feat: initialize project structure with SQLite database, crawler framework, and LLM-based JD analysis integration

internal/analyzer/deepseek.go

@@ -0,0 +1,118 @@
+package analyzer
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+	"strings"
+	"time"
+)
+
+type DeepSeekAnalyzer struct {
+	apiKey  string
+	baseURL string
+	client  *http.Client
+}
+
+func NewDeepSeekAnalyzer(apiKey, baseURL string) *DeepSeekAnalyzer {
+	if baseURL == "" {
+		baseURL = "https://api.deepseek.com"
+	}
+	return &DeepSeekAnalyzer{
+		apiKey:  apiKey,
+		baseURL: strings.TrimRight(baseURL, "/"),
+		client:  &http.Client{Timeout: 30 * time.Second},
+	}
+}
+
+func (d *DeepSeekAnalyzer) AnalyzeJD(ctx context.Context, jobTitle, rawContent string) (*AnalysisOutput, error) {
+	prompt := fmt.Sprintf(`You are an expert technical resume screener. Analyze the following job description for the title "%s".
+Provide a structured JSON output with 3 fields:
+- "matched_highlights": list of 3-5 core technical skills/requirements matched (e.g. ["Go (Golang)", "Microservices", "REST APIs"]).
+- "missing_highlights": list of 1-3 missing skills, experience gaps, or extra requirements (e.g. ["10+ yrs experience", "Kubernetes administration"]).
+- "tailoring_suggestions": list of 2-3 specific action points for tailoring a resume to this JD.
+
+Job Title: %s
+Job Content:
+%s`, jobTitle, jobTitle, rawContent)
+
+	reqBody := map[string]interface{}{
+		"model": "deepseek-chat",
+		"messages": []map[string]string{
+			{"role": "system", "content": "You are a professional hiring assistant. You MUST respond ONLY with valid JSON matching {\"matched_highlights\": [...], \"missing_highlights\": [...], \"tailoring_suggestions\": [...]}."},
+			{"role": "user", "content": prompt},
+		},
+		"response_format": map[string]string{
+			"type": "json_object",
+		},
+	}
+
+	jsonBytes, err := json.Marshal(reqBody)
+	if err != nil {
+		return nil, fmt.Errorf("failed to marshal DeepSeek payload: %w", err)
+	}
+
+	url := fmt.Sprintf("%s/chat/completions", d.baseURL)
+	req, err := http.NewRequestWithContext(ctx, "POST", url, bytes.NewBuffer(jsonBytes))
+	if err != nil {
+		return nil, fmt.Errorf("failed to create DeepSeek request: %w", err)
+	}
+
+	req.Header.Set("Content-Type", "application/json")
+	req.Header.Set("Authorization", fmt.Sprintf("Bearer %s", d.apiKey))
+
+	resp, err := d.client.Do(req)
+	if err != nil {
+		return nil, fmt.Errorf("DeepSeek API call failed: %w", err)
+	}
+	defer resp.Body.Close()
+
+	respBytes, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return nil, fmt.Errorf("failed to read DeepSeek response: %w", err)
+	}
+
+	if resp.StatusCode != http.StatusOK {
+		return nil, fmt.Errorf("DeepSeek API error (status %d): %s", resp.StatusCode, string(respBytes))
+	}
+
+	var dsResp struct {
+		Choices []struct {
+			Message struct {
+				Content string `json:"content"`
+			} `json:"message"`
+		} `json:"choices"`
+	}
+
+	if err := json.Unmarshal(respBytes, &dsResp); err != nil {
+		return nil, fmt.Errorf("failed to decode DeepSeek envelope: %w", err)
+	}
+
+	if len(dsResp.Choices) == 0 {
+		return nil, fmt.Errorf("empty choices in DeepSeek response")
+	}
+
+	rawJSON := cleanJSONResponse(dsResp.Choices[0].Message.Content)
+
+	var output AnalysisOutput
+	if err := json.Unmarshal([]byte(rawJSON), &output); err != nil {
+		return nil, fmt.Errorf("failed to parse DeepSeek JSON output: %w", err)
+	}
+
+	return &output, nil
+}
+
+func cleanJSONResponse(raw string) string {
+	cleaned := strings.TrimSpace(raw)
+	if strings.HasPrefix(cleaned, "```json") {
+		cleaned = strings.TrimPrefix(cleaned, "```json")
+		cleaned = strings.TrimSuffix(cleaned, "```")
+	} else if strings.HasPrefix(cleaned, "```") {
+		cleaned = strings.TrimPrefix(cleaned, "```")
+		cleaned = strings.TrimSuffix(cleaned, "```")
+	}
+	return strings.TrimSpace(cleaned)
+}