/*
 * # Licensed to the LF AI & Data foundation under one
 * # or more contributor license agreements. See the NOTICE file
 * # distributed with this work for additional information
 * # regarding copyright ownership. The ASF licenses this file
 * # to you under the Apache License, Version 2.0 (the
 * # "License"); you may not use this file except in compliance
 * # with the License. You may obtain a copy of the License at
 * #
 * #     http://www.apache.org/licenses/LICENSE-2.0
 * #
 * # Unless required by applicable law or agreed to in writing, software
 * # distributed under the License is distributed on an "AS IS" BASIS,
 * # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * # See the License for the specific language governing permissions and
 * # limitations under the License.
 */

package function

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

	"github.com/aws/aws-sdk-go-v2/service/bedrockruntime"

	"github.com/milvus-io/milvus/internal/util/function/models/ali"
	"github.com/milvus-io/milvus/internal/util/function/models/cohere"
	"github.com/milvus-io/milvus/internal/util/function/models/openai"
	"github.com/milvus-io/milvus/internal/util/function/models/vertexai"
	"github.com/milvus-io/milvus/internal/util/function/models/voyageai"
)

func mockEmbedding(texts []string, dim int) [][]float32 {
	embeddings := make([][]float32, 0)
	for i := 0; i < len(texts); i++ {
		f := float32(i)
		emb := make([]float32, 0)
		for j := 0; j < dim; j++ {
			emb = append(emb, f+float32(j)*0.1)
		}
		embeddings = append(embeddings, emb)
	}
	return embeddings
}

func CreateErrorEmbeddingServer() *httptest.Server {
	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.WriteHeader(http.StatusInternalServerError)
	}))
	return ts
}

func CreateOpenAIEmbeddingServer() *httptest.Server {
	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		var req openai.EmbeddingRequest
		body, _ := io.ReadAll(r.Body)
		defer r.Body.Close()
		json.Unmarshal(body, &req)
		embs := mockEmbedding(req.Input, req.Dimensions)
		var res openai.EmbeddingResponse
		res.Object = "list"
		res.Model = "text-embedding-3-small"
		for i := 0; i < len(req.Input); i++ {
			res.Data = append(res.Data, openai.EmbeddingData{
				Object:    "embedding",
				Embedding: embs[i],
				Index:     i,
			})
		}

		res.Usage = openai.Usage{
			PromptTokens: 1,
			TotalTokens:  100,
		}
		w.WriteHeader(http.StatusOK)
		data, _ := json.Marshal(res)
		w.Write(data)
	}))
	return ts
}

func CreateAliEmbeddingServer() *httptest.Server {
	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		var req ali.EmbeddingRequest
		body, _ := io.ReadAll(r.Body)
		defer r.Body.Close()
		json.Unmarshal(body, &req)
		embs := mockEmbedding(req.Input.Texts, req.Parameters.Dimension)
		var res ali.EmbeddingResponse
		for i := 0; i < len(req.Input.Texts); i++ {
			res.Output.Embeddings = append(res.Output.Embeddings, ali.Embeddings{
				Embedding: embs[i],
				TextIndex: i,
			})
		}

		res.Usage = ali.Usage{
			TotalTokens: 100,
		}
		w.WriteHeader(http.StatusOK)
		data, _ := json.Marshal(res)
		w.Write(data)
	}))
	return ts
}

func CreateVoyageAIEmbeddingServer() *httptest.Server {
	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		var req voyageai.EmbeddingRequest
		body, _ := io.ReadAll(r.Body)
		defer r.Body.Close()
		json.Unmarshal(body, &req)
		embs := mockEmbedding(req.Input, int(req.OutputDimension))
		var res voyageai.EmbeddingResponse
		for i := 0; i < len(req.Input); i++ {
			res.Data = append(res.Data, voyageai.EmbeddingData{
				Object:    "list",
				Embedding: embs[i],
				Index:     i,
			})
		}

		res.Usage = voyageai.Usage{
			TotalTokens: 100,
		}
		w.WriteHeader(http.StatusOK)
		data, _ := json.Marshal(res)
		w.Write(data)
	}))
	return ts
}

func CreateVertexAIEmbeddingServer() *httptest.Server {
	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		var req vertexai.EmbeddingRequest
		body, _ := io.ReadAll(r.Body)
		defer r.Body.Close()
		json.Unmarshal(body, &req)
		var texts []string
		for _, item := range req.Instances {
			texts = append(texts, item.Content)
		}
		embs := mockEmbedding(texts, int(req.Parameters.OutputDimensionality))
		var res vertexai.EmbeddingResponse
		for i := 0; i < len(req.Instances); i++ {
			res.Predictions = append(res.Predictions, vertexai.Prediction{
				Embeddings: vertexai.Embeddings{
					Statistics: vertexai.Statistics{
						Truncated:  false,
						TokenCount: 10,
					},
					Values: embs[i],
				},
			})
		}

		res.Metadata = vertexai.Metadata{
			BillableCharacterCount: 100,
		}
		w.WriteHeader(http.StatusOK)
		data, _ := json.Marshal(res)
		w.Write(data)
	}))
	return ts
}

func CreateCohereEmbeddingServer() *httptest.Server {
	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		var req cohere.EmbeddingRequest
		body, _ := io.ReadAll(r.Body)
		defer r.Body.Close()
		json.Unmarshal(body, &req)
		embs := mockEmbedding(req.Texts, 4)
		var res cohere.EmbeddingResponse
		res.Embeddings.Float = embs
		w.WriteHeader(http.StatusOK)
		data, _ := json.Marshal(res)
		w.Write(data)
	}))
	return ts
}

type MockBedrockClient struct {
	dim int
}

func (c *MockBedrockClient) InvokeModel(ctx context.Context, params *bedrockruntime.InvokeModelInput, optFns ...func(*bedrockruntime.Options)) (*bedrockruntime.InvokeModelOutput, error) {
	var req BedRockRequest
	json.Unmarshal(params.Body, &req)
	embs := mockEmbedding([]string{req.InputText}, c.dim)

	var resp BedRockResponse
	resp.Embedding = embs[0]
	resp.InputTextTokenCount = 2
	body, _ := json.Marshal(resp)
	return &bedrockruntime.InvokeModelOutput{Body: body}, nil
}