package llm

import (
	"bytes"
	"encoding/json"
	"io"
	"net/http"
	"strings"
	"testing"
	"time"
)

func f64p(v float64) *float64 { return &v }

func TestBuildOAChatRequest_TempFallbackAndFields(t *testing.T) {
	o := Options{Model: "m1", Temperature: 0, MaxTokens: 42, Stop: []string{"END"}}
	msgs := []Message{{Role: "user", Content: "hi"}}
	req := buildOAChatRequest(o, msgs, f64p(0.3), false)
	if req.Model != "m1" || req.Stream {
		t.Fatalf("model/stream mismatch: %+v", req)
	}
	if req.Temperature == nil || *req.Temperature != 0.3 {
		t.Fatalf("expected default temp 0.3, got %#v", req.Temperature)
	}
	if req.MaxTokens == nil || *req.MaxTokens != 42 {
		t.Fatalf("expected max tokens 42")
	}
	if len(req.Stop) != 1 || req.Stop[0] != "END" {
		t.Fatalf("stop not propagated: %#v", req.Stop)
	}
	if len(req.Messages) != 1 || req.Messages[0].Content != "hi" {
		t.Fatalf("messages not copied")
	}

	// stream on
	req2 := buildOAChatRequest(o, msgs, f64p(0.3), true)
	if !req2.Stream {
		t.Fatalf("expected stream=true")
	}
}

func TestHandleOpenAINon2xx_WithAPIError(t *testing.T) {
	api := oaChatResponse{Error: &struct {
		Message string `json:"message"`
		Type    string `json:"type"`
		Param   any    `json:"param"`
		Code    any    `json:"code"`
	}{Message: "bad", Type: "invalid"}}
	b, _ := json.Marshal(api)
	resp := &http.Response{StatusCode: 400, Body: io.NopCloser(bytes.NewReader(b))}
	if err := handleOpenAINon2xx(resp, time.Now()); err == nil {
		t.Fatalf("expected error for non-2xx with body")
	}
}

func TestParseOpenAIStream_DeliversChunks(t *testing.T) {
	stream := "data: {\"choices\":[{\"delta\":{\"content\":\"Hi\"}}]}\n\n" +
		"data: [DONE]\n"
	resp := &http.Response{Body: io.NopCloser(strings.NewReader(stream))}
	var got strings.Builder
	if err := parseOpenAIStream(resp, time.Now(), func(s string) { got.WriteString(s) }); err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
	if got.String() != "Hi" {
		t.Fatalf("got %q want %q", got.String(), "Hi")
	}
}