"""OmniParse AI — Database layer. SQLite fallback + optional Supabase. All queries parameterized."""

import sqlite3, json, secrets as _secrets
from datetime import datetime, timezone
from config import SQLITE_PATH, USE_SUPABASE, SUPABASE_URL, SUPABASE_KEY

_sb = None

def _supabase():
    global _sb
    if _sb is None and USE_SUPABASE:
        try:
            from supabase import create_client as sc
            _sb = sc(SUPABASE_URL, SUPABASE_KEY)
        except Exception as e:
            print(f"[WARN] Supabase init failed: {e}")
            return None
    return _sb

def _sqlite():
    c = sqlite3.connect(SQLITE_PATH)
    c.row_factory = sqlite3.Row
    c.execute("PRAGMA journal_mode=WAL")
    c.execute("PRAGMA foreign_keys=ON")
    return c

# ── Init ────────────────────────────────────────────────────────────────────
def db_init():
    sb = _supabase()
    if sb: return  # tables created in Supabase SQL editor
    c = _sqlite()
    c.executescript("""
        CREATE TABLE IF NOT EXISTS users (
            id INTEGER PRIMARY KEY AUTOINCREMENT,
            email TEXT UNIQUE NOT NULL COLLATE NOCASE,
            name TEXT NOT NULL,
            password_hash TEXT NOT NULL,
            plan TEXT NOT NULL DEFAULT 'free',
            stripe_cid TEXT,
            api_key TEXT UNIQUE,
            email_verified INTEGER NOT NULL DEFAULT 0,
            is_admin INTEGER NOT NULL DEFAULT 0,
            created_at TEXT NOT NULL,
            updated_at TEXT
        );
        CREATE TABLE IF NOT EXISTS sessions (
            token TEXT PRIMARY KEY,
            user_id INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE,
            expires_at TEXT NOT NULL,
            created_at TEXT NOT NULL
        );
        CREATE TABLE IF NOT EXISTS invoices (
            id INTEGER PRIMARY KEY AUTOINCREMENT,
            user_id INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE,
            filename TEXT, vendor TEXT, inv_number TEXT,
            inv_date TEXT, due_date TEXT, amount REAL,
            vat_amount REAL, total REAL, currency TEXT DEFAULT 'USD',
            status TEXT DEFAULT 'done', is_duplicate INTEGER DEFAULT 0,
            confidence REAL, raw_json TEXT, created_at TEXT NOT NULL
        );
        CREATE INDEX IF NOT EXISTS ix_inv_user ON invoices(user_id);
        CREATE INDEX IF NOT EXISTS ix_inv_date ON invoices(created_at);
        CREATE INDEX IF NOT EXISTS ix_ses_user ON sessions(user_id);
        CREATE INDEX IF NOT EXISTS ix_ses_exp  ON sessions(expires_at);
    """)
    c.commit(); c.close()

# ── Users ───────────────────────────────────────────────────────────────────
def create_user(email: str, name: str, password_hash: str, plan: str = "free") -> dict | None:
    email = email.strip().lower()
    api_key = "op_live_" + _secrets.token_hex(20)
    now = datetime.now(timezone.utc).isoformat()
    sb = _supabase()
    if sb:
        ex = sb.table("users").select("id").eq("email", email).execute()
        if ex.data: return None
        r = sb.table("users").insert({"email":email,"name":name,"password_hash":password_hash,
              "plan":plan,"api_key":api_key,"created_at":now}).execute()
        return r.data[0] if r.data else None
    c = _sqlite()
    try:
        cur = c.execute("INSERT INTO users(email,name,password_hash,plan,api_key,created_at) VALUES(?,?,?,?,?,?)",
                        (email, name, password_hash, plan, api_key, now))
        c.commit(); uid = cur.lastrowid
        row = c.execute("SELECT * FROM users WHERE id=?", (uid,)).fetchone()
        return dict(row)
    except sqlite3.IntegrityError: return None
    finally: c.close()

def get_user_by_email(email: str) -> dict | None:
    email = email.strip().lower()
    sb = _supabase()
    if sb:
        r = sb.table("users").select("*").eq("email",email).execute()
        return r.data[0] if r.data else None
    c = _sqlite()
    row = c.execute("SELECT * FROM users WHERE email=? COLLATE NOCASE", (email,)).fetchone()
    c.close(); return dict(row) if row else None

def get_user_by_id(uid: int) -> dict | None:
    sb = _supabase()
    if sb:
        r = sb.table("users").select("*").eq("id",uid).execute()
        return r.data[0] if r.data else None
    c = _sqlite()
    row = c.execute("SELECT * FROM users WHERE id=?", (uid,)).fetchone()
    c.close(); return dict(row) if row else None

def update_user(uid: int, fields: dict) -> None:
    fields["updated_at"] = datetime.now(timezone.utc).isoformat()
    sb = _supabase()
    if sb: sb.table("users").update(fields).eq("id",uid).execute(); return
    c = _sqlite()
    cols = ", ".join(f"{k}=?" for k in fields)
    vals = list(fields.values()) + [uid]
    c.execute(f"UPDATE users SET {cols} WHERE id=?", vals)
    c.commit(); c.close()

def delete_user(uid: int) -> None:
    sb = _supabase()
    if sb:
        sb.table("invoices").delete().eq("user_id",uid).execute()
        sb.table("sessions").delete().eq("user_id",uid).execute()
        sb.table("users").delete().eq("id",uid).execute(); return
    c = _sqlite()
    c.execute("DELETE FROM invoices WHERE user_id=?",(uid,))
    c.execute("DELETE FROM sessions WHERE user_id=?",(uid,))
    c.execute("DELETE FROM users WHERE id=?",(uid,))
    c.commit(); c.close()

