# utils/api.py
import os
import json
import logging
import requests
from urllib3.util.retry import Retry
from requests.adapters import HTTPAdapter

# ---- Setup ----
BACKEND = (os.getenv("BACKEND_URL") or "").strip().rstrip("/")
if not BACKEND:
    raise RuntimeError("BACKEND_URL is not set in Space secrets.")

TOKEN = (os.getenv("BACKEND_TOKEN") or os.getenv("HF_TOKEN") or "").strip()
DEFAULT_TIMEOUT = int(os.getenv("BACKEND_TIMEOUT", "120"))

_session = requests.Session()
retry = Retry(
    total=3,
    connect=3,
    read=3,
    backoff_factor=0.5,
    status_forcelist=(429, 500, 502, 503, 504),
    allowed_methods=frozenset(["GET", "POST", "PUT", "PATCH", "DELETE"]),
)
_session.mount("https://", HTTPAdapter(max_retries=retry))
_session.mount("http://", HTTPAdapter(max_retries=retry))
_session.headers.update({
    "Accept": "application/json, */*;q=0.1",
    "User-Agent": "FInFront/1.0 (+spaces)",
})
if TOKEN:
    _session.headers["Authorization"] = f"Bearer {TOKEN}"

logging.basicConfig(level=logging.INFO)
logger = logging.getLogger(__name__)

# --- Optional API prefix (e.g., "/api")
API_PREFIX_ENV = (os.getenv("BACKEND_API_PREFIX") or "").strip().rstrip("/")
def _prefixes():
    return ["/" + API_PREFIX_ENV.strip("/"), ""] if API_PREFIX_ENV else [""]

# ---- Core helpers ----
def _json_or_raise(resp: requests.Response):
    ctype = (resp.headers.get("content-type") or "").lower()
    if "application/json" in ctype:
        return resp.json()
    try:
        return resp.json()
    except Exception:
        snippet = (resp.text or "")[:300]
        raise RuntimeError(f"Expected JSON but got {ctype or 'unknown'}:\n{snippet}")

def _req(method: str, path: str, **kw):
    if not path.startswith("/"):
        path = "/" + path
    for pref in _prefixes():
        url = f"{BACKEND}{pref}{path}"
        try:
            r = _session.request(method, url, timeout=180, **kw)
            r.raise_for_status()
            return r
        except requests.HTTPError as e:
            status = getattr(e.response, "status_code", "?")
            # try next prefix on 404
            if status == 404:
                continue

            # ---------- friendlier auth errors ----------
            if status in (401, 403):
                # Normal bad credentials on the login endpoint
                if path.endswith("/auth/login"):
                    raise RuntimeError("Incorrect email or password.") from e
                # Generic auth issue elsewhere (expired session, etc.)
                raise RuntimeError("Authentication failed. Please sign in again.") from e
            # -------------------------------------------

            # keep a tiny body for other errors
            body = ""
            try:
                body = e.response.text[:500]
            except Exception:
                pass
            raise RuntimeError(f"{method} {url} failed [{status}]: {body}") from e
        except requests.RequestException:
            # try next prefix
            continue
    raise RuntimeError(f"No matching endpoint for {method} {path} with prefixes {list(_prefixes())}")

# ---- Public helpers ----
def health():
    try:
        return _json_or_raise(_req("GET", "/health"))
    except Exception:
        try:
            _req("GET", "/")
            return {"ok": True}
        except Exception:
            return {"ok": False}

# ---------- Auth ----------
def login(email: str, password: str):
    return _json_or_raise(_req("POST", "/auth/login", json={"email": email, "password": password}))

def signup_student(name: str, email: str, password: str, level_label: str, country_label: str):
    payload = {
        "name": name, "email": email, "password": password,
        "level_label": level_label, "country_label": country_label
    }
    return _json_or_raise(_req("POST", "/auth/signup/student", json=payload))

def signup_teacher(title: str, name: str, email: str, password: str):
    payload = {"title": title, "name": name, "email": email, "password": password}
    return _json_or_raise(_req("POST", "/auth/signup/teacher", json=payload))

