"""``/api/daily-challenge`` — Daily random challenge with 2× XP.

Every 24 hours a random challenge is picked from the pool. Students
who complete it get double XP (base + bonus via ``/claim``).
"""

import random
from datetime import datetime, date, timedelta, timezone
from typing import Optional

import httpx
from fastapi import APIRouter, Depends, HTTPException, Request
from pydantic import BaseModel

from app.core.auth import get_current_user
from app.core.config import SUPABASE_URL, SUPABASE_ANON_KEY, SUPABASE_EDGE_URL
from app.services.supabase_service import supabase_headers


router = APIRouter()


# Per-type tables we can pick a daily challenge from.
_TABLES: list[tuple[str, str, str]] = [
    ("encryption_challenges", "crypto", "red"),
    ("code_fixing_challenges", "code-fixing", "blue"),
    ("log_analysis_challenges", "log-analysis", "blue"),
    ("vulnerability_hunter_challenges", "vulnerability-hunter", "blue"),
    ("web_exploitation_challenges", "web-exploitation", "red"),
]


class DailyChallengeResponse(BaseModel):
    challengeId: str
    challengeType: str
    teamRole: str
    title: str
    difficulty: str
    xpReward: int
    xpMultiplier: int = 2
    timeRemaining: int  # seconds until midnight
    completed: bool = False


class ClaimRequest(BaseModel):
    challengeId: str
    xpAmount: int = 0


class ClaimResponse(BaseModel):
    bonus: int


# --------------------------------------------------------------------------- #
#  GET /api/daily-challenge                                                    #
# --------------------------------------------------------------------------- #

@router.get("/api/daily-challenge")
async def get_daily_challenge(user: dict = Depends(get_current_user)):
    today = date.today()

    dc = await _fetch_today_daily_challenge(today)
    if dc:
        challenge_info = await _fetch_challenge_info(
            dc["challenge_id"], dc["challenge_type"], dc["team_role"]
        )
        if challenge_info:
            remaining = _seconds_until_midnight()
            completed = await _check_user_completed(user["user_id"], today)
            return DailyChallengeResponse(
                challengeId=dc["challenge_id"],
                challengeType=dc["challenge_type"],
                teamRole=dc["team_role"],
                title=challenge_info["title"],
                difficulty=challenge_info["difficulty"],
                xpReward=int(dc.get("xp_reward", challenge_info["xp_reward"])),
                timeRemaining=remaining,
                completed=completed,
            )

    # No daily challenge for today yet — pick one.
    dc = await _pick_daily_challenge(today)
    if not dc:
        raise HTTPException(status_code=404, detail="لا توجد تحديات متاحة للتحدي اليومي")

    challenge_info = await _fetch_challenge_info(
        dc["challenge_id"], dc["challenge_type"], dc["team_role"]
    )
    if not challenge_info:
        raise HTTPException(status_code=404, detail="التحدي غير متاح حالياً")

    remaining = _seconds_until_midnight()
    completed = await _check_user_completed(user["user_id"], today)
    return DailyChallengeResponse(
        challengeId=dc["challenge_id"],
        challengeType=dc["challenge_type"],
        teamRole=dc["team_role"],
        title=challenge_info["title"],
        difficulty=challenge_info["difficulty"],
        xpReward=int(dc.get("xp_reward", challenge_info["xp_reward"])),
        timeRemaining=remaining,
        completed=completed,
    )


# --------------------------------------------------------------------------- #
#  POST /api/daily-challenge/claim                                             #
# --------------------------------------------------------------------------- #

@router.post("/api/daily-challenge/claim")
async def claim_daily_challenge(
    req: ClaimRequest,
    request: Request,
    user: dict = Depends(get_current_user),
):
    today = date.today()
    dc = await _fetch_today_daily_challenge(today)
    if not dc or dc["challenge_id"] != req.challengeId:
        return ClaimResponse(bonus=0)

    bonus = req.xpAmount or int(dc.get("xp_reward", 150))
    if bonus <= 0:
        return ClaimResponse(bonus=0)

    async with httpx.AsyncClient(timeout=30) as client:
        resp = await client.post(
            f"{SUPABASE_EDGE_URL}/apex-xp",
            json={"action": "add_xp", "user_id": user["user_id"], "xp_amount": bonus},
        )
    if resp.status_code != 200:
        raise HTTPException(status_code=502, detail="فشل إضافة نقاط XP")

    # Mark as completed for this user (idempotent via UNIQUE)
    await _mark_user_completed(user["user_id"], today, req.challengeId)

    return ClaimResponse(bonus=bonus)


