package xai_test

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

	"gitea.stevedudenhoeffer.com/steve/go-llm/v2/openaicompat"
	"gitea.stevedudenhoeffer.com/steve/go-llm/v2/provider"
	"gitea.stevedudenhoeffer.com/steve/go-llm/v2/xai"
)

// newReasoningServer is a httptest server that records the request body and
// returns a minimal valid completion. Used to assert the reasoning_effort
// field that lands on the wire.
func newReasoningServer(t *testing.T) (*httptest.Server, *[]byte) {
	t.Helper()
	var body []byte
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		b, _ := io.ReadAll(r.Body)
		body = b
		w.Header().Set("Content-Type", "application/json")
		_, _ = io.WriteString(w, `{"id":"x","object":"chat.completion","choices":[{"index":0,"message":{"role":"assistant","content":"ok"},"finish_reason":"stop"}],"usage":{"prompt_tokens":1,"completion_tokens":1,"total_tokens":2}}`)
	}))
	return srv, &body
}

// readEffort returns the value of the "reasoning_effort" field in the JSON
// body, or "" if absent.
func readEffort(t *testing.T, body []byte) string {
	t.Helper()
	if len(body) == 0 {
		return ""
	}
	var parsed map[string]any
	if err := json.Unmarshal(body, &parsed); err != nil {
		t.Fatalf("unmarshal body: %v", err)
	}
	if v, ok := parsed["reasoning_effort"]; ok {
		if s, ok := v.(string); ok {
			return s
		}
	}
	return ""
}

func TestNew_Basic(t *testing.T) {
	if p := xai.New("key", ""); p == nil {
		t.Fatal("New returned nil")
	}
}

func TestRules_ReasoningGate(t *testing.T) {
	srv, body := newReasoningServer(t)
	defer srv.Close()

	// grok-3-mini: reasoning supported, medium maps to high.
	p := xai.New("k", srv.URL)
	req := provider.Request{
		Model:     "grok-3-mini",
		Messages:  []provider.Message{{Role: "user", Content: "?"}},
		Reasoning: "medium",
	}
	if _, err := p.Complete(context.Background(), req); err != nil {
		t.Fatalf("Complete: %v", err)
	}
	if effort := readEffort(t, *body); effort != "high" {
		t.Errorf("grok-3-mini medium → effort=%q, want \"high\"", effort)
	}

	// grok-2 (no reasoning): effort must NOT be sent.
	req.Model = "grok-2"
	*body = nil
	if _, err := p.Complete(context.Background(), req); err != nil {
		t.Fatalf("Complete: %v", err)
	}
	if effort := readEffort(t, *body); effort != "" {
		t.Errorf("grok-2 → effort=%q, want absent", effort)
	}
}

func TestRules_Grok2RejectsImages(t *testing.T) {
	p := xai.New("key", "")
	req := provider.Request{
		Model: "grok-2",
		Messages: []provider.Message{{
			Role:   "user",
			Images: []provider.Image{{URL: "a"}},
		}},
	}
	_, err := p.Complete(context.Background(), req)
	var fue *openaicompat.FeatureUnsupportedError
	if !errors.As(err, &fue) || fue.Feature != "vision" {
		t.Fatalf("want FeatureUnsupportedError(vision), got %v", err)
	}
}