//
//  Copyright 2026 The InfiniFlow Authors. All Rights Reserved.
//
//  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
//
//      http://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 models

import (
	"bufio"
	"bytes"
	"encoding/base64"
	"encoding/json"
	"fmt"
	"io"
	"mime/multipart"
	"net/http"
	"os"
	"path/filepath"
	"ragflow/internal/common"
	"strings"
	"time"
)

// ZhipuAIModel implements ModelDriver for Zhipu AI
type ZhipuAIModel struct {
	BaseURL    map[string]string
	URLSuffix  URLSuffix
	httpClient *http.Client // Reusable HTTP client with connection pool
}

// NewZhipuAIModel creates a new Zhipu AI model instance
func NewZhipuAIModel(baseURL map[string]string, urlSuffix URLSuffix) *ZhipuAIModel {
	return &ZhipuAIModel{
		BaseURL:   baseURL,
		URLSuffix: urlSuffix,
		httpClient: &http.Client{
			Timeout: 120 * time.Second,
			Transport: &http.Transport{
				MaxIdleConns:        100,
				MaxIdleConnsPerHost: 10,
				IdleConnTimeout:     90 * time.Second,
				DisableCompression:  false,
			},
		},
	}
}

func (z *ZhipuAIModel) NewInstance(baseURL map[string]string) ModelDriver {
	return nil
}

func (z *ZhipuAIModel) Name() string {
	return "zhipu"
}

// ChatWithMessages sends multiple messages with roles and returns response
func (z *ZhipuAIModel) ChatWithMessages(modelName string, messages []Message, apiConfig *APIConfig, chatModelConfig *ChatConfig) (*ChatResponse, error) {
	if apiConfig == nil || apiConfig.ApiKey == nil || *apiConfig.ApiKey == "" {
		return nil, fmt.Errorf("api key is nil or empty")
	}

	if len(messages) == 0 {
		return nil, fmt.Errorf("messages is empty")
	}

	region := "default"
	if apiConfig.Region != nil && *apiConfig.Region != "" {
		region = *apiConfig.Region
	}
	url := fmt.Sprintf("%s/%s", z.BaseURL[region], z.URLSuffix.Chat)

	// Convert messages to the format expected by API
	apiMessages := make([]map[string]interface{}, len(messages))
	for i, msg := range messages {
		apiMessages[i] = map[string]interface{}{
			"role":    msg.Role,
			"content": msg.Content,
		}
	}

	// Build request body
	reqBody := map[string]interface{}{
		"model":       modelName,
		"messages":    apiMessages,
		"stream":      false,
		"temperature": 1,
	}

	if chatModelConfig != nil {
		if chatModelConfig.Stream != nil {
			reqBody["stream"] = *chatModelConfig.Stream
		}

		if chatModelConfig.MaxTokens != nil {
			reqBody["max_tokens"] = *chatModelConfig.MaxTokens
		}

		if chatModelConfig.Temperature != nil {
			reqBody["temperature"] = *chatModelConfig.Temperature
		}

		if chatModelConfig.TopP != nil {
			reqBody["top_p"] = *chatModelConfig.TopP
		}

		if chatModelConfig.Stop != nil {
			reqBody["stop"] = *chatModelConfig.Stop
		}

		if chatModelConfig.Thinking != nil {
			if *chatModelConfig.Thinking {
				reqBody["thinking"] = map[string]interface{}{
					"type": "enabled",
				}
			} else {
				reqBody["thinking"] = map[string]interface{}{
					"type": "disabled",
				}
			}
		}
	}

	jsonData, err := json.Marshal(reqBody)
	if err != nil {
		return nil, fmt.Errorf("failed to marshal request: %w", err)
	}

	req, err := http.NewRequest("POST", url, bytes.NewBuffer(jsonData))
	if err != nil {
		return nil, fmt.Errorf("failed to create request: %w", err)
	}

	req.Header.Set("Content-Type", "application/json")
	req.Header.Set("Authorization", fmt.Sprintf("Bearer %s", *apiConfig.ApiKey))

	resp, err := z.httpClient.Do(req)
	if err != nil {
		return nil, fmt.Errorf("failed to send request: %w", err)
	}
	defer resp.Body.Close()

