import asyncio
import logging
import os
import sqlite3
from contextlib import asynccontextmanager
from typing import Any, Dict, List, Optional

import aiohttp
import uvicorn
from fastapi import FastAPI, File, Form, HTTPException, UploadFile
from fastapi.responses import JSONResponse
from llama_cpp import Llama
from pydantic import BaseModel, Field

# ------------------------------------------------------------
# Configuration (env overrides)
# ------------------------------------------------------------
MODEL_PATH = os.getenv("MODEL_PATH", "models/gemma-3-1b-it-Q4_K_M.gguf")
N_CTX = int(os.getenv("N_CTX", "2048"))
N_THREADS = int(os.getenv("N_THREADS", "4"))
ORANGE_PI_PORT = int(os.getenv("ORANGE_PI_PORT", "8080"))  # default port
UPLOAD_TIMEOUT = float(os.getenv("UPLOAD_TIMEOUT", "300.0"))  # for uploads
REQUEST_TIMEOUT = float(os.getenv("REQUEST_TIMEOUT", "30.0"))  # for other requests
DB_PATH = os.getenv("DB_PATH", "orangepi.db")

SYNTHESIS_TEMP = float(os.getenv("SYNTHESIS_TEMP", "0.5"))
SYNTHESIS_MAX_TOKENS = int(os.getenv("SYNTHESIS_MAX_TOKENS", "512"))

# ------------------------------------------------------------
# Logging
# ------------------------------------------------------------
logging.basicConfig(level=logging.INFO)
logger = logging.getLogger("orchestrator")


# ------------------------------------------------------------
# Database helpers
# ------------------------------------------------------------
def init_db():
    conn = sqlite3.connect(DB_PATH)
    c = conn.cursor()
    c.execute("""
        CREATE TABLE IF NOT EXISTS orangepi_devices (
            id INTEGER PRIMARY KEY AUTOINCREMENT,
            ip TEXT NOT NULL UNIQUE,
            port INTEGER DEFAULT 8080,
            enabled INTEGER DEFAULT 1,
            name TEXT
        )
    """)
    conn.commit()
    conn.close()


def get_all_enabled_ips() -> List[Dict[str, Any]]:
    conn = sqlite3.connect(DB_PATH)
    c = conn.cursor()
    c.execute("SELECT ip, port FROM orangepi_devices WHERE enabled = 1")
    rows = c.fetchall()
    conn.close()
    return [{"ip": row[0], "port": row[1]} for row in rows]


def get_device(ip: str) -> Optional[Dict[str, Any]]:
    conn = sqlite3.connect(DB_PATH)
    c = conn.cursor()
    c.execute(
        "SELECT ip, port FROM orangepi_devices WHERE ip = ? AND enabled = 1", (ip,)
    )
    row = c.fetchone()
    conn.close()
    if row:
        return {"ip": row[0], "port": row[1]}
    return None


def add_or_update_device(ip: str, port: int = None, name: str = None):
    if port is None:
        port = ORANGE_PI_PORT
    conn = sqlite3.connect(DB_PATH)
    c = conn.cursor()
    c.execute(
        """
        INSERT INTO orangepi_devices (ip, port, name)
        VALUES (?, ?, ?)
        ON CONFLICT(ip) DO UPDATE SET
            port = excluded.port,
            name = excluded.name,
            enabled = 1
    """,
        (ip, port, name),
    )
    conn.commit()
    conn.close()


def remove_device(ip: str):
    conn = sqlite3.connect(DB_PATH)
    c = conn.cursor()
    c.execute("UPDATE orangepi_devices SET enabled = 0 WHERE ip = ?", (ip,))
    conn.commit()
    conn.close()


# ------------------------------------------------------------
# Global model
# ------------------------------------------------------------
llm_model = None


@asynccontextmanager
async def lifespan(app: FastAPI):
    global llm_model
    init_db()
    logger.info(f"Loading GGUF model from {MODEL_PATH} ...")
    try:
        llm_model = Llama(
            model_path=MODEL_PATH,
            n_ctx=N_CTX,
            n_threads=N_THREADS,
            verbose=False,
        )
        logger.info("Model loaded successfully.")
    except Exception as e:
        logger.error(f"Failed to load model: {e}")
        raise RuntimeError("Model loading failed")
    yield
    del llm_model


app = FastAPI(
    title="OrangePi Coordinator with File Upload & Document Listing",
    description="Orchestrate multiple Orange Pi RAG services: ask questions, upload files, list documents.",
    version="2.0",
    lifespan=lifespan,
)


