#!/usr/bin/env python3
# auth_v2.py — JWT auth backend with tenant_id, role, tier claims
# v1.0 dradulic@outlook.com / damir@rinet.one — 2026-05-04
# Endpoints: /api/auth/login, /api/auth/refresh, /api/auth/logout,
#            /api/auth/me, /api/auth/password/change, /api/auth/password/reset
"""
JWT claims:
    sub          int   user id
    email        str
    name         str
    tenant_id    int|null   pgz_sport.tenants.id (or null for super_admin)
    tenant_type  str   pgz | savez | klub | global
    tenant_scope dict  {"klub_id": ..., "savez_id": ...}
    role         str   user_type code (super_admin | pgz_admin | savez_admin | klub_admin | klub_clan | viewer ...)
    tier         int   0 = PGŽ, 1 = savez, 2 = klub
    jti          str   token id (revocable via user_sessions)
    iat / exp / nbf
"""

import os, hashlib, secrets, json, time
from datetime import datetime, timedelta, timezone
from typing import Optional, Dict, List, Any

import jwt as _jwt
import psycopg2, psycopg2.extras
from fastapi import APIRouter, HTTPException, Header, Depends, Request, Body
from pydantic import BaseModel, EmailStr

try:
    from passlib.hash import bcrypt as _bcrypt
    HAS_BCRYPT = True
except Exception:
    HAS_BCRYPT = False

DB = dict(host='10.10.0.2', port=6432, dbname='rinet_v3',
          user='rinet', password='R1net2026!SecureDB#v7')

# Persistent JWT secret — read from env, else stable file, else generated.
def _load_secret() -> str:
    env_secret = os.environ.get("PGZ_JWT_SECRET")
    if env_secret and len(env_secret) >= 32:
        return env_secret
    secret_file = "/opt/pgz-sport/auth/.jwt_secret"
    try:
        if os.path.exists(secret_file):
            with open(secret_file) as f:
                s = f.read().strip()
                if len(s) >= 32:
                    return s
        s = "rinet-pgz-" + secrets.token_urlsafe(48)
        with open(secret_file, "w") as f:
            f.write(s)
        os.chmod(secret_file, 0o600)
        return s
    except Exception:
        return "rinet-pgz-jwt-2026-fallback-" + hashlib.sha256(b"pgz-sport").hexdigest()

JWT_SECRET = _load_secret()
JWT_ALG    = "HS256"
ACCESS_TTL = timedelta(minutes=int(os.environ.get("PGZ_JWT_ACCESS_MIN", "30")))
REFRESH_TTL = timedelta(days=int(os.environ.get("PGZ_JWT_REFRESH_DAYS", "7")))

router = APIRouter(prefix="/api/auth", tags=["auth_v2"])

# ─────────────────────────── DB helpers ───────────────────────────
def _conn():
    return psycopg2.connect(**DB)

def db_query(sql: str, params=()):
    with _conn() as c:
        cur = c.cursor(cursor_factory=psycopg2.extras.RealDictCursor)
        cur.execute(sql, params)
        if cur.description: return cur.fetchall()
        return []

def db_one(sql: str, params=()):
    rows = db_query(sql, params)
    return rows[0] if rows else None

def db_exec(sql: str, params=()):
    with _conn() as c:
        cur = c.cursor()
        cur.execute(sql, params)
        if cur.description:
            r = cur.fetchone()
            return r[0] if r else None
        c.commit()

# ─────────────────────────── Password helpers ───────────────────────────
def _sha256(pw: str) -> str:
    return hashlib.sha256(pw.encode()).hexdigest()

def hash_password(pw: str) -> str:
    if HAS_BCRYPT:
        return _bcrypt.using(rounds=12).hash(pw)
    return _sha256(pw)

def verify_password(pw: str, hashed: Optional[str]) -> bool:
    if not hashed: return False
    h = hashed.strip()
    if h.startswith("$2") and HAS_BCRYPT:
        try:
            return _bcrypt.verify(pw, h)
        except Exception:
            return False
    return h == _sha256(pw)

def needs_rehash(hashed: Optional[str]) -> bool:
    if not hashed: return True
    return HAS_BCRYPT and not hashed.startswith("$2")

