//
//  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/json"
	"fmt"
	"io"
	"net/http"
	"strings"
	"time"
)

type JieKouAIModel struct {
	baseModel BaseModel
}

func NewJieKouAIModel(baseURL map[string]string, urlSuffix URLSuffix) *JieKouAIModel {
	return &JieKouAIModel{
		baseModel: BaseModel{
			BaseURL:   baseURL,
			URLSuffix: urlSuffix,
			httpClient: &http.Client{
				Timeout: time.Second * 120,
				Transport: &http.Transport{
					MaxIdleConns:       10,
					MaxConnsPerHost:    100,
					IdleConnTimeout:    time.Second * 90,
					DisableCompression: false,
				},
			},
		},
	}
}

func (j *JieKouAIModel) NewInstance(baseURL map[string]string) ModelDriver {
	return NewJieKouAIModel(baseURL, j.baseModel.URLSuffix)
}

func (j *JieKouAIModel) Name() string {
	return "jiekouai"
}

func validateJieKouAIModelName(modelName *string) (string, error) {
	if modelName == nil || strings.TrimSpace(*modelName) == "" {
		return "", fmt.Errorf("model name is required")
	}
	return strings.TrimSpace(*modelName), nil
}

func (j *JieKouAIModel) ChatWithMessages(modelName string, messages []Message, apiConfig *APIConfig, chatModelConfig *ChatConfig) (*ChatResponse, error) {
	if err := j.baseModel.APIConfigCheck(apiConfig); err != nil {
		return nil, err
	}
	apiKey := strings.TrimSpace(*apiConfig.ApiKey)
	if modelName = strings.TrimSpace(modelName); modelName == "" {
		return nil, fmt.Errorf("model name is required")
	}
	if len(messages) == 0 {
		return nil, fmt.Errorf("messages is empty")
	}

	resolvedBaseURL, err := j.baseModel.GetBaseURL(apiConfig)
	if err != nil {
		return nil, err
	}
	url := fmt.Sprintf("%s/%s", resolvedBaseURL, j.baseModel.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
	reqBody := map[string]interface{}{
		"model":       modelName,
		"messages":    apiMessages,
		"stream":      false,
		"temperature": 1,
	}

	if chatModelConfig != nil {
		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
		}

		// For zai-org/glm-4.5: https://docs.jiekou.ai/docs/models/reference-llm-create-chat-completion
		if chatModelConfig.Thinking != nil {
			if *chatModelConfig.Thinking {
				reqBody["enable_thinking"] = *chatModelConfig.Thinking
			}
		}
	}

	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", apiKey))
	req.Header.Set("Accept", "application/json")

	resp, err := j.baseModel.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
}

func (j *JieKouAIModel) ChatStreamlyWithSender(modelName string, messages []Message, apiConfig *APIConfig, modelConfig *ChatConfig, sender func(*string, *string) error) error {
	if err := j.baseModel.APIConfigCheck(apiConfig); err != nil {
		return err
	}
	apiKey := strings.TrimSpace(*apiConfig.ApiKey)
	if modelName = strings.TrimSpace(modelName); modelName == "" {
		return fmt.Errorf("model name is required")
	}
	if sender == nil {
		return fmt.Errorf("sender is required")
	}
	if len(messages) == 0 {
		return fmt.Errorf("messages is empty")
	}

	resolvedBaseURL, err := j.baseModel.GetBaseURL(apiConfig)
	if err != nil {
		return err
	}
	url := fmt.Sprintf("%s/%s", strings.TrimSuffix(resolvedBaseURL, "/"), j.baseModel.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 modelConfig != nil {
		if modelConfig.MaxTokens != nil {
			reqBody["max_tokens"] = *modelConfig.MaxTokens
		}

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

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

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

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

		if modelConfig.Thinking != nil {
			if *modelConfig.Thinking {
				reqBody["enable_thinking"] = *modelConfig.Thinking
			}
		}
	}

	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", apiKey))
	req.Header.Set("Accept", "text/event-stream")

	resp, err := j.baseModel.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)
	scanner.Buffer(make([]byte, 64*1024), 1024*1024)
	for scanner.Scan() {
		line := scanner.Text()

		// 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()
}

func (j *JieKouAIModel) Embed(modelName *string, texts []string, apiConfig *APIConfig, embeddingConfig *EmbeddingConfig) ([]EmbeddingData, error) {
	if err := j.baseModel.APIConfigCheck(apiConfig); err != nil {
		return nil, err
	}

	if len(texts) == 0 {
		return []EmbeddingData{}, fmt.Errorf("texts is empty")
	}
	model, err := validateJieKouAIModelName(modelName)
	if err != nil {
		return nil, err
	}
	apiKey := strings.TrimSpace(*apiConfig.ApiKey)

	resolvedBaseURL, err := j.baseModel.GetBaseURL(apiConfig)
	if err != nil {
		return nil, err
	}
	url := fmt.Sprintf("%s/%s", strings.TrimSuffix(resolvedBaseURL, "/"), j.baseModel.URLSuffix.Embedding)

	reqBody := map[string]interface{}{
		"model": model,
		"input": texts,
	}

	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", apiKey))

	resp, err := j.baseModel.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("API request failed with status %d: %s", resp.StatusCode, string(body))
	}

	var parsedResponse struct {
		Data []struct {
			Embedding []float64 `json:"embedding"`
			Index     int       `json:"index"`
		} `json:"data"`
	}

