Metrics and logs - MongoDB Submission (#43)

Adds MongoDB-backed submission for survey statistics/metrics and introduces MongoDB ObjectID-based participant/task identifiers to support upserts and linking metrics to a participant.

It introduces breaking changes to the exsisting json stat and metric files. Delete the old ones

Changes:

Add internal/storage/MongoStorage and wire pm survey submit / pm start to submit local .pm/*.json files to MongoDB.
Extend stats/metrics models to include MongoDB _id / participant_id fields and add participant ID propagation into task metrics.
Update app initialization to generate ObjectIDs for new participants and expose GetParticipantID() via StatsService.

internal/storage/mongo.go

@@ -0,0 +1,180 @@
+package storage
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"os"
+	"strings"
+
+	"github.com/LazyBachelor/LazyPM/internal/models"
+	"github.com/charmbracelet/huh"
+	"go.mongodb.org/mongo-driver/bson"
+	"go.mongodb.org/mongo-driver/mongo"
+	"go.mongodb.org/mongo-driver/mongo/options"
+)
+
+type MongoStorage struct {
+	client *mongo.Client
+}
+
+func NewMongoStorage(ctx context.Context, uri, username, password string) (*MongoStorage, error) {
+	credentials := options.Credential{
+		Username: username,
+		Password: password,
+	}
+
+	client, err := mongo.Connect(ctx,
+		options.Client().ApplyURI(uri).SetAuth(credentials))
+
+	if err != nil {
+		return nil, fmt.Errorf("failed to connect to MongoDB: %v", err)
+	}
+
+	if err := client.Ping(ctx, nil); err != nil {
+		return nil, fmt.Errorf("cannot reach MongoDB: %v", err)
+	}
+
+	return &MongoStorage{client: client}, nil
+}
+
+func NewMongoStorageInteractive(ctx context.Context, uri string) (*MongoStorage, error) {
+	var username, password string
+	if os.Getenv("DB_USER") == "" {
+		if err := huh.NewInput().
+			Title("Enter the Database Username").
+			Value(&username).
+			WithTheme(huh.ThemeBase16()).Run(); err != nil {
+			return nil, fmt.Errorf("failed to read username: %w", err)
+		}
+	} else {
+		username = os.Getenv("DB_USER")
+	}
+
+	if username == "" {
+		return nil, fmt.Errorf("No username provided.")
+	}
+
+	if os.Getenv("DB_PASSWORD") == "" {
+		if err := huh.NewInput().
+			Title("Enter the Survey Password").
+			EchoMode(huh.EchoModePassword).
+			Value(&password).
+			WithTheme(huh.ThemeBase16()).Run(); err != nil {
+			return nil, fmt.Errorf("failed to read password: %w", err)
+		}
+	} else {
+		password = os.Getenv("DB_PASSWORD")
+	}
+
+	if password == "" {
+		return nil, fmt.Errorf("No password provided.")
+
+	}
+
+	mongoClient, err := NewMongoStorage(ctx, uri, username, password)
+	if err != nil {
+		return nil, fmt.Errorf("failed to connect to database: %w", err)
+	}
+	return mongoClient, nil
+}
+
+func (s *MongoStorage) Close() error {
+	return s.client.Disconnect(context.Background())
+}
+
+func (s *MongoStorage) SubmitSurveyResponsesCmd(ctx context.Context, dir string) error {
+	pmDir := dir
+	userStatscollection := s.client.Database("Responses").Collection("stats")
+	taskMetricsCollection := s.client.Database("Responses").Collection("metrics")
+
+	entries, err := os.ReadDir(pmDir)
+	if err != nil {
+		return fmt.Errorf("Failed to read .pm directory: %v", err)
+	}
+
+	if len(entries) == 0 {
+		return fmt.Errorf("No files found in .pm directory")
+	}
+
+	statFile := pmDir + "stats.json"
+	if _, err := os.Stat(statFile); os.IsNotExist(err) {
+		return fmt.Errorf("stats.json not found in .pm directory")
+	}
+
+	stats, err := getStats(statFile)
+	if err != nil {
+		return fmt.Errorf("Failed to read stats.json: %v", err)
+	}
+
+	_, err = userStatscollection.UpdateOne(ctx,
+		bson.M{"_id": stats.ID},
+		bson.M{"$set": stats},
+		options.Update().SetUpsert(true))
+
+	if err != nil {
+		return fmt.Errorf("Failed to insert stats into database: %v", err)
+	}
+
+	metricFiles := []string{}
+	for _, entry := range entries {
+		if entry.IsDir() {
+			continue
+		}
+
+		if entry.Name() == "stats.json" {
+			continue
+		}
+
+		if strings.HasSuffix(entry.Name(), "-stats.json") {
+			metricFiles = append(metricFiles, pmDir+entry.Name())
+			continue
+		}
+	}
+
+	for _, file := range metricFiles {
+		metrics, err := getTaskMetrics(file)
+		if err != nil {
+			fmt.Printf("failed to read metrics from %s: %v", file, err)
+			continue
+		}
+
+		_, err = taskMetricsCollection.UpdateOne(ctx, bson.M{"_id": metrics.ID}, bson.M{"$set": metrics},
+			options.Update().SetUpsert(true))
+
+		if err != nil {
+			fmt.Printf("failed to insert metrics from %s: %v", file, err)
+			continue
+		}
+	}
+
+	return nil
+}
+
+func getStats(file string) (*models.Statistics, error) {
+	data, err := os.ReadFile(file)
+	if err != nil {
+		return nil, err
+	}
+
+	var stats models.Statistics
+	if err := json.Unmarshal(data, &stats); err != nil {
+		return nil, err
+	}
+
+	return &stats, nil
+}
+
+func getTaskMetrics(file string) (*models.TaskMetricsFile, error) {
+	data, err := os.ReadFile(file)
+	if err != nil {
+		return nil, err
+	}
+
+	var metrics models.TaskMetricsFile
+	if err := json.Unmarshal(data, &metrics); err != nil {
+		return nil, err
+	}
+
+	return &metrics, nil
+}