"""
med_tracker.py — Medication CRUD with persistent JSON storage.
Each record is scoped to a care profile via profile_id.
"""

from __future__ import annotations

import json
import os
import uuid
from datetime import datetime
from typing import List, Dict, Any, Optional

from config import MEDICATIONS_JSON


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


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


def _new_id() -> str:
    return str(uuid.uuid4())


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


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


def add_medication(
    name: str,
    dosage: str = "",
    frequency: str = "",
    status: str = "current",
    side_effects: str = "",
    personal_notes: str = "",
    category: str = "",
    profile_id: str = "",
) -> Dict[str, Any]:
    """Add a new medication for profile_id. status: current | past."""
    if not profile_id:
        raise ValueError("No active care profile.")
    if not name.strip():
        raise ValueError("Medication name is required.")

    status = status if status in ("current", "past") else "current"

    med = {
        "id": _new_id(),
        "profile_id": profile_id,
        "name": name.strip(),
        "dosage": dosage.strip(),
        "frequency": frequency.strip(),
        "status": status,
        "side_effects": side_effects.strip(),
        "personal_notes": personal_notes.strip(),
        "category": category.strip(),
        "created_at": _now(),
        "updated_at": _now(),
    }

    meds = _load()
    meds.append(med)
    _save(meds)
    return med


def edit_medication(
    med_id: str,
    name: Optional[str] = None,
    dosage: Optional[str] = None,
    frequency: Optional[str] = None,
    status: Optional[str] = None,
    side_effects: Optional[str] = None,
    personal_notes: Optional[str] = None,
    category: Optional[str] = None,
) -> Optional[Dict[str, Any]]:
    meds = _load()
    for med in meds:
        if med["id"] == med_id:
            if name is not None:
                med["name"] = name.strip()
            if dosage is not None:
                med["dosage"] = dosage.strip()
            if frequency is not None:
                med["frequency"] = frequency.strip()
            if status is not None and status in ("current", "past"):
                med["status"] = status
            if side_effects is not None:
                med["side_effects"] = side_effects.strip()
            if personal_notes is not None:
                med["personal_notes"] = personal_notes.strip()
            if category is not None:
                med["category"] = category.strip()
            med["updated_at"] = _now()
            _save(meds)
            return med
    return None


def delete_medication(med_id: str) -> bool:
    meds = _load()
    new_meds = [m for m in meds if m["id"] != med_id]
    if len(new_meds) == len(meds):
        return False
    _save(new_meds)
    return True


def get_medications(filter: str = "all", profile_id: Optional[str] = None) -> List[Dict[str, Any]]:
    meds = _for_profile(_load(), profile_id)
    if filter in ("current", "past"):
        meds = [m for m in meds if m.get("status") == filter]
    return sorted(meds, key=lambda m: m.get("name", "").lower())


def get_medication_by_id(med_id: str) -> Optional[Dict[str, Any]]:
    for m in _load():
        if m["id"] == med_id:
            return m
    return None


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