Additional abstractions for both sqlite and chroma.

internal/db/sqlite/helpers.go

@@ -0,0 +1,160 @@
+// Package sqlite provides SQLite database operations for claude-mnemonic.
+package sqlite
+
+import (
+	"context"
+	"database/sql"
+	"net/http"
+	"strconv"
+	"time"
+
+	"github.com/lukaszraczylo/claude-mnemonic/pkg/models"
+)
+
+// EnsureSessionExists creates a session if it doesn't exist.
+// This is shared between ObservationStore and SummaryStore to avoid duplication.
+func EnsureSessionExists(ctx context.Context, store *Store, sdkSessionID, project string) error {
+	const checkQuery = `SELECT id FROM sdk_sessions WHERE sdk_session_id = ?`
+	var id int64
+	err := store.QueryRowContext(ctx, checkQuery, sdkSessionID).Scan(&id)
+	if err == nil {
+		return nil // Session exists
+	}
+	if err != sql.ErrNoRows {
+		return err
+	}
+
+	// Auto-create session
+	now := time.Now()
+	const insertQuery = `
+		INSERT INTO sdk_sessions
+		(claude_session_id, sdk_session_id, project, started_at, started_at_epoch, status)
+		VALUES (?, ?, ?, ?, ?, 'active')
+	`
+	_, err = store.ExecContext(ctx, insertQuery,
+		sdkSessionID, sdkSessionID, project,
+		now.Format(time.RFC3339), now.UnixMilli(),
+	)
+	return err
+}
+
+// nullString converts a string to sql.NullString.
+func nullString(s string) sql.NullString {
+	return sql.NullString{String: s, Valid: s != ""}
+}
+
+// nullInt converts an int to sql.NullInt64.
+func nullInt(i int) sql.NullInt64 {
+	return sql.NullInt64{Int64: int64(i), Valid: i > 0}
+}
+
+// repeatPlaceholders generates n comma-prefixed placeholders for SQL IN clauses.
+// e.g., repeatPlaceholders(2) returns ", ?, ?"
+func repeatPlaceholders(n int) string {
+	if n <= 0 {
+		return ""
+	}
+	result := ""
+	for i := 0; i < n; i++ {
+		result += ", ?"
+	}
+	return result
+}
+
+// int64SliceToInterface converts []int64 to []interface{} for SQL queries.
+func int64SliceToInterface(ids []int64) []interface{} {
+	args := make([]interface{}, len(ids))
+	for i, id := range ids {
+		args[i] = id
+	}
+	return args
+}
+
+// ParseLimitParam parses a limit query parameter with a default value.
+func ParseLimitParam(r *http.Request, defaultLimit int) int {
+	if l := r.URL.Query().Get("limit"); l != "" {
+		if parsed, err := strconv.Atoi(l); err == nil && parsed > 0 {
+			return parsed
+		}
+	}
+	return defaultLimit
+}
+
+// scanSummary scans a single summary from a row scanner.
+func scanSummary(scanner interface{ Scan(...interface{}) error }) (*models.SessionSummary, error) {
+	var summary models.SessionSummary
+	if err := scanner.Scan(
+		&summary.ID, &summary.SDKSessionID, &summary.Project,
+		&summary.Request, &summary.Investigated, &summary.Learned, &summary.Completed,
+		&summary.NextSteps, &summary.Notes, &summary.PromptNumber, &summary.DiscoveryTokens,
+		&summary.CreatedAt, &summary.CreatedAtEpoch,
+	); err != nil {
+		return nil, err
+	}
+	return &summary, nil
+}
+
+// scanSummaryRows scans multiple summaries from rows.
+func scanSummaryRows(rows *sql.Rows) ([]*models.SessionSummary, error) {
+	var summaries []*models.SessionSummary
+	for rows.Next() {
+		summary, err := scanSummary(rows)
+		if err != nil {
+			return nil, err
+		}
+		summaries = append(summaries, summary)
+	}
+	return summaries, rows.Err()
+}
+
+// scanPromptWithSession scans a single prompt with session info from a row scanner.
+func scanPromptWithSession(scanner interface{ Scan(...interface{}) error }) (*models.UserPromptWithSession, error) {
+	var prompt models.UserPromptWithSession
+	if err := scanner.Scan(
+		&prompt.ID, &prompt.ClaudeSessionID, &prompt.PromptNumber, &prompt.PromptText,
+		&prompt.MatchedObservations, &prompt.CreatedAt, &prompt.CreatedAtEpoch,
+		&prompt.Project, &prompt.SDKSessionID,
+	); err != nil {
+		return nil, err
+	}
+	return &prompt, nil
+}
+
+// scanPromptWithSessionRows scans multiple prompts with session info from rows.
+func scanPromptWithSessionRows(rows *sql.Rows) ([]*models.UserPromptWithSession, error) {
+	var prompts []*models.UserPromptWithSession
+	for rows.Next() {
+		prompt, err := scanPromptWithSession(rows)
+		if err != nil {
+			return nil, err
+		}
+		prompts = append(prompts, prompt)
+	}
+	return prompts, rows.Err()
+}
+
+// BuildGetByIDsQuery builds a query for fetching records by IDs with optional ordering and limit.
+// Returns the query string and args slice.
+func BuildGetByIDsQuery(baseQuery string, ids []int64, orderBy string, limit int) (string, []interface{}) {
+	// Build query with placeholders
+	// #nosec G202 -- query uses parameterized placeholders, not user input
+	query := baseQuery + ` WHERE id IN (?` + repeatPlaceholders(len(ids)-1) + `)
+		ORDER BY created_at_epoch `
+
+	if orderBy == "date_asc" {
+		query += "ASC"
+	} else {
+		query += "DESC"
+	}
+
+	if limit > 0 {
+		query += " LIMIT ?"
+	}
+
+	args := int64SliceToInterface(ids)
+	if limit > 0 {
+		args = append(args, limit)
+	}
+
+	return query, args
+}

