"""Tests for the GET /metrics endpoint on dispatcher.

Seeds a throwaway temp DB and asserts on the actual JSON returned by a real
TestClient GET (never a mock-call assertion), to defeat
``misleading_success_output``.
"""

from __future__ import annotations

import sqlite3
from datetime import datetime, timedelta, timezone
from pathlib import Path

import pytest
from starlette.testclient import TestClient

import dispatcher
from config import load_config

ROOT = Path(__file__).resolve().parent.parent
SCHEMA_SQL = (ROOT / "schema.sql").read_text()
CFG = load_config(str(ROOT / "config.yaml"))


def _now() -> datetime:
    return datetime.now(timezone.utc)


def _make_db(tmp_path: Path) -> sqlite3.Connection:
    conn = sqlite3.connect(str(tmp_path / "test.db"))
    conn.row_factory = sqlite3.Row
    conn.executescript(SCHEMA_SQL)
    return conn


def _seed_models(conn: sqlite3.Connection) -> None:
    for model_id, tier, context, cost, vision in (
        ("cheap", 2, 262128, 0.30, 1),
        ("dear", 2, 262128, 9.00, 0),
        ("tiny", 1, 131072, 0.10, 1),
    ):
        conn.execute(
            """
            INSERT INTO models (
                model_id, provider, base_model_id, tier, context_window,
                effective_context_window, max_output_tokens,
                cost_per_1m_prompt, cost_per_1m_completion,
                supports_vision, supports_json_mode,
                latency_class, reasoning_mode, context_variant,
                access_level, availability, last_updated
            ) VALUES (?, 'neuralwatt', ?, ?, ?, 192500, 16384, ?, ?,
                      ?, 1, 'standard', 'default', 'full', 'public', 'active',
                      '2026-08-22T00:00:00+00:00')
            """,
            (model_id, model_id, tier, context, cost, cost / 3, vision),
        )
    conn.commit()


def _seed_decision(conn: sqlite3.Connection) -> None:
    conn.execute(
        """
        INSERT INTO route_decisions (
            observed_at, kind, task_category, task_tier, required_context_tokens,
            confidence, classifier_ms, classification_source, latency_tolerance,
            candidates_considered, selected_model, selected_provider,
            runner_up_models, est_cost_usd, est_proficiency,
            session_key, tools, images, json_mode, streamed
        ) VALUES (?, 'route', 'coding_general', 2, 100, 0.95, 200,
                  'classifier', 'interactive', 5, 'cheap', 'neuralwatt',
                  '[{"model_id":"dear","provider":"neuralwatt"}]',
                  0.001, 0.9, 'abc123', 0, 0, 0, 0)
        """,
        (_now().isoformat(),),
    )
    conn.commit()


def _seed_energy(conn: sqlite3.Connection) -> None:
    now = _now()
    conn.execute(
        "INSERT INTO energy_observations "
        "(model_id, provider, task_category, completion_tokens, energy_kwh, "
        "cost_usd, carbon_g_co2eq, attribution_ratio, observed_at) "
        "VALUES ('cheap', 'neuralwatt', 'coding_general', 100, 5.0e-05, 0.001, "
        "2.4e-03, 0.25, ?)",
        ((now - timedelta(days=2)).isoformat(),),
    )
    conn.commit()


def _seed_verification(conn: sqlite3.Connection) -> None:
    conn.execute(
        "INSERT INTO verifications (model_id, provider, kind, verdict, observed_at) "
        "VALUES ('cheap', 'neuralwatt', 'structural', 'ok', ?)",
        (_now().isoformat(),),
    )
    conn.commit()


def _seed_proficiency(conn: sqlite3.Connection) -> None:
    conn.execute(
        "INSERT INTO proficiency (model_id, provider, category, blended_score, "
        "source, last_updated) "
        "VALUES ('cheap', 'neuralwatt', 'coding_general', 0.9, "
        "'self_eval_thin', '2026-01-01T00:00:00+00:00')",
    )
    conn.commit()


@pytest.fixture
def seeded_client(tmp_path, monkeypatch):
    """A TestClient wired to a seeded temp DB, at /metrics."""
    conn = _make_db(tmp_path)
    _seed_models(conn)
    for i in range(60):  # exceed the 50 cap
        _seed_decision(conn)
    _seed_energy(conn)
    _seed_verification(conn)
    _seed_proficiency(conn)
    conn.close()

    monkeypatch.setattr(dispatcher.cfg.database, "path", str(tmp_path / "test.db"))
    monkeypatch.setattr(dispatcher.cfg.verification, "local_llm_enabled", False)
    monkeypatch.setattr(dispatcher.cfg.routing, "require_vision", False)
    monkeypatch.setenv("NEURALWATT_API_KEY", "test-key")

    with TestClient(dispatcher.app) as client:
        yield client


def test_metrics_endpoint_has_all_top_level_keys(seeded_client):
    """GET /metrics returns 200 with every required top-level key."""
    resp = seeded_client.get("/metrics")
    assert resp.status_code == 200
    data = resp.json()
    for key in (
        "quota",
        "coverage",
        "recent_decisions",
        "per_model",
        "verdict_mix",
        "top_proficiency",
        "generated_at",
    ):
        assert key in data, f"missing top-level key {key!r}"


def test_metrics_recent_decisions_capped_and_carries_provider(seeded_client):
    """recent_decisions is capped at 50 and each row has selected_provider."""
    resp = seeded_client.get("/metrics")
    data = resp.json()
    decisions = data["recent_decisions"]
    assert isinstance(decisions, list)
    assert len(decisions) <= 50
    assert len(decisions) > 0
    for row in decisions:
        assert "selected_provider" in row
    # DESC order: the first decision has the largest id.
    first_id = decisions[0]["id"]
    for row in decisions[1:]:
        assert row["id"] <= first_id


def test_metrics_aggregations_are_populated(seeded_client):
    """per_model / verdict_mix / top_proficiency reflect seeded data."""
    resp = seeded_client.get("/metrics")
    data = resp.json()
    assert isinstance(data["per_model"], list)
    assert any(r["model_id"] == "cheap" for r in data["per_model"])
    assert data["per_model"][0]["calls"] == 1
    assert data["verdict_mix"]["ok"] == 1
    assert isinstance(data["top_proficiency"], list)
    assert data["top_proficiency"][0]["model_id"] == "cheap"
    assert data["quota"] is not None


def test_metrics_contains_no_session_dir(seeded_client):
    """The JSON must never name session_dir or expose conversation text."""
    body = seeded_client.get("/metrics").text
    assert "session_dir" not in body


def test_metrics_empty_db_returns_200(monkeypatch, tmp_path):
    """Fresh empty temp DB: 200 with empty arrays, no exception."""
    conn = _make_db(tmp_path)
    conn.close()
    monkeypatch.setattr(dispatcher.cfg.database, "path", str(tmp_path / "test.db"))
    monkeypatch.setattr(dispatcher.cfg.verification, "local_llm_enabled", False)
    monkeypatch.setattr(dispatcher.cfg.routing, "require_vision", False)
    monkeypatch.setenv("NEURALWATT_API_KEY", "test-key")

    with TestClient(dispatcher.app) as client:
        resp = client.get("/metrics")
    assert resp.status_code == 200
    data = resp.json()
    assert data["recent_decisions"] == []
    assert data["per_model"] == []
    assert data["verdict_mix"] == {}
    assert data["top_proficiency"] == []
    assert "generated_at" in data