package models

import (
	"bufio"
	"bytes"
	"encoding/json"
	"fmt"
	"io"
	"net/http"
	"strings"
	"time"
)

// NvidiaModel implements ModelDriver for Nvidia
type NvidiaModel struct {
	BaseURL    map[string]string
	URLSuffix  URLSuffix
	httpClient *http.Client
}

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

func (n NvidiaModel) Name() string {
	return "nvidia"
}

func (n *NvidiaModel) ChatWithMessages(modelName string, messages []Message, apiConfig *APIConfig, chatModelConfig *ChatConfig) (*ChatResponse, error) {
	if len(messages) == 0 {
		return nil, fmt.Errorf("messages is empty")
	}

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

	baseURL := n.BaseURL[region]
	if baseURL == "" {
		baseURL = n.BaseURL["default"]
	}
	url := fmt.Sprintf("%s/%s", baseURL, n.URLSuffix.Chat)

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

	reqBody := map[string]interface{}{
		"model":    modelName,
		"messages": apiMessages,
		"stream":   false,
	}

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

	resp, err := n.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))
	}

	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 modelClass *string
	if chatModelConfig != nil {
		modelClass = chatModelConfig.ModelClass
	}
	thinking, answer := GetThinkingAndAnswer(modelClass, &content)

	chatResponse := &ChatResponse{
		Answer:        answer,
		ReasonContent: thinking,
	}

	return chatResponse, nil
}

func (n *NvidiaModel) ChatStreamlyWithSender(modelName string, messages []Message, apiConfig *APIConfig, modelConfig *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 {
		region = *apiConfig.Region
	}

	baseURL := n.BaseURL[region]
	if baseURL == "" {
		baseURL = n.BaseURL["default"]
	}
	url := fmt.Sprintf("%s/%s", baseURL, n.URLSuffix.Chat)

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

	reqBody := map[string]interface{}{
		"model":    modelName,
		"messages": apiMessages,
		"stream":   true,
	}

	if modelConfig != nil {
		if modelConfig.Stream != nil {
			reqBody["stream"] = *modelConfig.Stream
		}
		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["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")
	if apiConfig != nil && apiConfig.ApiKey != nil {
		req.Header.Set("Authorization", fmt.Sprintf("Bearer %s", *apiConfig.ApiKey))
	}

	resp, err := n.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))
	}

	scanner := bufio.NewScanner(resp.Body)
	for scanner.Scan() {
		line := scanner.Text()

		if !strings.HasPrefix(line, "data:") {
			continue
		}

		data := strings.TrimSpace(line[5:])
		if data == "[DONE]" {
			break
		}

		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
		}
	}

	endOfStream := "[DONE]"
	if err = sender(&endOfStream, nil); err != nil {
		return err
	}

	return scanner.Err()
}

func (n NvidiaModel) Encode(modelName *string, texts []string, apiConfig *APIConfig, embeddingConfig *EmbeddingConfig) ([][]float64, error) {
	return nil, fmt.Errorf("no such method")
}

func (n NvidiaModel) Rerank(modelName *string, query string, texts []string, apiConfig *APIConfig) ([]float64, error) {
	return nil, fmt.Errorf("no such method")
}

func (n NvidiaModel) ListModels(apiConfig *APIConfig) ([]string, error) {
	return nil, fmt.Errorf("no such method")
}

func (n NvidiaModel) Balance(apiConfig *APIConfig) (map[string]interface{}, error) {
	return nil, fmt.Errorf("no such method")
}

func (n NvidiaModel) CheckConnection(apiConfig *APIConfig) error {
	return fmt.Errorf("no such method")
}