Initialize blog scaffold

Add the CLI, site, and sample content so the project can run locally.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

backend/internal/ai/deepseek.go

@@ -0,0 +1,183 @@
+package ai
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"net/http"
+	"regexp"
+	"strings"
+	"time"
+)
+
+const (
+	DefaultDeepSeekBaseURL = "https://api.deepseek.com"
+	DefaultDeepSeekModel   = "deepseek-v4-pro"
+)
+
+type Config struct {
+	APIKey  string
+	BaseURL string
+	Model   string
+}
+
+type deepSeekMessage struct {
+	Role    string `json:"role"`
+	Content string `json:"content"`
+}
+
+type deepSeekChatRequest struct {
+	Model          string            `json:"model"`
+	Messages       []deepSeekMessage `json:"messages"`
+	Thinking       map[string]string `json:"thinking,omitempty"`
+	ResponseFormat map[string]string `json:"response_format,omitempty"`
+	Temperature    float64           `json:"temperature"`
+	MaxTokens      int               `json:"max_tokens"`
+}
+
+type deepSeekChatResponse struct {
+	Choices []struct {
+		FinishReason string `json:"finish_reason"`
+		Message      struct {
+			Role             string `json:"role"`
+			Content          string `json:"content"`
+			ReasoningContent string `json:"reasoning_content"`
+		} `json:"message"`
+	} `json:"choices"`
+	Error *struct {
+		Message string `json:"message"`
+		Type    string `json:"type"`
+	} `json:"error,omitempty"`
+}
+
+type slugResponse struct {
+	Slug         string   `json:"slug"`
+	Alternatives []string `json:"alternatives"`
+}
+
+func GenerateSlug(ctx context.Context, config Config, title string, summary string) (string, error) {
+	apiKey := strings.TrimSpace(config.APIKey)
+	if apiKey == "" {
+		return "", errors.New("DeepSeek API key is empty")
+	}
+
+	baseURL := strings.TrimRight(strings.TrimSpace(config.BaseURL), "/")
+	if baseURL == "" {
+		baseURL = DefaultDeepSeekBaseURL
+	}
+	model := strings.TrimSpace(config.Model)
+	if model == "" {
+		model = DefaultDeepSeekModel
+	}
+
+	userPrompt := fmt.Sprintf("Title: %s\nSummary: %s", title, summary)
+	payload := deepSeekChatRequest{
+		Model: model,
+		Messages: []deepSeekMessage{
+			{
+				Role: "system",
+				Content: `You generate concise English URL slugs for blog posts.
+Return JSON only.
+Rules:
+- lowercase English
+- use hyphen separators
+- only a-z, 0-9, and hyphen
+- translate non-English titles by meaning into natural English
+- do not use pinyin, transliteration, romanization, or pronunciation-based spellings
+- no leading or trailing hyphen
+- max 80 characters
+- preserve important technical terms
+- do not include explanations
+Examples:
+- title "喜欢你" -> {"slug":"like-you","alternatives":["i-like-you","loving-you"]}
+- title "用 Go 和 Astro 构建个人博客" -> {"slug":"building-a-personal-blog-with-go-and-astro","alternatives":["go-astro-personal-blog"]}
+JSON format: {"slug":"example-slug","alternatives":["another-slug"]}`,
+			},
+			{Role: "user", Content: userPrompt},
+		},
+		Thinking:       map[string]string{"type": "disabled"},
+		ResponseFormat: map[string]string{"type": "json_object"},
+		Temperature:    0.2,
+		MaxTokens:      300,
+	}
+
+	body, err := json.Marshal(payload)
+	if err != nil {
+		return "", err
+	}
+
+	req, err := http.NewRequestWithContext(ctx, http.MethodPost, baseURL+"/chat/completions", bytes.NewReader(body))
+	if err != nil {
+		return "", err
+	}
+	req.Header.Set("Authorization", "Bearer "+apiKey)
+	req.Header.Set("Content-Type", "application/json")
+
+	client := &http.Client{Timeout: 30 * time.Second}
+	resp, err := client.Do(req)
+	if err != nil {
+		return "", err
+	}
+	defer resp.Body.Close()
+
+	respBody, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return "", err
+	}
+	if resp.StatusCode < 200 || resp.StatusCode >= 300 {
+		return "", fmt.Errorf("DeepSeek API returned %s: %s", resp.Status, strings.TrimSpace(string(respBody)))
+	}
+
+	var chatResp deepSeekChatResponse
+	if err := json.Unmarshal(respBody, &chatResp); err != nil {
+		return "", err
+	}
+	if chatResp.Error != nil {
+		return "", fmt.Errorf("DeepSeek API error: %s", chatResp.Error.Message)
+	}
+	if len(chatResp.Choices) == 0 {
+		return "", errors.New("DeepSeek API returned no choices")
+	}
+
+	choice := chatResp.Choices[0]
+	content := strings.TrimSpace(choice.Message.Content)
+	if content == "" {
+		return "", fmt.Errorf("DeepSeek returned empty content, finish_reason=%q", choice.FinishReason)
+	}
+
+	var slugResp slugResponse
+	if err := json.Unmarshal([]byte(content), &slugResp); err != nil {
+		return "", fmt.Errorf("failed to parse DeepSeek slug JSON: %w", err)
+	}
+
+	slug := sanitizeSlug(slugResp.Slug)
+	if slug == "" {
+		for _, alternative := range slugResp.Alternatives {
+			slug = sanitizeSlug(alternative)
+			if slug != "" {
+				break
+			}
+		}
+	}
+	if slug == "" {
+		return "", errors.New("DeepSeek returned an empty slug")
+	}
+	return slug, nil
+}
+
+func sanitizeSlug(slug string) string {
+	slug = strings.ToLower(strings.TrimSpace(slug))
+	re := regexp.MustCompile(`[^a-z0-9]+`)
+	slug = re.ReplaceAllString(slug, "-")
+	slug = strings.Trim(slug, "-")
+	for strings.Contains(slug, "--") {
+		slug = strings.ReplaceAll(slug, "--", "-")
+	}
+	if len(slug) > 80 {
+		slug = strings.Trim(slug[:80], "-")
+	}
+	return slug
+}