package relay

import (
	"bytes"
	"fmt"
	"io"
	"net/http"
	"strings"

	"github.com/QuantumNous/new-api/common"
	"github.com/QuantumNous/new-api/constant"
	"github.com/QuantumNous/new-api/dto"
	"github.com/QuantumNous/new-api/logger"
	"github.com/QuantumNous/new-api/relay/channel/gemini"
	relaycommon "github.com/QuantumNous/new-api/relay/common"
	"github.com/QuantumNous/new-api/relay/helper"
	"github.com/QuantumNous/new-api/service"
	"github.com/QuantumNous/new-api/setting/model_setting"
	"github.com/QuantumNous/new-api/types"

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

func isNoThinkingRequest(req *dto.GeminiChatRequest) bool {
	if req.GenerationConfig.ThinkingConfig != nil && req.GenerationConfig.ThinkingConfig.ThinkingBudget != nil {
		configBudget := req.GenerationConfig.ThinkingConfig.ThinkingBudget
		if configBudget != nil && *configBudget == 0 {
			// 如果思考预算为 0，则认为是非思考请求
			return true
		}
	}
	return false
}

func trimModelThinking(modelName string) string {
	// 去除模型名称中的 -nothinking 后缀
	if strings.HasSuffix(modelName, "-nothinking") {
		return strings.TrimSuffix(modelName, "-nothinking")
	}
	// 去除模型名称中的 -thinking 后缀
	if strings.HasSuffix(modelName, "-thinking") {
		return strings.TrimSuffix(modelName, "-thinking")
	}

	// 去除模型名称中的 -thinking-number
	if strings.Contains(modelName, "-thinking-") {
		parts := strings.Split(modelName, "-thinking-")
		if len(parts) > 1 {
			return parts[0] + "-thinking"
		}
	}
	return modelName
}

func GeminiHelper(c *gin.Context, info *relaycommon.RelayInfo) (newAPIError *types.NewAPIError) {
	info.InitChannelMeta(c)

	geminiReq, ok := info.Request.(*dto.GeminiChatRequest)
	if !ok {
		return types.NewErrorWithStatusCode(fmt.Errorf("invalid request type, expected *dto.GeminiChatRequest, got %T", info.Request), types.ErrorCodeInvalidRequest, http.StatusBadRequest, types.ErrOptionWithSkipRetry())
	}

	request, err := common.DeepCopy(geminiReq)
	if err != nil {
		return types.NewError(fmt.Errorf("failed to copy request to GeminiChatRequest: %w", err), types.ErrorCodeInvalidRequest, types.ErrOptionWithSkipRetry())
	}

	// model mapped 模型映射
	err = helper.ModelMappedHelper(c, info, request)
	if err != nil {
		return types.NewError(err, types.ErrorCodeChannelModelMappedError, types.ErrOptionWithSkipRetry())
	}

	if model_setting.GetGeminiSettings().ThinkingAdapterEnabled {
		if isNoThinkingRequest(request) {
			// check is thinking
			if !strings.Contains(info.OriginModelName, "-nothinking") {
				// try to get no thinking model price
				noThinkingModelName := info.OriginModelName + "-nothinking"
				containPrice := helper.HasModelBillingConfig(noThinkingModelName)
				if containPrice {
					info.OriginModelName = noThinkingModelName
					info.UpstreamModelName = noThinkingModelName
				}
			}
		}
		if request.GenerationConfig.ThinkingConfig == nil {
			gemini.ThinkingAdaptor(request, info)
		}
	}

	adaptor := GetAdaptor(info.ApiType)
	if adaptor == nil {
		return types.NewError(fmt.Errorf("invalid api type: %d", info.ApiType), types.ErrorCodeInvalidApiType, types.ErrOptionWithSkipRetry())
	}

	adaptor.Init(info)

	if info.ChannelSetting.SystemPrompt != "" {
		if request.SystemInstructions == nil {
			request.SystemInstructions = &dto.GeminiChatContent{
				Parts: []dto.GeminiPart{
					{Text: info.ChannelSetting.SystemPrompt},
				},
			}
		} else if len(request.SystemInstructions.Parts) == 0 {
			request.SystemInstructions.Parts = []dto.GeminiPart{{Text: info.ChannelSetting.SystemPrompt}}
		} else if info.ChannelSetting.SystemPromptOverride {
			common.SetContextKey(c, constant.ContextKeySystemPromptOverride, true)
			merged := false
			for i := range request.SystemInstructions.Parts {
				if request.SystemInstructions.Parts[i].Text == "" {
					continue
				}
				request.SystemInstructions.Parts[i].Text = info.ChannelSetting.SystemPrompt + "\n" + request.SystemInstructions.Parts[i].Text
				merged = true
				break
			}
			if !merged {
				request.SystemInstructions.Parts = append([]dto.GeminiPart{{Text: info.ChannelSetting.SystemPrompt}}, request.SystemInstructions.Parts...)
			}
		}
	}

	// Clean up empty system instruction
	if request.SystemInstructions != nil {
		hasContent := false
		for _, part := range request.SystemInstructions.Parts {
			if part.Text != "" {
				hasContent = true
				break
			}
		}
		if !hasContent {
			request.SystemInstructions = nil
		}
	}

	var requestBody io.Reader
	if model_setting.GetGlobalSettings().PassThroughRequestEnabled || info.ChannelSetting.PassThroughBodyEnabled {
		storage, err := common.GetBodyStorage(c)
		if err != nil {
			return types.NewErrorWithStatusCode(err, types.ErrorCodeReadRequestBodyFailed, http.StatusBadRequest, types.ErrOptionWithSkipRetry())
		}
		requestBody = common.ReaderOnly(storage)
	} else {
		// 使用 ConvertGeminiRequest 转换请求格式
		convertedRequest, err := adaptor.ConvertGeminiRequest(c, info, request)
		if err != nil {
			return types.NewError(err, types.ErrorCodeConvertRequestFailed, types.ErrOptionWithSkipRetry())
		}
		relaycommon.AppendRequestConversionFromRequest(info, convertedRequest)
		jsonData, err := common.Marshal(convertedRequest)
		if err != nil {
			return types.NewError(err, types.ErrorCodeConvertRequestFailed, types.ErrOptionWithSkipRetry())
		}

