from fastapi import FastAPI, Request, HTTPException
from fastapi.middleware.cors import CORSMiddleware
from pydantic import BaseModel, EmailStr, Field
from typing import Optional, List
import os, time, json
from app.emailer import send_smtp_email, send_webhook
from dotenv import load_dotenv
load_dotenv()

RATE_LIMIT_BUCKETS = {}  # {ip: [timestamps]}
RL_WINDOW_SEC = int(os.getenv("RL_WINDOW_SEC", "600"))   # 10 min
RL_MAX_REQ = int(os.getenv("RL_MAX_REQ", "5"))

ALLOW_ORIGINS = [o.strip() for o in os.getenv("ALLOW_ORIGINS", "*").split(",")]
SMTP_HOST = os.getenv("SMTP_HOST")
SMTP_PORT = int(os.getenv("SMTP_PORT", "587"))
SMTP_USER = os.getenv("SMTP_USER")
SMTP_PASS = os.getenv("SMTP_PASS")
MAIL_TO = os.getenv("MAIL_TO")         # where to send
MAIL_FROM = os.getenv("MAIL_FROM", SMTP_USER or "noreply@example.com")

WEBHOOK_URL = os.getenv("WEBHOOK_URL")  # alternative to SMTP

# ------- Models
class ContactIn(BaseModel):
    name: str = Field(min_length=2, max_length=120)
    email: EmailStr
    subject: str = Field(min_length=2, max_length=200)
    message: str = Field(min_length=5, max_length=5000)
    company: Optional[str] = None  # honeypot
    _href: Optional[str] = None
    _ua: Optional[str] = None

class ContactOut(BaseModel):
    ok: bool
    message: str

# ------- App
app = FastAPI(title="Contact API", version="1.0.0")

app.add_middleware(
    CORSMiddleware,
    allow_origins=["*"] if ALLOW_ORIGINS == ["*"] else ALLOW_ORIGINS,
    allow_credentials=False,
    allow_methods=["POST", "GET", "OPTIONS"],
    allow_headers=["*"],
)

# ------- Helpers
def client_ip(req: Request) -> str:
    # trust proxy headers if present (Traefik/Nginx)
    xff = req.headers.get("x-forwarded-for")
    if xff:
        return xff.split(",")[0].strip()
    return req.client.host if req.client else "unknown"

def rate_limit_check(ip: str):
    now = time.time()
    window_start = now - RL_WINDOW_SEC
    bucket = RATE_LIMIT_BUCKETS.get(ip, [])
    bucket = [t for t in bucket if t >= window_start]
    if len(bucket) >= RL_MAX_REQ:
        raise HTTPException(status_code=429, detail="Too many requests. Try again later.")
    bucket.append(now)
    RATE_LIMIT_BUCKETS[ip] = bucket

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

@app.post("/api/contact", response_model=ContactOut)
async def contact(req: Request, data: ContactIn):
    ip = client_ip(req)
    rate_limit_check(ip)

    # Prepare content
    meta = {
        "ip": ip,
        "href": data._href,
        "ua": data._ua,
    }
    subject = f"[Contact] {data.subject} — {data.name}"
    text_body = (
        f"Name: {data.name}\n"
        f"Email: {data.email}\n"
        f"Subject: {data.subject}\n\n"
        f"{data.message}\n\n"
        f"--\nmeta: {json.dumps(meta, ensure_ascii=False)}"
    )

    # Dispatch: SMTP preferred, else webhook
    delivered = False
    error_messages: List[str] = []

    if SMTP_HOST and MAIL_TO:
        try:
            send_smtp_email(
                host=SMTP_HOST,
                port=SMTP_PORT,
                user=SMTP_USER,
                password=SMTP_PASS,
                mail_from=MAIL_FROM,
                mail_to=MAIL_TO,
                subject=subject,
                body=text_body,
            )
            delivered = True
        except Exception as e:
            error_messages.append(f"smtp: {e}")

    if not delivered and WEBHOOK_URL:
        try:
            send_webhook(WEBHOOK_URL, {
                "subject": subject,
                "from": f"{data.name} <{data.email}>",
                "message": data.message,
                "meta": meta,
            })
            delivered = True
        except Exception as e:
            error_messages.append(f"webhook: {e}")

    if not delivered:
        print("[WARN] Contact not delivered", {"errors": error_messages})
        return ContactOut(ok=False, message="Sorry, something went wrong. Please try again later.")

    return ContactOut(ok=True, message="Thanks! I’ll reply soon.")


if __name__ == "__main__":
    import uvicorn
    uvicorn.run(app, host="0.0.0.0", port=8000)