refactor: memo filter

plugin/filter/dialect.go

+package filter
+
+import (
+	"fmt"
+	"strings"
+)
+
+// SQLDialect defines database-specific SQL generation methods
+type SQLDialect interface {
+	// Basic field access
+	GetTablePrefix() string
+	GetParameterPlaceholder(index int) string
+
+	// JSON operations
+	GetJSONExtract(path string) string
+	GetJSONArrayLength(path string) string
+	GetJSONContains(path, element string) string
+	GetJSONLike(path, pattern string) string
+
+	// Boolean operations
+	GetBooleanValue(value bool) interface{}
+	GetBooleanComparison(path string, value bool) string
+	GetBooleanCheck(path string) string
+
+	// Timestamp operations
+	GetTimestampComparison(field string) string
+	GetCurrentTimestamp() string
+}
+
+// DatabaseType represents the type of database
+type DatabaseType string
+
+const (
+	SQLite     DatabaseType = "sqlite"
+	MySQL      DatabaseType = "mysql"
+	PostgreSQL DatabaseType = "postgres"
+)
+
+// GetDialect returns the appropriate dialect for the database type
+func GetDialect(dbType DatabaseType) SQLDialect {
+	switch dbType {
+	case SQLite:
+		return &SQLiteDialect{}
+	case MySQL:
+		return &MySQLDialect{}
+	case PostgreSQL:
+		return &PostgreSQLDialect{}
+	default:
+		return &SQLiteDialect{} // default fallback
+	}
+}
+
+// SQLiteDialect implements SQLDialect for SQLite
+type SQLiteDialect struct{}
+
+func (d *SQLiteDialect) GetTablePrefix() string {
+	return "`memo`"
+}
+
+func (d *SQLiteDialect) GetParameterPlaceholder(index int) string {
+	return "?"
+}
+
+func (d *SQLiteDialect) GetJSONExtract(path string) string {
+	return fmt.Sprintf("JSON_EXTRACT(%s.`payload`, '%s')", d.GetTablePrefix(), path)
+}
+
+func (d *SQLiteDialect) GetJSONArrayLength(path string) string {
+	return fmt.Sprintf("JSON_ARRAY_LENGTH(COALESCE(%s, JSON_ARRAY()))", d.GetJSONExtract(path))
+}
+
+func (d *SQLiteDialect) GetJSONContains(path, element string) string {
+	return fmt.Sprintf("%s LIKE ?", d.GetJSONExtract(path))
+}
+
+func (d *SQLiteDialect) GetJSONLike(path, pattern string) string {
+	return fmt.Sprintf("%s LIKE ?", d.GetJSONExtract(path))
+}
+
+func (d *SQLiteDialect) GetBooleanValue(value bool) interface{} {
+	if value {
+		return 1
+	}
+	return 0
+}
+
+func (d *SQLiteDialect) GetBooleanComparison(path string, value bool) string {
+	return fmt.Sprintf("%s = %d", d.GetJSONExtract(path), d.GetBooleanValue(value))
+}
+
+func (d *SQLiteDialect) GetBooleanCheck(path string) string {
+	return fmt.Sprintf("%s IS TRUE", d.GetJSONExtract(path))
+}
+
+func (d *SQLiteDialect) GetTimestampComparison(field string) string {
+	return fmt.Sprintf("%s.`%s`", d.GetTablePrefix(), field)
+}
+
+func (d *SQLiteDialect) GetCurrentTimestamp() string {
+	return "strftime('%s', 'now')"
+}
+
+// MySQLDialect implements SQLDialect for MySQL
+type MySQLDialect struct{}
+
+func (d *MySQLDialect) GetTablePrefix() string {
+	return "`memo`"
+}
+
+func (d *MySQLDialect) GetParameterPlaceholder(index int) string {
+	return "?"
+}
+
+func (d *MySQLDialect) GetJSONExtract(path string) string {
+	return fmt.Sprintf("JSON_EXTRACT(%s.`payload`, '%s')", d.GetTablePrefix(), path)
+}
+
+func (d *MySQLDialect) GetJSONArrayLength(path string) string {