internal/db/sqlite/observation.go

@@ -91,28 +91,7 @@ func (s *ObservationStore) StoreObservation(ctx context.Context, sdkSessionID, p
 
 // ensureSessionExists creates a session if it doesn't exist.
 func (s *ObservationStore) ensureSessionExists(ctx context.Context, sdkSessionID, project string) error {
-	const checkQuery = `SELECT id FROM sdk_sessions WHERE sdk_session_id = ?`
-	var id int64
-	err := s.store.QueryRowContext(ctx, checkQuery, sdkSessionID).Scan(&id)
-	if err == nil {
-		return nil // Session exists
-	}
-	if err != sql.ErrNoRows {
-		return err
-	}
-
-	// Auto-create session
-	now := time.Now()
-	const insertQuery = `
-		INSERT INTO sdk_sessions
-		(claude_session_id, sdk_session_id, project, started_at, started_at_epoch, status)
-		VALUES (?, ?, ?, ?, ?, 'active')
-	`
-	_, err = s.store.ExecContext(ctx, insertQuery,
-		sdkSessionID, sdkSessionID, project,
-		now.Format(time.RFC3339), now.UnixMilli(),
-	)
-	return err
+	return EnsureSessionExists(ctx, s.store, sdkSessionID, project)
 }
 
 // GetObservationByID retrieves an observation by ID.
@@ -159,10 +138,7 @@ func (s *ObservationStore) GetObservationsByIDs(ctx context.Context, ids []int64
 	}
 
 	// Convert []int64 to []interface{}
-	args := make([]interface{}, len(ids))
-	for i, id := range ids {
-		args[i] = id
-	}
+	args := int64SliceToInterface(ids)
 	if limit > 0 {
 		args = append(args, limit)
 	}
@@ -355,37 +331,6 @@ func extractKeywords(query string) []string {
 	return keywords
 }
 
