// Copyright (c) 2021 Proton Technologies AG
//
// This file is part of ProtonMail Bridge.
//
// ProtonMail Bridge is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// ProtonMail Bridge 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 General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with ProtonMail Bridge.  If not, see <https://www.gnu.org/licenses/>.

package pmapi

import (
	"bytes"
	"context"
	"encoding/base64"
	"encoding/json"
	"fmt"
	"io"
	"io/ioutil"
	"mime/multipart"
	"net/http"
	"net/textproto"
	"strings"
	"testing"

	pmmime "github.com/ProtonMail/proton-bridge/pkg/mime"

	a "github.com/stretchr/testify/assert"
	r "github.com/stretchr/testify/require"
)

var testAttachment = &Attachment{
	ID:         "y6uKIlc2HdoHPAwPSrvf7dXoZNMYvBgxshYUN67cY5DJjL2O8NYewuvGHcYvCfd8LpEoAI_GdymO0Jr0mHlsEw==",
	Name:       "croutonmail.txt",
	Size:       77,
	MIMEType:   "text/plain",
	KeyPackets: "wcBMA0fcZ7XLgmf2AQgAiRsOlnm1kSB4/lr7tYe6pBsRGn10GqwUhrwU5PMKOHdCgnO12jO3y3CzP0Yl/jGhAYja9wLDqH8X0sk3tY32u4Sb1Qe5IuzggAiCa4dwOJj5gEFMTHMzjIMPHR7A70XqUxMhmILye8V4KRm/j4c1sxbzA1rM3lYBumQuB5l/ck0Kgt4ZqxHVXHK5Q1l65FHhSXRj8qnunasHa30TYNzP8nmBA8BinnJxpiQ7FGc2umnUhgkFtjm5ixu9vyjr9ukwDTbwAXXfmY+o7tK7kqIXJcmTL6k2UeC6Mz1AagQtRCRtU+bv/3zGojq/trZo9lom3naIeQYa36Ketmcpj2Qwjg==",
	Header: textproto.MIMEHeader{
		"Content-Description": {"You'll never believe what's in this text file"},
		"X-Mailer":            {"Microsoft Outlook 15.0", "Microsoft Live Mail 42.0"},
	},
	MessageID: "h3CD-DT7rLoAw1vmpcajvIPAl-wwDfXR2MHtWID3wuQURDBKTiGUAwd6E2WBbS44QQKeXImW-axm6X0hAfcVCA==",
}

const testAttachmentJSON = `{
    "ID": "y6uKIlc2HdoHPAwPSrvf7dXoZNMYvBgxshYUN67cY5DJjL2O8NYewuvGHcYvCfd8LpEoAI_GdymO0Jr0mHlsEw==",
    "Name": "croutonmail.txt",
    "Size": 77,
    "MIMEType": "text/plain",
    "KeyPackets": "wcBMA0fcZ7XLgmf2AQgAiRsOlnm1kSB4/lr7tYe6pBsRGn10GqwUhrwU5PMKOHdCgnO12jO3y3CzP0Yl/jGhAYja9wLDqH8X0sk3tY32u4Sb1Qe5IuzggAiCa4dwOJj5gEFMTHMzjIMPHR7A70XqUxMhmILye8V4KRm/j4c1sxbzA1rM3lYBumQuB5l/ck0Kgt4ZqxHVXHK5Q1l65FHhSXRj8qnunasHa30TYNzP8nmBA8BinnJxpiQ7FGc2umnUhgkFtjm5ixu9vyjr9ukwDTbwAXXfmY+o7tK7kqIXJcmTL6k2UeC6Mz1AagQtRCRtU+bv/3zGojq/trZo9lom3naIeQYa36Ketmcpj2Qwjg==",
    "Headers": {
        "content-description": "You'll never believe what's in this text file",
        "x-mailer": [
            "Microsoft Outlook 15.0",
            "Microsoft Live Mail 42.0"
        ]
    }
}
`

const testAttachmentCleartext = `cc,
dille.
`

const testAttachmentEncrypted = `wcBMA0fcZ7XLgmf2AQf/cHhfDRM9zlIuBi+h2W6DKjbbyIHMkgF6ER3JEvn/tSruUH8KTGt0N7Z+a80FFMCuXn1Y1I/nW7MVrNhGuJZAF4OymD8ugvuoAMIQX0eCYEpPXzRIWJBZg82AuowmFMsv8Dgvq4bTZq4cttI3CZcxKUNXuAearmNpmgplUKWj5USmRXK4iGB3VFGjidXkxbElrP4fD5A/rfEZ5aJgCsegqcXxX3MEjWXi9pFzgd/9phOvl1ZFm9U9hNoVAW3QsgmVeihnKaDZUyf2Qsigij21QKAUxw9U3y89eTUIqZAcmIgqeDujA3RWBgJwjtY/lOyhEmkf3AWKzehvf1xtJmCWDtJLAekuH+JfAtTQfMs5nf4zYtMahGbMkwy3Uz/jeEMYdzWY5WvshkbwvaxpqFC+11cqMLBvxik39i1xf+RORZF/91jGMCL9Z9dRMcgB`

