package migrate

import (
	"bytes"
	"encoding/json"
	"os"
	"testing"

	"github.com/stretchr/testify/require"

	"github.com/cosmos/cosmos-sdk/x/genutil/types"
)

var oldGenFilePath = "./testdata/old_app_genesis.json"

func TestMigration(t *testing.T) {
	tempDir := t.TempDir()

	// clean all content on this directory
	err := os.RemoveAll(tempDir)
	require.NoError(t, err)

	// should not be able to get app genesis from new genesis file
	// since validators address are still in hex string and not cons address
	_, err = types.AppGenesisFromFile(oldGenFilePath)
	require.ErrorContains(t, err, "error unmarshalling AppGenesis: decoding bech32 failed")

	newAppGenesis, err := MigrateGenesisFile(oldGenFilePath)
	require.NoError(t, err)
	// save the new app genesis to new temp dir
	err = newAppGenesis.SaveAs(tempDir)
	require.NoError(t, err)

	// read the old app genesis to compare with the new app genesis
	var oldAppGenesis legacyAppGenesis
	r, err := os.Open(oldGenFilePath)
	require.NoError(t, err)
	err = json.NewDecoder(r).Decode(&oldAppGenesis)
	require.NoError(t, err)

	// should be able to get app genesis from new genesis file
	newAppGenesis, err = types.AppGenesisFromFile(tempDir)
	require.NotNil(t, newAppGenesis)
	require.NotNil(t, newAppGenesis.Consensus)
	require.True(t, bytes.Equal(oldAppGenesis.AppHash, newAppGenesis.AppHash))
	require.True(t, bytes.Equal(oldAppGenesis.Consensus.Validators[0].Address.Bytes(), newAppGenesis.Consensus.Validators[0].Address.Bytes()))
	require.True(t, bytes.Equal(oldAppGenesis.Consensus.Validators[0].PubKey.Bytes(), newAppGenesis.Consensus.Validators[0].PubKey.Bytes()))
	require.Equal(t, len(oldAppGenesis.Consensus.Validators), len(newAppGenesis.Consensus.Validators), "Number of validators should remain the same after migration")

	require.NoError(t, err)
}