package app

import (
	"encoding/json"
	"errors"
	"fmt"
	"io"
	"net/http"
	"strings"
	"time"

	"git.echol.cn/loser/ai_proxy/server/global"
	"git.echol.cn/loser/ai_proxy/server/model/app"
	"git.echol.cn/loser/ai_proxy/server/model/app/request"
	"git.echol.cn/loser/ai_proxy/server/model/app/response"
)

type AiProviderService struct{}

// CreateAiProvider 创建AI提供商
func (s *AiProviderService) CreateAiProvider(req *request.CreateAiProviderRequest) (provider app.AiProvider, err error) {
	provider = app.AiProvider{
		Name:        req.Name,
		Type:        req.Type,
		BaseURL:     req.BaseURL,
		Endpoint:    req.Endpoint,
		UpstreamKey: req.UpstreamKey,
		Model:       req.Model,
		ProxyKey:    req.ProxyKey,
		Config:      req.Config,
		IsActive:    req.IsActive,
	}
	err = global.GVA_DB.Create(&provider).Error
	return provider, err
}

// DeleteAiProvider 删除AI提供商
func (s *AiProviderService) DeleteAiProvider(id uint) (err error) {
	return global.GVA_DB.Delete(&app.AiProvider{}, id).Error
}

// UpdateAiProvider 更新AI提供商
func (s *AiProviderService) UpdateAiProvider(req *request.UpdateAiProviderRequest) (provider app.AiProvider, err error) {
	err = global.GVA_DB.First(&provider, req.ID).Error
	if err != nil {
		return provider, err
	}

	if req.Name != "" {
		provider.Name = req.Name
	}
	if req.Type != "" {
		provider.Type = req.Type
	}
	if req.BaseURL != "" {
		provider.BaseURL = req.BaseURL
	}
	if req.Endpoint != "" {
		provider.Endpoint = req.Endpoint
	}
	if req.UpstreamKey != "" {
		provider.UpstreamKey = req.UpstreamKey
	}
	if req.Model != "" {
		provider.Model = req.Model
	}
	if req.ProxyKey != "" {
		provider.ProxyKey = req.ProxyKey
	}
	if req.Config != nil {
		provider.Config = req.Config
	}
	provider.IsActive = req.IsActive

	err = global.GVA_DB.Save(&provider).Error
	return provider, err
}

// GetAiProvider 获取AI提供商详情
func (s *AiProviderService) GetAiProvider(id uint) (provider app.AiProvider, err error) {
	err = global.GVA_DB.First(&provider, id).Error
	return provider, err
}

// GetAiProviderList 获取AI提供商列表
func (s *AiProviderService) GetAiProviderList() (list []app.AiProvider, err error) {
	err = global.GVA_DB.Where("is_active = ?", true).Find(&list).Error
	return list, err
}

// TestConnection 测试连接
func (s *AiProviderService) TestConnection(req *request.TestConnectionRequest) (resp response.TestConnectionResponse, err error) {
	startTime := time.Now()

	// 根据类型构建测试 URL
	var testURL string
	switch strings.ToLower(req.Type) {
	case "openai":
		testURL = strings.TrimSuffix(req.BaseURL, "/") + "/v1/models"
	case "claude":
		testURL = strings.TrimSuffix(req.BaseURL, "/") + "/v1/messages"
	default:
		testURL = strings.TrimSuffix(req.BaseURL, "/") + "/v1/models"
	}

	// 创建 HTTP 请求
	httpReq, err := http.NewRequest("GET", testURL, nil)
	if err != nil {
		return response.TestConnectionResponse{
			Success: false,
			Message: fmt.Sprintf("创建请求失败: %v", err),
			Latency: 0,
		}, nil
	}

	// 设置请求头
	httpReq.Header.Set("Authorization", "Bearer "+req.UpstreamKey)
	httpReq.Header.Set("Content-Type", "application/json")