-// ExistsSimilarObservation checks if an observation about the same files exists for a project.
-// Used to prevent duplicate observations when re-reading the same files.
-func (s *ObservationStore) ExistsSimilarObservation(ctx context.Context, project string, filesRead, filesModified []string) (bool, error) {
-	// If no files tracked, can't deduplicate
-	if len(filesRead) == 0 && len(filesModified) == 0 {
-		return false, nil
-	}
-
-	// Check if any observation exists with the same primary file
-	// Use the first file as the key identifier
-	var primaryFile string
-	if len(filesRead) > 0 {
-		primaryFile = filesRead[0]
-	} else if len(filesModified) > 0 {
-		primaryFile = filesModified[0]
-	}
-
-	const query = `
-		SELECT COUNT(*) FROM observations
-		WHERE project = ? AND (files_read LIKE ? OR files_modified LIKE ?)
-	`
-	pattern := "%" + primaryFile + "%"
-
-	var count int
-	err := s.store.QueryRowContext(ctx, query, project, pattern, pattern).Scan(&count)
-	if err != nil {
-		return false, err
-	}
-	return count > 0, nil
-}
-
 // DeleteObservations deletes multiple observations by ID.
 func (s *ObservationStore) DeleteObservations(ctx context.Context, ids []int64) (int64, error) {
 	if len(ids) == 0 {
@@ -497,21 +442,4 @@ func scanObservationRows(rows *sql.Rows) ([]*models.Observation, error) {
 	return observations, rows.Err()
 }
 
-func nullString(s string) sql.NullString {
-	return sql.NullString{String: s, Valid: s != ""}
-}
-
-func nullInt(i int) sql.NullInt64 {
-	return sql.NullInt64{Int64: int64(i), Valid: i > 0}
-}
-
-func repeatPlaceholders(n int) string {
-	if n <= 0 {
-		return ""
-	}
-	result := ""
-	for i := 0; i < n; i++ {
-		result += ", ?"
-	}
-	return result
-}
+// Note: nullString, nullInt, and repeatPlaceholders are in helpers.go

internal/db/sqlite/prompt.go

@@ -128,9 +128,12 @@ func (s *PromptStore) GetPromptsByIDs(ctx context.Context, ids []int64, orderBy
 	// #nosec G202 -- query uses parameterized placeholders, not user input
 	query := `
 		SELECT up.id, up.claude_session_id, up.prompt_number, up.prompt_text,
-		       up.created_at, up.created_at_epoch, s.project, s.sdk_session_id
+		       COALESCE(up.matched_observations, 0) as matched_observations,
+		       up.created_at, up.created_at_epoch,
+		       COALESCE(s.project, '') as project,
+		       COALESCE(s.sdk_session_id, '') as sdk_session_id
 		FROM user_prompts up
-		JOIN sdk_sessions s ON up.claude_session_id = s.claude_session_id
+		LEFT JOIN sdk_sessions s ON up.claude_session_id = s.claude_session_id
 		WHERE up.id IN (?` + repeatPlaceholders(len(ids)-1) + `)
 		ORDER BY up.created_at_epoch `
 
@@ -144,11 +147,7 @@ func (s *PromptStore) GetPromptsByIDs(ctx context.Context, ids []int64, orderBy
 		query += " LIMIT ?"
 	}
 
-	// Convert []int64 to []interface{}
-	args := make([]interface{}, len(ids))
-	for i, id := range ids {
-		args[i] = id
-	}
+	args := int64SliceToInterface(ids)
 	if limit > 0 {
 		args = append(args, limit)
 	}
@@ -159,18 +158,7 @@ func (s *PromptStore) GetPromptsByIDs(ctx context.Context, ids []int64, orderBy
 	}
 	defer rows.Close()
 
