package gollm_test

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

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

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

	client, err := gollm.NewClient(gollm.AdapterOllama, srv.URL, "")
	if err != nil {
		t.Fatal(err)
	}
	temp := 0.2
	maxTok := 64
	text, err := client.Chat(context.Background(), []gollm.Message{
		{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["stream"] != false {
		t.Fatalf("stream %#v", gotBody["stream"])
	}
	opts, _ := gotBody["options"].(map[string]any)
	if opts["temperature"] != 0.2 {
		t.Fatalf("temperature %#v", opts["temperature"])
	}
	if opts["num_predict"] != float64(64) {
		t.Fatalf("num_predict %#v", opts["num_predict"])
	}
}

func TestStreamYieldsOllamaChunks(t *testing.T) {
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if r.URL.Path != "/api/chat" {
			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", "application/x-ndjson")
		io.WriteString(w, `{"message":{"content":"Once"},"done":false}`+"\n")
		io.WriteString(w, `{"message":{"content":" upon"},"done":true}`+"\n")
	}))
	t.Cleanup(srv.Close)

	client, err := gollm.NewClient(gollm.AdapterOllama, 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 TestListModelsReturnsOllamaNames(t *testing.T) {
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if r.URL.Path != "/api/tags" || r.Method != http.MethodGet {
			t.Errorf("got %s %s", r.Method, r.URL.Path)
		}
		w.Header().Set("Content-Type", "application/json")
		io.WriteString(w, `{"models":[{"name":"llama3:latest"},{"name":"mistral"}]}`)
	}))
	t.Cleanup(srv.Close)

	client, err := gollm.NewClient(gollm.AdapterOllama, 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] != "llama3:latest" || names[1] != "mistral" {
		t.Fatalf("got %#v", names)
	}
}