package batcher_test

import (
	"io"
	"math/big"
	"testing"

	"github.com/ethereum-optimism/optimism/op-batcher/batcher"
	"github.com/ethereum-optimism/optimism/op-node/eth"
	"github.com/ethereum-optimism/optimism/op-node/rollup/derive"
	"github.com/ethereum-optimism/optimism/op-node/testlog"
	"github.com/ethereum/go-ethereum/common"
	"github.com/ethereum/go-ethereum/core/types"
	"github.com/ethereum/go-ethereum/log"
	"github.com/ethereum/go-ethereum/trie"
	"github.com/stretchr/testify/require"
)

// TestChannelManagerReturnsErrReorg ensures that the channel manager
// detects a reorg when it has cached L1 blocks.
func TestChannelManagerReturnsErrReorg(t *testing.T) {
	log := testlog.Logger(t, log.LvlCrit)
	m := batcher.NewChannelManager(log, batcher.ChannelConfig{})

	a := types.NewBlock(&types.Header{
		Number: big.NewInt(0),
	}, nil, nil, nil, nil)
	b := types.NewBlock(&types.Header{
		Number:     big.NewInt(1),
		ParentHash: a.Hash(),
	}, nil, nil, nil, nil)
	c := types.NewBlock(&types.Header{
		Number:     big.NewInt(2),
		ParentHash: b.Hash(),
	}, nil, nil, nil, nil)
	x := types.NewBlock(&types.Header{
		Number:     big.NewInt(2),
		ParentHash: common.Hash{0xff},
	}, nil, nil, nil, nil)

	err := m.AddL2Block(a)
	require.NoError(t, err)
	err = m.AddL2Block(b)
	require.NoError(t, err)
	err = m.AddL2Block(c)
	require.NoError(t, err)
	err = m.AddL2Block(x)
	require.ErrorIs(t, err, batcher.ErrReorg)
}

// TestChannelManagerReturnsErrReorgWhenDrained ensures that the channel manager
// detects a reorg even if it does not have any blocks inside it.
func TestChannelManagerReturnsErrReorgWhenDrained(t *testing.T) {
	log := testlog.Logger(t, log.LvlCrit)
	m := batcher.NewChannelManager(log, batcher.ChannelConfig{
		TargetFrameSize:  0,
		MaxFrameSize:     100,
		ApproxComprRatio: 1.0,
	})
	lBlock := types.NewBlock(&types.Header{
		BaseFee:    big.NewInt(10),
		Difficulty: common.Big0,
		Number:     big.NewInt(100),
	}, nil, nil, nil, trie.NewStackTrie(nil))
	l1InfoTx, err := derive.L1InfoDeposit(0, lBlock, eth.SystemConfig{}, false)
	require.NoError(t, err)
	txs := []*types.Transaction{types.NewTx(l1InfoTx)}

	a := types.NewBlock(&types.Header{
		Number: big.NewInt(0),
	}, txs, nil, nil, trie.NewStackTrie(nil))
	x := types.NewBlock(&types.Header{
		Number:     big.NewInt(1),
		ParentHash: common.Hash{0xff},
	}, txs, nil, nil, trie.NewStackTrie(nil))

	err = m.AddL2Block(a)
	require.NoError(t, err)

	_, err = m.TxData(eth.BlockID{})
	require.NoError(t, err)
	_, err = m.TxData(eth.BlockID{})
	require.ErrorIs(t, err, io.EOF)
	err = m.AddL2Block(x)
	require.ErrorIs(t, err, batcher.ErrReorg)
}
