"""AI provider service — routes requests to configured provider."""

from __future__ import annotations

import sys
from typing import Any

from voice_to_notes.providers.base import AIProvider


class AIProviderService:
    """Manages AI provider selection and routes chat requests."""

    def __init__(self) -> None:
        self._providers: dict[str, AIProvider] = {}
        self._active_provider: str | None = None

    def register_provider(self, name: str, provider: AIProvider) -> None:
        """Register an AI provider."""
        self._providers[name] = provider

    def set_active(self, name: str) -> None:
        """Set the active provider by name."""
        if name not in self._providers:
            raise ValueError(f"Unknown provider: {name}. Available: {list(self._providers.keys())}")
        self._active_provider = name

    def get_active(self) -> AIProvider | None:
        """Get the currently active provider."""
        if self._active_provider:
            return self._providers.get(self._active_provider)
        # Auto-select first available provider
        for name, provider in self._providers.items():
            if provider.is_available():
                self._active_provider = name
                return provider
        return None

    def list_providers(self) -> list[dict[str, Any]]:
        """List all registered providers with their status."""
        return [
            {
                "name": name,
                "display_name": provider.name,
                "available": provider.is_available(),
                "active": name == self._active_provider,
            }
            for name, provider in self._providers.items()
        ]

    def chat(
        self,
        messages: list[dict[str, str]],
        transcript_context: str = "",
        **kwargs: Any,
    ) -> str:
        """Send a chat request to the active provider.

        Automatically prepends transcript context as a system message if provided.
        """
        provider = self.get_active()
        if provider is None:
            raise RuntimeError(
                "No AI provider available. Configure a provider in settings or start the local AI server."
            )

        # Build messages with transcript context
        full_messages: list[dict[str, str]] = []
        if transcript_context:
            full_messages.append({
                "role": "system",
                "content": (
                    "You are a helpful assistant analyzing a transcript. "
                    "Here is the transcript for context:\n\n"
                    f"{transcript_context}\n\n"
                    "Answer the user's questions about this transcript. "
                    "Be concise and helpful."
                ),
            })

        full_messages.extend(messages)

        print(
            f"[sidecar] AI chat via {provider.name}, {len(full_messages)} messages",
            file=sys.stderr,
            flush=True,
        )

        return provider.chat(full_messages, **kwargs)


def create_default_service() -> AIProviderService:
    """Create an AIProviderService with all supported providers registered."""
    from voice_to_notes.providers.anthropic_provider import AnthropicProvider
    from voice_to_notes.providers.litellm_provider import LiteLLMProvider
    from voice_to_notes.providers.local_provider import LocalProvider
    from voice_to_notes.providers.openai_provider import OpenAIProvider

    service = AIProviderService()
    service.register_provider("local", LocalProvider())
    service.register_provider("openai", OpenAIProvider())
    service.register_provider("anthropic", AnthropicProvider())
    service.register_provider("litellm", LiteLLMProvider())
    return service