init

internal/client/llm.go

@@ -0,0 +1,150 @@
+package client
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"strings"
+
+	"github.com/fjurmanovic/sugarr/internal/model"
+	"github.com/fjurmanovic/sugarr/internal/utl/configs"
+)
+
+type LLMClient struct {
+	baseURL string
+	apiKey  string
+	model   string
+	http    *http.Client
+}
+
+func NewLLMClient(cfg *configs.Config) *LLMClient {
+	return &LLMClient{
+		baseURL: cfg.LLMBaseURL,
+		apiKey:  cfg.LLMAPIKey,
+		model:   cfg.LLMModel,
+		http:    &http.Client{},
+	}
+}
+
+type chatRequest struct {
+	Model    string        `json:"model"`
+	Messages []chatMessage `json:"messages"`
+}
+
+type chatMessage struct {
+	Role    string `json:"role"`
+	Content string `json:"content"`
+}
+
+type chatResponse struct {
+	Choices []struct {
+		Message chatMessage `json:"message"`
+	} `json:"choices"`
+}
+
+func (c *LLMClient) Recommend(prompt string) ([]model.MovieSuggestion, error) {
+	payload := chatRequest{
+		Model:    c.model,
+		Messages: []chatMessage{{Role: "user", Content: prompt}},
+	}
+	body, err := json.Marshal(payload)
+	if err != nil {
+		return nil, err
+	}
+
+	req, err := http.NewRequest(http.MethodPost, c.baseURL+"/chat/completions", bytes.NewReader(body))
+	if err != nil {
+		return nil, err
+	}
+	req.Header.Set("Content-Type", "application/json")
+	req.Header.Set("Accept", "application/json")
+	if c.apiKey != "" {
+		req.Header.Set("Authorization", "Bearer "+c.apiKey)
+	}
+
+	resp, err := c.http.Do(req)
+	if err != nil {
+		return nil, fmt.Errorf("llm request failed: %w", err)
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != http.StatusOK {
+		return nil, fmt.Errorf("llm returned status %d", resp.StatusCode)
+	}
+
+	var chatResp chatResponse
+	if err := json.NewDecoder(resp.Body).Decode(&chatResp); err != nil {
+		return nil, fmt.Errorf("decoding llm response: %w", err)
+	}
+	if len(chatResp.Choices) == 0 {
+		return nil, fmt.Errorf("llm returned no choices")
+	}
+
+	return parseMovieSuggestions(chatResp.Choices[0].Message.Content)
+}
+
+// parseMovieSuggestions extracts a JSON array from LLM output,
+// handling markdown code fences and surrounding prose.
+func parseMovieSuggestions(content string) ([]model.MovieSuggestion, error) {
+	content = strings.TrimSpace(content)
+
+	// Strip markdown fences
+	if idx := strings.Index(content, "```"); idx != -1 {
+		content = content[idx:]
+		content = strings.TrimPrefix(content, "```json")
+		content = strings.TrimPrefix(content, "```")
+		if end := strings.Index(content, "```"); end != -1 {
+			content = content[:end]
+		}
+		content = strings.TrimSpace(content)
+	}
+
+	// Find JSON array boundaries
+	start := strings.Index(content, "[")
+	end := strings.LastIndex(content, "]")
+	if start == -1 || end == -1 || end <= start {
+		return nil, fmt.Errorf("no JSON array found in llm response: %s", content)
+	}
+
+	var suggestions []model.MovieSuggestion
+	if err := json.Unmarshal([]byte(content[start:end+1]), &suggestions); err != nil {
+		return nil, fmt.Errorf("parsing llm json: %w", err)
+	}
+	return suggestions, nil
+}
+
+// BuildPrompt constructs the recommendation prompt sent to the LLM.
+func BuildPrompt(favorites, watched, library []model.Movie, count int) string {
+	var sb strings.Builder
+	sb.WriteString(fmt.Sprintf(
+		"You are a movie recommendation engine. Based on the user's favorite and recently watched movies below, suggest exactly %d movies they would enjoy.\n\n"+
+			"IMPORTANT:\n"+
+			"- Do NOT suggest any movie from the \"Already In Library\" list.\n"+
+			"- Return ONLY a JSON array, no other text.\n"+
+			"- Each entry: {\"title\": \"Movie Title\", \"year\": 2024, \"reason\": \"brief reason\"}\n\n"+
+			"User's favorite movies:\n", count))
+
+	if len(favorites) == 0 {
+		sb.WriteString("(none)\n")
+	} else {
+		for _, m := range favorites {
+			sb.WriteString(fmt.Sprintf("- %s (%d)\n", m.Name, m.Year))
+		}
+	}
+
+	sb.WriteString("\nUser's recently watched movies:\n")
+	if len(watched) == 0 {
+		sb.WriteString("(none)\n")
+	} else {
+		for _, m := range watched {
+			sb.WriteString(fmt.Sprintf("- %s (%d)\n", m.Name, m.Year))
+		}
+	}
+
+	sb.WriteString("\nAlready in library (DO NOT suggest these):\n")
+	for _, m := range library {
+		sb.WriteString(fmt.Sprintf("- %s (%d)\n", m.Name, m.Year))
+	}
+	return sb.String()
+}