"""
DealFlow AI — Configuration
Loads env vars and constructs the LLM clients for CrewAI.

AMD Fallback Status: LOCKED at T+63h (2026-05-06).
Primary backend: HuggingFace Serverless Inference API (Qwen/Qwen2.5-72B-Instruct).
AMD MI300X bonus track abandoned per PRE-FLIGHT SPEC #3.
"""
from __future__ import annotations

import os
from enum import Enum
from pathlib import Path
from typing import Optional

from dotenv import load_dotenv
from loguru import logger
from pydantic import BaseModel, Field

load_dotenv()


class Backend(str, Enum):
    VLLM = "vllm"
    HF = "hf"
    OPENAI = "openai"


# HF Serverless Inference — featherless-ai provider (supports Qwen2.5-72B)
# Verified working endpoint for Qwen/Qwen2.5-72B-Instruct
HF_ROUTER_BASE_URL = "https://router.huggingface.co/featherless-ai/v1"


def hf_base_url_for(model: str) -> str:  # noqa: ARG001 — kept for future provider routing
    return HF_ROUTER_BASE_URL

# Primary model locked at T+63h (AMD credits never arrived)
HF_PRIMARY_MODEL = "Qwen/Qwen2.5-72B-Instruct"
HF_FALLBACK_MODEL = "Qwen/Qwen2.5-32B-Instruct"   # if 72B latency is an issue


class AppConfig(BaseModel):
    # Inference backend — default is now "hf" (AMD locked out at T+63h)
    llm_backend: Backend = Field(
        default_factory=lambda: Backend(os.getenv("LLM_BACKEND", "hf"))
    )

    # HuggingFace Serverless (primary)
    hf_token: str = Field(
        default_factory=lambda: (
            os.environ.get("HF_TOKEN")
            or os.environ.get("HUGGINGFACE_TOKEN")
            or ""
        )
    )
    hf_model: str = Field(
        default_factory=lambda: os.getenv("HF_MODEL", HF_PRIMARY_MODEL)
    )
    # Computed dynamically from hf_model if not explicitly overridden
    hf_base_url: Optional[str] = Field(
        default_factory=lambda: os.getenv("HF_BASE_URL")
    )

    # vLLM (AMD MI300X — kept for future use, currently inactive)
    vllm_base_url: str = Field(
        default_factory=lambda: os.getenv("VLLM_BASE_URL", "http://localhost:8000/v1")
    )
    vllm_api_key: str = Field(
        default_factory=lambda: os.environ.get("VLLM_API_KEY", "")
    )
    vllm_model: str = Field(
        default_factory=lambda: os.getenv("VLLM_MODEL", "Qwen/Qwen3-VL-32B-Instruct-FP8")
    )

    # Search
    serper_api_key: Optional[str] = Field(
        default_factory=lambda: os.environ.get("SERPER_API_KEY")
    )

    # Memory
    mem0_api_key: Optional[str] = Field(
        default_factory=lambda: os.getenv("MEM0_API_KEY")
    )
    mem0_base_url: Optional[str] = Field(
        default_factory=lambda: os.getenv("MEM0_BASE_URL")
    )

    # App
    output_dir: Path = Field(
        default_factory=lambda: Path(os.getenv("OUTPUT_DIR", "./outputs"))
    )
    max_crew_iterations: int = Field(
        default_factory=lambda: int(os.getenv("MAX_CREW_ITERATIONS", "3"))
    )
    verbose_agents: bool = Field(
        default_factory=lambda: os.getenv("VERBOSE_AGENTS", "false").lower() == "true"
    )

    model_config = {"arbitrary_types_allowed": True}


def get_config() -> AppConfig:
    return AppConfig()


def get_llm(config: Optional[AppConfig] = None):
    """Return a CrewAI-compatible LLM instance based on active backend."""
    if config is None:
        config = get_config()

    from crewai import LLM

    if config.llm_backend == Backend.HF:
        if not config.hf_token:
            raise ValueError("HF_TOKEN (or HUGGINGFACE_TOKEN) must be set for HF backend")
        # HF Serverless uses model-specific OpenAI-compatible paths:
        # https://api-inference.huggingface.co/models/{model}/v1/chat/completions
        base_url = config.hf_base_url or hf_base_url_for(config.hf_model)
        logger.info(
            f"Using HF Serverless Inference: model={config.hf_model} base_url={base_url}"
        )
        return LLM(
            model=f"openai/{config.hf_model}",
            base_url=base_url,
            api_key=config.hf_token,
            temperature=0.1,
            max_tokens=4096,
        )

    elif config.llm_backend == Backend.VLLM:
        logger.info(
            f"Using vLLM backend: {config.vllm_base_url} model={config.vllm_model}"
        )
        return LLM(
            model=f"openai/{config.vllm_model}",
            base_url=config.vllm_base_url,
            api_key=config.vllm_api_key,
            temperature=0.1,
            max_tokens=4096,
        )

    elif config.llm_backend == Backend.OPENAI:
        api_key = os.getenv("OPENAI_API_KEY")
        if not api_key:
            raise ValueError("OPENAI_API_KEY not set for openai backend")
        return LLM(
            model="gpt-4o",
            api_key=api_key,
            temperature=0.1,
            max_tokens=4096,
        )

    else:
        raise ValueError(f"Unknown LLM_BACKEND: {config.llm_backend}")