1 files changed, 119 insertions, 0 deletions
diff --git a/modules/indexer/internal/meilisearch/filter.go b/modules/indexer/internal/meilisearch/filter.go
new file mode 100644
index 0000000..593177f
--- /dev/null
+++ b/modules/indexer/internal/meilisearch/filter.go
@@ -0,0 +1,119 @@
+// Copyright 2023 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package meilisearch
+
+import (
+	"fmt"
+	"strings"
+)
+
+// Filter represents a filter for meilisearch queries.
+// It's just a simple wrapper around a string.
+// DO NOT assume that it is a complete implementation.
+type Filter interface {
+	Statement() string
+}
+
+type FilterAnd struct {
+	filters []Filter
+}
+
+func (f *FilterAnd) Statement() string {
+	var statements []string
+	for _, filter := range f.filters {
+		if s := filter.Statement(); s != "" {
+			statements = append(statements, fmt.Sprintf("(%s)", s))
+		}
+	}
+	return strings.Join(statements, " AND ")
+}
+
+func (f *FilterAnd) And(filter Filter) *FilterAnd {
+	f.filters = append(f.filters, filter)
+	return f
+}
+
+type FilterOr struct {
+	filters []Filter
+}
+
+func (f *FilterOr) Statement() string {
+	var statements []string
+	for _, filter := range f.filters {
+		if s := filter.Statement(); s != "" {
+			statements = append(statements, fmt.Sprintf("(%s)", s))
+		}
+	}
+	return strings.Join(statements, " OR ")
+}
+
+func (f *FilterOr) Or(filter Filter) *FilterOr {
+	f.filters = append(f.filters, filter)
+	return f
+}
+
+type FilterIn string
+
+// NewFilterIn creates a new FilterIn.
+// It supports int64 only, to avoid extra works to handle strings with special characters.
+func NewFilterIn[T int64](field string, values ...T) FilterIn {
+	if len(values) == 0 {
+		return ""
+	}
+	vs := make([]string, len(values))
+	for i, v := range values {
+		vs[i] = fmt.Sprintf("%v", v)
+	}
+	return FilterIn(fmt.Sprintf("%s IN [%v]", field, strings.Join(vs, ", ")))
+}
+
+func (f FilterIn) Statement() string {
+	return string(f)
+}
+
+type FilterEq string
+
+// NewFilterEq creates a new FilterEq.
+// It supports int64 and bool only, to avoid extra works to handle strings with special characters.
+func NewFilterEq[T bool | int64](field string, value T) FilterEq {
+	return FilterEq(fmt.Sprintf("%s = %v", field, value))
+}
+
+func (f FilterEq) Statement() string {
+	return string(f)
+}
+
+type FilterNot string
+
+func NewFilterNot(filter Filter) FilterNot {
+	return FilterNot(fmt.Sprintf("NOT (%s)", filter.Statement()))
+}
+
+func (f FilterNot) Statement() string {
+	return string(f)
+}
+
+type FilterGte string
+
+// NewFilterGte creates a new FilterGte.
+// It supports int64 only, to avoid extra works to handle strings with special characters.
+func NewFilterGte[T int64](field string, value T) FilterGte {
+	return FilterGte(fmt.Sprintf("%s >= %v", field, value))
+}
+
+func (f FilterGte) Statement() string {
+	return string(f)
+}
+
+type FilterLte string
+
+// NewFilterLte creates a new FilterLte.
+// It supports int64 only, to avoid extra works to handle strings with special characters.
+func NewFilterLte[T int64](field string, value T) FilterLte {
+	return FilterLte(fmt.Sprintf("%s <= %v", field, value))
+}
+
+func (f FilterLte) Statement() string {
+	return string(f)
+}