"""Tests for P3.1 scoring-based model selection."""
import sys
import os

sys.path.insert(0, os.path.join(os.path.dirname(__file__), "..", "services", "router"))

from model_select import (
    score_candidate,
    select_best_model,
    ProfileRequirements,
    ModelSelection,
    LOCAL_THRESHOLD_MS,
)


def _caps(served, node_load=None, runtime_load=None, nodes=None):
    return {
        "served_models": served,
        "node_load": node_load or {},
        "runtime_load": runtime_load or [],
        "nodes": nodes or {},
    }


def _model(name, typ="llm", local=True, node="n1", runtime="ollama", **kw):
    return {"name": name, "type": typ, "local": local, "node": node,
            "runtime": runtime, "base_url": "http://x", **kw}


def _reqs(typ="llm", prefer=None):
    return ProfileRequirements("test", typ, prefer or [])


# ── 1) local wins when scores close ────────────────────────────────────────

def test_local_wins_when_scores_close():
    caps = _caps(
        served=[
            _model("qwen3:14b", local=True, node="n1"),
            _model("qwen3:14b", local=False, node="n2"),
        ],
        node_load={"estimated_wait_ms": 0, "rtt_ms_to_hub": None},
    )
    sel = select_best_model(_reqs(), caps)
    assert sel is not None
    assert sel.local is True
    assert sel.node == "n1"


# ── 2) remote wins when local wait is high ─────────────────────────────────

def test_remote_wins_when_local_wait_high():
    caps = _caps(
        served=[
            _model("qwen3:14b", local=True, node="n1"),
            _model("qwen3:14b", local=False, node="n2"),
        ],
        node_load={"estimated_wait_ms": 5000, "rtt_ms_to_hub": None},
        nodes={"n2": {"node_id": "n2", "node_load": {"estimated_wait_ms": 0, "rtt_ms_to_hub": 50}}},
    )
    sel = select_best_model(_reqs(), caps)
    assert sel is not None
    assert sel.local is False
    assert sel.node == "n2"


# ── 3) exclude_nodes works ─────────────────────────────────────────────────

def test_exclude_nodes_works():
    caps = _caps(served=[
        _model("qwen3:14b", local=False, node="n2"),
        _model("qwen3:14b", local=False, node="n3"),
    ])
    sel = select_best_model(_reqs(), caps, exclude_nodes={"n2"})
    assert sel is not None
    assert sel.node == "n3"


# ── 4) breaker open → node excluded (via exclude_nodes) ───────────────────

def test_breaker_excludes_node():
    caps = _caps(served=[
        _model("qwen3:14b", local=False, node="broken"),
        _model("qwen3:14b", local=True, node="n1"),
    ])
    sel = select_best_model(_reqs(), caps, exclude_nodes={"broken"})
    assert sel is not None
    assert sel.node == "n1"


# ── 5) required_type filter ────────────────────────────────────────────────

def test_required_type_filter():
    caps = _caps(served=[
        _model("qwen3:14b", typ="llm"),
        _model("llava:13b", typ="vision"),
    ])
    sel = select_best_model(_reqs(typ="vision"), caps)
    assert sel is not None
    assert sel.name == "llava:13b"


# ── 6) prefer list filter ─────────────────────────────────────────────────

def test_prefer_list_selects_preferred():
    caps = _caps(served=[
        _model("qwen3:14b"),
        _model("qwen3.5:35b"),
    ])
    sel = select_best_model(_reqs(prefer=["qwen3.5:35b"]), caps)
    assert sel is not None
    assert sel.name == "qwen3.5:35b"


# ── 7) score formula — prefer bonus lowers score ──────────────────────────

def test_prefer_bonus_lowers_score():
    m1 = _model("qwen3:14b")
    m2 = _model("qwen3.5:35b")
    caps = _caps(served=[m1, m2])
    s1 = score_candidate(m1, caps, prefer=["qwen3:14b"])
    s2 = score_candidate(m2, caps, prefer=["qwen3:14b"])
    assert s1 < s2


# ── 8) score formula — cross_penalty for remote ──────────────────────────

def test_cross_penalty_for_remote():
    local = _model("m", local=True)
    remote = _model("m", local=False, node="r1")
    caps = _caps(served=[local, remote])
    sl = score_candidate(local, caps, prefer=[])
    sr = score_candidate(remote, caps, prefer=[], rtt_hint_ms=50)
    assert sr > sl


# ── 9) score formula — wait increases score ──────────────────────────────

def test_wait_increases_score():
    m = _model("m", local=True)
    caps_idle = _caps(served=[m], node_load={"estimated_wait_ms": 0})
    caps_busy = _caps(served=[m], node_load={"estimated_wait_ms": 3000})
    s_idle = score_candidate(m, caps_idle, prefer=[])
    s_busy = score_candidate(m, caps_busy, prefer=[])
    assert s_busy > s_idle


# ── 10) no candidates → None ─────────────────────────────────────────────

def test_no_candidates_returns_none():
    caps = _caps(served=[_model("m", typ="stt")])
    sel = select_best_model(_reqs(typ="llm"), caps)
    assert sel is None


# ── 11) local threshold: local wins within threshold even if remote lower ─

def test_local_threshold():
    caps = _caps(
        served=[
            _model("qwen3:14b", local=True, node="n1"),
            _model("qwen3:14b", local=False, node="n2"),
        ],
        node_load={"estimated_wait_ms": 100},
        nodes={"n2": {"node_id": "n2", "node_load": {"estimated_wait_ms": 0, "rtt_ms_to_hub": 10}}},
    )
    sel = select_best_model(_reqs(), caps)
    assert sel.local is True


# ── 12) code type cross-filters with llm ─────────────────────────────────

def test_code_type_finds_llm_models():
    caps = _caps(served=[_model("qwen3:14b", typ="llm")])
    sel = select_best_model(_reqs(typ="code"), caps)
    assert sel is not None
    assert sel.name == "qwen3:14b"