// VulcanizeDB
// Copyright © 2018 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 utils

import (
	"io"
	"math/big"
	"os"
	"path/filepath"
	"strings"
	"syscall"

	"github.com/mitchellh/go-homedir"
	log "github.com/sirupsen/logrus"

	"github.com/vulcanize/vulcanizedb/pkg/config"
	"github.com/vulcanize/vulcanizedb/pkg/core"
	"github.com/vulcanize/vulcanizedb/pkg/datastore/postgres"
	"github.com/vulcanize/vulcanizedb/pkg/geth"
)

func LoadPostgres(database config.Database, node core.Node) postgres.DB {
	db, err := postgres.NewDB(database, node)
	if err != nil {
		log.Fatalf("Error loading postgres\n%v", err)
	}
	return *db
}

func ReadAbiFile(abiFilepath string) string {
	abiFilepath = AbsFilePath(abiFilepath)
	abi, err := geth.ReadAbiFile(abiFilepath)
	if err != nil {
		log.Fatalf("Error reading ABI file at \"%s\"\n %v", abiFilepath, err)
	}
	return abi
}

func AbsFilePath(filePath string) string {
	if !filepath.IsAbs(filePath) {
		cwd, _ := os.Getwd()
		filePath = filepath.Join(cwd, filePath)
	}
	return filePath
}

func GetAbi(abiFilepath string, contractHash string, network string) string {
	var contractAbiString string
	if abiFilepath != "" {
		contractAbiString = ReadAbiFile(abiFilepath)
	} else {
		url := geth.GenURL(network)
		etherscan := geth.NewEtherScanClient(url)
		log.Printf("No ABI supplied. Retrieving ABI from Etherscan: %s", url)
		contractAbiString, _ = etherscan.GetAbi(contractHash)
	}
	_, err := geth.ParseAbi(contractAbiString)
	if err != nil {
		log.Fatalln("Invalid ABI")
	}
	return contractAbiString
}

func RequestedBlockNumber(blockNumber *int64) *big.Int {
	var _blockNumber *big.Int
	if *blockNumber == -1 {
		_blockNumber = nil
	} else {
		_blockNumber = big.NewInt(*blockNumber)
	}
	return _blockNumber
}

func CleanPath(str string) (string, error) {
	path, err := homedir.Expand(filepath.Clean(str))
	if err != nil {
		return "", err
	}
	if strings.Contains(path, "$GOPATH") {
		env := os.Getenv("GOPATH")
		spl := strings.Split(path, "$GOPATH")[1]
		path = filepath.Join(env, spl)
	}

	return path, nil
}

func ClearFiles(files ...string) error {
	for _, file := range files {
		if _, err := os.Stat(file); err == nil {
			err = os.Remove(file)
			if err != nil {
				return err
			}
		} else if os.IsNotExist(err) {
			// fall through
		} else {
			return err
		}
	}

	return nil
}

func CopyFile(src, dst string) error {
	in, err := os.Open(src)
	if err != nil {
		return err
	}
	defer in.Close()
	out, err := os.OpenFile(dst, syscall.O_CREAT|syscall.O_EXCL|os.O_WRONLY, os.FileMode(0666)) // Doesn't overwrite files
	if err != nil {
		return err
	}
	defer out.Close()

	_, err = io.Copy(out, in)
	if err != nil {
		return err
	}
	return out.Close()
}