# --------------------------------------------------------------------------- #
#  Internal helpers                                                            #
# --------------------------------------------------------------------------- #

async def _check_user_completed(user_id: str, today: date) -> bool:
    if not SUPABASE_URL or not SUPABASE_ANON_KEY:
        return False
    url = (
        f"{SUPABASE_URL}/rest/v1/user_daily_completions"
        f"?user_id=eq.{user_id}&active_date=eq.{today.isoformat()}&limit=1"
    )
    try:
        async with httpx.AsyncClient(timeout=10) as client:
            r = await client.get(url, headers=supabase_headers())
            if r.status_code == 200:
                return len(r.json()) > 0
    except Exception as e:
        print(f"[daily_challenge] check_completed error: {e}")
    return False


async def _mark_user_completed(user_id: str, today: date, challenge_id: str):
    if not SUPABASE_URL or not SUPABASE_ANON_KEY:
        return
    url = f"{SUPABASE_URL}/rest/v1/user_daily_completions"
    headers = supabase_headers(content_type=True)
    headers["Prefer"] = "return=minimal,resolution=ignore-duplicates"
    payload = {
        "user_id": user_id,
        "active_date": today.isoformat(),
        "challenge_id": challenge_id,
    }
    try:
        async with httpx.AsyncClient(timeout=10) as client:
            await client.post(url, json=payload, headers=headers)
    except Exception as e:
        print(f"[daily_challenge] mark_completed error: {e}")


async def _fetch_today_daily_challenge(today: date) -> Optional[dict]:
    if not SUPABASE_URL or not SUPABASE_ANON_KEY:
        return None
    url = (
        f"{SUPABASE_URL}/rest/v1/daily_challenges"
        f"?active_date=eq.{today.isoformat()}&limit=1"
        f"&order=created_at.desc"
    )
    try:
        async with httpx.AsyncClient(timeout=10) as client:
            r = await client.get(url, headers=supabase_headers())
            if r.status_code == 200:
                rows = r.json()
                if rows:
                    return rows[0]
    except Exception as e:
        print(f"[daily_challenge] fetch error: {e}")
    return None


async def _pick_daily_challenge(today: date) -> Optional[dict]:
    if not SUPABASE_URL or not SUPABASE_ANON_KEY:
        return None

    candidates = []
    for table, ctype, team in _TABLES:
        try:
            async with httpx.AsyncClient(timeout=10) as client:
                r = await client.get(
                    f"{SUPABASE_URL}/rest/v1/{table}"
                    f"?select=id,title,difficulty,xp_reward"
                    f"&order=created_at.desc&limit=50",
                    headers=supabase_headers(),
                )
                if r.status_code == 200:
                    rows = r.json()
                    for row in rows:
                        candidates.append((row, ctype, team))
        except Exception as e:
            print(f"[daily_challenge] {table}: {e}")
            continue

    if not candidates:
        return None

    row, ctype, team = random.choice(candidates)
    xp_reward = int(row.get("xp_reward") or 150)

    payload = {
        "challenge_id": row["id"],
        "challenge_type": ctype,
        "team_role": team,
        "xp_reward": xp_reward,
        "active_date": today.isoformat(),
    }

    url = f"{SUPABASE_URL}/rest/v1/daily_challenges"
    headers = supabase_headers(content_type=True)
    headers["Prefer"] = "return=representation,resolution=ignore-duplicates"
    try:
        async with httpx.AsyncClient(timeout=10) as client:
            r = await client.post(url, json=payload, headers=headers)
            if r.status_code in (200, 201):
                rows = r.json()
                if rows:
                    return rows[0]
            else:
                print(f"[daily_challenge] insert failed: {r.status_code} {r.text[:200]}")
    except Exception as e:
        print(f"[daily_challenge] insert exception: {e}")

    return payload  # best-effort return


async def _fetch_challenge_info(
    challenge_id: str, challenge_type: str, team_role: str
) -> Optional[dict]:
    table = {
        "crypto": "encryption_challenges",
        "code-fixing": "code_fixing_challenges",
        "log-analysis": "log_analysis_challenges",
        "vulnerability-hunter": "vulnerability_hunter_challenges",
        "web-exploitation": "web_exploitation_challenges",
    }.get(challenge_type)

    if not table or not SUPABASE_URL or not SUPABASE_ANON_KEY:
        return None

    url = f"{SUPABASE_URL}/rest/v1/{table}?id=eq.{challenge_id}&limit=1"
    try:
        async with httpx.AsyncClient(timeout=10) as client:
            r = await client.get(url, headers=supabase_headers())
            if r.status_code == 200:
                rows = r.json()
                if rows:
                    return rows[0]
    except Exception as e:
        print(f"[daily_challenge] fetch_challenge_info: {e}")
    return None


def _seconds_until_midnight() -> int:
    now = datetime.now(timezone.utc)
    midnight = datetime(now.year, now.month, now.day, tzinfo=timezone.utc).replace(
        hour=0, minute=0, second=0
    ) + timedelta(days=1)
    return int((midnight - now).total_seconds())