package gollm_test

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

	gollm "gitea.neitzel.de/konrad/go-llm"
)

func TestChatReturnsAssistantTextFromOpenAICompatibleServer(t *testing.T) {
	var gotBody map[string]any
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if r.URL.Path != "/v1/chat/completions" || r.Method != http.MethodPost {
			t.Errorf("got %s %s", r.Method, r.URL.Path)
		}
		if r.Header.Get("Authorization") != "Bearer secret-key" {
			t.Errorf("Authorization %q", r.Header.Get("Authorization"))
		}
		if err := json.NewDecoder(r.Body).Decode(&gotBody); err != nil {
			t.Fatal(err)
		}
		w.Header().Set("Content-Type", "application/json")
		io.WriteString(w, `{"choices":[{"message":{"role":"assistant","content":"Once upon a time."}}]}`)
	}))
	t.Cleanup(srv.Close)

	client, err := gollm.NewClient(gollm.AdapterOpenAI, srv.URL, "secret-key")
	if err != nil {
		t.Fatal(err)
	}
	temp := 0.2
	maxTok := 64
	text, err := client.Chat(context.Background(), []gollm.Message{
		{Role: gollm.RoleSystem, Content: "You write prose."},
		{Role: gollm.RoleUser, Content: "Begin."},
	}, gollm.Options{Model: "llama", Temperature: &temp, MaxTokens: &maxTok})
	if err != nil {
		t.Fatal(err)
	}
	if text != "Once upon a time." {
		t.Fatalf("got %q", text)
	}
	if gotBody["model"] != "llama" {
		t.Fatalf("model %#v", gotBody["model"])
	}
	if gotBody["temperature"] != 0.2 {
		t.Fatalf("temperature %#v", gotBody["temperature"])
	}
	if gotBody["max_tokens"] != float64(64) {
		t.Fatalf("max_tokens %#v", gotBody["max_tokens"])
	}
	msgs, _ := gotBody["messages"].([]any)
	if len(msgs) != 2 {
		t.Fatalf("messages %#v", gotBody["messages"])
	}
}

func TestStreamYieldsOpenAICompatibleChunks(t *testing.T) {
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if r.URL.Path != "/v1/chat/completions" {
			t.Errorf("path %s", r.URL.Path)
		}
		var body map[string]any
		if err := json.NewDecoder(r.Body).Decode(&body); err != nil {
			t.Fatal(err)
		}
		if body["stream"] != true {
			t.Fatalf("stream %#v", body["stream"])
		}
		w.Header().Set("Content-Type", "text/event-stream")
		io.WriteString(w, "data: {\"choices\":[{\"delta\":{\"content\":\"Once\"}}]}\n\n")
		io.WriteString(w, "data: {\"choices\":[{\"delta\":{\"content\":\" upon\"}}]}\n\n")
		io.WriteString(w, "data: [DONE]\n\n")
	}))
	t.Cleanup(srv.Close)

	client, err := gollm.NewClient(gollm.AdapterOpenAI, srv.URL, "")
	if err != nil {
		t.Fatal(err)
	}
	var chunks []string
	err = client.Stream(context.Background(), []gollm.Message{
		{Role: gollm.RoleUser, Content: "Begin."},
	}, gollm.Options{Model: "llama"}, func(chunk string) error {
		chunks = append(chunks, chunk)
		return nil
	})
	if err != nil {
		t.Fatal(err)
	}
	if strings.Join(chunks, "") != "Once upon" {
		t.Fatalf("chunks %#v", chunks)
	}
}

func TestListModelsReturnsOpenAICompatibleNames(t *testing.T) {
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if r.URL.Path != "/v1/models" || r.Method != http.MethodGet {
			t.Errorf("got %s %s", r.Method, r.URL.Path)
		}
		w.Header().Set("Content-Type", "application/json")
		io.WriteString(w, `{"data":[{"id":"llama"},{"id":"mistral"}]}`)
	}))
	t.Cleanup(srv.Close)

	client, err := gollm.NewClient(gollm.AdapterOpenAI, srv.URL, "")
	if err != nil {
		t.Fatal(err)
	}
	names, err := client.ListModels(context.Background())
	if err != nil {
		t.Fatal(err)
	}
	if len(names) != 2 || names[0] != "llama" || names[1] != "mistral" {
		t.Fatalf("got %#v", names)
	}
}