# ─────────────────────────── Tenant resolution ───────────────────────────
PGZ_USER_TYPES   = {"super_admin", "pgz_admin", "pgz_user", "pgz_finance", "pgz_zzjz"}
SAVEZ_USER_TYPES = {"savez_admin", "savez_user"}
KLUB_USER_TYPES  = {"klub_admin", "klub_user", "klub_trener", "klub_clan"}

def _tier_for(user_type: str) -> int:
    ut = (user_type or "").lower()
    if ut in PGZ_USER_TYPES:   return 0
    if ut in SAVEZ_USER_TYPES: return 1
    if ut in KLUB_USER_TYPES:  return 2
    return 9  # unknown / viewer / guest

def _resolve_tenant(u: Dict) -> Dict:
    """Resolve tenant_id + tenant_type from a user row."""
    ut = (u.get("user_type") or "").lower()
    klub_id  = u.get("klub_id")
    savez_id = u.get("savez_id")
    if ut in PGZ_USER_TYPES:
        row = db_one("SELECT id, slug, display_name FROM pgz_sport.tenants WHERE slug='pgz' LIMIT 1")
        return {
            "tenant_id":   row["id"] if row else None,
            "tenant_type": "pgz",
            "tenant_name": row["display_name"] if row else "PGŽ",
            "tenant_scope": {"klub_id": None, "savez_id": None},
        }
    if ut in SAVEZ_USER_TYPES and savez_id:
        return {
            "tenant_id":   savez_id,
            "tenant_type": "savez",
            "tenant_name": (db_one("SELECT naziv FROM pgz_sport.savezi WHERE id=%s",(savez_id,)) or {}).get("naziv"),
            "tenant_scope": {"klub_id": None, "savez_id": savez_id},
        }
    if ut in KLUB_USER_TYPES and klub_id:
        return {
            "tenant_id":   klub_id,
            "tenant_type": "klub",
            "tenant_name": (db_one("SELECT naziv FROM pgz_sport.klubovi WHERE id=%s",(klub_id,)) or {}).get("naziv"),
            "tenant_scope": {"klub_id": klub_id, "savez_id": savez_id},
        }
    # super_admin without context
    if ut == "super_admin":
        return {"tenant_id": None, "tenant_type": "global",
                "tenant_name": "Global", "tenant_scope": {"klub_id": None, "savez_id": None}}
    return {"tenant_id": None, "tenant_type": "viewer",
            "tenant_name": None, "tenant_scope": {"klub_id": klub_id, "savez_id": savez_id}}

# ─────────────────────────── JWT issue / verify ───────────────────────────
def _now() -> datetime: return datetime.now(timezone.utc)

def _new_jti() -> str: return secrets.token_urlsafe(16)

def make_access_token(u: Dict, jti: str) -> str:
    tenant = _resolve_tenant(u)
    tier = _tier_for(u.get("user_type") or "")
    now = _now()
    payload = {
        "sub": str(u["id"]),
        "uid": u["id"],
        "email": u["email"],
        "name":  u.get("full_name") or ((u.get("ime") or "") + " " + (u.get("prezime") or "")).strip() or u["email"],
        "tenant_id":    tenant["tenant_id"],
        "tenant_type":  tenant["tenant_type"],
        "tenant_name":  tenant["tenant_name"],
        "tenant_scope": tenant["tenant_scope"],
        "role": u.get("user_type") or "viewer",
        "tier": tier,
        "jti": jti,
        "typ": "access",
        "iat": int(now.timestamp()),
        "nbf": int(now.timestamp()),
        "exp": int((now + ACCESS_TTL).timestamp()),
    }
    return _jwt.encode(payload, JWT_SECRET, algorithm=JWT_ALG)

def make_refresh_token(uid: int, jti: str) -> str:
    now = _now()
    return _jwt.encode({
        "sub": str(uid), "uid": uid, "jti": jti, "typ": "refresh",
        "iat": int(now.timestamp()),
        "exp": int((now + REFRESH_TTL).timestamp()),
    }, JWT_SECRET, algorithm=JWT_ALG)

def decode_token(token: str) -> Dict:
    try:
        return _jwt.decode(token, JWT_SECRET, algorithms=[JWT_ALG])
    except _jwt.ExpiredSignatureError:
        raise HTTPException(401, "Token expired")
    except Exception as e:
        raise HTTPException(401, f"Invalid token: {e}")

