package ai

import (
	"bytes"
	"encoding/json"
	"fmt"
	"io"
	"log"
	"net/http"
	"regexp"
	"strings"
)

// AIClient 定义了与 AI 服务交互的接口
type AIClient interface {
	Chat(systemMsg, prompt string) (string, error)
}

// Client 实现了 AIClient 接口
type Client struct {
	apiBase     string
	apiKey      string
	model       string
	aiType      string
	stream      bool
	temperature float64
	client      *http.Client
}

// NewClient 创建新的 AI 客户端
func NewClient(apiBase, apiKey, model, aiType string, temperature float64) *Client {
	return &Client{
		apiBase:     apiBase,
		apiKey:      apiKey,
		model:       model,
		aiType:      aiType,
		temperature: temperature,
		client:      &http.Client{},
	}
}

// Chat 发送聊天请求到 AI 服务
func (c *Client) Chat(systemMsg, prompt string) (string, error) {
	// 根据配置的类型判断使用哪个服务
	var response string
	var err error

	if c.aiType == "ollama" {
		response, err = c.ollamaChat(systemMsg, prompt)
	} else {
		response, err = c.openAIChat(systemMsg, prompt)
	}

	if err != nil {
		log.Printf("AI 聊天请求失败: error=%v", err)
		return "", fmt.Errorf("AI 聊天请求失败: %w", err)
	}

	return response, nil
}

// ollamaChat 发送请求到 Ollama API
func (c *Client) ollamaChat(systemMsg, prompt string) (string, error) {
	// 组合系统提示词和用户提示词
	fullPrompt := fmt.Sprintf("%s\n\n%s", systemMsg, prompt)

	reqBody := map[string]interface{}{
		"model":       c.model,
		"prompt":      fullPrompt,
		"stream":      c.stream,
		"temperature": c.temperature,
	}

	jsonData, err := json.Marshal(reqBody)
	if err != nil {
		return "", fmt.Errorf("序列化请求失败: %w", err)
	}

	req, err := http.NewRequest("POST", c.apiBase+"/api/generate", bytes.NewBuffer(jsonData))
	if err != nil {
		return "", fmt.Errorf("创建请求失败: %w", err)
	}

	req.Header.Set("Content-Type", "application/json")

	resp, err := c.client.Do(req)
	if err != nil {
		return "", fmt.Errorf("发送请求失败: %w", err)
	}
	defer resp.Body.Close()

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

	var result struct {
		Response string `json:"response"`
		Done     bool   `json:"done"`
	}

	if err := json.NewDecoder(resp.Body).Decode(&result); err != nil {
		body, _ := io.ReadAll(resp.Body)
		log.Printf("响应内容: %s", string(body))
		return "", fmt.Errorf("解析响应失败: %w", err)
	}

	if !result.Done {
		return "", fmt.Errorf("AI 响应未完成")
	}

	pattern := "(?s)<think>(.*?)</think>"

	reg := regexp.MustCompile(pattern)
	matches := reg.ReplaceAllString(result.Response, "")

	return strings.TrimSpace(matches), nil
}

// openAIChat 发送请求到 OpenAI API
func (c *Client) openAIChat(systemMsg, prompt string) (string, error) {
	reqBody := map[string]interface{}{
		"model": c.model,
		"messages": []map[string]string{
			{
				"role":    "system",
				"content": systemMsg,
			},
			{
				"role":    "user",
				"content": prompt,
			},
		},
		"stream":      false,
		"temperature": c.temperature,
	}

	jsonData, err := json.Marshal(reqBody)
	if err != nil {
		return "", fmt.Errorf("序列化请求失败: %w", err)
	}

	req, err := http.NewRequest("POST", c.apiBase+"/v1/chat/completions", bytes.NewBuffer(jsonData))
	if err != nil {
		return "", fmt.Errorf("创建请求失败: %w", err)
	}

	req.Header.Set("Content-Type", "application/json")
	req.Header.Set("Authorization", "Bearer "+c.apiKey)

	resp, err := c.client.Do(req)
	if err != nil {
		return "", fmt.Errorf("发送请求失败: %w", err)
	}
	defer resp.Body.Close()

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

	var result struct {
		Choices []struct {
			Message struct {
				Content string `json:"content"`
			} `json:"message"`
		} `json:"choices"`
	}

	if err := json.NewDecoder(resp.Body).Decode(&result); err != nil {
		return "", fmt.Errorf("解析响应失败: %w", err)
	}

	if len(result.Choices) == 0 {
		return "", fmt.Errorf("AI 响应为空")
	}

	pattern := "(?s)<think>(.*?)</think>"

	reg := regexp.MustCompile(pattern)
	matches := reg.ReplaceAllString(result.Choices[0].Message.Content, "")

	return strings.TrimSpace(matches), nil
}