/*
 * Copyright 2024-2025 the original author or authors.
 *
 * Licensed 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
 *
 *      https://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 org.springframework.ai.openai.chat.proxy;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.Map;
import java.util.stream.Collectors;

import org.junit.jupiter.api.Disabled;
import org.junit.jupiter.api.Test;
import org.junit.jupiter.api.condition.EnabledIfEnvironmentVariable;
import org.junit.jupiter.params.ParameterizedTest;
import org.junit.jupiter.params.provider.ValueSource;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import reactor.core.publisher.Flux;

import org.springframework.ai.chat.client.ChatClient;
import org.springframework.ai.chat.messages.AssistantMessage;
import org.springframework.ai.chat.messages.Message;
import org.springframework.ai.chat.messages.UserMessage;
import org.springframework.ai.chat.model.ChatResponse;
import org.springframework.ai.chat.model.Generation;
import org.springframework.ai.chat.prompt.Prompt;
import org.springframework.ai.chat.prompt.PromptTemplate;
import org.springframework.ai.chat.prompt.SystemPromptTemplate;
import org.springframework.ai.converter.BeanOutputConverter;
import org.springframework.ai.converter.ListOutputConverter;
import org.springframework.ai.converter.MapOutputConverter;
import org.springframework.ai.openai.OpenAiChatModel;
import org.springframework.ai.openai.OpenAiChatOptions;
import org.springframework.ai.openai.api.OpenAiApi;
import org.springframework.ai.openai.api.tool.MockWeatherService;
import org.springframework.ai.openai.chat.ActorsFilms;
import org.springframework.ai.tool.function.FunctionToolCallback;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.boot.SpringBootConfiguration;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.context.annotation.Bean;
import org.springframework.core.convert.support.DefaultConversionService;
import org.springframework.core.io.Resource;

import static org.assertj.core.api.Assertions.assertThat;

/**
 * @author Alexandros Pappas
 *
 * The DeepSeek API uses an API format compatible with OpenAI, allowing developers to
 * easily integrate it into existing systems that use the OpenAI SDK5.
 *
 * For more information on DeepSeek behavior, refer to its API documentation:
 * <a href="https://api-docs.deepseek.com/">DeepSeek API</a>
 */
@SpringBootTest(classes = DeepSeekWithOpenAiChatModelIT.Config.class)
@EnabledIfEnvironmentVariable(named = "DEEPSEEK_API_KEY", matches = ".+")
@Disabled("Requires DeepSeek credits")
class DeepSeekWithOpenAiChatModelIT {

	private static final Logger logger = LoggerFactory.getLogger(DeepSeekWithOpenAiChatModelIT.class);

	private static final String DEEPSEEK_BASE_URL = "https://api.deepseek.com";

	private static final String DEFAULT_DEEPSEEK_MODEL = "deepseek-chat";

	@Value("classpath:/prompts/system-message.st")
	private Resource systemResource;

	@Autowired
	private OpenAiChatModel chatModel;

	@Test
	void roleTest() {
		UserMessage userMessage = new UserMessage(
				"Tell me about 3 famous pirates from the Golden Age of Piracy and what they did.");
		SystemPromptTemplate systemPromptTemplate = new SystemPromptTemplate(this.systemResource);
		Message systemMessage = systemPromptTemplate.createMessage(Map.of("name", "Bob", "voice", "pirate"));
		Prompt prompt = new Prompt(List.of(userMessage, systemMessage));
		ChatResponse response = this.chatModel.call(prompt);
		assertThat(response.getResults()).hasSize(1);
		assertThat(response.getResults().get(0).getOutput().getText()).contains("Blackbeard");
	}

	@Test
	void streamRoleTest() {
		UserMessage userMessage = new UserMessage(
				"Tell me about 3 famous pirates from the Golden Age of Piracy and what they did.");
		SystemPromptTemplate systemPromptTemplate = new SystemPromptTemplate(this.systemResource);
		Message systemMessage = systemPromptTemplate.createMessage(Map.of("name", "Bob", "voice", "pirate"));
		Prompt prompt = new Prompt(List.of(userMessage, systemMessage));
		Flux<ChatResponse> flux = this.chatModel.stream(prompt);

		List<ChatResponse> responses = flux.collectList().block();
		assertThat(responses.size()).isGreaterThan(1);