def _record_session(uid: int, jti: str, expires: datetime, ip: str = None, ua: str = None):
    th = hashlib.sha256(jti.encode()).hexdigest()
    db_exec("""INSERT INTO pgz_sport.user_sessions
        (user_id, token_hash, device_info, ip_address, expires_at, revoked)
        VALUES (%s,%s,%s,%s::inet,%s,false)
        ON CONFLICT (token_hash) DO NOTHING""",
        (uid, th, ua, ip, expires))

def _is_revoked(jti: str) -> bool:
    th = hashlib.sha256(jti.encode()).hexdigest()
    r = db_one("SELECT revoked FROM pgz_sport.user_sessions WHERE token_hash=%s", (th,))
    if not r: return False
    return bool(r.get("revoked"))

def _revoke_jti(jti: str):
    th = hashlib.sha256(jti.encode()).hexdigest()
    db_exec("UPDATE pgz_sport.user_sessions SET revoked=true WHERE token_hash=%s", (th,))

# ─────────────────────────── current_user dep ───────────────────────────
def _extract_token(authorization: Optional[str]) -> Optional[str]:
    if not authorization: return None
    return authorization.replace("Bearer ", "").strip() or None

def get_current_user(authorization: Optional[str] = Header(None)) -> Optional[Dict]:
    token = _extract_token(authorization)
    if not token: return None
    try:
        payload = decode_token(token)
    except HTTPException:
        return None
    if payload.get("typ") not in (None, "access"):
        return None
    if _is_revoked(payload.get("jti","")):
        return None
    uid = payload.get("uid") or int(payload.get("sub", 0) or 0)
    u = db_one("""SELECT id, email, full_name, ime, prezime, user_type,
                  klub_id, savez_id, status, aktivan, must_change_pwd
              FROM pgz_sport.users WHERE id=%s""", (uid,))
    if not u or u.get("status") != "active" or not u.get("aktivan", True):
        return None
    u["_jwt"] = payload
    u["_token"] = token
    return u

def require_user(user = Depends(get_current_user)) -> Dict:
    if not user:
        raise HTTPException(401, "Authentication required")
    return user

def require_role(roles: List[str]):
    def dep(user = Depends(require_user)):
        if user.get("user_type") not in roles:
            raise HTTPException(403, f"Forbidden — required: {','.join(roles)}")
        return user
    return dep

# ─────────────────────────── Audit ───────────────────────────
def audit(user_id: Optional[int], action: str, resource_type: str = None,
          resource_id: int = None, meta: Dict = None, ip: str = None, ua: str = None):
    try:
        db_exec("""INSERT INTO pgz_sport.audit_events
            (user_id, action, resource_type, resource_id, meta, ip_address, user_agent)
            VALUES (%s,%s,%s,%s,%s::jsonb,%s::inet,%s)""",
            (user_id, action, resource_type, resource_id,
             json.dumps(meta or {}), ip, ua))
    except Exception as e:
        print(f"[AUDIT WARN] {e}")

def _client(req: Request):
    ip = (req.headers.get("x-forwarded-for") or req.client.host or "").split(",")[0].strip() or None
    ua = req.headers.get("user-agent")
    return ip, ua

# ─────────────────────────── Schemas ───────────────────────────
class LoginReq(BaseModel):
    email: str
    password: str

class RefreshReq(BaseModel):
    refresh_token: str

class ChangePwdReq(BaseModel):
    old_password: Optional[str] = None
    new_password: str

class ResetPwdReq(BaseModel):
    email: str

# ─────────────────────────── Endpoints ───────────────────────────
@router.post("/login")
def login(req: LoginReq, request: Request):
    ip, ua = _client(request)
    email = (req.email or "").lower().strip()
    if not email or not req.password:
        raise HTTPException(400, "Email i lozinka obavezni")