		// apply param override
		if len(info.ParamOverride) > 0 {
			jsonData, err = relaycommon.ApplyParamOverrideWithRelayInfo(jsonData, info)
			if err != nil {
				return newAPIErrorFromParamOverride(err)
			}
		}

		logger.LogDebug(c, "Gemini request body: "+string(jsonData))

		requestBody = bytes.NewReader(jsonData)
	}

	resp, err := adaptor.DoRequest(c, info, requestBody)
	if err != nil {
		logger.LogError(c, "Do gemini request failed: "+err.Error())
		return types.NewOpenAIError(err, types.ErrorCodeDoRequestFailed, http.StatusInternalServerError)
	}

	statusCodeMappingStr := c.GetString("status_code_mapping")

	var httpResp *http.Response
	if resp != nil {
		httpResp = resp.(*http.Response)
		info.IsStream = info.IsStream || strings.HasPrefix(httpResp.Header.Get("Content-Type"), "text/event-stream")
		if httpResp.StatusCode != http.StatusOK {
			newAPIError = service.RelayErrorHandler(c.Request.Context(), httpResp, false)
			// reset status code 重置状态码
			service.ResetStatusCode(newAPIError, statusCodeMappingStr)
			return newAPIError
		}
	}

	usage, openaiErr := adaptor.DoResponse(c, resp.(*http.Response), info)
	if openaiErr != nil {
		service.ResetStatusCode(openaiErr, statusCodeMappingStr)
		return openaiErr
	}

	service.PostTextConsumeQuota(c, info, usage.(*dto.Usage), nil)
	return nil
}

func GeminiEmbeddingHandler(c *gin.Context, info *relaycommon.RelayInfo) (newAPIError *types.NewAPIError) {
	info.InitChannelMeta(c)

	isBatch := strings.HasSuffix(c.Request.URL.Path, "batchEmbedContents")
	info.IsGeminiBatchEmbedding = isBatch

	var req dto.Request
	var err error
	var inputTexts []string

	if isBatch {
		batchRequest := &dto.GeminiBatchEmbeddingRequest{}
		err = common.UnmarshalBodyReusable(c, batchRequest)
		if err != nil {
			return types.NewError(err, types.ErrorCodeInvalidRequest, types.ErrOptionWithSkipRetry())
		}
		req = batchRequest
		for _, r := range batchRequest.Requests {
			for _, part := range r.Content.Parts {
				if part.Text != "" {
					inputTexts = append(inputTexts, part.Text)
				}
			}
		}
	} else {
		singleRequest := &dto.GeminiEmbeddingRequest{}
		err = common.UnmarshalBodyReusable(c, singleRequest)
		if err != nil {
			return types.NewError(err, types.ErrorCodeInvalidRequest, types.ErrOptionWithSkipRetry())
		}
		req = singleRequest
		for _, part := range singleRequest.Content.Parts {
			if part.Text != "" {
				inputTexts = append(inputTexts, part.Text)
			}
		}
	}

	err = helper.ModelMappedHelper(c, info, req)
	if err != nil {
		return types.NewError(err, types.ErrorCodeChannelModelMappedError, types.ErrOptionWithSkipRetry())
	}

	req.SetModelName("models/" + info.UpstreamModelName)

	adaptor := GetAdaptor(info.ApiType)
	if adaptor == nil {
		return types.NewError(fmt.Errorf("invalid api type: %d", info.ApiType), types.ErrorCodeInvalidApiType, types.ErrOptionWithSkipRetry())
	}
	adaptor.Init(info)

	var requestBody io.Reader
	jsonData, err := common.Marshal(req)
	if err != nil {
		return types.NewError(err, types.ErrorCodeConvertRequestFailed, types.ErrOptionWithSkipRetry())
	}

	// apply param override
	if len(info.ParamOverride) > 0 {
		jsonData, err = relaycommon.ApplyParamOverrideWithRelayInfo(jsonData, info)
		if err != nil {
			return newAPIErrorFromParamOverride(err)
		}
	}
	logger.LogDebug(c, "Gemini embedding request body: "+string(jsonData))
	requestBody = bytes.NewReader(jsonData)

	resp, err := adaptor.DoRequest(c, info, requestBody)
	if err != nil {
		logger.LogError(c, "Do gemini request failed: "+err.Error())
		return types.NewOpenAIError(err, types.ErrorCodeDoRequestFailed, http.StatusInternalServerError)
	}

	statusCodeMappingStr := c.GetString("status_code_mapping")
	var httpResp *http.Response
	if resp != nil {
		httpResp = resp.(*http.Response)
		if httpResp.StatusCode != http.StatusOK {
			newAPIError = service.RelayErrorHandler(c.Request.Context(), httpResp, false)
			service.ResetStatusCode(newAPIError, statusCodeMappingStr)
			return newAPIError
		}
	}

	usage, openaiErr := adaptor.DoResponse(c, resp.(*http.Response), info)
	if openaiErr != nil {
		service.ResetStatusCode(openaiErr, statusCodeMappingStr)
		return openaiErr
	}

	service.PostTextConsumeQuota(c, info, usage.(*dto.Usage), nil)
	return nil
}
