package service

import (
	"encoding/json"
	"errors"
	"fmt"
	"github.com/gin-gonic/gin"
	"net/http"
	"one-api/common"
	"one-api/dto"
)

func SetEventStreamHeaders(c *gin.Context) {
	c.Writer.Header().Set("Content-Type", "text/event-stream")
	c.Writer.Header().Set("Cache-Control", "no-cache")
	c.Writer.Header().Set("Connection", "keep-alive")
	c.Writer.Header().Set("Transfer-Encoding", "chunked")
	c.Writer.Header().Set("X-Accel-Buffering", "no")
}

func StringData(c *gin.Context, str string) error {
	//str = strings.TrimPrefix(str, "data: ")
	//str = strings.TrimSuffix(str, "\r")
	c.Render(-1, common.CustomEvent{Data: "data: " + str})
	if flusher, ok := c.Writer.(http.Flusher); ok {
		flusher.Flush()
	} else {
		return errors.New("streaming error: flusher not found")
	}
	return nil
}

func ObjectData(c *gin.Context, object interface{}) error {
	jsonData, err := json.Marshal(object)
	if err != nil {
		return fmt.Errorf("error marshalling object: %w", err)
	}
	return StringData(c, string(jsonData))
}

func Done(c *gin.Context) {
	_ = StringData(c, "[DONE]")
}

func GetResponseID(c *gin.Context) string {
	logID := c.GetString("X-Oneapi-Request-Id")
	return fmt.Sprintf("chatcmpl-%s", logID)
}

func GenerateStopResponse(id string, createAt int64, model string, finishReason string) *dto.ChatCompletionsStreamResponse {
	return &dto.ChatCompletionsStreamResponse{
		Id:                id,
		Object:            "chat.completion.chunk",
		Created:           createAt,
		Model:             model,
		SystemFingerprint: nil,
		Choices: []dto.ChatCompletionsStreamResponseChoice{
			{
				FinishReason: &finishReason,
			},
		},
	}
}

func GenerateFinalUsageResponse(id string, createAt int64, model string, usage dto.Usage) *dto.ChatCompletionsStreamResponse {
	return &dto.ChatCompletionsStreamResponse{
		Id:                id,
		Object:            "chat.completion.chunk",
		Created:           createAt,
		Model:             model,
		SystemFingerprint: nil,
		Choices:           make([]dto.ChatCompletionsStreamResponseChoice, 0),
		Usage:             &usage,
	}
}