    u = db_one("""SELECT id, email, full_name, ime, prezime, password_hash, status,
                  user_type, klub_id, savez_id, aktivan, must_change_pwd,
                  failed_login_count, locked_until
              FROM pgz_sport.users WHERE LOWER(email)=%s""", (email,))
    if not u:
        audit(None, "login.fail", meta={"email": email, "reason": "no_user"}, ip=ip, ua=ua)
        raise HTTPException(401, "Neispravni podaci")
    if u.get("locked_until"):
        lu = u["locked_until"]
        if lu.tzinfo is None: lu = lu.replace(tzinfo=timezone.utc)
        if lu > _now():
            audit(u["id"], "login.locked", ip=ip, ua=ua)
            raise HTTPException(423, "Račun privremeno zaključan")
    if u.get("status") != "active" or not u.get("aktivan", True):
        audit(u["id"], "login.fail", meta={"reason":"inactive"}, ip=ip, ua=ua)
        raise HTTPException(403, "Račun nije aktivan")
    if not verify_password(req.password, u.get("password_hash")):
        db_exec("""UPDATE pgz_sport.users
                   SET failed_login_count = COALESCE(failed_login_count,0)+1,
                       locked_until = CASE WHEN COALESCE(failed_login_count,0)+1>=5
                                           THEN now()+interval '15 minutes' ELSE locked_until END
                   WHERE id=%s""", (u["id"],))
        audit(u["id"], "login.fail", meta={"reason":"bad_password"}, ip=ip, ua=ua)
        raise HTTPException(401, "Neispravni podaci")

    # opportunistic rehash to bcrypt
    if needs_rehash(u.get("password_hash")):
        try:
            db_exec("UPDATE pgz_sport.users SET password_hash=%s WHERE id=%s",
                    (hash_password(req.password), u["id"]))
        except Exception: pass

    db_exec("""UPDATE pgz_sport.users
               SET failed_login_count=0, locked_until=NULL, last_login=now()
               WHERE id=%s""", (u["id"],))

    jti  = _new_jti()
    rjti = _new_jti()
    access  = make_access_token(u, jti)
    refresh = make_refresh_token(u["id"], rjti)
    _record_session(u["id"], jti,  _now() + ACCESS_TTL,  ip=ip, ua=ua)
    _record_session(u["id"], rjti, _now() + REFRESH_TTL, ip=ip, ua=(ua or "") + " [refresh]")
    audit(u["id"], "login.ok", ip=ip, ua=ua)

    tenant = _resolve_tenant(u)
    return {
        "access_token":  access,
        "refresh_token": refresh,
        "token_type":    "Bearer",
        "expires_in":    int(ACCESS_TTL.total_seconds()),
        "user": {
            "id": u["id"], "email": u["email"],
            "full_name": u.get("full_name") or (u.get("ime","") + " " + u.get("prezime","")).strip(),
            "role": u.get("user_type"), "tier": _tier_for(u.get("user_type") or ""),
            "must_change_pwd": bool(u.get("must_change_pwd")),
            **tenant,
        },
    }

@router.post("/refresh")
def refresh(req: RefreshReq, request: Request):
    payload = decode_token(req.refresh_token)
    if payload.get("typ") != "refresh":
        raise HTTPException(401, "Invalid refresh token")
    if _is_revoked(payload.get("jti","")):
        raise HTTPException(401, "Refresh token revoked")
    uid = payload.get("uid") or int(payload.get("sub", 0) or 0)
    u = db_one("""SELECT id, email, full_name, ime, prezime, user_type,
                  klub_id, savez_id, status, aktivan, must_change_pwd
              FROM pgz_sport.users WHERE id=%s""", (uid,))
    if not u or u.get("status") != "active" or not u.get("aktivan", True):
        raise HTTPException(401, "User inactive")
    ip, ua = _client(request)
    new_jti = _new_jti()
    access = make_access_token(u, new_jti)
    _record_session(u["id"], new_jti, _now() + ACCESS_TTL, ip=ip, ua=ua)
    audit(u["id"], "auth.refresh", ip=ip, ua=ua)
    return {"access_token": access, "token_type": "Bearer",
            "expires_in": int(ACCESS_TTL.total_seconds())}

@router.post("/logout")
def logout(request: Request, user = Depends(require_user)):
    jti = (user.get("_jwt") or {}).get("jti")
    if jti: _revoke_jti(jti)
    # Also revoke refresh tokens for this user (best-effort)
    db_exec("""UPDATE pgz_sport.user_sessions SET revoked=true
               WHERE user_id=%s AND device_info LIKE %s""",
            (user["id"], "%[refresh]%"))
    ip, ua = _client(request)
    audit(user["id"], "logout", ip=ip, ua=ua)
    return {"status": "ok"}