	// 发送请求
	client := &http.Client{
		Timeout: 10 * time.Second,
	}
	httpResp, err := client.Do(httpReq)
	if err != nil {
		return response.TestConnectionResponse{
			Success: false,
			Message: fmt.Sprintf("连接失败: %v", err),
			Latency: time.Since(startTime).Milliseconds(),
		}, nil
	}
	defer httpResp.Body.Close()

	latency := time.Since(startTime).Milliseconds()

	// 检查响应状态
	if httpResp.StatusCode == http.StatusOK || httpResp.StatusCode == http.StatusCreated {
		return response.TestConnectionResponse{
			Success: true,
			Message: "连接成功",
			Latency: latency,
		}, nil
	}

	// 读取错误响应
	body, _ := io.ReadAll(httpResp.Body)
	return response.TestConnectionResponse{
		Success: false,
		Message: fmt.Sprintf("连接失败 (状态码: %d): %s", httpResp.StatusCode, string(body)),
		Latency: latency,
	}, nil
}

// GetModels 获取模型列表
func (s *AiProviderService) GetModels(req *request.GetModelsRequest) (models []response.ModelInfo, err error) {
	// 根据类型构建 URL
	var modelsURL string
	switch strings.ToLower(req.Type) {
	case "openai":
		modelsURL = strings.TrimSuffix(req.BaseURL, "/") + "/v1/models"
	case "claude":
		// Claude API 不提供模型列表接口，返回预定义的模型
		return []response.ModelInfo{
			{ID: "claude-opus-4-6", Name: "Claude Opus 4.6", OwnedBy: "anthropic"},
			{ID: "claude-sonnet-4-6", Name: "Claude Sonnet 4.6", OwnedBy: "anthropic"},
			{ID: "claude-haiku-4-5-20251001", Name: "Claude Haiku 4.5", OwnedBy: "anthropic"},
			{ID: "claude-3-5-sonnet-20241022", Name: "Claude 3.5 Sonnet", OwnedBy: "anthropic"},
			{ID: "claude-3-opus-20240229", Name: "Claude 3 Opus", OwnedBy: "anthropic"},
		}, nil
	default:
		modelsURL = strings.TrimSuffix(req.BaseURL, "/") + "/v1/models"
	}

	// 创建 HTTP 请求
	httpReq, err := http.NewRequest("GET", modelsURL, nil)
	if err != nil {
		return nil, errors.New("创建请求失败: " + err.Error())
	}

	// 设置请求头
	httpReq.Header.Set("Authorization", "Bearer "+req.UpstreamKey)
	httpReq.Header.Set("Content-Type", "application/json")

	// 发送请求
	client := &http.Client{
		Timeout: 10 * time.Second,
	}
	httpResp, err := client.Do(httpReq)
	if err != nil {
		return nil, errors.New("请求失败: " + err.Error())
	}
	defer httpResp.Body.Close()

	// 检查响应状态
	if httpResp.StatusCode != http.StatusOK {
		body, _ := io.ReadAll(httpResp.Body)
		return nil, fmt.Errorf("获取模型列表失败 (状态码: %d): %s", httpResp.StatusCode, string(body))
	}

	// 解析响应
	body, err := io.ReadAll(httpResp.Body)
	if err != nil {
		return nil, errors.New("读取响应失败: " + err.Error())
	}

	// OpenAI 格式的响应
	var modelsResp struct {
		Data []struct {
			ID      string `json:"id"`
			Object  string `json:"object"`
			OwnedBy string `json:"owned_by"`
		} `json:"data"`
	}

	if err := json.Unmarshal(body, &modelsResp); err != nil {
		return nil, errors.New("解析响应失败: " + err.Error())
	}

	// 转换为响应格式
	models = make([]response.ModelInfo, len(modelsResp.Data))
	for i, model := range modelsResp.Data {
		models[i] = response.ModelInfo{
			ID:      model.ID,
			Name:    model.ID,
			OwnedBy: model.OwnedBy,
		}
	}

	return models, nil
}