package api

import (
	"bufio"
	"crypto/rand"
	"encoding/base64"
	"encoding/json"
	"fmt"
	"git.openprivacy.ca/openprivacy/log"
	"github.com/therecipe/qt/core"
	"github.com/therecipe/qt/qml"
	"golang.org/x/crypto/curve25519"
	"golang.org/x/crypto/nacl/box"
	"io/ioutil"
	"os"
	path "path/filepath"
	"sort"
	"strings"
)

type LockBoxAPI struct {
	core.QObject

	QMLEngine  *qml.QQmlApplicationEngine
	Translator *core.QTranslator

	_ func(bool, string) `signal:"Decrypted"`
	_ func(bool, string) `signal:"Saved"`

	_ func(inputFilename string, outputFilename string, keyfile string) `signal:"decryptFile,auto"`
	_ func(keyFilename string)                                          `signal:"generateKey,auto"`
}

func (lapi *LockBoxAPI) decryptFile(inputFilename string, outputFilename string, keyfile string) {
	log.Infof("Decrypting File...%v to %v", inputFilename, outputFilename)
	privateKey := [32]byte{}
	publicKey := [32]byte{}
	keyencoded, err := ioutil.ReadFile(cleanPath(keyfile))
	if err == nil {
		key, err := base64.StdEncoding.DecodeString(string(keyencoded))
		if err == nil {
			copy(privateKey[:], key[:])
			curve25519.ScalarBaseMult(&publicKey, &privateKey)
		}
	}

	file, err := os.Open(cleanPath(inputFilename))
	outputfile := []string{}
	count := 1
	if err == nil {
		defer file.Close()

		scanner := bufio.NewScanner(file)
		schemeDefined := false
		schema := []string{}
		for scanner.Scan() {
			line := scanner.Text()
			lines := strings.Split(line, "|")
			if len(lines) == 2 {
				data, err := base64.StdEncoding.DecodeString(lines[1])
				if err == nil {
					message, ok := box.OpenAnonymous([]byte{}, data, &publicKey, &privateKey)
					if ok {
						log.Infof("Message: %v, %v\n", string(message), ok)
						data := make(map[string]string)
						err := json.Unmarshal(message, &data)
						if err == nil {
							outputLine := "num,"
							if schemeDefined == false {
								for k := range data {
									schema = append(schema, k)
								}

								sort.Strings(schema)

								for _, k := range schema {
									parts := strings.SplitN(k, "_", 2)
									var str string
									if len(parts) > 1 {
										str = parts[1]
									} else {
										str = k
									}
									outputLine += fmt.Sprintf(`"%v",`, strings.ReplaceAll(str, "\"", "\\\""))
								}

								outputfile = append(outputfile, outputLine)
								schemeDefined = true
							}
							outputLine = fmt.Sprintf("%d,", count)
							for _, k := range schema {
								outputLine += fmt.Sprintf(`"%v",`, strings.ReplaceAll(data[k], "\"", "\\\""))
							}
							outputfile = append(outputfile, outputLine)
							count++
						}
					} else {
						lapi.Decrypted(false, "Error Decrypting File: You might be using the wrong decryption key with this file")
						return
					}
				}
			}
		}

		if err := scanner.Err(); err != nil {
		}
		err := ioutil.WriteFile(cleanPath(outputFilename), []byte(strings.Join(outputfile, "\n")), 0644)
		if err == nil {
			lapi.Decrypted(true, "File Decrypted Successfully!")
			return
		}
	}

	lapi.Decrypted(false, err.Error())
}

func (lapi *LockBoxAPI) generateKey(keyPath string) {
	log.Infof("Saving Key to Path to %v", keyPath)

	_,err := os.Stat(cleanPath(path.Join(cleanPath(keyPath), "key.private")))
	if err == nil {
		lapi.Saved(false, "Cannot generate keys without deleting keys that already exist. Please choose a different directory or remove the existing keys.")
		return
	}
	if os.IsNotExist(err) {
		public, private, err := box.GenerateKey(rand.Reader)
		if err == nil {
			publicStr := base64.StdEncoding.EncodeToString(public[:])
			privateStr := base64.StdEncoding.EncodeToString(private[:])
			err = ioutil.WriteFile(cleanPath(path.Join(cleanPath(keyPath), "key.public")), []byte(publicStr), 0644)
			if err == nil {
				err = ioutil.WriteFile(cleanPath(path.Join(cleanPath(keyPath), "key.private")), []byte(privateStr), 0644)
				if err == nil {
					lapi.Saved(true, "Key File Saved")
					return
				} else {
					lapi.Saved(false, err.Error())
					return
				}
			} else {
				lapi.Saved(false, err.Error())
				return
			}
		}
	}
	lapi.Saved(false, err.Error())
}

func cleanPath(uncleanPath string) string {
	cleanPath := path.Join(strings.Replace(uncleanPath, "file://", "", 1))

	if len(cleanPath) > 1 && cleanPath[0] == '\\' {
		return cleanPath[1:]
	}
	return cleanPath
}