/*
Copyright DTCC 2016 All Rights Reserved.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

         http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

package java

import (
	"archive/tar"
	"bytes"
	"compress/gzip"
	"errors"
	"fmt"
	"net/url"
	"strings"

	cutil "github.com/hyperledger/fabric/core/container/util"
	pb "github.com/hyperledger/fabric/protos/peer"
	//	"path/filepath"
)

// Platform for java chaincodes in java
type Platform struct {
}

var buildCmds = map[string]string{
	"src/build.gradle": "gradle -b build.gradle clean && gradle -b build.gradle build",
	"src/pom.xml":      "mvn -f pom.xml clean && mvn -f pom.xml package",
}

//getBuildCmd returns the type of build gradle/maven based on the file
//found in java chaincode project root
//build.gradle - gradle  - returns the first found build type
//pom.xml - maven
func getBuildCmd(codePackage []byte) (string, error) {

	is := bytes.NewReader(codePackage)
	gr, err := gzip.NewReader(is)
	if err != nil {
		return "", fmt.Errorf("failure opening gzip stream: %s", err)
	}
	tr := tar.NewReader(gr)

	for {
		header, err := tr.Next()
		if err != nil {
			return "", errors.New("Build file not found")
		}

		if cmd, ok := buildCmds[header.Name]; ok == true {
			return cmd, nil
		}
	}
}

//ValidateSpec validates the java chaincode specs
func (javaPlatform *Platform) ValidateSpec(spec *pb.ChaincodeSpec) error {
	path, err := url.Parse(spec.ChaincodeId.Path)
	if err != nil || path == nil {
		return fmt.Errorf("invalid path: %s", err)
	}

	//we have no real good way of checking existence of remote urls except by downloading and testing
	//which we do later anyway. But we *can* - and *should* - test for existence of local paths.
	//Treat empty scheme as a local filesystem path
	//	if url.Scheme == "" {
	//		pathToCheck := filepath.Join(os.Getenv("GOPATH"), "src", spec.ChaincodeId.Path)
	//		exists, err := pathExists(pathToCheck)
	//		if err != nil {
	//			return fmt.Errorf("Error validating chaincode path: %s", err)
	//		}
	//		if !exists {
	//			return fmt.Errorf("Path to chaincode does not exist: %s", spec.ChaincodeId.Path)
	//		}
	//	}
	return nil
}

func (javaPlatform *Platform) ValidateDeploymentSpec(cds *pb.ChaincodeDeploymentSpec) error {
	// FIXME: Java platform needs to implement its own validation similar to GOLANG
	return nil
}

// WritePackage writes the java chaincode package
func (javaPlatform *Platform) GetDeploymentPayload(spec *pb.ChaincodeSpec) ([]byte, error) {

	var err error

	inputbuf := bytes.NewBuffer(nil)
	gw := gzip.NewWriter(inputbuf)
	tw := tar.NewWriter(gw)

	//ignore the generated hash. Just use the tw
	//The hash could be used in a future enhancement
	//to check, warn of duplicate installs etc.
	_, err = collectChaincodeFiles(spec, tw)
	if err != nil {
		return nil, err
	}

	err = writeChaincodePackage(spec, tw)

	tw.Close()
	gw.Close()

	if err != nil {
		return nil, err
	}

	payload := inputbuf.Bytes()

	return payload, nil
}

func (javaPlatform *Platform) GenerateDockerfile(cds *pb.ChaincodeDeploymentSpec) (string, error) {
	var err error
	var buf []string

	buildCmd, err := getBuildCmd(cds.CodePackage)
	if err != nil {
		return "", err
	}

	buf = append(buf, cutil.GetDockerfileFromConfig("chaincode.java.Dockerfile"))
	buf = append(buf, "ADD codepackage.tgz /root/chaincode")
	buf = append(buf, "RUN  cd /root/chaincode/src && "+buildCmd)
	buf = append(buf, "RUN  cp /root/chaincode/src/build/chaincode.jar /root")
	buf = append(buf, "RUN  cp /root/chaincode/src/build/libs/* /root/libs")

	dockerFileContents := strings.Join(buf, "\n")

	return dockerFileContents, nil
}

func (javaPlatform *Platform) GenerateDockerBuild(cds *pb.ChaincodeDeploymentSpec, tw *tar.Writer) error {
	return cutil.WriteBytesToPackage("codepackage.tgz", cds.CodePackage, tw)
}