"""
database.py — Firebase Realtime Database backend for MechanicGo
Uses Firebase REST API directly (no MySQL, no IP whitelisting needed)
"""

import os, hashlib, datetime
import requests as http
from dotenv import load_dotenv

load_dotenv()

FIREBASE_URL = os.getenv(
    "FIREBASE_DATABASE_URL",
    "https://mechanic-go-e3f05-default-rtdb.firebaseio.com"
)

# ─── Low-level REST helpers ───────────────────────────────────────────────────

def _url(path):
    return f"{FIREBASE_URL}/{path}.json"

def fb_get(path):
    """GET a node. Returns dict/list/scalar or None."""
    r = http.get(_url(path), timeout=10)
    r.raise_for_status()
    return r.json()

def fb_set(path, data):
    """PUT (overwrite) a node."""
    r = http.put(_url(path), json=data, timeout=10)
    r.raise_for_status()
    return r.json()

def fb_push(path, data):
    """POST to auto-generate a Firebase key. Returns the new key string."""
    r = http.post(_url(path), json=data, timeout=10)
    r.raise_for_status()
    return r.json().get("name")   # Firebase returns {"name": "-NxABC..."}

def fb_patch(path, data):
    """PATCH (merge-update) a node."""
    r = http.patch(_url(path), json=data, timeout=10)
    r.raise_for_status()
    return r.json()

def fb_delete(path):
    """DELETE a node."""
    r = http.delete(_url(path), timeout=10)
    r.raise_for_status()

# ─── Structured helpers ───────────────────────────────────────────────────────

def fb_list(path):
    """Return list of dicts from a Firebase collection, each with '_id' key."""
    data = fb_get(path)
    if not data or not isinstance(data, dict):
        return []
    return [{"_id": k, **v} for k, v in data.items() if isinstance(v, dict)]

def fb_find_one(path, field, value):
    """Linear scan to find first item where field == value."""
    for item in fb_list(path):
        if item.get(field) == value:
            return item
    return None

def fb_find_one_by_id(path, key):
    """Get a single item by its Firebase key."""
    data = fb_get(f"{path}/{key}")
    if not data:
        return None
    return {"_id": key, **data}

# ─── Init — seeds admin account ───────────────────────────────────────────────

def init_db():
    try:
        existing = fb_find_one("users", "email", "admin@mechanicgo.com")
        if not existing:
            pw = hashlib.sha256("admin123".encode()).hexdigest()
            fb_push("users", {
                "name":          "Admin",
                "email":         "admin@mechanicgo.com",
                "password_hash": pw,
                "role":          "admin",
                "phone":         "",
                "is_active":     True,
                "created_at":    datetime.datetime.utcnow().isoformat()
            })
            print("✅ Default admin seeded  →  admin@mechanicgo.com / admin123")
        else:
            print("✅ Firebase Realtime DB connected")
    except Exception as e:
        print(f"⚠️  Firebase init warning: {e}")
        print("   Make sure FIREBASE_DATABASE_URL is correct and DB rules allow read/write")

def get_db():
    raise RuntimeError("MySQL removed. Use fb_* helpers from database.py directly.")