-	var prompts []*models.UserPromptWithSession
-	for rows.Next() {
-		var prompt models.UserPromptWithSession
-		if err := rows.Scan(
-			&prompt.ID, &prompt.ClaudeSessionID, &prompt.PromptNumber, &prompt.PromptText,
-			&prompt.CreatedAt, &prompt.CreatedAtEpoch, &prompt.Project, &prompt.SDKSessionID,
-		); err != nil {
-			return nil, err
-		}
-		prompts = append(prompts, &prompt)
-	}
-	return prompts, rows.Err()
+	return scanPromptWithSessionRows(rows)
 }
 
 // GetAllRecentUserPrompts retrieves recent user prompts across all sessions.
@@ -193,19 +181,7 @@ func (s *PromptStore) GetAllRecentUserPrompts(ctx context.Context, limit int) ([
 	}
 	defer rows.Close()
 
-	var prompts []*models.UserPromptWithSession
-	for rows.Next() {
-		var prompt models.UserPromptWithSession
-		if err := rows.Scan(
-			&prompt.ID, &prompt.ClaudeSessionID, &prompt.PromptNumber, &prompt.PromptText,
-			&prompt.MatchedObservations, &prompt.CreatedAt, &prompt.CreatedAtEpoch,
-			&prompt.Project, &prompt.SDKSessionID,
-		); err != nil {
-			return nil, err
-		}
-		prompts = append(prompts, &prompt)
-	}
-	return prompts, rows.Err()
+	return scanPromptWithSessionRows(rows)
 }
 
 // GetRecentUserPromptsByProject retrieves recent user prompts for a specific project.
@@ -229,17 +205,5 @@ func (s *PromptStore) GetRecentUserPromptsByProject(ctx context.Context, project
 	}
 	defer rows.Close()
 
-	var prompts []*models.UserPromptWithSession
-	for rows.Next() {
-		var prompt models.UserPromptWithSession
-		if err := rows.Scan(
-			&prompt.ID, &prompt.ClaudeSessionID, &prompt.PromptNumber, &prompt.PromptText,
-			&prompt.MatchedObservations, &prompt.CreatedAt, &prompt.CreatedAtEpoch,
-			&prompt.Project, &prompt.SDKSessionID,
-		); err != nil {
-			return nil, err
-		}
-		prompts = append(prompts, &prompt)
-	}
-	return prompts, rows.Err()
+	return scanPromptWithSessionRows(rows)
 }

internal/db/sqlite/summary.go

@@ -3,7 +3,6 @@ package sqlite
 
 import (
 	"context"
-	"database/sql"
 	"time"
 
 	"github.com/lukaszraczylo/claude-mnemonic/pkg/models"
@@ -54,28 +53,7 @@ func (s *SummaryStore) StoreSummary(ctx context.Context, sdkSessionID, project s
 
 // ensureSessionExists creates a session if it doesn't exist.
 func (s *SummaryStore) ensureSessionExists(ctx context.Context, sdkSessionID, project string) error {
-	const checkQuery = `SELECT id FROM sdk_sessions WHERE sdk_session_id = ?`
-	var id int64
-	err := s.store.QueryRowContext(ctx, checkQuery, sdkSessionID).Scan(&id)
-	if err == nil {
-		return nil // Session exists
-	}
-	if err != sql.ErrNoRows {
-		return err
-	}
-
-	// Auto-create session
-	now := time.Now()
-	const insertQuery = `
-		INSERT INTO sdk_sessions
-		(claude_session_id, sdk_session_id, project, started_at, started_at_epoch, status)
-		VALUES (?, ?, ?, ?, ?, 'active')
-	`
-	_, err = s.store.ExecContext(ctx, insertQuery,
-		sdkSessionID, sdkSessionID, project,
-		now.Format(time.RFC3339), now.UnixMilli(),
-	)
-	return err
+	return EnsureSessionExists(ctx, s.store, sdkSessionID, project)
 }
 
 // GetSummariesByIDs retrieves summaries by a list of IDs.
@@ -84,33 +62,12 @@ func (s *SummaryStore) GetSummariesByIDs(ctx context.Context, ids []int64, order
 		return nil, nil
 	}
 
