"""llama.cpp runtime: spawns `llama-server` (Metal) for GGUF models."""

from __future__ import annotations

import os
import shutil

import httpx

from .base import RuntimeAdapter, WorkerHandle


class LlamaCppAdapter(RuntimeAdapter):
    name = "llamacpp"

    def binary(self) -> str | None:
        b = self.settings.llama_server_bin
        if os.path.isabs(b) and os.path.exists(b):
            return b
        found = shutil.which(b)
        if found:
            return found
        for cand in ("/opt/homebrew/bin/llama-server", "/usr/local/bin/llama-server"):
            if os.path.exists(cand):
                return cand
        return None

    def available(self) -> bool:
        return self.binary() is not None

    def build_command(self, model: dict, port: int, context: int) -> list[str]:
        b = self.binary()
        assert b, "llama-server not found"
        threads = max(4, (os.cpu_count() or 8) - 2)
        cmd = [b, "-m", model["weights_file"], "--host", "127.0.0.1", "--port", str(port), "-ngl", "999",
               "-c", str(context), "--alias", model["id"], "--no-webui", "-np", "1", "-fa", "auto",
               "-t", str(threads), "--cache-reuse", "256", "--metrics", "--slots", "--jinja"]
        if model.get("embedding"):
            cmd += ["--embeddings", "-ub", "2048", "-b", "2048"]
            # Pooling: model default unless overridden
            pooling = (model.get("overrides") or {}).get("pooling")
            if pooling:
                cmd += ["--pooling", pooling]
        elif model.get("reranker"):
            cmd += ["--reranking"]
        else:
            if model.get("thinking"):
                cmd += ["--reasoning-format", "deepseek"]
        if model.get("mmproj_file"):
            cmd += ["--mmproj", model["mmproj_file"]]
        overrides = model.get("overrides") or {}
        if overrides.get("kv_bits") in (4, 8):
            t = "q4_0" if overrides["kv_bits"] == 4 else "q8_0"
            cmd += ["-ctk", t, "-ctv", t]
        for extra in overrides.get("llama_args") or []:
            if isinstance(extra, str) and not extra.startswith(("|", ";", "&", "$", "`")):
                cmd.append(extra)
        return cmd

    async def is_ready(self, handle: WorkerHandle, client: httpx.AsyncClient) -> tuple[str, str | None]:
        try:
            r = await client.get(f"{handle.base_url}/health", timeout=3)
        except Exception:
            return "loading", None
        if r.status_code == 200:
            return "ready", None
        if r.status_code == 503:
            return "loading", None
        return "loading", None