from fastapi import FastAPI, Depends, Request
from fastapi.staticfiles import StaticFiles
from fastapi.middleware.cors import CORSMiddleware
from fastapi.middleware.gzip import GZipMiddleware
from fastapi.responses import JSONResponse
from slowapi import Limiter
from slowapi.util import get_remote_address
from slowapi.errors import RateLimitExceeded
from routers import docker_router, gitea, files, terminal, system, auth, chat_summary, security, passkey, totp, litellm, cc_connect, info_engine
import auth as auth_module
from rbac import require_page, require_write

import asyncio
import httpx
import logging
import time
import jwt
from datetime import datetime, timezone, timedelta
from config import TELEGRAM_BOT_TOKEN, TELEGRAM_CHAT_ID, CORS_ORIGINS, SECRET_KEY, ALGORITHM, VOLUME_ROOT

_tz_cst = timezone(timedelta(hours=8))

limiter = Limiter(key_func=get_remote_address)
app = FastAPI(title="NAS Dashboard")
app.state.limiter = limiter

app.add_middleware(
    CORSMiddleware,
    allow_origins=CORS_ORIGINS,
    allow_credentials=True,
    allow_methods=["GET", "POST", "DELETE", "OPTIONS"],
    allow_headers=["Authorization", "Content-Type"],
)

# Compress responses (static files and API responses)
app.add_middleware(GZipMiddleware, minimum_size=1000)

@app.exception_handler(RateLimitExceeded)
async def rate_limit_handler(request: Request, exc: RateLimitExceeded):
    return JSONResponse(status_code=429, content={"detail": "Too many requests, try again later"})

@app.middleware("http")
async def security_headers(request: Request, call_next):
    response = await call_next(request)
    response.headers["X-Content-Type-Options"] = "nosniff"
    response.headers["X-Frame-Options"] = "DENY"
    response.headers["X-XSS-Protection"] = "1; mode=block"
    response.headers["Referrer-Policy"] = "strict-origin-when-cross-origin"
    response.headers["Content-Security-Policy"] = "default-src 'self'; script-src 'self'; style-src 'self' 'unsafe-inline'; img-src 'self' data:; connect-src 'self' wss: ws:; frame-ancestors 'none'"

    # Cache static assets with hashed filenames (Vite generates these)
    if request.url.path.startswith("/assets/"):
        response.headers["Cache-Control"] = "public, max-age=31536000, immutable"

    return response

# Audit logger
import os
_audit_log_path = os.path.join(VOLUME_ROOT, "docker/nas-dashboard/audit.log")
os.makedirs(os.path.dirname(_audit_log_path), exist_ok=True)
_audit_logger = logging.getLogger("audit")
_audit_logger.setLevel(logging.INFO)
_audit_handler = logging.FileHandler(_audit_log_path)
_audit_handler.setFormatter(logging.Formatter("%(message)s"))
_audit_logger.addHandler(_audit_handler)
_audit_logger.propagate = False

@app.middleware("http")
async def audit_log(request: Request, call_next):
    start = time.time()
    response = await call_next(request)
    duration = int((time.time() - start) * 1000)
    user = "-"
    try:
        auth_header = request.headers.get("authorization", "")
        if auth_header.startswith("Bearer "):
            payload = jwt.decode(auth_header[7:], SECRET_KEY, algorithms=[ALGORITHM])
            user = payload.get("sub", "-")
    except jwt.PyJWTError:
        user = "Invalid/Malformed Token"
    except Exception:
        pass
    _audit_logger.info(
        "%s %s %s %s %s %d %dms",
        datetime.now(_tz_cst).strftime("%Y-%m-%dT%H:%M:%S"), request.client.host, user,
        request.method, request.url.path, response.status_code, duration,
    )
    return response

async def monitor_containers():
    import docker
    from config import DOCKER_HOST
    client = docker.DockerClient(base_url=DOCKER_HOST)
    