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

	if resp.StatusCode != http.StatusOK {
		return nil, fmt.Errorf("API request failed with status %d: %s", resp.StatusCode, string(body))
	}

	// Parse response
	var result map[string]interface{}
	if err = json.Unmarshal(body, &result); err != nil {
		return nil, fmt.Errorf("failed to parse response: %w", err)
	}

	choices, ok := result["choices"].([]interface{})
	if !ok || len(choices) == 0 {
		return nil, fmt.Errorf("no choices in response")
	}

	firstChoice, ok := choices[0].(map[string]interface{})
	if !ok {
		return nil, fmt.Errorf("invalid choice format")
	}

	messageMap, ok := firstChoice["message"].(map[string]interface{})
	if !ok {
		return nil, fmt.Errorf("invalid message format")
	}

	content, ok := messageMap["content"].(string)
	if !ok {
		return nil, fmt.Errorf("invalid content format")
	}

	var reasonContent string
	if chatModelConfig != nil && chatModelConfig.Thinking != nil && *chatModelConfig.Thinking {
		reasonContent, ok = messageMap["reasoning_content"].(string)
		if !ok {
			return nil, fmt.Errorf("invalid content format")
		}
		// if first char of reasonContent is \n remove the '\n'
		if reasonContent != "" && reasonContent[0] == '\n' {
			reasonContent = reasonContent[1:]
		}
	}

	chatResponse := &ChatResponse{
		Answer:        &content,
		ReasonContent: &reasonContent,
	}

	return chatResponse, nil
}

// ChatStreamlyWithSender sends messages and streams response via sender function (best performance, no channel)
func (z *ZhipuAIModel) ChatStreamlyWithSender(modelName string, messages []Message, apiConfig *APIConfig, chatModelConfig *ChatConfig, sender func(*string, *string) error) error {
	if len(messages) == 0 {
		return fmt.Errorf("messages is empty")
	}

	var region = "default"
	if apiConfig != nil && apiConfig.Region != nil && *apiConfig.Region != "" {
		region = *apiConfig.Region
	}

	url := fmt.Sprintf("%s/%s", strings.TrimSuffix(z.BaseURL[region], "/"), z.URLSuffix.Chat)

	// Convert messages to API format
	apiMessages := make([]map[string]interface{}, len(messages))
	for i, msg := range messages {
		apiMessages[i] = map[string]interface{}{
			"role":    msg.Role,
			"content": msg.Content,
		}
	}

	// Build request body with streaming enabled
	reqBody := map[string]interface{}{
		"model":       modelName,
		"messages":    apiMessages,
		"stream":      true,
		"temperature": 1,
	}

	if chatModelConfig != nil {
		if chatModelConfig.Stream != nil {
			reqBody["stream"] = *chatModelConfig.Stream
		}

		if chatModelConfig.MaxTokens != nil {
			reqBody["max_tokens"] = *chatModelConfig.MaxTokens
		}

		if chatModelConfig.Temperature != nil {
			reqBody["temperature"] = *chatModelConfig.Temperature
		}

		if chatModelConfig.DoSample != nil {
			reqBody["do_sample"] = *chatModelConfig.DoSample
		}

		if chatModelConfig.TopP != nil {
			reqBody["top_p"] = *chatModelConfig.TopP
		}

		if chatModelConfig.Stop != nil {
			reqBody["stop"] = *chatModelConfig.Stop
		}

		if chatModelConfig.Thinking != nil {
			if *chatModelConfig.Thinking {
				reqBody["thinking"] = map[string]interface{}{
					"type": "enabled",
				}
			} else {
				reqBody["thinking"] = map[string]interface{}{
					"type": "disabled",
				}
			}
		}
	}

	jsonData, err := json.Marshal(reqBody)
	if err != nil {
		return fmt.Errorf("failed to marshal request: %w", err)
	}

	req, err := http.NewRequest("POST", url, bytes.NewBuffer(jsonData))
	if err != nil {
		return fmt.Errorf("failed to create request: %w", err)
	}

	req.Header.Set("Content-Type", "application/json")
	req.Header.Set("Authorization", fmt.Sprintf("Bearer %s", *apiConfig.ApiKey))

	resp, err := z.httpClient.Do(req)
	if err != nil {
		return fmt.Errorf("failed to send request: %w", err)
	}
	defer resp.Body.Close()

	if resp.StatusCode != http.StatusOK {
		body, _ := io.ReadAll(resp.Body)
		return fmt.Errorf("API request failed with status %d: %s", resp.StatusCode, string(body))
	}