# ---------- Classes ----------
def create_class(teacher_id: int, name: str):
    return _json_or_raise(_req("POST", f"/teachers/{teacher_id}/classes", json={"name": name}))

def list_classes_by_teacher(teacher_id: int):
    return _json_or_raise(_req("GET", f"/teachers/{teacher_id}/classes"))

def join_class_by_code(student_id: int, code: str):
    d = _json_or_raise(_req("POST", f"/students/{student_id}/classes/join", json={"code": code}))
    return d.get("class_id", d)

def leave_class(student_id: int, class_id: int):
    _json_or_raise(_req("POST", f"/classes/{class_id}/leave", json={"student_id": student_id}))
    return True

def list_students_in_class(class_id: int):
    return _json_or_raise(_req("GET", f"/classes/{class_id}/students"))

def class_content_counts(class_id: int):
    return _json_or_raise(_req("GET", f"/classes/{class_id}/content_counts"))

def list_class_assignments(class_id: int):
    return _json_or_raise(_req("GET", f"/classes/{class_id}/assignments"))

def class_analytics(class_id: int):
    return _json_or_raise(_req("GET", f"/classes/{class_id}/analytics"))

def class_student_metrics(class_id: int):
    return _json_or_raise(_req("GET", f"/classes/{class_id}/students/metrics"))

def class_weekly_activity(class_id: int):
    return _json_or_raise(_req("GET", f"/classes/{class_id}/activity/weekly"))

def class_progress_overview(class_id: int):
    return _json_or_raise(_req("GET", f"/classes/{class_id}/progress"))

def class_recent_activity(class_id: int, limit=6, days=30):
    return _json_or_raise(_req("GET", f"/classes/{class_id}/activity/recent",
                               params={"limit": limit, "days": days}))

def student_class_progress(student_id: int, class_id: int):
    return _json_or_raise(_req("GET", f"/classes/{class_id}/students/{student_id}/progress"))

def student_assignments_for_class(student_id: int, class_id: int):
    return _json_or_raise(_req("GET", f"/classes/{class_id}/students/{student_id}/assignments"))

# ---------- Lessons ----------
def list_lessons_by_teacher(teacher_id: int):
    return _json_or_raise(_req("GET", f"/teachers/{teacher_id}/lessons"))

def create_lesson(teacher_id: int, title: str, description: str,
                  subject: str, level: str, sections: list[dict]):
    payload = {
        "title": title, "description": description,
        "subject": subject, "level": level, "sections": sections,
    }
    d = _json_or_raise(_req("POST", f"/teachers/{teacher_id}/lessons", json=payload))
    return d.get("lesson_id", d.get("id", d))

def get_lesson(lesson_id: int):
    return _json_or_raise(_req("GET", f"/lessons/{lesson_id}"))

def update_lesson(lesson_id: int, teacher_id: int, title: str, description: str,
                  subject: str, level: str, sections: list[dict]):
    d = _json_or_raise(_req("PUT", f"/lessons/{lesson_id}", json={
        "teacher_id": teacher_id, "title": title, "description": description,
        "subject": subject, "level": level, "sections": sections
    }))
    return bool(d.get("ok", True))

def delete_lesson(lesson_id: int, teacher_id: int):
    d = _json_or_raise(_req("DELETE", f"/lessons/{lesson_id}", json={"teacher_id": teacher_id}))
    return bool(d.get("ok", True)), d.get("message", "")

def list_assigned_students_for_lesson(lesson_id: int):
    return _json_or_raise(_req("GET", f"/lessons/{lesson_id}/assignees"))

# ---------- Quizzes ----------
def list_quizzes_by_teacher(teacher_id: int):
    return _json_or_raise(_req("GET", f"/teachers/{teacher_id}/quizzes"))

def get_quiz(quiz_id: int):
    return _json_or_raise(_req("GET", f"/quizzes/{quiz_id}"))

def create_quiz(lesson_id: int, title: str, items: list[dict], settings: dict):
    d = _json_or_raise(_req("POST", "/quizzes", json={
        "lesson_id": lesson_id, "title": title, "items": items, "settings": settings
    }))
    return d.get("quiz_id", d.get("id", d))