+	return fmt.Sprintf("JSON_LENGTH(COALESCE(%s, JSON_ARRAY()))", d.GetJSONExtract(path))
+}
+
+func (d *MySQLDialect) GetJSONContains(path, element string) string {
+	return fmt.Sprintf("JSON_CONTAINS(%s, ?)", d.GetJSONExtract(path))
+}
+
+func (d *MySQLDialect) GetJSONLike(path, pattern string) string {
+	return fmt.Sprintf("%s LIKE ?", d.GetJSONExtract(path))
+}
+
+func (d *MySQLDialect) GetBooleanValue(value bool) interface{} {
+	return value
+}
+
+func (d *MySQLDialect) GetBooleanComparison(path string, value bool) string {
+	boolStr := "false"
+	if value {
+		boolStr = "true"
+	}
+	return fmt.Sprintf("%s = CAST('%s' AS JSON)", d.GetJSONExtract(path), boolStr)
+}
+
+func (d *MySQLDialect) GetBooleanCheck(path string) string {
+	return fmt.Sprintf("%s = CAST('true' AS JSON)", d.GetJSONExtract(path))
+}
+
+func (d *MySQLDialect) GetTimestampComparison(field string) string {
+	return fmt.Sprintf("UNIX_TIMESTAMP(%s.`%s`)", d.GetTablePrefix(), field)
+}
+
+func (d *MySQLDialect) GetCurrentTimestamp() string {
+	return "UNIX_TIMESTAMP()"
+}
+
+// PostgreSQLDialect implements SQLDialect for PostgreSQL
+type PostgreSQLDialect struct{}
+
+func (d *PostgreSQLDialect) GetTablePrefix() string {
+	return "memo"
+}
+
+func (d *PostgreSQLDialect) GetParameterPlaceholder(index int) string {
+	return fmt.Sprintf("$%d", index)
+}
+
+func (d *PostgreSQLDialect) GetJSONExtract(path string) string {
+	// Convert $.property.hasTaskList to payload->'property'->>'hasTaskList'
+	parts := strings.Split(strings.TrimPrefix(path, "$."), ".")
+	result := fmt.Sprintf("%s.payload", d.GetTablePrefix())
+	for i, part := range parts {
+		if i == len(parts)-1 {
+			result += fmt.Sprintf("->>'%s'", part)
+		} else {
+			result += fmt.Sprintf("->'%s'", part)
+		}
+	}
+	return result
+}
+
+func (d *PostgreSQLDialect) GetJSONArrayLength(path string) string {
+	jsonPath := strings.Replace(path, "$.tags", "payload->'tags'", 1)
+	return fmt.Sprintf("jsonb_array_length(COALESCE(%s.%s, '[]'::jsonb))", d.GetTablePrefix(), jsonPath)
+}
+
+func (d *PostgreSQLDialect) GetJSONContains(path, element string) string {
+	jsonPath := strings.Replace(path, "$.tags", "payload->'tags'", 1)
+	return fmt.Sprintf("%s.%s @> jsonb_build_array(?)", d.GetTablePrefix(), jsonPath)
+}
+
+func (d *PostgreSQLDialect) GetJSONLike(path, pattern string) string {
+	jsonPath := strings.Replace(path, "$.tags", "payload->'tags'", 1)
+	return fmt.Sprintf("%s.%s @> jsonb_build_array(?)", d.GetTablePrefix(), jsonPath)
+}
+
+func (d *PostgreSQLDialect) GetBooleanValue(value bool) interface{} {
+	return value
+}
+
+func (d *PostgreSQLDialect) GetBooleanComparison(path string, value bool) string {
+	return fmt.Sprintf("(%s)::boolean = ?", d.GetJSONExtract(path))
+}
+
+func (d *PostgreSQLDialect) GetBooleanCheck(path string) string {
+	return fmt.Sprintf("(%s)::boolean IS TRUE", d.GetJSONExtract(path))
+}
+
+func (d *PostgreSQLDialect) GetTimestampComparison(field string) string {
+	return fmt.Sprintf("EXTRACT(EPOCH FROM %s.%s)", d.GetTablePrefix(), field)
+}
+
+func (d *PostgreSQLDialect) GetCurrentTimestamp() string {
+	return "EXTRACT(EPOCH FROM NOW())"
+}