# ── Sessions ────────────────────────────────────────────────────────────────
def create_session(user_id: int, token: str, expires_at: str) -> None:
    now = datetime.now(timezone.utc).isoformat()
    sb = _supabase()
    if sb:
        sb.table("sessions").insert({"token":token,"user_id":user_id,"expires_at":expires_at,"created_at":now}).execute()
        return
    c = _sqlite()
    c.execute("INSERT INTO sessions(token,user_id,expires_at,created_at) VALUES(?,?,?,?)",(token,user_id,expires_at,now))
    c.commit(); c.close()

def get_session(token: str) -> dict | None:
    if not token: return None
    sb = _supabase()
    if sb:
        r = sb.table("sessions").select("*").eq("token",token).execute()
        if not r.data: return None
        session = r.data[0]
    else:
        c = _sqlite()
        row = c.execute("SELECT * FROM sessions WHERE token=?",(token,)).fetchone()
        c.close()
        if not row: return None
        session = dict(row)
    try:
        expires = datetime.fromisoformat(session["expires_at"])
        if expires.tzinfo is None: expires = expires.replace(tzinfo=timezone.utc)
        if expires < datetime.now(timezone.utc): delete_session(token); return None
    except (ValueError, KeyError): return None
    return session

def delete_session(token: str) -> None:
    if not token: return
    sb = _supabase()
    if sb: sb.table("sessions").delete().eq("token",token).execute(); return
    c = _sqlite()
    c.execute("DELETE FROM sessions WHERE token=?",(token,))
    c.commit(); c.close()

def cleanup_sessions() -> int:
    now = datetime.now(timezone.utc).isoformat()
    sb = _supabase()
    if sb:
        r = sb.table("sessions").delete().lt("expires_at",now).execute()
        return len(r.data) if r.data else 0
    c = _sqlite()
    cur = c.execute("DELETE FROM sessions WHERE expires_at<?",(now,))
    c.commit(); n = cur.rowcount; c.close(); return n

# ── Invoices ────────────────────────────────────────────────────────────────
def insert_invoice(user_id: int, data: dict) -> dict:
    now = datetime.now(timezone.utc).isoformat()
    row = {
        "user_id": user_id,
        "filename": data.get("filename"),
        "vendor": data.get("vendor"),
        "inv_number": data.get("invoice_number"),
        "inv_date": data.get("invoice_date"),
        "due_date": data.get("due_date"),
        "amount": data.get("amount"),
        "vat_amount": data.get("vat_amount"),
        "total": data.get("total"),
        "currency": data.get("currency","USD"),
        "status": data.get("status","done"),
        "is_duplicate": bool(data.get("is_duplicate", False)),
        "confidence": data.get("confidence"),
        "raw_json": json.dumps(data, ensure_ascii=False, default=str),
        "created_at": now,
    }
    sb = _supabase()
    if sb:
        r = sb.table("invoices").insert(row).execute()
        return r.data[0] if r.data else row
    c = _sqlite()
    cols = ", ".join(row.keys())
    phs  = ", ".join("?" for _ in row)
    c.execute(f"INSERT INTO invoices({cols}) VALUES({phs})", tuple(row.values()))
    c.commit()
    iid = c.execute("SELECT last_insert_rowid()").fetchone()[0]
    res = c.execute("SELECT * FROM invoices WHERE id=?",(iid,)).fetchone()
    c.close(); return dict(res)

def get_invoices(user_id: int) -> list[dict]:
    sb = _supabase()
    if sb:
        r = sb.table("invoices").select("*").eq("user_id",user_id).order("created_at",desc=True).execute()
        return r.data or []
    c = _sqlite()
    rows = c.execute("SELECT * FROM invoices WHERE user_id=? ORDER BY created_at DESC",(user_id,)).fetchall()
    c.close(); return [dict(r) for r in rows]

def delete_invoice(user_id: int, invoice_id: int) -> None:
    sb = _supabase()
    if sb: sb.table("invoices").delete().eq("id",invoice_id).eq("user_id",user_id).execute(); return
    c = _sqlite()
    c.execute("DELETE FROM invoices WHERE id=? AND user_id=?",(invoice_id,user_id))
    c.commit(); c.close()

def count_invoices_this_month(user_id: int) -> int:
    invs = get_invoices(user_id); now = datetime.now(timezone.utc); n = 0
    for inv in invs:
        try:
            cr = datetime.fromisoformat(inv["created_at"])
            if cr.year == now.year and cr.month == now.month: n += 1
        except (ValueError, KeyError): pass
    return n

def check_duplicate(user_id: int, vendor: str, total: float) -> bool:
    if not vendor or total is None: return False
    invs = get_invoices(user_id); now = datetime.now(timezone.utc)
    vl = vendor.strip().lower()
    for inv in invs:
        try: cr = datetime.fromisoformat(inv["created_at"])
        except: continue
        if cr.year == now.year and cr.month == now.month:
            iv = (inv.get("vendor") or "").strip().lower()
            it = inv.get("total")
            if iv == vl and it is not None and abs(float(it)-float(total))<0.01: return True
    return False