indent=2, ensure_ascii=False)
        f.flush()
        os.fsync(f.fileno())


def _now() -> str:
    return datetime.now().isoformat(timespec="seconds")

def _today_str() -> str:
    return date.today().isoformat()

def _days_until(date_str: str) -> int:
    try:
        return (date.fromisoformat(date_str) - date.today()).days
    except Exception:
        return 9999


def _for_profile(appts: List[Dict[str, Any]], profile_id: Optional[str]) -> List[Dict[str, Any]]:
    if not profile_id:
        return []
    return [a for a in appts if a.get("profile_id") == profile_id]


def _is_in_current_window(appt: Dict[str, Any]) -> bool:
    try:
        now = datetime.now()
        appt_date = date.fromisoformat(appt["date"])
        time_str = appt.get("time", "00:00").strip()
        try:
            appt_time = datetime.strptime(time_str[:8], "%I:%M %p").time()
        except ValueError:
            try:
                appt_time = datetime.strptime(time_str[:5], "%H:%M").time()
            except ValueError:
                appt_time = datetime.strptime("00:00", "%H:%M").time()
        appt_dt = datetime.combine(appt_date, appt_time)
        return appt_dt <= now <= (appt_dt + timedelta(hours=3))
    except Exception:
        return False


def run_lifecycle_check(profile_id: Optional[str] = None) -> int:
    appts = _load()
    count = 0
    for appt in appts:
        if profile_id and appt.get("profile_id") != profile_id:
            continue
        status = appt.get("status", "scheduled")
        if status == "scheduled" and _is_in_current_window(appt):
            appt["status"] = "current"
            count += 1
        elif status == "current" and not _is_in_current_window(appt):
            appt["status"] = "completed"
            appt["completed_at"] = _now()
            count += 1
    if count:
        _save(appts)
    return count


def add_appointment(
    title: str,
    appt_date: str,
    appt_time: str = "",
    location: str = "",
    notes: str = "",
    reminders: Optional[List[int]] = None,
    recurrence: Optional[Dict[str, Any]] = None,
    profile_id: str = "",
) -> Dict[str, Any]:
    if not profile_id:
        raise ValueError("No active care profile.")
    if not title.strip():
        raise ValueError("Appointment title is required.")
    if not appt_date.strip():
        raise ValueError("Appointment date is required.")
    try:
        date.fromisoformat(appt_date.strip())
    except ValueError:
        raise ValueError(f"Invalid date: {appt_date!r}. Use YYYY-MM-DD.")
    appt = {
        "id": str(uuid.uuid4()),
        "profile_id": profile_id,
        "title": title.strip(),
        "date": appt_date.strip(),
        "time": appt_time.strip(),
        "location": location.strip(),
        "notes": notes.strip(),
        "reminders": reminders or [],
        "recurrence": recurrence if recurrence is not None else _default_recurrence(),
        "status": "scheduled",
        "completed_at": "",
        "created_at": _now(),
        "updated_at": _now(),
    }
    appts = _load()
    appts.append(appt)
    _save(appts)
    return appt


def edit_appointment(
    appt_id: str,
    title: Optional[str] = None,
    appt_date: Optional[str] = None,
    appt_time: Optional[str] = None,
    location: Optional[str] = None,
    notes: Optional[str] = None,
    reminders: Optional[List[int]] = None,
    recurrence: Optional[Dict[str, Any]] = None,
) -> Optional[Dict[str, Any]]:
    appts = _load()
    for appt in appts:
        if appt["id"] == appt_id:
            if title      is not None: appt["title"]      = title.strip()
            if appt_date  is not None: appt["date"]       = appt_date.strip()
            if appt_time  is not None: appt["time"]       = appt_time.strip()
            if location   is not None: appt["location"]   = location.strip()
            if notes      is not None: appt["notes"]      = notes.strip()
            if reminders  is not None: appt["reminders"]  = reminders
            if recurrence is not None: appt["recurrence"] = recurrence
            appt["updated_at"] = _now()
            _save(appts)
            return appt
    return None


def complete_appointment(appt_id: str) -> bool:
    appts = _load()
    for appt in appts:
        if appt["id"] == appt_id:
            appt["status"] = "completed"
            appt["completed_at"] = _now()
            appt["updated_at"] = _now()
            _save(appts)
            return True
    return False


def delete_appointment(appt_id: str) -> bool:
    appts = _load()
    new_appts = [a for a in appts if a["id"] != appt_id]
    if len(new_appts) == len(appts):
        return False
    _save(new_appts)
    return True


def get_all_appointments(include_past: bool = False, profile_id: Optional[str] = None) -> List[Dict[str, Any]]:
    today = _today_str()
    appts = [a for a in _for_profile(_load(), profile_id) if a.get("status") != "completed"]
    if not include_past:
        appts = [a for a in appts if a.get("date", "") >= today]
    appts.sort(key=lambda a: (a.get("date", ""), a.get("time", "")))
    return appts


def get_completed_appointments(profile_id: Optional[str] = None) -> List[Dict[str, Any]]:
    appts = [a for a in _for_profile(_load(), profile_id) if a.get("status") == "completed"]
    appts.sort(key=lambda a: a.get("completed_at", ""), reverse=True)
    return appts


def has_conflicting_appointment(
    appt_date: str,
    appt_time: str,
    exclude_id: str = None,
    profile_id: Optional[str] = None,
) -> bool:
    for a in _for_profile(_load(), profile_id):
        if a.get("status") == "completed":
            continue
        if exclude_id and a.get("id") == exclude_id:
            continue
        if a.get("date") == appt_date and a.get("time") == appt_time:
            return True
    return False


def get_recent_completed(days: int = 30, profile_id: Optional[str] = None) -> List[Dict[str, Any]]:
    cutoff_dt = datetime.now() - timedelta(days=days)
    cutoff = cutoff_dt.isoformat(timespec="seconds")
    appts = [a for a in _for_profile(_load(), profile_id)
             if a.get("status") == "completed" and a.get("completed_at", "") >= cutoff]
    appts.sort(key=lambda a: a.get("completed_at", ""), reverse=True)
    return appts


def get_today(profile_id: Optional[str] = None) -> List[Dict[str, Any]]:
    today = _today_str()
    appts = [a for a in _for_profile(_load(), profile_id)
             if a.get("date", "") == today and a.get("status") != "completed"]
    appts.sort(key=lambda a: a.get("time", ""))
    return appts


def get_upcoming(profile_id: Optional[str] = None) -> List[Dict[str, Any]]:
    today = _today_str()
    appts = [a for a in _for_profile(_load(), profile_id)
             if a.get("date", "") >= today and a.get("status") != "completed"]
    appts.sort(key=lambda a: (a.get("date", ""), a.get("time", "")))
    return appts


def get_appointment_by_id(appt_id: str) -> Optional[Dict[str, Any]]:
    for a in _load():
        if a["id"] == appt_id:
            return a
    return None


def get_due_reminders(profile_id: Optional[str] = None) -> List[Dict[str, Any]]:
    results = []
    for appt in _for_profile(_load(), profile_id):
        if appt.get("status") == "completed":
            continue
        days = _days_until(appt.get("date", ""))
        if days >= 0 and days in appt.get("reminders", []):
            results.append({**appt, "days_until": days})
    return results


def delete_for_profile(profile_id: str) -> int:
    appts = _load()
    kept = [a for a in appts if a.get("profile_id") != profile_id]
    deleted = len(appts) - len(kept)
    if deleted:
        _save(kept)
    return deleted