"""
Integrate Agenta with FastAPI for production deployments.
"""
from fastapi import FastAPI, HTTPException
from pydantic import BaseModel
from typing import Optional
import agenta as ag
from agenta import Agenta

app = FastAPI(title="Agenta-Powered API")

# Initialize Agenta
ag.init()
client = Agenta()


class QueryRequest(BaseModel):
    """Request model for queries."""
    input: str
    variant: Optional[str] = None
    parameters: Optional[dict] = None


class QueryResponse(BaseModel):
    """Response model."""
    output: str
    variant_used: str
    latency: float


@app.post("/generate", response_model=QueryResponse)
async def generate(request: QueryRequest):
    """Generate response using Agenta-managed prompts."""
    import time

    try:
        # Get variant (default or specified)
        if request.variant:
            variant = client.get_variant_by_name(
                app_name="production-app",
                variant_name=request.variant
            )
        else:
            variant = client.get_default_variant(app_name="production-app")

        # Get prompt template
        template = variant.config.get("template", "{input}")
        prompt = template.format(input=request.input)

        # Get parameters
        params = variant.config.get("parameters", {})
        if request.parameters:
            params.update(request.parameters)

        # Generate
        start_time = time.time()
        response = ag.llm.complete(prompt=prompt, **params)
        latency = time.time() - start_time

        return QueryResponse(
            output=response.text,
            variant_used=variant.name,
            latency=latency
        )

    except Exception as e:
        raise HTTPException(status_code=500, detail=str(e))


@app.get("/variants")
async def list_variants():
    """List available variants."""
    variants = client.list_variants(app_name="production-app")
    return [{"name": v.name, "id": v.id, "is_default": v.is_default} for v in variants]


# Run with: uvicorn api:app --reload