plugin/filter/filter.go

@@ -18,6 +18,7 @@ var MemoFilterCELAttributes = []cel.EnvOption{
 	cel.Variable("updated_ts", cel.IntType),
 	cel.Variable("pinned", cel.BoolType),
 	cel.Variable("tag", cel.StringType),
+	cel.Variable("tags", cel.ListType(cel.StringType)),
 	cel.Variable("visibility", cel.StringType),
 	cel.Variable("has_task_list", cel.BoolType),
 	// Current timestamp function.

plugin/filter/templates.go

+package filter
+
+import (
+	"fmt"
+)
+
+// SQLTemplate holds database-specific SQL fragments
+type SQLTemplate struct {
+	SQLite     string
+	MySQL      string
+	PostgreSQL string
+}
+
+// TemplateDBType represents the database type for templates
+type TemplateDBType string
+
+const (
+	SQLiteTemplate     TemplateDBType = "sqlite"
+	MySQLTemplate      TemplateDBType = "mysql"
+	PostgreSQLTemplate TemplateDBType = "postgres"
+)
+
+// SQLTemplates contains common SQL patterns for different databases
+var SQLTemplates = map[string]SQLTemplate{
+	"json_extract": {
+		SQLite:     "JSON_EXTRACT(`memo`.`payload`, '%s')",
+		MySQL:      "JSON_EXTRACT(`memo`.`payload`, '%s')",
+		PostgreSQL: "memo.payload%s",
+	},
+	"json_array_length": {
+		SQLite:     "JSON_ARRAY_LENGTH(COALESCE(JSON_EXTRACT(`memo`.`payload`, '$.tags'), JSON_ARRAY()))",
+		MySQL:      "JSON_LENGTH(COALESCE(JSON_EXTRACT(`memo`.`payload`, '$.tags'), JSON_ARRAY()))",
+		PostgreSQL: "jsonb_array_length(COALESCE(memo.payload->'tags', '[]'::jsonb))",
+	},
+	"json_contains_element": {
+		SQLite:     "JSON_EXTRACT(`memo`.`payload`, '$.tags') LIKE ?",
+		MySQL:      "JSON_CONTAINS(JSON_EXTRACT(`memo`.`payload`, '$.tags'), ?)",
+		PostgreSQL: "memo.payload->'tags' @> jsonb_build_array(?)",
+	},
+	"json_contains_tag": {
+		SQLite:     "JSON_EXTRACT(`memo`.`payload`, '$.tags') LIKE ?",
+		MySQL:      "JSON_CONTAINS(JSON_EXTRACT(`memo`.`payload`, '$.tags'), ?)",
+		PostgreSQL: "memo.payload->'tags' @> jsonb_build_array(?)",
+	},
+	"boolean_true": {
+		SQLite:     "JSON_EXTRACT(`memo`.`payload`, '$.property.hasTaskList') = 1",
+		MySQL:      "JSON_EXTRACT(`memo`.`payload`, '$.property.hasTaskList') = CAST('true' AS JSON)",
+		PostgreSQL: "(memo.payload->'property'->>'hasTaskList')::boolean = true",
+	},
+	"boolean_false": {
+		SQLite:     "JSON_EXTRACT(`memo`.`payload`, '$.property.hasTaskList') = 0",
+		MySQL:      "JSON_EXTRACT(`memo`.`payload`, '$.property.hasTaskList') = CAST('false' AS JSON)",
+		PostgreSQL: "(memo.payload->'property'->>'hasTaskList')::boolean = false",
+	},
+	"boolean_not_true": {
+		SQLite:     "JSON_EXTRACT(`memo`.`payload`, '$.property.hasTaskList') != 1",
+		MySQL:      "JSON_EXTRACT(`memo`.`payload`, '$.property.hasTaskList') != CAST('true' AS JSON)",
+		PostgreSQL: "(memo.payload->'property'->>'hasTaskList')::boolean != true",
+	},
+	"boolean_not_false": {
