package rpc

import (
	"encoding/json"
	"testing"

	"github.com/stretchr/testify/require"
)

func TestDeferredDecoding(t *testing.T) {
	rawMsg := `{"dinetrpc" : 1, "time": 1234, "req":"config:set", "id":1,
			"device:uid": "1337", "params": {"uid":100, "value":2}}`
	msg := &Msg{}
	err := json.Unmarshal([]byte(rawMsg), msg)
	require.Nil(t, err)
	require.False(t, msg.Params.IsEmpty())
	require.True(t, msg.Result.IsEmpty())

	def := msg.Params.(*deferredDecoder)
	require.Equal(t, decoderDataTypeJSON, def.dataType)

	cp := &ConfigParam{}
	err = msg.Params.Unmarshal(cp)
	require.Nil(t, err)
	require.Equal(t, float64(2), cp.Value.(float64))
	require.Equal(t, uint16(100), cp.UID)

	// remarshall the data with the deferredDecoder in it
	ret, err := json.Marshal(msg)
	require.Nil(t, err)
	require.JSONEq(t, rawMsg, string(ret))
}

func TestDecodeCustomType(t *testing.T) {
	rawMsg := `{"dinetrpc" : 1, "time": 1234, "req":"config:set", "id":2,
			"device:uid": "1337", "params": {"uid":1, "value":2}}`
	msg := &Msg{Params: &ConfigParam{}} // immediately attach ConfigParam

	err := json.Unmarshal([]byte(rawMsg), msg)
	require.Nil(t, err)
	require.False(t, msg.Params.IsEmpty())
	require.True(t, msg.Result.IsEmpty())

	// after unmarshall it should still be ConfigParam
	cp := msg.Params.(*ConfigParam)

	require.Equal(t, float64(2), cp.Value.(float64))
	require.Equal(t, uint16(1), cp.UID)
}

func TestFaultyParamDecoding(t *testing.T) {
	cases := []struct {
		name   string
		rawMsg string
	}{
		{"no params", `{"dinetrpc" : 1, "time": 1234, "req":"config:set",
			"id":3, "device:uid": "1337"}`},
		{"null params", `{"dinetrpc" : 1, "time": 1234, "req":"config:set",
			"id":4, "device:uid": "1337", "params": null}`},
	}
	for _, c := range cases {
		// Transfer tc to local variable for fixing schope
		c := c
		t.Run(c.name, func(t *testing.T) {
			msg := &Msg{}
			err := json.Unmarshal([]byte(c.rawMsg), msg)
			require.Nil(t, err)

			require.True(t, msg.Params.IsEmpty())
			require.True(t, msg.Result.IsEmpty())

			def := msg.Params.(*deferredDecoder)
			require.Nil(t, def.unmarshaller)

			cp := &ConfigParam{}
			err = msg.Params.Unmarshal(cp)
			require.Equal(t, ErrMsgNoData, err)
		})
	}
}