def update_quiz(quiz_id: int, teacher_id: int, title: str, items: list[dict], settings: dict):
    d = _json_or_raise(_req("PUT", f"/quizzes/{quiz_id}", json={
        "teacher_id": teacher_id, "title": title, "items": items, "settings": settings
    }))
    return bool(d.get("ok", True))

def delete_quiz(quiz_id: int, teacher_id: int):
    d = _json_or_raise(_req("DELETE", f"/quizzes/{quiz_id}", json={"teacher_id": teacher_id}))
    return bool(d.get("ok", True)), d.get("message", "")

def generate_quiz_from_text(content: str, n_questions: int = 5, subject: str = "finance", level: str = "beginner"):
    return _json_or_raise(_req("POST", "/quiz/generate", json={
        "content": content, "n_questions": n_questions, "subject": subject, "level": level
    }))

def generate_quiz(*, lesson_id: int | None, level_slug: str | None, lesson_title: str | None):
    payload = {
        "lesson_id": int(lesson_id) if lesson_id is not None else None,
        "level_slug": level_slug,
        "lesson_title": lesson_title,
    }
    resp = _req("POST", "/quiz/auto", json=payload)
    result = _json_or_raise(resp)
    if isinstance(result, dict) and "items" in result:
        return result["items"]
    return result if isinstance(result, list) else []

def submit_quiz(*, student_id: int, lesson_id: int, level_slug: str,
                user_answers: list[dict], original_quiz: list[dict], assignment_id: int | None = None):
    payload = {
        "student_id": student_id,
        "lesson_id": lesson_id,
        "level_slug": level_slug,
        "user_answers": user_answers,
        "original_quiz": original_quiz,
        "assignment_id": assignment_id,
    }
    return _json_or_raise(_req("POST", "/quiz/grade", json=payload))

# ---------- Tutor explain ----------
def tutor_explain(lesson_id: int, level_slug: str, wrong: list[dict]):
    payload = {"lesson_id": lesson_id, "level_slug": level_slug, "wrong": wrong}
    return _json_or_raise(_req("POST", "/tutor/explain", json=payload, timeout=60))

# ---------- Student dashboard ----------
def user_stats(student_id: int):
    return _json_or_raise(_req("GET", f"/students/{student_id}/stats"))

def list_assignments_for_student(student_id: int):
    return _json_or_raise(_req("GET", f"/students/{student_id}/assignments"))

def student_quiz_average(student_id: int):
    d = _json_or_raise(_req("GET", f"/students/{student_id}/quiz_avg"))
    # backend returns {"avg_pct": ...}
    for k in ("avg_pct", "avg", "average", "score_pct", "score", "value"):
        if k in d:
            try:
                return int(round(float(str(d[k]).strip().rstrip("%"))))
            except Exception:
                break
    return 0

def recent_lessons_for_student(student_id: int, limit: int = 5):
    return _json_or_raise(_req("GET", f"/students/{student_id}/recent", params={"limit": limit}))

def list_classes_for_student(student_id: int):
    return _json_or_raise(_req("GET", f"/students/{student_id}/classes"))

def level_from_xp(xp: int):
    return _json_or_raise(_req("GET", "/level-from-xp", params={"xp": xp}))["level"]

# ---------- Games ----------
def record_money_match_play(user_id: int, target: int, total: int,
                            elapsed_ms: int, matched: bool, gained_xp: int | None = None):
    payload = {
        "user_id": user_id,
        "target": target,
        "total": total,
        "elapsed_ms": elapsed_ms,
        "matched": bool(matched),
        "gained_xp": gained_xp,
    }
    return _json_or_raise(_req("POST", "/games/money_match/record", json=payload))

def record_budget_builder_play(user_id: int, weekly_allowance: int,
                               allocations: list[dict], gained_xp: int | None = None):
    payload = {
        "user_id": user_id,
        "weekly_allowance": weekly_allowance,
        "allocations": allocations,
        "gained_xp": gained_xp,
    }
    return _json_or_raise(_req("POST", "/games/budget_builder/record", json=payload))