# ------------------------------------------------------------
# Request/Response Schemas
# ------------------------------------------------------------
class AskRequest(BaseModel):
    question: str


class DeviceRegister(BaseModel):
    ip: str
    port: int = Field(ORANGE_PI_PORT, ge=1, le=65535)
    name: str | None = None


class DeviceRemove(BaseModel):
    ip: str


class AskResponse(BaseModel):
    final_answer: str
    raw_responses: Dict[str, str]
    synthesis_used: bool = True


# ------------------------------------------------------------
# Helper: forward requests to Orange Pi
# ------------------------------------------------------------
async def forward_to_orange_pi(
    ip: str,
    port: int,
    path: str,
    method: str = "GET",
    data: Any = None,
    files: Any = None,
    is_upload: bool = False,
) -> tuple[dict, int]:
    url = f"http://{ip}:{port}{path}"
    timeout = UPLOAD_TIMEOUT if is_upload else REQUEST_TIMEOUT
    async with aiohttp.ClientSession() as session:
        try:
            if method.upper() == "GET":
                async with session.get(url, timeout=timeout) as resp:
                    text = await resp.text()
                    if resp.content_type == "application/json":
                        return await resp.json(), resp.status
                    else:
                        return {
                            "error": f"Non-JSON response: {text[:200]}"
                        }, resp.status
            elif method.upper() == "POST":
                if files:
                    form_data = aiohttp.FormData()
                    for key, file_obj in files.items():
                        # Stream the file without reading entirely into memory
                        # file_obj is starlette.datastructures.UploadFile
                        # We'll read in chunks, but aiohttp can handle streaming if we pass a file-like object
                        # However, file_obj.file is a SpooledTemporaryFile; we can pass it directly
                        form_data.add_field(
                            key,
                            file_obj.file,
                            filename=file_obj.filename,
                            content_type=file_obj.content_type
                            or "application/octet-stream",
                        )
                    async with session.post(
                        url, data=form_data, timeout=timeout
                    ) as resp:
                        return await resp.json(), resp.status
                else:
                    async with session.post(url, json=data, timeout=timeout) as resp:
                        return await resp.json(), resp.status
            else:
                return {"error": "Unsupported method"}, 405
        except asyncio.TimeoutError:
            logger.error(f"Timeout forwarding to {ip}:{port}{path}")
            return {"error": "Request timeout"}, 504
        except Exception as e:
            logger.error(f"Error forwarding to {ip}:{port}{path}: {e}", exc_info=True)
            return {"error": str(e)}, 500


# ------------------------------------------------------------
# Existing: query all Orange Pis for an answer
# ------------------------------------------------------------
async def query_orange_pi_answer(
    ip: str, port: int, question: str, session: aiohttp.ClientSession
) -> tuple[str, str | None, str | None]:
    url = f"http://{ip}:{port}/answer"
    payload = {"question": question}
    try:
        async with session.post(url, json=payload, timeout=REQUEST_TIMEOUT) as resp:
            if resp.status == 200:
                data = await resp.json()
                answer = data.get("answer", "")
                return (ip, answer, None)
            else:
                return (ip, None, f"HTTP {resp.status}")
    except asyncio.TimeoutError:
        return (ip, None, "Timeout")
    except Exception as e:
        return (ip, None, str(e))


async def gather_responses(question: str) -> Dict[str, str]:
    devices = get_all_enabled_ips()
    if not devices:
        return {}
    async with aiohttp.ClientSession() as session:
        tasks = [
            query_orange_pi_answer(dev["ip"], dev["port"], question, session)
            for dev in devices
        ]
        results = await asyncio.gather(*tasks)
    response_map = {}
    for ip, answer, error in results:
        if answer is not None:
            response_map[ip] = answer
        else:
            response_map[ip] = f"[ERROR: {error}]"
    return response_map


def synthesize_answer(original_question: str, responses: Dict[str, str]) -> str:
    if not responses:
        return "No responses received from any Orange Pi device."
    responses_text = "\n".join(
        [f"- Device {ip}: {resp}" for ip, resp in responses.items()]
    )
    prompt = f"""You are an aggregator that synthesizes answers from multiple sources.