		String stitchedResponseContent = responses.stream()
			.map(ChatResponse::getResults)
			.flatMap(List::stream)
			.map(Generation::getOutput)
			.map(AssistantMessage::getText)
			.collect(Collectors.joining());

		assertThat(stitchedResponseContent).contains("Blackbeard");
	}

	@Test
	void streamingWithTokenUsage() {
		var promptOptions = OpenAiChatOptions.builder().streamUsage(true).seed(1).build();

		var prompt = new Prompt("List two colors of the Polish flag. Be brief.", promptOptions);

		var streamingTokenUsage = this.chatModel.stream(prompt).blockLast().getMetadata().getUsage();
		var referenceTokenUsage = this.chatModel.call(prompt).getMetadata().getUsage();

		assertThat(streamingTokenUsage.getPromptTokens()).isGreaterThan(0);
		assertThat(streamingTokenUsage.getCompletionTokens()).isGreaterThan(0);
		assertThat(streamingTokenUsage.getTotalTokens()).isGreaterThan(0);

		assertThat(streamingTokenUsage.getPromptTokens()).isEqualTo(referenceTokenUsage.getPromptTokens());
		assertThat(streamingTokenUsage.getCompletionTokens()).isEqualTo(referenceTokenUsage.getCompletionTokens());
		assertThat(streamingTokenUsage.getTotalTokens()).isEqualTo(referenceTokenUsage.getTotalTokens());

	}

	@Test
	void listOutputConverter() {
		DefaultConversionService conversionService = new DefaultConversionService();
		ListOutputConverter outputConverter = new ListOutputConverter(conversionService);

		String format = outputConverter.getFormat();
		String template = """
				List five {subject}
				{format}
				""";
		PromptTemplate promptTemplate = PromptTemplate.builder()
			.template(template)
			.variables(Map.of("subject", "ice cream flavors", "format", format))
			.build();
		Prompt prompt = new Prompt(promptTemplate.createMessage());
		Generation generation = this.chatModel.call(prompt).getResult();

		List<String> list = outputConverter.convert(generation.getOutput().getText());
		assertThat(list).hasSize(5);

	}

	@Test
	void mapOutputConverter() {
		MapOutputConverter outputConverter = new MapOutputConverter();

		String format = outputConverter.getFormat();
		String template = """
				Provide me a List of {subject}
				{format}
				""";
		PromptTemplate promptTemplate = PromptTemplate.builder()
			.template(template)
			.variables(Map.of("subject", "numbers from 1 to 9 under they key name 'numbers'", "format", format))
			.build();
		Prompt prompt = new Prompt(promptTemplate.createMessage());
		Generation generation = this.chatModel.call(prompt).getResult();

		Map<String, Object> result = outputConverter.convert(generation.getOutput().getText());
		assertThat(result.get("numbers")).isEqualTo(Arrays.asList(1, 2, 3, 4, 5, 6, 7, 8, 9));

	}

	@Test
	void beanOutputConverter() {

		BeanOutputConverter<ActorsFilms> outputConverter = new BeanOutputConverter<>(ActorsFilms.class);

		String format = outputConverter.getFormat();
		String template = """
				Generate the filmography for a random actor.
				{format}
				""";
		PromptTemplate promptTemplate = PromptTemplate.builder()
			.template(template)
			.variables(Map.of("format", format))
			.build();
		Prompt prompt = new Prompt(promptTemplate.createMessage());
		Generation generation = this.chatModel.call(prompt).getResult();

		ActorsFilms actorsFilms = outputConverter.convert(generation.getOutput().getText());
		assertThat(actorsFilms.getActor()).isNotEmpty();
	}

	@Test
	void beanOutputConverterRecords() {

		BeanOutputConverter<DeepSeekWithOpenAiChatModelIT.ActorsFilmsRecord> outputConverter = new BeanOutputConverter<>(
				DeepSeekWithOpenAiChatModelIT.ActorsFilmsRecord.class);

		String format = outputConverter.getFormat();
		String template = """
				Generate the filmography of 5 movies for Tom Hanks.
				{format}
				""";
		PromptTemplate promptTemplate = PromptTemplate.builder()
			.template(template)
			.variables(Map.of("format", format))
			.build();
		Prompt prompt = new Prompt(promptTemplate.createMessage());
		Generation generation = this.chatModel.call(prompt).getResult();

		DeepSeekWithOpenAiChatModelIT.ActorsFilmsRecord actorsFilms = outputConverter
			.convert(generation.getOutput().getText());
		logger.info("{}", actorsFilms);
		assertThat(actorsFilms.actor()).isEqualTo("Tom Hanks");
		assertThat(actorsFilms.movies()).hasSize(5);
	}

	@Test
	void beanStreamOutputConverterRecords() {

		BeanOutputConverter<DeepSeekWithOpenAiChatModelIT.ActorsFilmsRecord> outputConverter = new BeanOutputConverter<>(
				DeepSeekWithOpenAiChatModelIT.ActorsFilmsRecord.class);