def record_debt_dilemma_play(user_id: int, *, level: int, round_no: int,
                             wallet: int, health: int, happiness: int, credit_score: int,
                             event_json: dict, outcome: str, gained_xp: int | None = None):
    payload = {
        "user_id": user_id,
        "level": level,
        "round_no": round_no,
        "wallet": wallet,
        "health": health,
        "happiness": happiness,
        "credit_score": credit_score,
        "event_json": event_json,
        "outcome": outcome,
        "gained_xp": gained_xp,
    }
    return _json_or_raise(_req("POST", "/games/debt_dilemma/record", json=payload))

def record_profit_puzzler_play(user_id: int, scenario_id: str, title: str,
                               units: int, price: int, cost: int,
                               user_answer: float, actual_profit: float, is_correct: bool,
                               gained_xp: int | None = None):
    payload = {
        "user_id": user_id, "scenario_id": scenario_id, "title": title,
        "units": units, "price": price, "cost": cost,
        "user_answer": user_answer, "actual_profit": actual_profit,
        "is_correct": bool(is_correct), "gained_xp": gained_xp,
    }
    return _json_or_raise(_req("POST", "/games/profit_puzzler/record", json=payload))

# ---------- RAG passthrough ----------
def retrieve(query: str, lesson_id: int, level_slug: str = "beginner", k: int = 3) -> str:
    try:
        d = _json_or_raise(_req("GET", "/retrieve",
                                params={"query": query, "lesson_id": lesson_id, "level_slug": level_slug, "k": k}))
        return d.get("context", "")
    except Exception as e:
        return f"(retrieval failed: {e})"

def chat_ai(query: str, lesson_id: int, level_slug: str, history=None) -> str:
    payload = {
        "query": query,
        "lesson_id": int(lesson_id) if lesson_id is not None else 0,
        "level_slug": level_slug or "beginner",
        "history": history or [],
    }
    try:
        url = f"{BACKEND}/chat"
        with requests.Session() as s:
            s.headers.update(_session.headers)
            r = s.post(url, json=payload, timeout=DEFAULT_TIMEOUT)  # no retry adapter
        r.raise_for_status()
        return r.json().get("answer", "")
    except Exception as e:
        return f"(chat failed: {e})"
    
# ---------- Direct requests (no prefix) ----------

def signup_student(name: str, email: str, password: str, level_label: str, country_label: str):
    payload = {
        "name": name,
        "email": email,
        "password": password,
        "level_label": level_label,   # match your backend param names
        "country_label": country_label,
    }
    try:
        url = f"{BACKEND}/auth/signup/student"
        r = _session.post(url, json=payload, timeout=DEFAULT_TIMEOUT)
        r.raise_for_status()
        return r.json()
    except Exception as e:
        raise RuntimeError(f"Signup failed: {e}")

def signup_teacher(title: str, name: str, email: str, password: str):
    payload = {
        "title": title,
        "name": name,
        "email": email,
        "password": password,
    }
    try:
        url = f"{BACKEND}/auth/signup/teacher"
        r = _session.post(url, json=payload, timeout=DEFAULT_TIMEOUT)
        r.raise_for_status()
        return r.json()
    except Exception as e:
        raise RuntimeError(f"Signup failed: {e}")

def login(email: str, password: str):
    payload = {
        "email": email,
        "password": password,
    }
    try:
        url = f"{BACKEND}/auth/login"
        r = _session.post(url, json=payload, timeout=DEFAULT_TIMEOUT)
        r.raise_for_status()
        return r.json()
    except Exception as e:
        raise RuntimeError(f"Login failed: {e}")


# ---------- LangGraph-backed ----------
def fetch_lesson_content(lesson: str, module: str, topic: str):
    d = _json_or_raise(_req("POST", "/lesson", json={"lesson": lesson, "module": module, "topic": topic}))
    return d.get("lesson_content", "")

def submit_lesson_quiz(lesson: str, module: str, topic: str, responses: dict):
    return _json_or_raise(_req("POST", "/lesson-quiz",
                               json={"lesson": lesson, "module": module, "topic": topic, "responses": responses}))

def submit_practice_quiz(lesson: str, responses: dict):
    return _json_or_raise(_req("POST", "/practice-quiz", json={"lesson": lesson, "responses": responses}))