from fastapi import APIRouter, Depends, HTTPException
from datetime import datetime, timezone
from typing import List
import random

from app.database import get_db
from app.models.pronunciation import PronunciationDB
from app.services.gemini_service import get_word_pronunciation

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

TECH_TERMS = [
    "Kubernetes", "PostgreSQL", "Nginx", "Polymorphism", "Encapsulation",
    "Asynchronous", "Concurrency", "Django", "Vue", "TypeScript",
    "GraphQL", "Docker", "Microservices", "Idempotent", "Heuristic",
    "Tuple", "Boolean", "JSON", "YAML", "Ubuntu",
    "Vite", "Pinia", "Axios", "FastAPI", "Uvicorn",
    "OAuth", "JWT", "PyMuPDF", "GridFS", "MongoDB",
    "Motor", "Asynchronous", "Middleware", "Interceptor", "Composition",
    "Component", "Reactive", "Computed", "State", "Mutation",
    "Action", "Getter", "Router", "Guard", "Plugin"
]

@router.get("/tech-terms", response_model=List[str])
async def get_tech_terms():
    """Returns a list of 50 common tech terms to prepopulate the UI."""
    return TECH_TERMS

@router.get("/word-of-the-day")
async def get_word_of_the_day(db=Depends(get_db)):
    """Returns a random word from the DB, or a default one if DB is empty."""
    count = await db["pronunciations"].count_documents({})
    if count == 0:
        return {"word": "Polymorphism", "phonetic": "/ˌpɒlɪˈmɔːfɪzəm/", "definition": "The provision of a single interface to entities of different types."}
    
    # Pick a random document
    import random
    random_skip = random.randint(0, count - 1)
    doc = await db["pronunciations"].find().skip(random_skip).limit(1).to_list(length=1)
    
    if doc:
        return {
            "word": doc[0]["word"],
            "phonetic": doc[0]["phonetic"],
            "definition": doc[0]["definition"]
        }
    return {"word": "Polymorphism", "phonetic": "/ˌpɒlɪˈmɔːfɪzəm/", "definition": "The provision of a single interface to entities of different types."}

@router.get("/{word}", response_model=PronunciationDB)
async def get_pronunciation(word: str, db=Depends(get_db)):
    """Fetches pronunciation info from MongoDB or Gemini."""
    word_lower = word.lower().strip()
    
    # 1. Check DB Cache
    existing = await db["pronunciations"].find_one({"word_lower": word_lower})
    if existing:
        existing["id"] = str(existing.pop("_id"))
        return existing
        
    # 2. Call Gemini
    try:
        data = await get_word_pronunciation(word)
    except Exception as e:
        raise HTTPException(status_code=500, detail=str(e))
        
    # 3. Store in DB
    now = datetime.now(timezone.utc)
    doc = {
        "word": data["word"],
        "word_lower": word_lower,
        "phonetic": data["phonetic"],
        "syllables": data["syllables"],
        "definition": data["definition"],
        "created_at": now
    }
    
    result = await db["pronunciations"].insert_one(doc)
    doc["id"] = str(result.inserted_id)
    return doc