// VulcanizeDB
// Copyright © 2019 Vulcanize

// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Affero General Public License for more details.

// You should have received a copy of the GNU Affero General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

package pgipfsethdb_test

import (
	"math/big"
	"time"

	"github.com/cerc-io/ipfs-ethdb/v4/postgres/shared"

	"github.com/ethereum/go-ethereum/core/types"
	"github.com/ethereum/go-ethereum/ethdb"
	"github.com/ethereum/go-ethereum/rlp"
	"github.com/jmoiron/sqlx"
	"github.com/mailgun/groupcache/v2"
	. "github.com/onsi/ginkgo"
	. "github.com/onsi/gomega"

	pgipfsethdb "github.com/cerc-io/ipfs-ethdb/v4/postgres/v1"
)

var (
	database        ethdb.Database
	db              *sqlx.DB
	err             error
	testBlockNumber = big.NewInt(1337)
	testHeader      = types.Header{Number: testBlockNumber}
	testValue, _    = rlp.EncodeToBytes(testHeader)
	testEthKey      = testHeader.Hash().Bytes()
	testMhKey, _    = pgipfsethdb.MultihashKeyFromKeccak256(testEthKey)
)

var _ = Describe("Database", func() {
	BeforeEach(func() {
		db, err = shared.TestDB()
		Expect(err).ToNot(HaveOccurred())

		cacheConfig := pgipfsethdb.CacheConfig{
			Name:           "db",
			Size:           3000000, // 3MB
			ExpiryDuration: time.Hour,
		}

		database = pgipfsethdb.NewDatabase(db, cacheConfig)

		databaseWithBlock, ok := database.(*pgipfsethdb.Database)
		Expect(ok).To(BeTrue())
		(*databaseWithBlock).BlockNumber = testBlockNumber
	})
	AfterEach(func() {
		groupcache.DeregisterGroup("db")
		err = shared.ResetTestDB(db)
		Expect(err).ToNot(HaveOccurred())
	})

	Describe("Has", func() {
		It("returns false if a key-pair doesn't exist in the db", func() {
			has, err := database.Has(testEthKey)
			Expect(err).ToNot(HaveOccurred())
			Expect(has).ToNot(BeTrue())
		})
		It("returns true if a key-pair exists in the db", func() {
			_, err = db.Exec("INSERT into public.blocks (key, data, block_number) VALUES ($1, $2, $3)", testMhKey, testValue, testBlockNumber.Uint64())
			Expect(err).ToNot(HaveOccurred())
			has, err := database.Has(testEthKey)
			Expect(err).ToNot(HaveOccurred())
			Expect(has).To(BeTrue())
		})
	})

	Describe("Get", func() {
		It("throws an err if the key-pair doesn't exist in the db", func() {
			_, err = database.Get(testEthKey)
			Expect(err).To(HaveOccurred())
			Expect(err.Error()).To(ContainSubstring("sql: no rows in result set"))
		})
		It("returns the value associated with the key, if the pair exists", func() {
			_, err = db.Exec("INSERT into public.blocks (key, data, block_number) VALUES ($1, $2, $3)", testMhKey, testValue, testBlockNumber.Uint64())
			Expect(err).ToNot(HaveOccurred())
			val, err := database.Get(testEthKey)
			Expect(err).ToNot(HaveOccurred())
			Expect(val).To(Equal(testValue))
		})
	})

	Describe("Put", func() {
		It("persists the key-value pair in the database", func() {
			_, err = database.Get(testEthKey)
			Expect(err).To(HaveOccurred())
			Expect(err.Error()).To(ContainSubstring("sql: no rows in result set"))

			err = database.Put(testEthKey, testValue)
			Expect(err).ToNot(HaveOccurred())
			val, err := database.Get(testEthKey)
			Expect(err).ToNot(HaveOccurred())
			Expect(val).To(Equal(testValue))
		})
	})

	Describe("Delete", func() {
		It("removes the key-value pair from the database", func() {
			err = database.Put(testEthKey, testValue)
			Expect(err).ToNot(HaveOccurred())
			val, err := database.Get(testEthKey)
			Expect(err).ToNot(HaveOccurred())
			Expect(val).To(Equal(testValue))

			err = database.Delete(testEthKey)
			Expect(err).ToNot(HaveOccurred())
			_, err = database.Get(testEthKey)
			Expect(err).To(HaveOccurred())
			Expect(err.Error()).To(ContainSubstring("sql: no rows in result set"))
		})
	})
})