package main

import (
	"bytes"
	"context"
	"encoding/json"
	"fmt"
	"io"
	"net/http"
	"text/template"
	"time"

	"github.com/gofiber/fiber/v2"
	"go.mongodb.org/mongo-driver/bson"
	"go.mongodb.org/mongo-driver/bson/primitive"
)

type dataForTemplate struct {
	Message OpenaiMessage
}

type ChatCompletionRequest struct {
	Model       string          `json:"model"`
	Messages    []OpenaiMessage `json:"messages"`
	Temperature float64         `json:"temperature"`
}

type OpenaiMessage struct {
	Role    string `json:"role"`
	Content string `json:"content"`
}

type ChatCompletionResponse struct {
	ID      string         `json:"id"`
	Object  string         `json:"object"`
	Created int64          `json:"created"`
	Model   string         `json:"model"`
	Usage   OpenaiUsage    `json:"usage"`
	Choices []OpenaiChoice `json:"choices"`
}

type OpenaiUsage struct {
	PromptTokens     int `json:"prompt_tokens"`
	CompletionTokens int `json:"completion_tokens"`
	TotalTokens      int `json:"total_tokens"`
}

type OpenaiChoice struct {
	Message      OpenaiMessage `json:"message"`
	FinishReason string        `json:"finish_reason"`
	Index        int           `json:"index"`
}

var lastMessageAsked string // TODO Remove this

func addOpenaiMessage(c *fiber.Ctx) error {
	message := lastMessageAsked // TODO Remove this

	chatCompletion, err := RequestOpenai("gpt-3.5-turbo", []Message{{Content: message, Role: "user", Date: time.Now(), ID: primitive.NilObjectID}}, 0.7)
	if err != nil {
		// Print error
		fmt.Println("Error:", err)
		return err
	} else if len(chatCompletion.Choices) == 0 {
		fmt.Println("No response from OpenAI")
		return err
	}

	collection := mongoClient.Database("chat").Collection("messages")
	collection.InsertOne(context.Background(), bson.M{"message": message, "role": "user", "date": time.Now()})

	// Render bot message MAYBE to optimize
	// HOW TO GET STRING OF HTML FROM TEMPLATE
	tmpl, err := template.ParseFiles("views/partials/bot-message.gohtml")
	if err != nil {
		fmt.Println("Error parsing template:", err)
		return err
	}

	// Add bot message if there is no error
	var renderedMessage bytes.Buffer
	Message := chatCompletion.Choices[0].Message
	if err := tmpl.Execute(&renderedMessage, Message); err != nil {
		fmt.Println("Error rendering template:", err)
		return err
	}

	collection.InsertOne(context.Background(), bson.M{"message": Message.Content, "role": "bot", "date": time.Now()})

	return c.SendString(renderedMessage.String())
}

func Message2OpenaiMessage(message Message) OpenaiMessage {
	return OpenaiMessage{
		Role:    message.Role,
		Content: message.Content,
	}
}

func Messages2OpenaiMessages(messages []Message) []OpenaiMessage {
	var openaiMessages []OpenaiMessage
	for _, message := range messages {
		openaiMessages = append(openaiMessages, Message2OpenaiMessage(message))
	}
	return openaiMessages
}

func RequestOpenai(model string, messages []Message, temperature float64) (ChatCompletionResponse, error) {
	apiKey := "sk-proj-f7StCvXCtcmiOOayiVmgT3BlbkFJlVtAcOo3JcrnGq1cPa5o" // TODO Use env variable
	url := "https://api.openai.com/v1/chat/completions"

	// Convert messages to OpenAI format
	openaiMessages := Messages2OpenaiMessages(messages)

	requestBody := ChatCompletionRequest{
		Model:       model,
		Messages:    openaiMessages,
		Temperature: temperature,
	}

	jsonBody, err := json.Marshal(requestBody)
	if err != nil {
		return ChatCompletionResponse{}, fmt.Errorf("error marshaling JSON: %w", err)
	}

	req, err := http.NewRequest("POST", url, bytes.NewBuffer(jsonBody))
	if err != nil {
		return ChatCompletionResponse{}, fmt.Errorf("error creating request: %w", err)
	}

	req.Header.Set("Content-Type", "application/json")
	req.Header.Set("Authorization", "Bearer "+apiKey)

	client := &http.Client{}
	resp, err := client.Do(req)
	if err != nil {
		return ChatCompletionResponse{}, fmt.Errorf("error sending request: %w", err)
	}
	defer resp.Body.Close()

	body, err := io.ReadAll(resp.Body)
	if err != nil {
		return ChatCompletionResponse{}, fmt.Errorf("error reading response body: %w", err)
	}

	var chatCompletionResponse ChatCompletionResponse
	err = json.Unmarshal(body, &chatCompletionResponse)
	if err != nil {
		return ChatCompletionResponse{}, fmt.Errorf("error unmarshaling JSON: %w", err)
	}

	return chatCompletionResponse, nil
}