	// SSE parsing: read line by line
	scanner := bufio.NewScanner(resp.Body)
	for scanner.Scan() {
		line := scanner.Text()
		common.Info(line)

		// SSE data line starts with "data:"
		if !strings.HasPrefix(line, "data:") {
			continue
		}

		// Extract JSON after "data:"
		data := strings.TrimSpace(line[5:])

		// [DONE] marks the end of stream
		if data == "[DONE]" {
			break
		}

		// Parse the JSON event
		var event map[string]interface{}
		if err = json.Unmarshal([]byte(data), &event); err != nil {
			continue
		}

		choices, ok := event["choices"].([]interface{})
		if !ok || len(choices) == 0 {
			continue
		}

		firstChoice, ok := choices[0].(map[string]interface{})
		if !ok {
			continue
		}

		delta, ok := firstChoice["delta"].(map[string]interface{})
		if !ok {
			continue
		}

		reasoningContent, ok := delta["reasoning_content"].(string)
		if ok && reasoningContent != "" {
			if err := sender(nil, &reasoningContent); err != nil {
				return err
			}
		}

		content, ok := delta["content"].(string)
		if ok && content != "" {
			if err := sender(&content, nil); err != nil {
				return err
			}
		}

		finishReason, ok := firstChoice["finish_reason"].(string)
		if ok && finishReason != "" {
			break
		}
	}

	// Send [DONE] marker for OpenAI compatibility
	endOfStream := "[DONE]"
	if err = sender(&endOfStream, nil); err != nil {
		return err
	}

	return scanner.Err()
}

type zhipuEmbeddingResponse struct {
	Data   []zhipuEmbeddingData `json:"data"`
	Model  string               `json:"model"`
	Object string               `json:"object"`
	Usage  zhipuUsage           `json:"usage"`
}

type zhipuEmbeddingData struct {
	Embedding []float64 `json:"embedding"`
	Index     int       `json:"index"`
	Object    string    `json:"object"`
}

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

// Encode encodes a list of texts into embeddings
func (z *ZhipuAIModel) Embed(modelName *string, texts []string, apiConfig *APIConfig, embeddingConfig *EmbeddingConfig) ([]EmbeddingData, error) {
	if len(texts) == 0 {
		return []EmbeddingData{}, nil
	}

	if apiConfig == nil || apiConfig.ApiKey == nil || *apiConfig.ApiKey == "" {
		return nil, fmt.Errorf("api key is required")
	}

	if modelName == nil || *modelName == "" {
		return nil, fmt.Errorf("model name is required")
	}

	var region = "default"
	if apiConfig.Region != nil && *apiConfig.Region != "" {
		region = *apiConfig.Region
	}

	url := fmt.Sprintf("%s/%s", strings.TrimSuffix(z.BaseURL[region], "/"), z.URLSuffix.Embedding)

	reqBody := map[string]interface{}{}
	reqBody["model"] = modelName
	reqBody["input"] = texts
	if embeddingConfig.Dimension > 0 {
		reqBody["dimensions"] = embeddingConfig.Dimension
	}

	jsonData, err := json.Marshal(reqBody)
	if err != nil {
		return nil, fmt.Errorf("failed to marshal request: %w", err)
	}

	req, err := http.NewRequest("POST", url, bytes.NewBuffer(jsonData))
	if err != nil {
		return nil, fmt.Errorf("failed to create request: %w", err)
	}

	req.Header.Set("Content-Type", "application/json")
	req.Header.Set("Authorization", fmt.Sprintf("Bearer %s", *apiConfig.ApiKey))

	resp, err := z.httpClient.Do(req)
	if err != nil {
		return nil, fmt.Errorf("failed to send request: %w", err)
	}

	body, err := io.ReadAll(resp.Body)
	resp.Body.Close()

	if err != nil {
		return nil, fmt.Errorf("failed to read response: %w", err)
	}

	if resp.StatusCode != http.StatusOK {
		return nil, fmt.Errorf("API request failed with status %d: %s", resp.StatusCode, string(body))
	}