    # Store initial states
    previous_states = {}
    
    while True:
        try:
            for c in client.containers.list(all=True):
                current_status = c.status
                if c.id in previous_states:
                    prev_status = previous_states[c.id]
                    # Alert if it transitioned from running to exited or unhealthy
                    if prev_status == "running" and current_status in ("exited", "dead"):
                        msg = f"⚠️ *Container Alert* ⚠️\nContainer `{c.name}` just stopped unexpectedly (Status: {current_status})."
                        # Use httpx directly as system.send_notification expects a FastAPI request object usually
                        if TELEGRAM_BOT_TOKEN and TELEGRAM_CHAT_ID:
                            proxy_url = os.environ.get("TELEGRAM_PROXY")
                            async with httpx.AsyncClient(proxy=proxy_url) as hc:
                                await hc.post(
                                    f"https://api.telegram.org/bot{TELEGRAM_BOT_TOKEN}/sendMessage",
                                    data={"chat_id": TELEGRAM_CHAT_ID, "text": msg, "parse_mode": "Markdown"},
                                )
                previous_states[c.id] = current_status
        except Exception as e:
            logging.getLogger(__name__).error("Error in container monitor: %s", e)
        
        await asyncio.sleep(60)

@app.on_event("startup")
async def startup_event():
    asyncio.create_task(monitor_containers())

@app.get("/api/health")
async def health():
    return {"status": "ok"}

@app.get("/api/client-ip")
async def client_ip(request: Request):
    ip = request.client.host
    import config
    if config.is_trusted_proxy(ip):
        forwarded = request.headers.get("x-forwarded-for", "").split(",")[0].strip()
        if forwarded:
            ip = forwarded

    # LAN detection logic:
    # - True LAN IP (192.168.31.x) → lan=True
    # - Tailscale IP with router reachable → lan=True (user at home with Tailscale)
    # - Tailscale IP without router reachable → lan=False (remote via VPS proxy)
    # - Other IPs → lan=False (public internet)
    if config.is_lan_ip(ip):
        lan = True
    elif config.is_tailscale_ip(ip):
        lan = _router_reachable()
    else:
        lan = False

    return {"lan": lan}

def _router_reachable():
    import socket
    try:
        s = socket.socket()
        s.settimeout(1)
        s.connect(("192.168.31.1", 80))
        s.close()
        return True
    except Exception:
        return False

# Dependency to store user in request.state for rbac dependencies
async def _inject_user(request: Request, user = Depends(auth_module.get_current_user)):
    request.state.user = user
    return user

# Public auth endpoints
app.include_router(auth.router, prefix="/api/auth", tags=["auth"])
app.include_router(passkey.router, prefix="/api/auth", tags=["passkey"])
app.include_router(totp.router, prefix="/api/auth", tags=["totp"])

# Protected endpoints with page-level RBAC
app.include_router(docker_router.router, prefix="/api/docker",
    dependencies=[Depends(_inject_user), Depends(require_page("docker")), Depends(require_write())])
app.include_router(gitea.router, prefix="/api/gitea",
    dependencies=[Depends(_inject_user), Depends(require_page("gitea"))])
app.include_router(files.router, prefix="/api/files",
    dependencies=[Depends(_inject_user), Depends(require_page("files")), Depends(require_write())])
app.include_router(system.router, prefix="/api/system",
    dependencies=[Depends(_inject_user), Depends(require_page("dashboard"))])
app.include_router(litellm.router, prefix="/api/litellm",
    dependencies=[Depends(_inject_user), Depends(require_page("dashboard"))])
app.include_router(cc_connect.router, prefix="/api/cc-connect",
    dependencies=[Depends(_inject_user), Depends(require_page("dashboard"))])
app.include_router(chat_summary.router, prefix="/api/chat-summary",
    dependencies=[Depends(_inject_user), Depends(require_page("chat-digest"))])
app.include_router(info_engine.router, prefix="/api/info-engine",
    dependencies=[Depends(_inject_user), Depends(require_page("dashboard"))])
app.include_router(security.router, prefix="/api/security",
    dependencies=[Depends(_inject_user), Depends(require_page("security"))])

# WebSocket endpoint (auth handled inside handler via Query param)
app.add_api_websocket_route("/ws/terminal", terminal.ws_endpoint)

app.mount("/", StaticFiles(directory="/app/static", html=True), name="static")