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

internal/analyzer/gemini.go

@@ -0,0 +1,106 @@
+package analyzer
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+	"time"
+)
+
+type GeminiAnalyzer struct {
+	apiKey string
+	client *http.Client
+}
+
+func NewGeminiAnalyzer(apiKey string) *GeminiAnalyzer {
+	return &GeminiAnalyzer{
+		apiKey: apiKey,
+		client: &http.Client{Timeout: 30 * time.Second},
+	}
+}
+
+func (g *GeminiAnalyzer) 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
+
+Respond STRICTLY with valid JSON matching the format:
+{"matched_highlights": [...], "missing_highlights": [...], "tailoring_suggestions": [...]}`, jobTitle, jobTitle, rawContent)
+
+	reqBody := map[string]interface{}{
+		"contents": []map[string]interface{}{
+			{
+				"parts": []map[string]string{
+					{"text": prompt},
+				},
+			},
+		},
+		"generationConfig": map[string]interface{}{
+			"response_mime_type": "application/json",
+		},
+	}
+
+	jsonBytes, err := json.Marshal(reqBody)
+	if err != nil {
+		return nil, fmt.Errorf("failed to marshal Gemini payload: %w", err)
+	}
+
+	url := fmt.Sprintf("https://generativelanguage.googleapis.com/v1beta/models/gemini-1.5-flash:generateContent?key=%s", g.apiKey)
+	req, err := http.NewRequestWithContext(ctx, "POST", url, bytes.NewBuffer(jsonBytes))
+	if err != nil {
+		return nil, fmt.Errorf("failed to create Gemini HTTP request: %w", err)
+	}
+	req.Header.Set("Content-Type", "application/json")
+
+	resp, err := g.client.Do(req)
+	if err != nil {
+		return nil, fmt.Errorf("Gemini 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 Gemini response: %w", err)
+	}
+
+	if resp.StatusCode != http.StatusOK {
+		return nil, fmt.Errorf("Gemini API error (status %d): %s", resp.StatusCode, string(respBytes))
+	}
+
+	var geminiResp struct {
+		Candidates []struct {
+			Content struct {
+				Parts []struct {
+					Text string `json:"text"`
+				} `json:"parts"`
+			} `json:"content"`
+		} `json:"candidates"`
+	}
+
+	if err := json.Unmarshal(respBytes, &geminiResp); err != nil {
+		return nil, fmt.Errorf("failed to decode Gemini envelope: %w", err)
+	}
+
+	if len(geminiResp.Candidates) == 0 || len(geminiResp.Candidates[0].Content.Parts) == 0 {
+		return nil, fmt.Errorf("empty candidates in Gemini response")
+	}
+
+	rawJSON := geminiResp.Candidates[0].Content.Parts[0].Text
+	rawJSON = cleanJSONResponse(rawJSON)
+
+	var output AnalysisOutput
+	if err := json.Unmarshal([]byte(rawJSON), &output); err != nil {
+		return nil, fmt.Errorf("failed to parse Gemini JSON output: %w", err)
+	}
+
+	return &output, nil
+}