package mongoext

import (
	"bytes"
	"testing"

	"git.blackforestbytes.com/BlackForestBytes/goext/tst"
	"go.mongodb.org/mongo-driver/v2/bson"
)

func TestCreateGoExtBsonRegistryNotNil(t *testing.T) {
	reg := CreateGoExtBsonRegistry()
	if reg == nil {
		t.Fatal("registry should not be nil")
	}
}

func TestCreateGoExtBsonRegistryEmbeddedDocumentDecodesAsBsonM(t *testing.T) {
	reg := CreateGoExtBsonRegistry()

	doc := bson.M{
		"name": "alice",
		"nested": bson.M{
			"key": "value",
			"num": int32(42),
		},
	}

	raw, err := bson.Marshal(doc)
	tst.AssertNoErr(t, err)

	dec := bson.NewDecoder(bson.NewDocumentReader(bytes.NewReader(raw)))
	dec.SetRegistry(reg)

	var decoded map[string]any
	err = dec.Decode(&decoded)
	tst.AssertNoErr(t, err)

	nested, ok := decoded["nested"].(bson.M)
	if !ok {
		t.Fatalf("expected nested to be bson.M, got %T", decoded["nested"])
	}

	tst.AssertEqual(t, nested["key"].(string), "value")
}

func TestCreateGoExtBsonRegistryStructFieldOfTypeAny(t *testing.T) {
	reg := CreateGoExtBsonRegistry()

	type wrapper struct {
		Payload any `bson:"payload"`
	}

	source := wrapper{Payload: bson.M{"x": "y"}}
	raw, err := bson.Marshal(source)
	tst.AssertNoErr(t, err)

	dec := bson.NewDecoder(bson.NewDocumentReader(bytes.NewReader(raw)))
	dec.SetRegistry(reg)

	var decoded wrapper
	err = dec.Decode(&decoded)
	tst.AssertNoErr(t, err)

	payload, ok := decoded.Payload.(bson.M)
	if !ok {
		t.Fatalf("expected Payload to be bson.M, got %T", decoded.Payload)
	}
	tst.AssertEqual(t, payload["x"].(string), "y")
}

func TestCreateGoExtBsonRegistryReturnsIndependentInstances(t *testing.T) {
	r1 := CreateGoExtBsonRegistry()
	r2 := CreateGoExtBsonRegistry()

	if r1 == r2 {
		t.Error("expected each call to return a new registry instance")
	}
}