	// Parse response
	var zhipuResp zhipuEmbeddingResponse
	if err = json.Unmarshal(body, &zhipuResp); err != nil {
		return nil, fmt.Errorf("failed to parse response: %w", err)
	}

	var embeddings []EmbeddingData
	for _, dataElem := range zhipuResp.Data {
		var embeddingData EmbeddingData
		embeddingData.Embedding = dataElem.Embedding
		embeddingData.Index = dataElem.Index
		embeddings = append(embeddings, embeddingData)
	}

	return embeddings, nil
}

func (z *ZhipuAIModel) ListModels(apiConfig *APIConfig) ([]string, error) {
	region := "default"
	if apiConfig != nil && apiConfig.Region != nil && *apiConfig.Region != "" {
		region = *apiConfig.Region
	}

	baseURL := z.BaseURL["default"]
	if region != "default" {
		if regional, ok := z.BaseURL[region]; ok && regional != "" {
			baseURL = regional
		}
	}
	if baseURL == "" {
		return nil, fmt.Errorf("zhipu-ai: no base URL configured for default region")
	}

	url := fmt.Sprintf("%s/%s", strings.TrimSuffix(baseURL, "/"), z.URLSuffix.Models)

	req, err := http.NewRequest("GET", url, nil)
	if err != nil {
		return nil, fmt.Errorf("failed to create request: %w", err)
	}

	req.Header.Set("Content-Type", "application/json")
	if apiConfig != nil && apiConfig.ApiKey != nil && *apiConfig.ApiKey != "" {
		req.Header.Set("Authorization", fmt.Sprintf("Bearer %s", *apiConfig.ApiKey))
	}

	resp, err := z.httpClient.Do(req)
	if err != nil {
		return nil, fmt.Errorf("failed to send request: %w", err)
	}
	defer resp.Body.Close()

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

	if resp.StatusCode != http.StatusOK {
		return nil, fmt.Errorf("ZhipuAI models API error: %s, body: %s", resp.Status, string(body))
	}

	var modelList DSModelList
	if err = json.Unmarshal(body, &modelList); err != nil {
		return nil, fmt.Errorf("failed to parse response: %w", err)
	}

	models := make([]string, 0, len(modelList.Models))
	for _, model := range modelList.Models {
		modelName := model.ID
		if model.OwnedBy != "" {
			modelName = model.ID + "@" + model.OwnedBy
		}
		models = append(models, modelName)
	}

	return models, nil
}

func (z *ZhipuAIModel) Balance(apiConfig *APIConfig) (map[string]interface{}, error) {
	return nil, fmt.Errorf("%s, no such method", z.Name())
}

func (z *ZhipuAIModel) CheckConnection(apiConfig *APIConfig) error {
	var region = "default"
	if apiConfig != nil && apiConfig.Region != nil && *apiConfig.Region != "" {
		region = *apiConfig.Region
	}

	url := fmt.Sprintf("%s/%s", z.BaseURL[region], z.URLSuffix.Files)

	req, err := http.NewRequest("GET", url, nil)
	if err != nil {
		return fmt.Errorf("failed to create request: %w", err)
	}

	req.Header.Set("Content-Type", "application/json")
	req.Header.Set("Authorization", fmt.Sprintf("Bearer %s", *apiConfig.ApiKey))

	resp, err := z.httpClient.Do(req)
	if err != nil {
		return fmt.Errorf("failed to send request: %w", err)
	}
	defer resp.Body.Close()

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

	if resp.StatusCode != http.StatusOK {
		return fmt.Errorf("API request failed with status %d: %s", resp.StatusCode, string(body))
	}

	return nil
}

// zhipuRerankRequest is the request body for the ZhipuAI rerank
// endpoint. The shape matches the standard OpenAI-compatible rerank
// API also used by SiliconFlow.
type zhipuRerankRequest struct {
	Model           string   `json:"model"`
	Query           string   `json:"query"`
	Documents       []string `json:"documents"`
	TopN            int      `json:"top_n"`
	ReturnDocuments bool     `json:"return_documents"`
}

