"""
Ollama endpoint resolver for AWOOOI workload placement.

ADR-110 gives AWOOOI three Ollama endpoints. Every runtime workload uses
GCP-A -> GCP-B -> host111. Gemini is owned by the caller/AI Router as the
final paid fallback after all three Ollama endpoints are exhausted.
"""

from __future__ import annotations

from dataclasses import dataclass
from typing import Literal, Protocol

from src.core.config import settings

OllamaWorkloadType = Literal[
    "interactive",
    "healthcheck",
    "alert_fast",
    "batch",
    "embedding",
    "rag",
    "code_review",
    "shadow",
    "canary",
    "deep_rca",
    "image_analysis",
    "hermes",
    "local_required",
    "privacy_sensitive",
    "dr",
]

class _OllamaSettings(Protocol):
    OLLAMA_URL: str
    OLLAMA_SECONDARY_URL: str
    OLLAMA_FALLBACK_URL: str


@dataclass(frozen=True)
class OllamaEndpointSelection:
    url: str
    provider_name: str
    workload_type: OllamaWorkloadType
    reason: str


def resolve_ollama_selection(
    workload_type: OllamaWorkloadType = "interactive",
    *,
    config: _OllamaSettings | None = None,
) -> OllamaEndpointSelection:
    """Return the preferred Ollama endpoint for a workload class."""
    return resolve_ollama_order(workload_type, config=config)[0]


def resolve_ollama_order(
    workload_type: OllamaWorkloadType = "interactive",
    *,
    config: _OllamaSettings | None = None,
) -> tuple[OllamaEndpointSelection, ...]:
    """Return the Ollama fallback order for the requested workload."""
    cfg = config or settings

    primary = (cfg.OLLAMA_URL, "ollama_gcp_a", "global_primary_gcp_a")
    secondary = (
        cfg.OLLAMA_SECONDARY_URL,
        "ollama_gcp_b",
        "global_secondary_gcp_b",
    )
    local = (cfg.OLLAMA_FALLBACK_URL, "ollama_local", "global_local_111")
    candidates = (primary, secondary, local)
    selections: list[OllamaEndpointSelection] = []
    seen: set[str] = set()
    for url, provider_name, reason in candidates:
        if not url or url in seen:
            continue
        seen.add(url)
        selections.append(
            OllamaEndpointSelection(
                url=url,
                provider_name=provider_name,
                workload_type=workload_type,
                reason=reason,
            )
        )

    if selections:
        return tuple(selections)

    return (
        OllamaEndpointSelection(
            url="",
            provider_name="ollama_unconfigured",
            workload_type=workload_type,
            reason="no_ollama_endpoint_configured",
        ),
    )


def resolve_ollama_endpoint(
    workload_type: OllamaWorkloadType = "interactive",
    *,
    config: _OllamaSettings | None = None,
) -> str:
    """Return only the preferred Ollama base URL."""
    return resolve_ollama_selection(workload_type, config=config).url