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

	if len(parsedResponse.Data) == 0 {
		return nil, fmt.Errorf("failed to parse response")
	}

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

	return embeddings, nil
}

func (j *JieKouAIModel) Rerank(modelName *string, query string, documents []string, apiConfig *APIConfig, rerankConfig *RerankConfig) (*RerankResponse, error) {
	if err := j.baseModel.APIConfigCheck(apiConfig); err != nil {
		return nil, err
	}

	if len(documents) == 0 {
		return &RerankResponse{}, nil
	}
	if strings.TrimSpace(query) == "" {
		return nil, fmt.Errorf("query is required")
	}
	model, err := validateJieKouAIModelName(modelName)
	if err != nil {
		return nil, err
	}
	apiKey := strings.TrimSpace(*apiConfig.ApiKey)

	resolvedBaseURL, err := j.baseModel.GetBaseURL(apiConfig)
	if err != nil {
		return nil, err
	}
	url := fmt.Sprintf("%s/%s", strings.TrimSuffix(resolvedBaseURL, "/"), j.baseModel.URLSuffix.Rerank)

	reqBody := map[string]interface{}{
		"model":     model,
		"query":     strings.TrimSpace(query),
		"documents": documents,
	}
	if rerankConfig != nil && rerankConfig.TopN != 0 {
		reqBody["top_n"] = rerankConfig.TopN
	}

	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", apiKey))

	resp, err := j.baseModel.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("API request failed with status %d: %s", resp.StatusCode, string(body))
	}

	var rerankResp struct {
		Results []struct {
			Index          int     `json:"index"`
			RelevanceScore float64 `json:"relevance_score"`
		} `json:"results"`
	}

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

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

	return &rerankResponse, nil
}

func (j *JieKouAIModel) TranscribeAudio(modelName *string, file *string, apiConfig *APIConfig, asrConfig *ASRConfig) (*ASRResponse, error) {
	return nil, fmt.Errorf("%s, no such method", j.Name())
}

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

func (j *JieKouAIModel) AudioSpeech(modelName *string, audioContent *string, apiConfig *APIConfig, ttsConfig *TTSConfig) (*TTSResponse, error) {
	return nil, fmt.Errorf("%s, no such method", j.Name())
}

func (j *JieKouAIModel) AudioSpeechWithSender(modelName *string, audioContent *string, apiConfig *APIConfig, ttsConfig *TTSConfig, sender func(*string, *string) error) error {
	return fmt.Errorf("%s, no such method", j.Name())
}

func (j *JieKouAIModel) OCRFile(modelName *string, content []byte, url *string, apiConfig *APIConfig, ocrConfig *OCRConfig) (*OCRFileResponse, error) {
	return nil, fmt.Errorf("%s, no such method", j.Name())
}

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

func (j *JieKouAIModel) ListModels(apiConfig *APIConfig) ([]string, error) {
	if err := j.baseModel.APIConfigCheck(apiConfig); err != nil {
		return nil, err
	}
	apiKey := strings.TrimSpace(*apiConfig.ApiKey)

	resolvedBaseURL, err := j.baseModel.GetBaseURL(apiConfig)
	if err != nil {
		return nil, err
	}
	url := fmt.Sprintf("%s/%s", resolvedBaseURL, j.baseModel.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("Authorization", fmt.Sprintf("Bearer %s", apiKey))
	req.Header.Set("Accept", "application/json")

	resp, err := j.baseModel.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("API request failed with status %d: %s", resp.StatusCode, string(body))
	}

	var result struct {
		Data []struct {
			ID string `json:"id"`
		} `json:"data"`
	}
	if err = json.Unmarshal(body, &result); err != nil {
		return nil, fmt.Errorf("failed to parse response: %w", err)
	}
	if result.Data == nil {
		return nil, fmt.Errorf("models response missing data")
	}

	models := make([]string, 0, len(result.Data))
	for _, model := range result.Data {
		if strings.TrimSpace(model.ID) == "" {
			return nil, fmt.Errorf("models response contains empty id")
		}
		models = append(models, strings.TrimSpace(model.ID))
	}

	return models, nil
}

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

func (j *JieKouAIModel) CheckConnection(apiConfig *APIConfig) error {
	_, err := j.ListModels(apiConfig)
	return err
}

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

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