// zhipuRerankResponse is the response shape for the ZhipuAI rerank
// endpoint.
type zhipuRerankResponse struct {
	Created   int64  `json:"created"`
	ID        string `json:"id"`
	RequestID string `json:"request_id"`
	Usage     struct {
		CompletionTokens int `json:"completion_tokens"`
		PromptTokens     int `json:"prompt_tokens"`
		TotalTokens      int `json:"total_tokens"`
	} `json:"usage"`
	Results []struct {
		Index          int     `json:"index"`
		RelevanceScore float64 `json:"relevance_score"`
	} `json:"results"`
}

type zhipuOCRResponse struct {
	MarkdownResults *string `json:"md_results"`
}

// Rerank calculates similarity scores between query and documents using
// the ZhipuAI /rerank endpoint (e.g. glm-rerank). The result is one
// score per input text, in the same order the documents were given.
func (z *ZhipuAIModel) Rerank(modelName *string, query string, documents []string, apiConfig *APIConfig, rerankConfig *RerankConfig) (*RerankResponse, error) {
	if len(documents) == 0 {
		return &RerankResponse{}, nil
	}

	if apiConfig == nil || apiConfig.ApiKey == nil || *apiConfig.ApiKey == "" {
		return nil, fmt.Errorf("api key is required")
	}

	if modelName == nil || *modelName == "" {
		return nil, fmt.Errorf("model name is required")
	}

	region := "default"
	if apiConfig.Region != nil {
		region = *apiConfig.Region
	}

	baseURL, ok := z.BaseURL[region]
	if !ok || baseURL == "" {
		return nil, fmt.Errorf("zhipu-ai: no base URL configured for region %q", region)
	}

	url := fmt.Sprintf("%s/%s", strings.TrimSuffix(baseURL, "/"), z.URLSuffix.Rerank)

	var topN = rerankConfig.TopN
	if rerankConfig.TopN == 0 {
		topN = len(documents)
	}

	reqBody := zhipuRerankRequest{
		Model:           *modelName,
		Query:           query,
		Documents:       documents,
		TopN:            topN,
		ReturnDocuments: false,
	}

	jsonData, err := json.Marshal(reqBody)
	if err != nil {
		return nil, fmt.Errorf("failed to marshal request: %w", err)
	}

	req, err := http.NewRequest("POST", url, bytes.NewBuffer(jsonData))
	if err != nil {
		return nil, fmt.Errorf("failed to create request: %w", err)
	}

	req.Header.Set("Content-Type", "application/json")
	req.Header.Set("Authorization", fmt.Sprintf("Bearer %s", *apiConfig.ApiKey))

	resp, err := z.httpClient.Do(req)
	if err != nil {
		return nil, fmt.Errorf("failed to send request: %w", err)
	}
	defer resp.Body.Close()

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

	if resp.StatusCode != http.StatusOK {
		return nil, fmt.Errorf("ZhipuAI rerank API error: %s, body: %s", resp.Status, string(body))
	}

	var zhipuRerankResp zhipuRerankResponse
	if err = json.Unmarshal(body, &zhipuRerankResp); err != nil {
		return nil, fmt.Errorf("failed to parse response: %w", err)
	}

	var rerankResponse RerankResponse
	for _, result := range zhipuRerankResp.Results {
		rerankResult := RerankResult{
			Index:          result.Index,
			RelevanceScore: result.RelevanceScore,
		}
		rerankResponse.Data = append(rerankResponse.Data, rerankResult)
	}

	return &rerankResponse, nil
}

// TranscribeAudio transcribe audio
func (z *ZhipuAIModel) TranscribeAudio(modelName *string, file *string, apiConfig *APIConfig, asrConfig *ASRConfig) (*ASRResponse, error) {
	if apiConfig == nil || apiConfig.ApiKey == nil || *apiConfig.ApiKey == "" {
		return nil, fmt.Errorf("api key is required")
	}
	if modelName == nil || *modelName == "" {
		return nil, fmt.Errorf("model name is required")
	}
	if file == nil || *file == "" {
		return nil, fmt.Errorf("file is required")
	}
	if z.URLSuffix.ASR == "" {
		return nil, fmt.Errorf("zhipu-ai: ASR URL suffix is not configured")
	}

