//
// Copyright (c) SAS Institute Inc.
//
// 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 signappx

import (
	"bytes"
	"crypto/x509"
	"encoding/xml"
	"fmt"

	"github.com/beevik/etree"

	"github.com/sassoftware/relic/v8/lib/x509tools"
)

type appxPackage struct {
	XMLName xml.Name

	Identity appxIdentity

	DisplayName          string `xml:"Properties>DisplayName"`
	PublisherDisplayName string `xml:"Properties>PublisherDisplayName"`
	Logo                 string `xml:"Properties>Logo"`

	Etree *etree.Document `xml:"-"`
}

type appxIdentity struct {
	Name                  string `xml:",attr"`
	Publisher             string `xml:",attr"`
	Version               string `xml:",attr"`
	ProcessorArchitecture string `xml:",attr"`
}

func parseManifest(blob []byte) (*appxPackage, error) {
	manifest := new(appxPackage)
	if err := xml.Unmarshal(blob, manifest); err != nil {
		return nil, err
	}
	manifest.Etree = etree.NewDocument()
	if err := manifest.Etree.ReadFromBytes(blob); err != nil {
		return nil, err
	}
	return manifest, nil
}

func checkManifest(files zipFiles, sig *AppxSignature) error {
	blob, err := readZipFile(files[appxManifest])
	if err != nil {
		return fmt.Errorf("appx manifest: %w", err)
	}
	var manifest appxPackage
	if err := xml.Unmarshal(blob, &manifest); err != nil {
		return fmt.Errorf("appx manifest: %w", err)
	}
	sig.Name = manifest.Identity.Name
	sig.DisplayName = manifest.DisplayName
	sig.Version = manifest.Identity.Version
	publisher := x509tools.FormatPkixName(sig.Signature.Certificate.RawSubject, x509tools.NameStyleMsOsco)
	if manifest.Identity.Publisher != publisher {
		return fmt.Errorf("appx manifest: publisher identity mismatch:\nexpected: %s\nactual: %s", publisher, manifest.Identity.Publisher)
	}
	return nil
}

func (m *appxPackage) SetPublisher(cert *x509.Certificate) {
	subj := x509tools.FormatPkixName(cert.RawSubject, x509tools.NameStyleMsOsco)
	m.Identity.Publisher = subj
	el := m.Etree.FindElement("Package/Identity")
	if el != nil {
		el.CreateAttr("Publisher", subj)
	}
}

func (m *appxPackage) Marshal() ([]byte, error) {
	b, err := m.Etree.WriteToBytes()
	if err != nil {
		return nil, err
	}
	return bytes.ReplaceAll(b, []byte{'\n'}, []byte{'\r', '\n'}), nil
}