Original user question: question{original_question}

Responses from different Orange Pi devices:
{responses_text}

Please provide a single, coherent, and concise final answer based on all the above responses.
If there are conflicts, mention the different viewpoints. If some responses are errors, ignore them.
Final answer:
"""
    output = llm_model.create_completion(
        prompt=prompt,
        max_tokens=SYNTHESIS_MAX_TOKENS,
        temperature=SYNTHESIS_TEMP,
        stop=["\n\n", "User question:", "Original user question:"],
        echo=False,
    )
    return output["choices"][0]["text"].strip()


# ------------------------------------------------------------
# NEW: Upload a PDF to a specific Orange Pi
# ------------------------------------------------------------
@app.post("/devices/{device_ip}/upload")
async def upload_to_device(device_ip: str, file: UploadFile = File(...)):
    """
    Upload a PDF file to a specific Orange Pi (by IP address).
    The Orange Pi must have the RAG service running with /upload endpoint.
    """
    # Check if device is registered and enabled
    device = get_device(device_ip)
    if not device:
        raise HTTPException(
            status_code=404, detail=f"Device {device_ip} not registered or disabled"
        )

    result, status = await forward_to_orange_pi(
        ip=device["ip"],
        port=device["port"],
        path="/upload",
        method="POST",
        files={"file": file},
        is_upload=True,
    )
    if status != 200:
        raise HTTPException(
            status_code=status,
            detail=result.get("detail", result.get("error", "Upload failed")),
        )
    return JSONResponse(content=result)


@app.get("/devices/documents")
async def list_all_documents(device_ip: Optional[str] = None):
    """Retrieve the list of indexed documents from all registered Orange Pis."""
    if device_ip:
        devices = [get_device(device_ip)]
        if not devices[0]:
            raise HTTPException(status_code=404, detail=f"Device {device_ip} not found")
    else:
        devices = get_all_enabled_ips()
        if not devices:
            raise HTTPException(
                status_code=404, detail="No Orange Pi devices registered"
            )

    results = {}
    async with aiohttp.ClientSession() as session:
        tasks = []
        for dev in devices:
            url = f"http://{dev['ip']}:{dev['port']}/documents"
            tasks.append(fetch_documents(session, dev["ip"], url))
        outcomes = await asyncio.gather(*tasks)
        for ip, docs, error in outcomes:
            if error:
                results[ip] = {"error": error}
            else:
                # Ensure docs is a dict before calling .get()
                if isinstance(docs, dict):
                    results[ip] = docs.get("documents", [])
                else:
                    results[ip] = []
    return {"documents_by_device": results}


async def fetch_documents(session: aiohttp.ClientSession, ip: str, url: str):
    try:
        async with session.get(url, timeout=REQUEST_TIMEOUT) as resp:
            if resp.status == 200:
                data = await resp.json()
                return (ip, data, None)
            else:
                return (ip, None, f"HTTP {resp.status}")
    except Exception as e:
        return (ip, None, str(e))


# ------------------------------------------------------------
# Existing endpoints (health, devices/register, devices/remove, devices/list, ask)
# ------------------------------------------------------------
@app.get("/health")
async def health():
    return {"status": "ok", "model_loaded": llm_model is not None}


@app.post("/devices/register")
async def register_device(device: DeviceRegister):
    add_or_update_device(device.ip, device.port, device.name)
    return {"message": f"Device {device.ip} registered/updated"}


@app.post("/devices/remove")
async def delete_device(device: DeviceRemove):
    remove_device(device.ip)
    return {"message": f"Device {device.ip} disabled"}


@app.get("/devices/list")
async def list_devices():
    devices = get_all_enabled_ips()
    return {"devices": devices}


@app.post("/ask", response_model=AskResponse)
async def ask_swarm(request: AskRequest):
    if llm_model is None:
        raise HTTPException(status_code=503, detail="Local GGUF model not loaded")
    responses = await gather_responses(request.question)
    if not responses:
        raise HTTPException(
            status_code=503,
            detail="No Orange Pi devices available or all requests failed",
        )
    final_answer = synthesize_answer(request.question, responses)
    return AskResponse(
        final_answer=final_answer, raw_responses=responses, synthesis_used=True
    )

@app.delete("/devices/{device_ip}/documents/{doc_id}")
async def delete_document_on_device(device_ip: str, doc_id: str):
    """Delete a document from a specific Orange Pi."""
    device = get_device(device_ip)
    if not device:
        raise HTTPException(status_code=404, detail=f"Device {device_ip} not registered")

    url = f"http://{device['ip']}:{device['port']}/documents/{doc_id}"
    async with aiohttp.ClientSession() as session:
        try:
            async with session.delete(url, timeout=REQUEST_TIMEOUT) as resp:
                if resp.status == 200:
                    result = await resp.json()
                    return result
                else:
                    error_text = await resp.text()
                    raise HTTPException(status_code=resp.status, detail=error_text)
        except Exception as e:
            logger.error(f"Error deleting document on {device_ip}: {e}")
            raise HTTPException(status_code=500, detail=str(e))

# ------------------------------------------------------------
# Run
# ------------------------------------------------------------
if __name__ == "__main__":
    uvicorn.run(
        "backend:app", host="0.0.0.0", port=8000, reload=False, log_level="info"
    )