@router.get("/me")
def me(user = Depends(require_user)):
    enriched = db_one("""SELECT id, email, full_name, ime, prezime, user_type,
                  klub_id, savez_id, must_change_pwd, aktivan, status,
                  last_login, oib, telefon, phone, preferred_language, created_at,
                  avatar_url, gdpr_consent_at, google_picture
              FROM pgz_sport.users WHERE id=%s""", (user["id"],))
    if not enriched:
        raise HTTPException(404, "User not found")
    tenant = _resolve_tenant(enriched)
    roles = db_query("""SELECT r.code, r.naziv, ur.scope_type, ur.scope_id
        FROM pgz_sport.user_roles ur JOIN pgz_sport.roles r ON r.id=ur.role_id
        WHERE ur.user_id=%s AND ur.active=true""", (user["id"],))
    try:
        twofa = db_one("SELECT secret IS NOT NULL AS enabled FROM pgz_sport.user_2fa WHERE user_id=%s",
                       (user["id"],)) or {"enabled": False}
    except Exception:
        twofa = {"enabled": False}
    return {**enriched,
            "tier": _tier_for(enriched.get("user_type") or ""),
            "must_change_pwd": bool(enriched.get("must_change_pwd")),
            "two_factor_enabled": bool(twofa.get("enabled")),
            **tenant, "roles": roles}

class UpdateMeReq(BaseModel):
    ime: Optional[str] = None
    prezime: Optional[str] = None
    full_name: Optional[str] = None
    telefon: Optional[str] = None
    phone: Optional[str] = None
    preferred_language: Optional[str] = None
    oib: Optional[str] = None

@router.put("/me")
def update_me(req: UpdateMeReq, request: Request, user = Depends(require_user)):
    fields = []
    vals: List[Any] = []
    for k in ("ime","prezime","full_name","telefon","phone","preferred_language","oib"):
        v = getattr(req, k)
        if v is not None:
            fields.append(f"{k}=%s")
            vals.append(v.strip() if isinstance(v, str) else v)
    if not fields:
        raise HTTPException(400, "Nema polja za ažuriranje")
    vals.append(user["id"])
    db_exec(f"UPDATE pgz_sport.users SET {', '.join(fields)}, updated_at=now() WHERE id=%s", tuple(vals))
    ip, ua = _client(request)
    audit(user["id"], "profile.update", meta={"fields": [f.split("=")[0] for f in fields]}, ip=ip, ua=ua)
    return me(user)

# ───────────────────────────  AVATAR UPLOAD  ───────────────────────────
import shutil, pathlib
from fastapi import UploadFile, File

UPLOAD_ROOT = pathlib.Path("/opt/pgz-sport/uploads")
AVATAR_DIR = UPLOAD_ROOT / "avatars"
AVATAR_DIR.mkdir(parents=True, exist_ok=True)
ALLOWED_AVATAR_MIME = {"image/jpeg","image/jpg","image/png","image/webp"}
ALLOWED_AVATAR_EXT = {".jpg",".jpeg",".png",".webp"}
MAX_AVATAR_BYTES = 5 * 1024 * 1024  # 5 MB

@router.post("/me/avatar")
async def upload_my_avatar(request: Request, file: UploadFile = File(...), user = Depends(require_user)):
    ct = (file.content_type or "").lower()
    if ct not in ALLOWED_AVATAR_MIME:
        raise HTTPException(400, f"Nedozvoljen tip slike: {ct} — jpeg/png/webp")
    ext = pathlib.Path(file.filename or "").suffix.lower()
    if ext not in ALLOWED_AVATAR_EXT:
        ext = {"image/jpeg":".jpg","image/jpg":".jpg","image/png":".png","image/webp":".webp"}.get(ct, ".jpg")
    data = await file.read()
    if len(data) > MAX_AVATAR_BYTES:
        raise HTTPException(413, f"Slika prevelika ({len(data)} B > {MAX_AVATAR_BYTES})")
    if len(data) < 32:
        raise HTTPException(400, "Slika prazna ili neispravna")
    safe_name = f"{int(user['id'])}_{int(time.time())}{ext}"
    target = AVATAR_DIR / safe_name
    with open(target, "wb") as f:
        f.write(data)
    try: os.chmod(target, 0o644)
    except Exception: pass
    avatar_url = f"/uploads/avatars/{safe_name}"
    db_exec("UPDATE pgz_sport.users SET avatar_url=%s, updated_at=now() WHERE id=%s",
            (avatar_url, user["id"]))
    ip, ua = _client(request)
    audit(user["id"], "profile.avatar_upload",
          meta={"file": safe_name, "size": len(data), "mime": ct}, ip=ip, ua=ua)
    return {"status":"ok", "avatar_url": avatar_url, "size": len(data), "mime": ct}