	region := "default"
	if apiConfig.Region != nil && *apiConfig.Region != "" {
		region = *apiConfig.Region
	}
	baseURL, ok := z.BaseURL[region]
	if !ok || baseURL == "" {
		return nil, fmt.Errorf("zhipu-ai: no base URL configured for region %q", region)
	}
	url := fmt.Sprintf("%s/%s", strings.TrimSuffix(baseURL, "/"), strings.TrimLeft(z.URLSuffix.ASR, "/"))

	var body bytes.Buffer
	writer := multipart.NewWriter(&body)
	if err := writer.WriteField("model", *modelName); err != nil {
		return nil, fmt.Errorf("failed to write model field: %w", err)
	}
	if err := writer.WriteField("stream", "false"); err != nil {
		return nil, fmt.Errorf("failed to write stream field: %w", err)
	}
	if err := writeZhipuASRParams(writer, asrConfig); err != nil {
		return nil, err
	}

	audioFile, err := os.Open(*file)
	if err != nil {
		return nil, fmt.Errorf("failed to open audio file: %w", err)
	}
	defer audioFile.Close()

	part, err := writer.CreateFormFile("file", filepath.Base(*file))
	if err != nil {
		return nil, fmt.Errorf("failed to create multipart file: %w", err)
	}
	if _, err = io.Copy(part, audioFile); err != nil {
		return nil, fmt.Errorf("failed to copy audio data: %w", err)
	}
	if err = writer.Close(); err != nil {
		return nil, fmt.Errorf("failed to close multipart writer: %w", err)
	}

	req, err := http.NewRequest(http.MethodPost, url, &body)
	if err != nil {
		return nil, fmt.Errorf("failed to create request: %w", err)
	}
	req.Header.Set("Authorization", fmt.Sprintf("Bearer %s", *apiConfig.ApiKey))
	req.Header.Set("Content-Type", writer.FormDataContentType())

	resp, err := z.httpClient.Do(req)
	if err != nil {
		return nil, fmt.Errorf("failed to send request: %w", err)
	}
	defer resp.Body.Close()

	respBody, err := io.ReadAll(resp.Body)
	if err != nil {
		return nil, fmt.Errorf("failed to read response body: %w", err)
	}
	if resp.StatusCode != http.StatusOK {
		return nil, fmt.Errorf("ZhipuAI ASR API error: %s, body: %s", resp.Status, string(respBody))
	}

	var result struct {
		Text string `json:"text"`
	}
	if err = json.Unmarshal(respBody, &result); err != nil {
		return nil, fmt.Errorf("failed to parse response: %w", err)
	}
	return &ASRResponse{Text: result.Text}, nil
}

func writeZhipuASRParams(writer *multipart.Writer, asrConfig *ASRConfig) error {
	if asrConfig == nil || asrConfig.Params == nil {
		return nil
	}
	for key, value := range asrConfig.Params {
		switch key {
		case "model", "stream", "file", "file_base64":
			continue
		}
		if err := writeZhipuASRField(writer, key, value); err != nil {
			return err
		}
	}
	return nil
}

func writeZhipuASRField(writer *multipart.Writer, key string, value interface{}) error {
	switch v := value.(type) {
	case nil:
		return nil
	case []string:
		for _, item := range v {
			if err := writer.WriteField(key, item); err != nil {
				return fmt.Errorf("failed to write field %s: %w", key, err)
			}
		}
		return nil
	case []interface{}:
		for _, item := range v {
			if err := writer.WriteField(key, fmt.Sprint(item)); err != nil {
				return fmt.Errorf("failed to write field %s: %w", key, err)
			}
		}
		return nil
	default:
		if err := writer.WriteField(key, fmt.Sprint(v)); err != nil {
			return fmt.Errorf("failed to write field %s: %w", key, err)
		}
		return nil
	}
}

func (z *ZhipuAIModel) TranscribeAudioWithSender(modelName *string, file *string, apiConfig *APIConfig, asrConfig *ASRConfig, sender func(*string, *string) error) error {
	return fmt.Errorf("%s, no such method", z.Name())
}