-	// Build query with placeholders
-	// #nosec G202 -- query uses parameterized placeholders, not user input
-	query := `
+	const baseQuery = `
 		SELECT id, sdk_session_id, project, request, investigated, learned, completed,
 		       next_steps, notes, prompt_number, discovery_tokens, created_at, created_at_epoch
-		FROM session_summaries
-		WHERE id IN (?` + repeatPlaceholders(len(ids)-1) + `)
-		ORDER BY created_at_epoch `
+		FROM session_summaries`
 
-	if orderBy == "date_asc" {
-		query += "ASC"
-	} else {
-		query += "DESC"
-	}
-
-	if limit > 0 {
-		query += " LIMIT ?"
-	}
-
-	// Convert []int64 to []interface{}
-	args := make([]interface{}, len(ids))
-	for i, id := range ids {
-		args[i] = id
-	}
-	if limit > 0 {
-		args = append(args, limit)
-	}
+	query, args := BuildGetByIDsQuery(baseQuery, ids, orderBy, limit)
 
 	rows, err := s.store.db.QueryContext(ctx, query, args...)
 	if err != nil {
@@ -118,20 +75,7 @@ func (s *SummaryStore) GetSummariesByIDs(ctx context.Context, ids []int64, order
 	}
 	defer rows.Close()
 
-	var summaries []*models.SessionSummary
-	for rows.Next() {
-		var summary models.SessionSummary
-		if err := rows.Scan(
-			&summary.ID, &summary.SDKSessionID, &summary.Project,
-			&summary.Request, &summary.Investigated, &summary.Learned, &summary.Completed,
-			&summary.NextSteps, &summary.Notes, &summary.PromptNumber, &summary.DiscoveryTokens,
-			&summary.CreatedAt, &summary.CreatedAtEpoch,
-		); err != nil {
-			return nil, err
-		}
-		summaries = append(summaries, &summary)
-	}
-	return summaries, rows.Err()
+	return scanSummaryRows(rows)
 }
 
 // GetRecentSummaries retrieves recent summaries for a project.
@@ -151,20 +95,7 @@ func (s *SummaryStore) GetRecentSummaries(ctx context.Context, project string, l
 	}
 	defer rows.Close()
 
-	var summaries []*models.SessionSummary
-	for rows.Next() {
-		var summary models.SessionSummary
-		if err := rows.Scan(
-			&summary.ID, &summary.SDKSessionID, &summary.Project,
-			&summary.Request, &summary.Investigated, &summary.Learned, &summary.Completed,
-			&summary.NextSteps, &summary.Notes, &summary.PromptNumber, &summary.DiscoveryTokens,
-			&summary.CreatedAt, &summary.CreatedAtEpoch,
-		); err != nil {
-			return nil, err
-		}
-		summaries = append(summaries, &summary)
-	}
-	return summaries, rows.Err()
+	return scanSummaryRows(rows)
 }
 
 // GetAllRecentSummaries retrieves recent summaries across all projects.
@@ -183,18 +114,5 @@ func (s *SummaryStore) GetAllRecentSummaries(ctx context.Context, limit int) ([]
 	}
 	defer rows.Close()
 
-	var summaries []*models.SessionSummary
-	for rows.Next() {
-		var summary models.SessionSummary
-		if err := rows.Scan(
-			&summary.ID, &summary.SDKSessionID, &summary.Project,
-			&summary.Request, &summary.Investigated, &summary.Learned, &summary.Completed,
-			&summary.NextSteps, &summary.Notes, &summary.PromptNumber, &summary.DiscoveryTokens,
-			&summary.CreatedAt, &summary.CreatedAtEpoch,
-		); err != nil {
-			return nil, err
-		}
-		summaries = append(summaries, &summary)
-	}
-	return summaries, rows.Err()
+	return scanSummaryRows(rows)
 }