		String format = outputConverter.getFormat();
		String template = """
				Generate the filmography of 5 movies for Tom Hanks.
				{format}
				""";
		PromptTemplate promptTemplate = PromptTemplate.builder()
			.template(template)
			.variables(Map.of("format", format))
			.build();
		Prompt prompt = new Prompt(promptTemplate.createMessage());

		String generationTextFromStream = this.chatModel.stream(prompt)
			.collectList()
			.block()
			.stream()
			.map(ChatResponse::getResults)
			.flatMap(List::stream)
			.map(Generation::getOutput)
			.map(AssistantMessage::getText)
			.collect(Collectors.joining());

		DeepSeekWithOpenAiChatModelIT.ActorsFilmsRecord actorsFilms = outputConverter.convert(generationTextFromStream);
		logger.info("{}", actorsFilms);
		assertThat(actorsFilms.actor()).isEqualTo("Tom Hanks");
		assertThat(actorsFilms.movies()).hasSize(5);
	}

	@Test
	@Disabled("The current version of the deepseek-chat model's Function Calling capability is unstable, which may result in looped calls or empty responses.")
	void functionCallTest() {

		UserMessage userMessage = new UserMessage("What's the weather like in San Francisco, Tokyo, and Paris?");

		List<Message> messages = new ArrayList<>(List.of(userMessage));

		var promptOptions = OpenAiChatOptions.builder()
			.toolCallbacks(List.of(FunctionToolCallback.builder("getCurrentWeather", new MockWeatherService())
				.description("Get the weather in location")
				.inputType(MockWeatherService.Request.class)
				.build()))
			.build();

		ChatResponse response = this.chatModel.call(new Prompt(messages, promptOptions));

		logger.info("Response: {}", response);

		assertThat(response.getResult().getOutput().getText()).contains("30", "10", "15");
	}

	@Test
	@Disabled("The current version of the deepseek-chat model's Function Calling capability is unstable, which may result in looped calls or empty responses.")
	void streamFunctionCallTest() {

		UserMessage userMessage = new UserMessage(
				"What's the weather like in San Francisco, Tokyo, and Paris? Return the temperature in Celsius.");

		List<Message> messages = new ArrayList<>(List.of(userMessage));

		var promptOptions = OpenAiChatOptions.builder()
			.toolCallbacks(List.of(FunctionToolCallback.builder("getCurrentWeather", new MockWeatherService())
				.description("Get the weather in location")
				.inputType(MockWeatherService.Request.class)
				.build()))
			.build();

		Flux<ChatResponse> response = this.chatModel.stream(new Prompt(messages, promptOptions));

		String content = response.collectList()
			.block()
			.stream()
			.map(ChatResponse::getResults)
			.flatMap(List::stream)
			.map(Generation::getOutput)
			.map(AssistantMessage::getText)
			.collect(Collectors.joining());
		logger.info("Response: {}", content);

		assertThat(content).contains("30", "10", "15");
	}

	@ParameterizedTest(name = "{0} : {displayName} ")
	@ValueSource(strings = { "deepseek-chat", "deepseek-reasoner" })
	void validateCallResponseMetadata(String model) {
		// @formatter:off
		ChatResponse response = ChatClient.create(this.chatModel).prompt()
				.options(OpenAiChatOptions.builder().model(model).build())
				.user("Tell me about 3 famous pirates from the Golden Age of Piracy and what they did")
				.call()
				.chatResponse();
		// @formatter:on

		logger.info(response.toString());
		assertThat(response.getMetadata().getId()).isNotEmpty();
		assertThat(response.getMetadata().getModel()).containsIgnoringCase(model);
		assertThat(response.getMetadata().getUsage().getPromptTokens()).isPositive();
		assertThat(response.getMetadata().getUsage().getCompletionTokens()).isPositive();
		assertThat(response.getMetadata().getUsage().getTotalTokens()).isPositive();
	}

	record ActorsFilmsRecord(String actor, List<String> movies) {

	}

	@SpringBootConfiguration
	static class Config {

		@Bean
		public OpenAiApi chatCompletionApi() {
			return OpenAiApi.builder().baseUrl(DEEPSEEK_BASE_URL).apiKey(System.getenv("DEEPSEEK_API_KEY")).build();
		}

		@Bean
		public OpenAiChatModel openAiClient(OpenAiApi openAiApi) {
			return OpenAiChatModel.builder()
				.openAiApi(openAiApi)
				.defaultOptions(OpenAiChatOptions.builder().model(DEFAULT_DEEPSEEK_MODEL).build())
				.build();
		}

	}

}
