package middleware

import (
	"fmt"
	"github.com/songquanpeng/one-api/common"
	"github.com/songquanpeng/one-api/common/logger"
	"github.com/songquanpeng/one-api/model"
	"net/http"
	"strconv"
	"strings"

	"github.com/gin-gonic/gin"
)

type ModelRequest struct {
	Model string `json:"model"`
}

func Distribute() func(c *gin.Context) {
	return func(c *gin.Context) {
		userId := c.GetInt("id")
		userGroup, _ := model.CacheGetUserGroup(userId)
		c.Set("group", userGroup)
		var requestModel string
		var channel *model.Channel
		channelId, ok := c.Get("specific_channel_id")
		if ok {
			id, err := strconv.Atoi(channelId.(string))
			if err != nil {
				abortWithMessage(c, http.StatusBadRequest, "无效的渠道 Id")
				return
			}
			channel, err = model.GetChannelById(id, true)
			if err != nil {
				abortWithMessage(c, http.StatusBadRequest, "无效的渠道 Id")
				return
			}
			if channel.Status != common.ChannelStatusEnabled {
				abortWithMessage(c, http.StatusForbidden, "该渠道已被禁用")
				return
			}
		} else {
			// Select a channel for the user
			var modelRequest ModelRequest
			err := common.UnmarshalBodyReusable(c, &modelRequest)
			if err != nil {
				abortWithMessage(c, http.StatusBadRequest, "无效的请求")
				return
			}
			if strings.HasPrefix(c.Request.URL.Path, "/v1/moderations") {
				if modelRequest.Model == "" {
					modelRequest.Model = "text-moderation-stable"
				}
			}
			if strings.HasSuffix(c.Request.URL.Path, "embeddings") {
				if modelRequest.Model == "" {
					modelRequest.Model = c.Param("model")
				}
			}
			if strings.HasPrefix(c.Request.URL.Path, "/v1/images/generations") {
				if modelRequest.Model == "" {
					modelRequest.Model = "dall-e-2"
				}
			}
			if strings.HasPrefix(c.Request.URL.Path, "/v1/audio/transcriptions") || strings.HasPrefix(c.Request.URL.Path, "/v1/audio/translations") {
				if modelRequest.Model == "" {
					modelRequest.Model = "whisper-1"
				}
			}
			requestModel = modelRequest.Model
			channel, err = model.CacheGetRandomSatisfiedChannel(userGroup, modelRequest.Model)
			if err != nil {
				message := fmt.Sprintf("当前分组 %s 下对于模型 %s 无可用渠道", userGroup, modelRequest.Model)
				if channel != nil {
					logger.SysError(fmt.Sprintf("渠道不存在：%d", channel.Id))
					message = "数据库一致性已被破坏，请联系管理员"
				}
				abortWithMessage(c, http.StatusServiceUnavailable, message)
				return
			}
		}
		SetupContextForSelectedChannel(c, channel, requestModel)
		c.Next()
	}
}

func SetupContextForSelectedChannel(c *gin.Context, channel *model.Channel, modelName string) {
	c.Set("channel", channel.Type)
	c.Set("channel_id", channel.Id)
	c.Set("channel_name", channel.Name)
	c.Set("model_mapping", channel.GetModelMapping())
	c.Set("original_model", modelName) // for retry
	c.Request.Header.Set("Authorization", fmt.Sprintf("Bearer %s", channel.Key))
	c.Set("base_url", channel.GetBaseURL())
	// this is for backward compatibility
	switch channel.Type {
	case common.ChannelTypeAzure:
		c.Set(common.ConfigKeyAPIVersion, channel.Other)
	case common.ChannelTypeXunfei:
		c.Set(common.ConfigKeyAPIVersion, channel.Other)
	case common.ChannelTypeGemini:
		c.Set(common.ConfigKeyAPIVersion, channel.Other)
	case common.ChannelTypeAIProxyLibrary:
		c.Set(common.ConfigKeyLibraryID, channel.Other)
	case common.ChannelTypeAli:
		c.Set(common.ConfigKeyPlugin, channel.Other)
	}
	cfg, _ := channel.LoadConfig()
	for k, v := range cfg {
		c.Set(common.ConfigKeyPrefix+k, v)
	}
}