package provider

import (
	"bytes"
	"context"
	"encoding/json"
	"fmt"
	"io"
	"net/http"
	"strings"

	"git.kingecg.top/kingecg/goaiagent/model"
	"github.com/sashabaranov/go-openai"
)

// ==============================
// DeepSeek API 实现:cite[1]:cite[7]
// ==============================
type DeepSeekProvider struct {
	apiKey   string
	model    string // deepseek-chat 或 deepseek-reasoner:cite[8]
	endpoint string
}

func NewDeepSeekProvider(apiKey, model string) *DeepSeekProvider {
	return &DeepSeekProvider{
		apiKey:   apiKey,
		model:    model,
		endpoint: "https://api.deepseek.com/v1/chat/completions", // DeepSeek官方API地址:cite[7]
	}
}
func (d *DeepSeekProvider) GetProviderName() string {
	return "DeepSeek"
}

func (d *DeepSeekProvider) CreateChatCompletion(ctx context.Context, req model.ChatRequest) (model.ChatResponse, error) {
	// 构造DeepSeek专属请求体:cite[1]
	deepseekReq := struct {
		Model     string                         `json:"model"`
		Messages  []openai.ChatCompletionMessage `json:"messages"`
		MaxTokens int                            `json:"max_tokens"`
	}{
		Model:     d.model,
		Messages:  req.Messages,
		MaxTokens: req.MaxTokens,
	}

	reqBody, _ := json.Marshal(deepseekReq)
	httpReq, _ := http.NewRequest("POST", d.endpoint, bytes.NewReader(reqBody))
	httpReq.Header.Set("Authorization", "Bearer "+d.apiKey)
	httpReq.Header.Set("Content-Type", "application/json")

	client := &http.Client{}
	resp, err := client.Do(httpReq)
	if err != nil {
		return model.ChatResponse{}, err
	}
	defer resp.Body.Close()

	body, _ := io.ReadAll(resp.Body)

	// 解析DeepSeek特有响应格式
	var result struct {
		Choices []struct {
			Message struct {
				Content string `json:"content"`
			} `json:"message"`
		} `json:"choices"`
		Usage struct {
			PromptTokens     int `json:"prompt_tokens"`
			CompletionTokens int `json:"completion_tokens"`
		} `json:"usage"`
	}

	if err := json.Unmarshal(body, &result); err != nil {
		return model.ChatResponse{}, err
	}

	if len(result.Choices) == 0 {
		return model.ChatResponse{}, fmt.Errorf("empty response from DeepSeek")
	}

	return model.ChatResponse{
		Content:      result.Choices[0].Message.Content,
		InputTokens:  result.Usage.PromptTokens,
		OutputTokens: result.Usage.CompletionTokens,
	}, nil
}

func (d *DeepSeekProvider) CreateChatCompletionStream(ctx context.Context, req model.ChatRequest) (*StreamReader, error) {
	streamClient := NewDeepSeekStreamClient(d.apiKey)
	return streamClient.CreateStream(ctx, req.Messages, d.model, req.MaxTokens)
	// return nil, fmt.Errorf("not implemented")
}

// 简化的Token计数器（实际生产应使用tiktoken）
func (d *DeepSeekProvider) CountTokens(text string) int {
	return len(strings.Fields(text)) // 按空格分词计数
}

func (d *DeepSeekProvider) GetModelName() string {
	return d.model
}