+		SQLite:     "JSON_EXTRACT(`memo`.`payload`, '$.property.hasTaskList') != 0",
+		MySQL:      "JSON_EXTRACT(`memo`.`payload`, '$.property.hasTaskList') != CAST('false' AS JSON)",
+		PostgreSQL: "(memo.payload->'property'->>'hasTaskList')::boolean != false",
+	},
+	"boolean_compare": {
+		SQLite:     "JSON_EXTRACT(`memo`.`payload`, '$.property.hasTaskList') %s ?",
+		MySQL:      "JSON_EXTRACT(`memo`.`payload`, '$.property.hasTaskList') %s CAST(? AS JSON)",
+		PostgreSQL: "(memo.payload->'property'->>'hasTaskList')::boolean %s ?",
+	},
+	"boolean_check": {
+		SQLite:     "JSON_EXTRACT(`memo`.`payload`, '$.property.hasTaskList') IS TRUE",
+		MySQL:      "JSON_EXTRACT(`memo`.`payload`, '$.property.hasTaskList') = CAST('true' AS JSON)",
+		PostgreSQL: "(memo.payload->'property'->>'hasTaskList')::boolean IS TRUE",
+	},
+	"table_prefix": {
+		SQLite:     "`memo`",
+		MySQL:      "`memo`",
+		PostgreSQL: "memo",
+	},
+	"timestamp_field": {
+		SQLite:     "`memo`.`%s`",
+		MySQL:      "UNIX_TIMESTAMP(`memo`.`%s`)",
+		PostgreSQL: "EXTRACT(EPOCH FROM memo.%s)",
+	},
+	"content_like": {
+		SQLite:     "`memo`.`content` LIKE ?",
+		MySQL:      "`memo`.`content` LIKE ?",
+		PostgreSQL: "memo.content ILIKE ?",
+	},
+	"visibility_in": {
+		SQLite:     "`memo`.`visibility` IN (%s)",
+		MySQL:      "`memo`.`visibility` IN (%s)",
+		PostgreSQL: "memo.visibility IN (%s)",
+	},
+}
+
+// GetSQL returns the appropriate SQL for the given template and database type
+func GetSQL(templateName string, dbType TemplateDBType) string {
+	template, exists := SQLTemplates[templateName]
+	if !exists {
+		return ""
+	}
+
+	switch dbType {
+	case SQLiteTemplate:
+		return template.SQLite
+	case MySQLTemplate:
+		return template.MySQL
+	case PostgreSQLTemplate:
+		return template.PostgreSQL
+	default:
+		return template.SQLite
+	}
+}
+
+// GetParameterPlaceholder returns the appropriate parameter placeholder for the database
+func GetParameterPlaceholder(dbType TemplateDBType, index int) string {
+	switch dbType {
+	case PostgreSQLTemplate:
+		return fmt.Sprintf("$%d", index)
+	default:
+		return "?"
+	}
+}
+
+// GetParameterValue returns the appropriate parameter value for the database
+func GetParameterValue(dbType TemplateDBType, templateName string, value interface{}) interface{} {
+	switch templateName {
+	case "json_contains_element", "json_contains_tag":
+		if dbType == SQLiteTemplate {
+			return fmt.Sprintf(`%%"%s"%%`, value)
+		}
+		return value
+	default:
+		return value
+	}
+}
+
+// FormatPlaceholders formats a list of placeholders for the given database type
+func FormatPlaceholders(dbType TemplateDBType, count int, startIndex int) []string {
+	placeholders := make([]string, count)
+	for i := 0; i < count; i++ {
+		placeholders[i] = GetParameterPlaceholder(dbType, startIndex+i)
+	}
+	return placeholders
+}