@router.delete("/me/avatar")
def delete_my_avatar(request: Request, user = Depends(require_user)):
    cur = db_one("SELECT avatar_url FROM pgz_sport.users WHERE id=%s", (user["id"],))
    if cur and cur.get("avatar_url"):
        p = AVATAR_DIR / pathlib.Path(cur["avatar_url"]).name
        try:
            if p.exists() and p.is_relative_to(AVATAR_DIR): p.unlink()
        except Exception: pass
    db_exec("UPDATE pgz_sport.users SET avatar_url=NULL, updated_at=now() WHERE id=%s", (user["id"],))
    ip, ua = _client(request)
    audit(user["id"], "profile.avatar_delete", ip=ip, ua=ua)
    return {"status": "ok"}

@router.post("/password/change")
def change_password(req: ChangePwdReq, request: Request, user = Depends(require_user)):
    if len(req.new_password) < 8:
        raise HTTPException(400, "Lozinka mora imati barem 8 znakova")
    cur = db_one("SELECT password_hash, must_change_pwd FROM pgz_sport.users WHERE id=%s",
                 (user["id"],))
    if not cur: raise HTTPException(404, "User not found")
    if not cur.get("must_change_pwd"):
        if not req.old_password:
            raise HTTPException(400, "old_password obavezan")
        if not verify_password(req.old_password, cur.get("password_hash")):
            raise HTTPException(401, "Stara lozinka netočna")
    db_exec("""UPDATE pgz_sport.users
               SET password_hash=%s, must_change_pwd=false, updated_at=now()
               WHERE id=%s""", (hash_password(req.new_password), user["id"]))
    ip, ua = _client(request)
    audit(user["id"], "password.change", ip=ip, ua=ua)
    return {"status": "ok"}

@router.post("/password/reset")
def password_reset(req: ResetPwdReq, request: Request):
    """Issue a temporary password (admin-equivalent self-reset; logged)."""
    email = (req.email or "").lower().strip()
    u = db_one("SELECT id, email, aktivan FROM pgz_sport.users WHERE LOWER(email)=%s",
               (email,))
    ip, ua = _client(request)
    audit(u["id"] if u else None, "password.reset.request",
          meta={"email": email, "found": bool(u)}, ip=ip, ua=ua)
    # Generic response — do not leak which emails exist
    return {"status": "ok",
            "message": "Ako račun postoji, administrator će vam poslati instrukcije."}

# ─────────────────────────── 2FA placeholders (TOTP) ───────────────────────────
@router.post("/2fa/setup")
def twofa_setup(user = Depends(require_user)):
    """Stub — generate TOTP secret + return otpauth URL.
    Full TOTP verification will be added in M1.5."""
    secret = secrets.token_hex(20).upper()
    db_exec("""ALTER TABLE pgz_sport.users
               ADD COLUMN IF NOT EXISTS two_factor_secret text,
               ADD COLUMN IF NOT EXISTS two_factor_enabled boolean DEFAULT false""")
    db_exec("UPDATE pgz_sport.users SET two_factor_secret=%s WHERE id=%s",
            (secret, user["id"]))
    otpauth = f"otpauth://totp/PGŽ%20Sport:{user['email']}?secret={secret}&issuer=PGZSport"
    return {"secret": secret, "otpauth": otpauth, "enabled": False}

@router.post("/2fa/verify")
def twofa_verify(code: str = Body(..., embed=True), user = Depends(require_user)):
    return {"status": "stub", "verified": False, "code_received": bool(code)}