const testCreateAttachmentBody = `{
    "Code": 1000,
    "Attachment": {"ID": "y6uKIlc2HdoHPAwPSrvf7dXoZNMYvBgxshYUN67cY5DJjL2O8NYewuvGHcYvCfd8LpEoAI_GdymO0Jr0mHlsEw=="}
}`

func TestAttachment_UnmarshalJSON(t *testing.T) {
	att := new(Attachment)
	err := json.Unmarshal([]byte(testAttachmentJSON), att)
	r.NoError(t, err)

	att.MessageID = testAttachment.MessageID // This isn't in the JSON object

	r.Equal(t, testAttachment, att)
}

func TestClient_CreateAttachment(t *testing.T) {
	s, c := newTestClient(http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
		r.NoError(t, checkMethodAndPath(req, "POST", "/mail/v4/attachments"))

		contentType, params, err := pmmime.ParseMediaType(req.Header.Get("Content-Type"))
		r.NoError(t, err)
		r.Equal(t, "multipart/form-data", contentType)

		mr := multipart.NewReader(req.Body, params["boundary"])
		form, err := mr.ReadForm(10 * 1024)
		r.NoError(t, err)
		defer r.NoError(t, form.RemoveAll())

		r.Equal(t, testAttachment.Name, form.Value["Filename"][0])
		r.Equal(t, testAttachment.MessageID, form.Value["MessageID"][0])
		r.Equal(t, testAttachment.MIMEType, form.Value["MIMEType"][0])

		dataFile, err := form.File["DataPacket"][0].Open()
		r.NoError(t, err)
		defer r.NoError(t, dataFile.Close())

		b, err := ioutil.ReadAll(dataFile)
		r.NoError(t, err)
		r.Equal(t, testAttachmentCleartext, string(b))

		w.Header().Set("Content-Type", "application/json")

		fmt.Fprint(w, testCreateAttachmentBody)
	}))
	defer s.Close()

	reader := strings.NewReader(testAttachmentCleartext) // In reality, this thing is encrypted
	created, err := c.CreateAttachment(context.Background(), testAttachment, reader, strings.NewReader(""))
	r.NoError(t, err)

	r.Equal(t, testAttachment.ID, created.ID)
}

func TestClient_GetAttachment(t *testing.T) {
	s, c := newTestClient(http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
		r.NoError(t, checkMethodAndPath(req, "GET", "/mail/v4/attachments/"+testAttachment.ID))

		w.Header().Set("Content-Type", "application/json")
		fmt.Fprint(w, testAttachmentCleartext)
	}))
	defer s.Close()

	att, err := c.GetAttachment(context.Background(), testAttachment.ID)
	r.NoError(t, err)
	defer att.Close() //nolint[errcheck]

	// In reality, r contains encrypted data
	b, err := ioutil.ReadAll(att)
	r.NoError(t, err)

	r.Equal(t, testAttachmentCleartext, string(b))
}

func TestAttachment_Encrypt(t *testing.T) {
	data := bytes.NewBufferString(testAttachmentCleartext)
	r, err := testAttachment.Encrypt(testPublicKeyRing, data)
	a.Nil(t, err)
	b, err := ioutil.ReadAll(r)
	a.Nil(t, err)

	// Result is always different, so the best way is to test it by decrypting again.
	// Another test for decrypting will help us to be sure it's working.
	dataEnc := bytes.NewBuffer(b)
	decryptAndCheck(t, dataEnc)
}

func TestAttachment_Decrypt(t *testing.T) {
	dataBytes, _ := base64.StdEncoding.DecodeString(testAttachmentEncrypted)
	dataReader := bytes.NewBuffer(dataBytes)
	decryptAndCheck(t, dataReader)
}

func decryptAndCheck(t *testing.T, data io.Reader) {
	r, err := testAttachment.Decrypt(data, testPrivateKeyRing)
	a.Nil(t, err)
	b, err := ioutil.ReadAll(r)
	a.Nil(t, err)
	a.Equal(t, testAttachmentCleartext, string(b))
}