Basic stuff, loadOne

mongox/query/compose.go

@@ -0,0 +1,53 @@
+package query
+
+import (
+	"github.com/mainnika/mongox-go-driver/mongox/errors"
+	"github.com/mongodb/mongo-go-driver/bson"
+)
+
+// ComposeQuery is a function to compose filters into a single query
+func Compose(filters ...interface{}) *Query {
+
+	q := &Query{}
+
+	for _, f := range filters {
+
+		ok := false
+		ok = ok || applyBson(q, f)
+		ok = ok || applyLimits(q, f)
+
+		if !ok {
+			panic(errors.InternalErrorf("unknown filter %v", f))
+		}
+	}
+
+	return q
+}
+
+// applyBson is a fallback for a custom bson.M
+func applyBson(q *Query, f interface{}) bool {
+
+	switch f := f.(type) {
+	case bson.M:
+		q.And(f)
+	default:
+		return false
+	}
+
+	return true
+}
+
+// applyLimits extends query with contol functions
+func applyLimits(q *Query, f interface{}) bool {
+
+	switch f := f.(type) {
+	case Limiter:
+		q.limiter = f
+	case Sorter:
+		q.sorter = f
+	default:
+		return false
+	}
+
+	return true
+}

mongox/query/query.go

@@ -0,0 +1,60 @@
+package query
+
+import (
+	"github.com/mongodb/mongo-go-driver/bson"
+
+	"reflect"
+)
+
+// Query is an enchanched bson.M map
+type Query struct {
+	m       bson.M
+	limiter Limiter
+	sorter  Sorter
+}
+
+// And function pushes the elem query to the $and array of the query
+func (q *Query) And(elem bson.M) *Query {
+
+	if q.m == nil {
+		q.m = bson.M{}
+	}
+
+	queries, exists := q.m["$and"].(bson.A)
+
+	if !exists {
+		q.m["$and"] = bson.A{elem}
+		return q
+	}
+
+	q.m["$and"] = append(queries, elem)
+
+	return q
+}
+
+// Limiter is a limit function for a query
+func (q *Query) Limiter() Limiter {
+
+	return q.limiter
+}
+
+// Sorter is a sort rule for a query
+func (q *Query) Sorter() Sorter {
+
+	return q.sorter
+}
+
+// Empty checks the query for any content
+func (q *Query) Empty() bool {
+
+	qv := reflect.ValueOf(q)
+	keys := qv.MapKeys()
+
+	return len(keys) == 0
+}
+
+// M returns underlying query map
+func (q *Query) M() bson.M {
+
+	return q.m
+}

mongox/query/sort.go

@@ -0,0 +1,20 @@
+package query
+
+import (
+	"github.com/mongodb/mongo-go-driver/bson"
+)
+
+// Sorter is a filter to sort the data before query
+type Sorter interface {
+	Sort() bson.M
+}
+
+// Sort is a simple implementations of the Sorter filter
+type Sort bson.M
+
+var _ Sorter = &Sort{}
+
+// Sort returns a slice of fields which have to be sorted
+func (f Sort) Sort() bson.M {
+	return bson.M(f)
+}