package llm

import (
	"context"
	"encoding/json"
	"io"
	"net/http"
	"net/http/httptest"
	"testing"
	"time"
)

// capturedTemperature runs one Complete against a fake gateway and returns the
// "temperature" field the request carried, and whether it was present at all.
func capturedTemperature(t *testing.T, opts ...Option) (float64, bool) {
	t.Helper()
	var body map[string]any
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		raw, _ := io.ReadAll(r.Body)
		_ = json.Unmarshal(raw, &body)
		w.Header().Set("Content-Type", "application/json")
		_ = json.NewEncoder(w).Encode(map[string]any{"choices": []map[string]any{{"message": map[string]any{"role": "assistant", "content": "ok"}}}})
	}))
	defer srv.Close()

	if _, err := New(srv.URL, "", "m", 5*time.Second, opts...).Complete(context.Background(), "s", "u"); err != nil {
		t.Fatalf("Complete: %v", err)
	}
	v, ok := body["temperature"].(float64)
	return v, ok
}

func TestClient_DefaultTemperatureIsUnchanged(t *testing.T) {
	got, ok := capturedTemperature(t)

	if !ok || got != 0.2 {
		t.Fatalf("default temperature = %v (present %v), want 0.2: existing callers must not change behaviour", got, ok)
	}
}

func TestClient_WithTemperatureZeroSendsExactlyZero(t *testing.T) {
	// The reconciler's accuracy (92%/97%) was measured at temperature 0. Zero must be
	// SENT, not treated as "unset" and replaced by the default.
	got, ok := capturedTemperature(t, WithTemperature(0))

	if !ok || got != 0 {
		t.Fatalf("temperature = %v (present %v), want an explicit 0", got, ok)
	}
}

func TestClient_WithTemperatureSendsTheGivenValue(t *testing.T) {
	got, ok := capturedTemperature(t, WithTemperature(0.7))

	if !ok || got != 0.7 {
		t.Fatalf("temperature = %v (present %v), want 0.7", got, ok)
	}
}