package mempool

import (
	"crypto/rand"
	"encoding/binary"
	"testing"
	"time"

	"github.com/tendermint/abci/example/counter"
	"github.com/tendermint/abci/example/dummy"
	"github.com/tendermint/tmlibs/log"

	cfg "github.com/tendermint/tendermint/config"
	"github.com/tendermint/tendermint/proxy"
	"github.com/tendermint/tendermint/types"
)

func newMempoolWithApp(t *testing.T, cc proxy.ClientCreator) *Mempool {
	config := cfg.ResetTestRoot("mempool_test")

	appConnMem, _ := cc.NewABCIClient()
	appConnMem.SetLogger(log.TestingLogger().With("module", "abci-client", "connection", "mempool"))
	if _, err := appConnMem.Start(); err != nil {
		t.Fatalf("Error starting ABCI client: %v", err.Error())
	}
	mempool := NewMempool(config.Mempool, appConnMem, 0)
	mempool.SetLogger(log.TestingLogger())
	return mempool
}

func ensureNoFire(t *testing.T, ch <-chan int, timeoutMS int) {
	timer := time.NewTimer(time.Duration(timeoutMS) * time.Millisecond)
	select {
	case <-ch:
		t.Fatal("Expected not to fire")
	case <-timer.C:
	}
}

func ensureFire(t *testing.T, ch <-chan int, timeoutMS int) {
	timer := time.NewTimer(time.Duration(timeoutMS) * time.Millisecond)
	select {
	case <-ch:
	case <-timer.C:
		t.Fatal("Expected to fire")
	}
}

func sendTxs(t *testing.T, mempool *Mempool, count int) types.Txs {
	txs := make(types.Txs, count)
	for i := 0; i < count; i++ {
		txBytes := make([]byte, 20)
		txs[i] = txBytes
		rand.Read(txBytes)
		err := mempool.CheckTx(txBytes, nil)
		if err != nil {
			t.Fatal("Error after CheckTx: %v", err)
		}
	}
	return txs
}

func TestTxsAvailable(t *testing.T) {
	app := dummy.NewDummyApplication()
	cc := proxy.NewLocalClientCreator(app)
	mempool := newMempoolWithApp(t, cc)
	mempool.EnableTxsAvailable()

	timeoutMS := 500

	// with no txs, it shouldnt fire
	ensureNoFire(t, mempool.TxsAvailable(), timeoutMS)

	// send a bunch of txs, it should only fire once
	txs := sendTxs(t, mempool, 100)
	ensureFire(t, mempool.TxsAvailable(), timeoutMS)
	ensureNoFire(t, mempool.TxsAvailable(), timeoutMS)

	// call update with half the txs.
	// it should fire once now for the new height
	// since there are still txs left
	committedTxs, txs := txs[:50], txs[50:]
	mempool.Update(1, committedTxs)
	ensureFire(t, mempool.TxsAvailable(), timeoutMS)
	ensureNoFire(t, mempool.TxsAvailable(), timeoutMS)

	// send a bunch more txs. we already fired for this height so it shouldnt fire again
	moreTxs := sendTxs(t, mempool, 50)
	ensureNoFire(t, mempool.TxsAvailable(), timeoutMS)

	// now call update with all the txs. it should not fire as there are no txs left
	committedTxs = append(txs, moreTxs...)
	mempool.Update(2, committedTxs)
	ensureNoFire(t, mempool.TxsAvailable(), timeoutMS)

	// send a bunch more txs, it should only fire once
	sendTxs(t, mempool, 100)
	ensureFire(t, mempool.TxsAvailable(), timeoutMS)
	ensureNoFire(t, mempool.TxsAvailable(), timeoutMS)
}

func TestSerialReap(t *testing.T) {
	app := counter.NewCounterApplication(true)
	app.SetOption("serial", "on")
	cc := proxy.NewLocalClientCreator(app)

	mempool := newMempoolWithApp(t, cc)
	appConnCon, _ := cc.NewABCIClient()
	appConnCon.SetLogger(log.TestingLogger().With("module", "abci-client", "connection", "consensus"))
	if _, err := appConnCon.Start(); err != nil {
		t.Fatalf("Error starting ABCI client: %v", err.Error())
	}

	deliverTxsRange := func(start, end int) {
		// Deliver some txs.
		for i := start; i < end; i++ {

			// This will succeed
			txBytes := make([]byte, 8)
			binary.BigEndian.PutUint64(txBytes, uint64(i))
			err := mempool.CheckTx(txBytes, nil)
			if err != nil {
				t.Fatal("Error after CheckTx: %v", err)
			}

			// This will fail because not serial (incrementing)
			// However, error should still be nil.
			// It just won't show up on Reap().
			err = mempool.CheckTx(txBytes, nil)
			if err != nil {
				t.Fatal("Error after CheckTx: %v", err)
			}

		}
	}

	reapCheck := func(exp int) {
		txs := mempool.Reap(-1)
		if len(txs) != exp {
			t.Fatalf("Expected to reap %v txs but got %v", exp, len(txs))
		}
	}

	updateRange := func(start, end int) {
		txs := make([]types.Tx, 0)
		for i := start; i < end; i++ {
			txBytes := make([]byte, 8)
			binary.BigEndian.PutUint64(txBytes, uint64(i))
			txs = append(txs, txBytes)
		}
		mempool.Update(0, txs)
	}

	commitRange := func(start, end int) {
		// Deliver some txs.
		for i := start; i < end; i++ {
			txBytes := make([]byte, 8)
			binary.BigEndian.PutUint64(txBytes, uint64(i))
			res := appConnCon.DeliverTxSync(txBytes)
			if !res.IsOK() {
				t.Errorf("Error committing tx. Code:%v result:%X log:%v",
					res.Code, res.Data, res.Log)
			}
		}
		res := appConnCon.CommitSync()
		if len(res.Data) != 8 {
			t.Errorf("Error committing. Hash:%X log:%v", res.Data, res.Log)
		}
	}

	//----------------------------------------

	// Deliver some txs.
	deliverTxsRange(0, 100)

	// Reap the txs.
	reapCheck(100)

	// Reap again.  We should get the same amount
	reapCheck(100)

	// Deliver 0 to 999, we should reap 900 new txs
	// because 100 were already counted.
	deliverTxsRange(0, 1000)

	// Reap the txs.
	reapCheck(1000)

	// Reap again.  We should get the same amount
	reapCheck(1000)

	// Commit from the conensus AppConn
	commitRange(0, 500)
	updateRange(0, 500)

	// We should have 500 left.
	reapCheck(500)

	// Deliver 100 invalid txs and 100 valid txs
	deliverTxsRange(900, 1100)

	// We should have 600 now.
	reapCheck(600)
}