//                           _       _
// __      _____  __ ___   ___  __ _| |_ ___
// \ \ /\ / / _ \/ _` \ \ / / |/ _` | __/ _ \
//  \ V  V /  __/ (_| |\ V /| | (_| | ||  __/
//   \_/\_/ \___|\__,_| \_/ |_|\__,_|\__\___|
//
//  Copyright © 2016 - 2024 Weaviate B.V. All rights reserved.
//
//  CONTACT: hello@weaviate.io
//

package clients

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

	"github.com/weaviate/weaviate/usecases/modulecomponents"

	"github.com/pkg/errors"
	"github.com/sirupsen/logrus"
	"github.com/sirupsen/logrus/hooks/test"
	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
)

func TestClient(t *testing.T) {
	t.Run("when all is fine", func(t *testing.T) {
		server := httptest.NewServer(&fakeHandler{t: t})
		defer server.Close()
		c := &vectorizer{
			apiKey:     "apiKey",
			httpClient: &http.Client{},
			logger:     nullLogger(),
		}
		expected := &modulecomponents.VectorizationResult[[]float32]{
			Text:       []string{"This is my text"},
			Vector:     [][]float32{{0.1, 0.2, 0.3}},
			Dimensions: 3,
		}
		res, _, _, err := c.Vectorize(context.Background(), []string{"This is my text"}, fakeClassConfig{classConfig: map[string]interface{}{"Model": "mistral-embed", "baseURL": server.URL}})

		assert.Nil(t, err)
		assert.Equal(t, expected, res)
	})

	t.Run("when the context is expired", func(t *testing.T) {
		server := httptest.NewServer(&fakeHandler{t: t})
		defer server.Close()
		c := &vectorizer{
			apiKey:     "apiKey",
			httpClient: &http.Client{},
			logger:     nullLogger(),
		}
		ctx, cancel := context.WithDeadline(context.Background(), time.Now())
		defer cancel()

		_, _, _, err := c.Vectorize(ctx, []string{"This is my text"}, fakeClassConfig{classConfig: map[string]interface{}{"Model": "mistral-embed"}})

		require.NotNil(t, err)
		assert.Contains(t, err.Error(), "context deadline exceeded")
	})

	t.Run("when the server returns an error", func(t *testing.T) {
		server := httptest.NewServer(&fakeHandler{
			t:           t,
			serverError: errors.Errorf("nope, not gonna happen"),
		})
		defer server.Close()
		c := &vectorizer{
			apiKey:     "apiKey",
			httpClient: &http.Client{},
			logger:     nullLogger(),
		}
		_, _, _, err := c.Vectorize(context.Background(), []string{"This is my text"}, fakeClassConfig{classConfig: map[string]interface{}{"Model": "mistral-embed", "baseURL": server.URL}})

		require.NotNil(t, err)
		assert.Equal(t, err.Error(), "connection to Mistral failed with status: 500 error: nope, not gonna happen")
	})

	t.Run("when Mistral key is passed using Mistral-Api-Key header", func(t *testing.T) {
		server := httptest.NewServer(&fakeHandler{t: t})
		defer server.Close()
		c := &vectorizer{
			apiKey:     "",
			httpClient: &http.Client{},
			logger:     nullLogger(),
		}
		ctxWithValue := context.WithValue(context.Background(),
			"X-Mistral-Api-Key", []string{"some-key"})

		expected := &modulecomponents.VectorizationResult[[]float32]{
			Text:       []string{"This is my text"},
			Vector:     [][]float32{{0.1, 0.2, 0.3}},
			Dimensions: 3,
		}
		res, _, _, err := c.Vectorize(ctxWithValue, []string{"This is my text"}, fakeClassConfig{classConfig: map[string]interface{}{"Model": "mistral-embed", "baseURL": server.URL}})

		require.Nil(t, err)
		assert.Equal(t, expected, res)
	})

	t.Run("when Mistral key is empty", func(t *testing.T) {
		server := httptest.NewServer(&fakeHandler{t: t})
		defer server.Close()
		c := &vectorizer{
			apiKey:     "",
			httpClient: &http.Client{},
			logger:     nullLogger(),
		}
		ctx, cancel := context.WithDeadline(context.Background(), time.Now())
		defer cancel()

		_, _, _, err := c.Vectorize(ctx, []string{"This is my text"}, fakeClassConfig{classConfig: map[string]interface{}{"Model": "mistral-embed"}})

		require.NotNil(t, err)
		assert.Equal(t, err.Error(), "Mistral API Key: no api key found "+
			"neither in request header: X-Mistral-Api-Key "+
			"nor in environment variable under MISTRAL_APIKEY")
	})

	t.Run("when X-Mistral-Api-Key header is passed but empty", func(t *testing.T) {
		server := httptest.NewServer(&fakeHandler{t: t})
		defer server.Close()
		c := &vectorizer{
			apiKey:     "",
			httpClient: &http.Client{},
			logger:     nullLogger(),
		}
		ctxWithValue := context.WithValue(context.Background(),
			"X-Mistral-Api-Key", []string{""})

		_, _, _, err := c.Vectorize(ctxWithValue, []string{"This is my text"}, fakeClassConfig{classConfig: map[string]interface{}{"Model": "mistral-embed"}})

		require.NotNil(t, err)
		assert.Equal(t, err.Error(), "Mistral API Key: no api key found "+
			"neither in request header: X-Mistral-Api-Key "+
			"nor in environment variable under MISTRAL_APIKEY")
	})
}

type fakeHandler struct {
	t           *testing.T
	serverError error
}

func (f *fakeHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
	assert.Equal(f.t, http.MethodPost, r.Method)

	if f.serverError != nil {
		resp := embeddingsResponse{Message: "nope, not gonna happen"}
		outBytes, err := json.Marshal(resp)
		require.Nil(f.t, err)

		w.WriteHeader(http.StatusInternalServerError)
		w.Write(outBytes)
		return
	}

	bodyBytes, err := io.ReadAll(r.Body)
	require.Nil(f.t, err)
	defer r.Body.Close()

	var req embeddingsRequest
	require.Nil(f.t, json.Unmarshal(bodyBytes, &req))

	assert.NotNil(f.t, req)
	assert.NotEmpty(f.t, req.Input)

	resp := embeddingsResponse{
		Data:  []embeddingsDataResponse{{Embeddings: []float32{0.1, 0.2, 0.3}}},
		Model: "model",
	}
	outBytes, err := json.Marshal(resp)
	require.Nil(f.t, err)

	w.Write(outBytes)
}

func nullLogger() logrus.FieldLogger {
	l, _ := test.NewNullLogger()
	return l
}
