from fastapi import FastAPI, HTTPException
from fastapi.middleware.cors import CORSMiddleware
from fastapi.staticfiles import StaticFiles
from fastapi.responses import FileResponse
from pydantic import BaseModel
import os
import json
import httpx
import redis

app = FastAPI(title="Manus Clone")

app.add_middleware(
    CORSMiddleware,
    allow_origins=["*"],
    allow_credentials=True,
    allow_methods=["*"],
    allow_headers=["*"],
)

# ── Redis connection (2GB, localhost) ──────────────────────────────────────────
try:
    r = redis.Redis(host="localhost", port=6379, db=0, decode_responses=True)
    r.ping()
    REDIS_OK = True
except Exception:
    REDIS_OK = False

class ChatRequest(BaseModel):
    prompt: str
    model: str = "llama-3.1-8b-instant"
    api_key: str = ""
    provider: str = "Groq"

PROVIDER_BASES = {
    "OpenAI":      "https://api.openai.com/v1",
    "Anthropic":   "https://api.anthropic.com/v1",
    "Groq":        "https://api.groq.com/openai/v1",
    "HuggingFace": "https://api-inference.huggingface.co/v1",
    "OpenRouter":  "https://openrouter.ai/api/v1",
    "Nvidia":      "https://integrate.api.nvidia.com/v1",
    "Mistral":     "https://api.mistral.ai/v1",
    "Cohere":      "https://api.cohere.ai/v1",
}

# ── API endpoints ─────────────────────────────────────────────────────────────

@app.get("/health")
def health():
    return {"status": "ok", "redis": REDIS_OK}

@app.post("/chat")
async def chat_endpoint(request: ChatRequest):
    api_key = (
        request.api_key.strip()
        or os.environ.get("GROQ_API_KEY", "")
        or os.environ.get("OPENAI_API_KEY", "")
    )

    if not api_key:
        return {
            "response": (
                f'[Manus] Received: "{request.prompt}"\n\n'
                "No API key configured. Please add your key via the Providers panel."
            ),
            "doc": True
        }

    base_url = PROVIDER_BASES.get(request.provider, PROVIDER_BASES["Groq"])

    # Build headers
    headers = {
        "Authorization": f"Bearer {api_key}",
        "Content-Type": "application/json",
    }

    # OpenRouter needs extra headers for some models
    if request.provider == "OpenRouter":
        headers["HTTP-Referer"] = "https://augment17-logic-engine.hf.space"
        headers["X-Title"] = "Manus Clone"

    try:
        async with httpx.AsyncClient(timeout=60) as client:
            resp = await client.post(
                f"{base_url}/chat/completions",
                headers=headers,
                json={
                    "model": request.model,
                    "messages": [
                        {"role": "system", "content": "You are Manus, a helpful and concise autonomous AI agent."},
                        {"role": "user", "content": request.prompt},
                    ],
                    "temperature": 0.7,
                }
            )
            resp.raise_for_status()
            data = resp.json()

            # Robust response extraction
            reply = None
            try:
                choices = data.get("choices", [])
                if choices and len(choices) > 0:
                    choice = choices[0]
                    msg = choice.get("message") or choice.get("delta") or {}
                    reply = msg.get("content") or choice.get("text") or ""
            except (KeyError, IndexError, TypeError):
                pass

            # Fallback keys
            if not reply:
                reply = (
                    data.get("text")
                    or data.get("output")
                    or data.get("response")
                    or data.get("content")
                    or data.get("result")
                    or ""
                )

            # Empty choices = model not found / not available
            if not reply:
                raise HTTPException(
                    status_code=404,
                    detail=(
                        f"Model '{request.model}' returned an empty response from {request.provider}. "
                        f"This usually means the model does not exist on {request.provider}'s API. "
                        f"Try a different model or switch to OpenRouter which supports more models."
                    )
                )

            # Cache to Redis if available
            if REDIS_OK:
                try:
                    cache_key = f"chat:{request.provider}:{request.model}:{request.prompt[:100]}"
                    r.setex(cache_key, 3600, reply)
                except Exception:
                    pass

            return {"response": reply, "doc": True}

    except HTTPException:
        raise
    except httpx.HTTPStatusError as e:
        status = e.response.status_code
        try:
            err_body = e.response.json()
            err_msg = err_body.get("error", {}).get("message", e.response.text[:300])
        except Exception:
            err_msg = e.response.text[:300]

        if status == 401:
            detail = (
                f"401 Unauthorized from {request.provider}. "
                f"Check that your API key is valid for {request.provider} "
                f"and that the model '{request.model}' is available on {request.provider}. "
                f"Tip: Make sure the model you selected belongs to the same provider as your API key."
            )
        elif status == 400:
            detail = f"400 Bad Request from {request.provider}: {err_msg}"
        elif status == 404:
            detail = f"404: Model '{request.model}' not found on {request.provider}. Select a model from the correct provider tab."
        else:
            detail = f"Provider error {status}: {err_msg}"
        raise HTTPException(status_code=status, detail=detail)
    except Exception as e:
        raise HTTPException(status_code=500, detail=str(e))

# ── Serve React UI (MUST be last, catches all non-API routes) ─────────────────
static_dir = os.path.join(os.path.dirname(__file__), "static")
if os.path.isdir(static_dir):
    @app.get("/{full_path:path}")
    async def serve_spa(full_path: str):
        file_path = os.path.join(static_dir, full_path)
        if full_path and os.path.isfile(file_path):
            return FileResponse(file_path)
        return FileResponse(os.path.join(static_dir, "index.html"))