store/db/mysql/memo_filter_test.go

@@ -95,6 +95,26 @@ func TestConvertExprToSQL(t *testing.T) {
 			want:   "UNIX_TIMESTAMP(`memo`.`created_ts`) > ?",
 			args:   []any{time.Now().Unix() - 60*60*24},
 		},
+		{
+			filter: `size(tags) == 0`,
+			want:   "JSON_LENGTH(COALESCE(JSON_EXTRACT(`memo`.`payload`, '$.tags'), JSON_ARRAY())) = ?",
+			args:   []any{int64(0)},
+		},
+		{
+			filter: `size(tags) > 0`,
+			want:   "JSON_LENGTH(COALESCE(JSON_EXTRACT(`memo`.`payload`, '$.tags'), JSON_ARRAY())) > ?",
+			args:   []any{int64(0)},
+		},
+		{
+			filter: `"work" in tags`,
+			want:   "JSON_CONTAINS(JSON_EXTRACT(`memo`.`payload`, '$.tags'), ?)",
+			args:   []any{"work"},
+		},
+		{
+			filter: `size(tags) == 2`,
+			want:   "JSON_LENGTH(COALESCE(JSON_EXTRACT(`memo`.`payload`, '$.tags'), JSON_ARRAY())) = ?",
+			args:   []any{int64(2)},
+		},
 	}
 
 	for _, tt := range tests {

store/db/postgres/memo_filter_test.go

@@ -95,6 +95,26 @@ func TestRestoreExprToSQL(t *testing.T) {
 			want:   "EXTRACT(EPOCH FROM memo.created_ts) > $1",
 			args:   []any{time.Now().Unix() - 60*60*24},
 		},
+		{
+			filter: `size(tags) == 0`,
+			want:   "jsonb_array_length(COALESCE(memo.payload->'tags', '[]'::jsonb)) = $1",
+			args:   []any{int64(0)},
+		},
+		{
+			filter: `size(tags) > 0`,
+			want:   "jsonb_array_length(COALESCE(memo.payload->'tags', '[]'::jsonb)) > $1",
+			args:   []any{int64(0)},
+		},
+		{
+			filter: `"work" in tags`,
+			want:   "memo.payload->'tags' @> jsonb_build_array($1)",
+			args:   []any{"work"},
+		},
+		{
+			filter: `size(tags) == 2`,
+			want:   "jsonb_array_length(COALESCE(memo.payload->'tags', '[]'::jsonb)) = $1",
+			args:   []any{int64(2)},
+		},
 	}
 
 	for _, tt := range tests {

store/db/sqlite/memo_filter_test.go

@@ -110,14 +110,40 @@ func TestConvertExprToSQL(t *testing.T) {
 			want:   "`memo`.`created_ts` > ?",
 			args:   []any{time.Now().Unix() - 60*60*24},
 		},
+		{
+			filter: `size(tags) == 0`,
+			want:   "JSON_ARRAY_LENGTH(COALESCE(JSON_EXTRACT(`memo`.`payload`, '$.tags'), JSON_ARRAY())) = ?",
+			args:   []any{int64(0)},
+		},
+		{
+			filter: `size(tags) > 0`,
+			want:   "JSON_ARRAY_LENGTH(COALESCE(JSON_EXTRACT(`memo`.`payload`, '$.tags'), JSON_ARRAY())) > ?",
+			args:   []any{int64(0)},
+		},
+		{
+			filter: `"work" in tags`,
+			want:   "JSON_EXTRACT(`memo`.`payload`, '$.tags') LIKE ?",
+			args:   []any{`%"work"%`},
+		},
+		{
+			filter: `size(tags) == 2`,
+			want:   "JSON_ARRAY_LENGTH(COALESCE(JSON_EXTRACT(`memo`.`payload`, '$.tags'), JSON_ARRAY())) = ?",
+			args:   []any{int64(2)},
+		},
 	}
 
 	for _, tt := range tests {
 		db := &DB{}
 		parsedExpr, err := filter.Parse(tt.filter, filter.MemoFilterCELAttributes...)
+		if err != nil {
+			t.Logf("Failed to parse filter: %s, error: %v", tt.filter, err)
+		}
 		require.NoError(t, err)
 		convertCtx := filter.NewConvertContext()
 		err = db.ConvertExprToSQL(convertCtx, parsedExpr.GetExpr())
+		if err != nil {
+			t.Logf("Failed to convert filter: %s, error: %v", tt.filter, err)
+		}
 		require.NoError(t, err)
 		require.Equal(t, tt.want, convertCtx.Buffer.String())
 		require.Equal(t, tt.args, convertCtx.Args)