package llm

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

func TestOpenAIStreamTextAndToolCalls(t *testing.T) {
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if r.Header.Get("Authorization") != "Bearer k" || r.URL.Path != "/v1/chat/completions" {
			http.Error(w, "bad", 400)
			return
		}
		var body map[string]any
		json.NewDecoder(r.Body).Decode(&body)
		if body["stream"] != true || len(body["tools"].([]any)) != 1 {
			http.Error(w, "bad body", 400)
			return
		}
		chunks := []string{
			`{"choices":[{"delta":{"content":"Hel"}}]}`,
			`{"choices":[{"delta":{"content":"lo"}}]}`,
			`{"choices":[{"delta":{"tool_calls":[{"index":0,"id":"c1","function":{"name":"time_now","arguments":"{\"tz\":"}}]}}]}`,
			`{"choices":[{"delta":{"tool_calls":[{"index":0,"function":{"arguments":"\"UTC\"}"}}]},"finish_reason":"tool_calls"}]}`,
		}
		for _, c := range chunks {
			fmt.Fprintf(w, "data: %s\n\n", c)
		}
		fmt.Fprint(w, "data: [DONE]\n\n")
	}))
	defer srv.Close()
	p := NewOpenAI(srv.URL+"/v1/", "k", "m", 0, 5*time.Second)
	var streamed strings.Builder
	resp, err := p.Chat(context.Background(), Request{
		Messages: []Message{{Role: RoleUser, Content: "hi"}},
		Tools:    []ToolSpec{{Name: "time_now", Parameters: map[string]any{"type": "object"}}},
	}, func(s string) { streamed.WriteString(s) })
	if err != nil {
		t.Fatal(err)
	}
	if resp.Content != "Hello" || streamed.String() != "Hello" {
		t.Fatalf("content %q streamed %q", resp.Content, streamed.String())
	}
	if len(resp.ToolCalls) != 1 || resp.ToolCalls[0].Arguments != `{"tz":"UTC"}` || resp.ToolCalls[0].ID != "c1" {
		t.Fatalf("tool calls %+v", resp.ToolCalls)
	}
	if resp.FinishReason != "tool_calls" {
		t.Fatal(resp.FinishReason)
	}
}

func TestOpenAIHTTPError(t *testing.T) {
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		http.Error(w, "nope", 401)
	}))
	defer srv.Close()
	_, err := NewOpenAI(srv.URL, "", "m", 0, time.Second).Chat(context.Background(), Request{}, nil)
	if err == nil || !strings.Contains(err.Error(), "401") {
		t.Fatalf("want 401 err, got %v", err)
	}
}