// AudioSpeech convert text to audio
func (z *ZhipuAIModel) AudioSpeech(modelName *string, audioContent *string, apiConfig *APIConfig, ttsConfig *TTSConfig) (*TTSResponse, error) {
	reqBody, url, err := z.buildTTSRequest(modelName, audioContent, apiConfig, ttsConfig, false)
	if err != nil {
		return nil, err
	}

	jsonData, err := json.Marshal(reqBody)
	if err != nil {
		return nil, fmt.Errorf("failed to marshal request: %w", err)
	}

	req, err := http.NewRequest(http.MethodPost, url, bytes.NewBuffer(jsonData))
	if err != nil {
		return nil, fmt.Errorf("failed to create request: %w", err)
	}
	req.Header.Set("Content-Type", "application/json")
	req.Header.Set("Authorization", fmt.Sprintf("Bearer %s", *apiConfig.ApiKey))

	resp, err := z.httpClient.Do(req)
	if err != nil {
		return nil, fmt.Errorf("failed to send request: %w", err)
	}
	defer resp.Body.Close()

	body, err := io.ReadAll(resp.Body)
	if err != nil {
		return nil, fmt.Errorf("failed to read response body: %w", err)
	}
	if resp.StatusCode != http.StatusOK {
		return nil, fmt.Errorf("ZhipuAI TTS API error: %s, body: %s", resp.Status, string(body))
	}

	return &TTSResponse{Audio: body}, nil
}

func (z *ZhipuAIModel) AudioSpeechWithSender(modelName *string, audioContent *string, apiConfig *APIConfig, ttsConfig *TTSConfig, sender func(*string, *string) error) error {
	if sender == nil {
		return fmt.Errorf("sender is required")
	}
	reqBody, url, err := z.buildTTSRequest(modelName, audioContent, apiConfig, ttsConfig, true)
	if err != nil {
		return err
	}

	jsonData, err := json.Marshal(reqBody)
	if err != nil {
		return fmt.Errorf("failed to marshal request: %w", err)
	}

	req, err := http.NewRequest(http.MethodPost, url, bytes.NewBuffer(jsonData))
	if err != nil {
		return fmt.Errorf("failed to create request: %w", err)
	}
	req.Header.Set("Content-Type", "application/json")
	req.Header.Set("Authorization", fmt.Sprintf("Bearer %s", *apiConfig.ApiKey))

	resp, err := z.httpClient.Do(req)
	if err != nil {
		return fmt.Errorf("failed to send request: %w", err)
	}
	defer resp.Body.Close()

	if resp.StatusCode != http.StatusOK {
		body, _ := io.ReadAll(resp.Body)
		return fmt.Errorf("ZhipuAI stream TTS API error: %s, body: %s", resp.Status, string(body))
	}

	buf := make([]byte, 32*1024)
	for {
		n, err := resp.Body.Read(buf)
		if n > 0 {
			chunk := string(buf[:n])
			if errSend := sender(&chunk, nil); errSend != nil {
				return errSend
			}
		}
		if err != nil {
			if err == io.EOF {
				break
			}
			return fmt.Errorf("error reading ZhipuAI binary audio stream: %w", err)
		}
	}
	return nil
}

func (z *ZhipuAIModel) buildTTSRequest(modelName *string, audioContent *string, apiConfig *APIConfig, ttsConfig *TTSConfig, stream bool) (map[string]interface{}, string, error) {
	if apiConfig == nil || apiConfig.ApiKey == nil || *apiConfig.ApiKey == "" {
		return nil, "", fmt.Errorf("api key is required")
	}
	if modelName == nil || *modelName == "" {
		return nil, "", fmt.Errorf("model name is required")
	}
	if audioContent == nil || *audioContent == "" {
		return nil, "", fmt.Errorf("audio content is empty")
	}
	if z.URLSuffix.TTS == "" {
		return nil, "", fmt.Errorf("zhipu-ai: TTS URL suffix is not configured")
	}

	region := "default"
	if apiConfig.Region != nil && *apiConfig.Region != "" {
		region = *apiConfig.Region
	}
	baseURL, ok := z.BaseURL[region]
	if !ok || baseURL == "" {
		return nil, "", fmt.Errorf("zhipu-ai: no base URL configured for region %q", region)
	}

	reqBody := map[string]interface{}{
		"model":  *modelName,
		"input":  *audioContent,
		"stream": stream,
	}
	if ttsConfig != nil {
		for key, value := range ttsConfig.Params {
			switch key {
			case "model", "input", "stream", "response_format":
				continue
			}
			reqBody[key] = value
		}
		if ttsConfig.Format != "" {
			reqBody["response_format"] = ttsConfig.Format
		}
	}

	url := fmt.Sprintf("%s/%s", strings.TrimSuffix(baseURL, "/"), strings.TrimLeft(z.URLSuffix.TTS, "/"))
	return reqBody, url, nil
}

