chore: 恢复旧布局基线（迁移改动丢失后重建，apps/packages 布局暂存）

server/internal/ai/openai.go

@@ -0,0 +1,117 @@
+package ai
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+	"regexp"
+	"strings"
+	"time"
+)
+
+const (
+	defaultOpenAIBaseURL = "https://api.openai.com/v1"
+	defaultOpenAIModel   = "gpt-4o-mini"
+)
+
+// OpenAIProvider OpenAI 兼容协议实现(DeepSeek/通义/本地 vLLM 同协议可用)。
+type OpenAIProvider struct {
+	baseURL string
+	apiKey  string
+	model   string
+	hc      *http.Client
+}
+
+func NewOpenAIProvider(cfg Config) *OpenAIProvider {
+	base := strings.TrimRight(strings.TrimSpace(cfg.BaseURL), "/")
+	if base == "" {
+		base = defaultOpenAIBaseURL
+	}
+	model := strings.TrimSpace(cfg.Model)
+	if model == "" {
+		model = defaultOpenAIModel
+	}
+	return &OpenAIProvider{
+		baseURL: base,
+		apiKey:  cfg.APIKey,
+		model:   model,
+		hc:      &http.Client{Timeout: 60 * time.Second},
+	}
+}
+
+func (p *OpenAIProvider) Name() string { return "openai" }
+
+type chatCompletionReq struct {
+	Model    string    `json:"model"`
+	Messages []Message `json:"messages"`
+}
+
+type chatCompletionRes struct {
+	Choices []struct {
+		Message Message `json:"message"`
+	} `json:"choices"`
+	Error *struct {
+		Message string `json:"message"`
+	} `json:"error"`
+}
+
+// Complete 单次非流式调用;ctx 全透传,HTTP 层 60s 超时兜底。
+func (p *OpenAIProvider) Complete(ctx context.Context, req ChatReq) (ChatRes, error) {
+	model := p.model
+	if strings.TrimSpace(req.Model) != "" {
+		model = strings.TrimSpace(req.Model)
+	}
+	payload := chatCompletionReq{
+		Model:    model,
+		Messages: BuildMessages(req),
+	}
+	body, err := json.Marshal(payload)
+	if err != nil {
+		return ChatRes{}, err
+	}
+	httpReq, err := http.NewRequestWithContext(ctx, http.MethodPost, p.baseURL+"/chat/completions", bytes.NewReader(body))
+	if err != nil {
+		return ChatRes{}, err
+	}
+	httpReq.Header.Set("Content-Type", "application/json")
+	httpReq.Header.Set("Authorization", "Bearer "+p.apiKey)
+
+	resp, err := p.hc.Do(httpReq)
+	if err != nil {
+		return ChatRes{}, fmt.Errorf("AI 请求失败: %w", err)
+	}
+	defer resp.Body.Close()
+	raw, err := io.ReadAll(io.LimitReader(resp.Body, 4<<20))
+	if err != nil {
+		return ChatRes{}, fmt.Errorf("读取 AI 响应失败: %w", err)
+	}
+	var out chatCompletionRes
+	if err := json.Unmarshal(raw, &out); err != nil {
+		return ChatRes{}, fmt.Errorf("解析 AI 响应失败(HTTP %d)", resp.StatusCode)
+	}
+	if out.Error != nil {
+		return ChatRes{}, fmt.Errorf("AI 服务返回错误: %s", out.Error.Message)
+	}
+	if resp.StatusCode != http.StatusOK {
+		return ChatRes{}, fmt.Errorf("AI 服务 HTTP %d", resp.StatusCode)
+	}
+	if len(out.Choices) == 0 {
+		return ChatRes{}, fmt.Errorf("AI 服务未返回候选结果")
+	}
+	content := strings.TrimSpace(out.Choices[0].Message.Content)
+	return ChatRes{Content: content, SQL: extractSQL(content)}, nil
+}
+
+var sqlFence = regexp.MustCompile("(?s)```sql\\s*\n(.+?)```")
+
+// extractSQL 从模型回复中提取 ```sql 代码块内容。
+func extractSQL(content string) string {
+	m := sqlFence.FindStringSubmatch(content)
+	if len(m) < 2 {
+		return ""
+	}
+	return strings.TrimSpace(m[1])
+}