// OCRFile OCR file
func (z *ZhipuAIModel) OCRFile(modelName *string, content []byte, fileURL *string, apiConfig *APIConfig, ocrConfig *OCRConfig) (*OCRFileResponse, error) {
	if apiConfig == nil || apiConfig.ApiKey == nil || *apiConfig.ApiKey == "" {
		return nil, fmt.Errorf("api key is required")
	}

	if modelName == nil || *modelName == "" {
		return nil, fmt.Errorf("model name is required")
	}

	if (fileURL == nil || *fileURL == "") && len(content) == 0 {
		return nil, fmt.Errorf("file url or content is required")
	}

	region := "default"
	if apiConfig.Region != nil && *apiConfig.Region != "" {
		region = *apiConfig.Region
	}

	baseURL, ok := z.BaseURL[region]
	if !ok || baseURL == "" {
		return nil, fmt.Errorf("zhipu-ai: no base URL configured for region %q", region)
	}

	if z.URLSuffix.OCR == "" {
		return nil, fmt.Errorf("zhipu-ai: no OCR URL suffix configured")
	}

	file := ""
	if fileURL != nil && *fileURL != "" {
		file = *fileURL
	} else {
		mimeType := http.DetectContentType(content)
		if len(content) > 4 && string(content[:4]) == "%PDF" {
			mimeType = "application/pdf"
		}
		file = fmt.Sprintf("data:%s;base64,%s", mimeType, base64.StdEncoding.EncodeToString(content))
	}

	reqBody := map[string]interface{}{
		"model": *modelName,
		"file":  file,
	}

	jsonData, err := json.Marshal(reqBody)
	if err != nil {
		return nil, fmt.Errorf("failed to marshal request: %w", err)
	}

	endpoint := fmt.Sprintf("%s/%s", strings.TrimSuffix(baseURL, "/"), strings.TrimPrefix(z.URLSuffix.OCR, "/"))
	req, err := http.NewRequest("POST", endpoint, bytes.NewBuffer(jsonData))
	if err != nil {
		return nil, fmt.Errorf("failed to create request: %w", err)
	}

	req.Header.Set("Content-Type", "application/json")
	req.Header.Set("Authorization", fmt.Sprintf("Bearer %s", *apiConfig.ApiKey))

	resp, err := z.httpClient.Do(req)
	if err != nil {
		return nil, fmt.Errorf("failed to send request: %w", err)
	}
	defer resp.Body.Close()

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

	if resp.StatusCode != http.StatusOK {
		return nil, fmt.Errorf("ZhipuAI OCR API error: %s, body: %s", resp.Status, string(body))
	}

	var zhipuResp zhipuOCRResponse
	if err = json.Unmarshal(body, &zhipuResp); err != nil {
		return nil, fmt.Errorf("failed to parse response: %w", err)
	}

	if zhipuResp.MarkdownResults == nil {
		return nil, fmt.Errorf("ZhipuAI OCR API response missing md_results")
	}

	return &OCRFileResponse{Text: zhipuResp.MarkdownResults}, nil
}

// ParseFile parse file
func (z *ZhipuAIModel) ParseFile(modelName *string, content []byte, url *string, apiConfig *APIConfig, parseFileConfig *ParseFileConfig) (*ParseFileResponse, error) {
	return nil, fmt.Errorf("%s, no such method", z.Name())
}

func (z *ZhipuAIModel) ListTasks(apiConfig *APIConfig) ([]ListTaskStatus, error) {
	return nil, fmt.Errorf("%s, no such method", z.Name())
}

func (z *ZhipuAIModel) ShowTask(taskID string, apiConfig *APIConfig) (*TaskResponse, error) {
	return nil, fmt.Errorf("%s, no such method", z.Name())
}
