package cmd

import (
	"bytes"
	"encoding/base64"
	"encoding/json"
	"fmt"
	"io"
	"io/ioutil"
	"os"
	"path"
	"path/filepath"

	"github.com/cozy/cozy-stack/client/request"
	"github.com/cozy/cozy-stack/model/account"
	"github.com/cozy/cozy-stack/pkg/config/config"
	"github.com/cozy/cozy-stack/pkg/crypto"
	"github.com/cozy/cozy-stack/pkg/keymgmt"
	"github.com/cozy/cozy-stack/pkg/utils"
	"github.com/howeyc/gopass"
	"github.com/spf13/cobra"
)

var configCmdGroup = &cobra.Command{
	Use:   "config <command>",
	Short: "Show and manage configuration elements",
	Long:  `cozy-stack config allows to print and generate some parts of the configuration`,
}

var adminPasswdCmd = &cobra.Command{
	Use:     "passwd <filepath>",
	Aliases: []string{"password", "passphrase", "pass"},
	Short:   "Generate an admin passphrase",
	Long: `
cozy-stack instances passphrase generate a passphrase hash and save it to the specified file. If no file is specified, it is directly printed in standard output. This passphrase is the one used to authenticate accesses to the administration API.

The environment variable 'COZY_ADMIN_PASSPHRASE' can be used to pass the passphrase if needed.
`,
	Example: "$ cozy-stack config passwd ~/.cozy/cozy-admin-passphrase",
	RunE: func(cmd *cobra.Command, args []string) error {
		if len(args) > 1 {
			return cmd.Usage()
		}
		var filename string
		if len(args) == 1 {
			filename = filepath.Join(utils.AbsPath(args[0]))
			ok, err := utils.DirExists(filename)
			if err == nil && ok {
				filename = path.Join(filename, config.GetConfig().AdminSecretFileName)
			}
		}

		if filename != "" {
			errPrintfln("Hashed passphrase will be written in %s", filename)
		}

		passphrase := []byte(os.Getenv("COZY_ADMIN_PASSPHRASE"))
		if len(passphrase) == 0 {
			errPrintf("Passphrase: ")
			pass1, err := gopass.GetPasswdPrompt("", false, os.Stdin, os.Stderr)
			if err != nil {
				return err
			}

			errPrintf("Confirmation: ")
			pass2, err := gopass.GetPasswdPrompt("", false, os.Stdin, os.Stderr)
			if err != nil {
				return err
			}
			if !bytes.Equal(pass1, pass2) {
				return fmt.Errorf("Passphrase missmatch")
			}

			passphrase = pass1
		}

		b, err := crypto.GenerateFromPassphrase(passphrase)
		if err != nil {
			return err
		}

		var out io.Writer
		if filename != "" {
			var f *os.File
			f, err = os.OpenFile(filename, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0440)
			if err != nil {
				return err
			}
			defer f.Close()

			if err = os.Chmod(filename, 0440); err != nil {
				return err
			}

			out = f
		} else {
			out = os.Stdout
		}

		_, err = fmt.Fprintln(out, string(b))
		return err
	},
}

var genKeysCmd = &cobra.Command{
	Use:   "gen-keys <filepath>",
	Short: "Generate an key pair for encryption and decryption of credentials",
	Long: `
cozy-stack config gen-keys generate a key-pair and save them in the specified path.

The decryptor key filename is given the ".dec" extension suffix.
The encryptor key filename is given the ".enc" extension suffix.

The files permissions are 0400.`,

	Example: `$ cozy-stack config gen-keys ~/credentials-key
keyfiles written in:
	~/credentials-key.enc
	~/credentials-key.dec
`,
	RunE: func(cmd *cobra.Command, args []string) error {
		if len(args) != 1 {
			return cmd.Usage()
		}

		filename := filepath.Join(utils.AbsPath(args[0]))
		encryptorFilename := filename + ".enc"
		decryptorFilename := filename + ".dec"

		marshaledEncryptorKey, marshaledDecryptorKey, err := keymgmt.GenerateEncodedNACLKeyPair()
		if err != nil {
			return nil
		}

		if err = writeFile(encryptorFilename, marshaledEncryptorKey, 0400); err != nil {
			return err
		}
		if err = writeFile(decryptorFilename, marshaledDecryptorKey, 0400); err != nil {
			return err
		}
		errPrintfln("keyfiles written in:\n  %s\n  %s", encryptorFilename, decryptorFilename)
		return nil
	},
}

var encryptCredentialsDataCmd = &cobra.Command{
	Use:   "encrypt-data <encoding keyfile> <text>",
	Short: "Encrypt data with the specified encryption keyfile.",
	Long:  `cozy-stack config encrypt-data encrypts any valid JSON data`,
	Example: `
$ ./cozy-stack config encrypt-data ~/.cozy/key.enc "{\"foo\": \"bar\"}"
$ bmFjbNFjY+XZkS26YtVPUIKKm/JdnAGwG30n6A4ypS1p1dHev8hOtaRbW+lGneoO7PS9JCW8U5GSXhASu+c3UkaZ
`,
	RunE: func(cmd *cobra.Command, args []string) error {
		if len(args) != 2 {
			return cmd.Usage()
		}

		// Check if we have good-formatted JSON
		var result map[string]interface{}
		err := json.Unmarshal([]byte(args[1]), &result)
		if err != nil {
			return err
		}

		encKeyStruct, err := readKeyFromFile(args[0])
		if err != nil {
			return err
		}
		dataEncrypted, err := account.EncryptBufferWithKey(encKeyStruct, []byte(args[1]))
		if err != nil {
			return err
		}
		data := base64.StdEncoding.EncodeToString(dataEncrypted)
		fmt.Printf("%s\n", data)

		return nil
	},
}

var decryptCredentialsDataCmd = &cobra.Command{
	Use:   "decrypt-data <decoding keyfile> <ciphertext>",
	Short: "Decrypt data with the specified decryption keyfile.",
	RunE: func(cmd *cobra.Command, args []string) error {
		if len(args) != 2 {
			return cmd.Usage()
		}

		decKeyStruct, err := readKeyFromFile(args[0])
		if err != nil {
			return err
		}

		dataEncrypted, err := base64.StdEncoding.DecodeString(args[1])
		if err != nil {
			return err
		}
		decrypted, err := account.DecryptBufferWithKey(decKeyStruct, dataEncrypted)
		if err != nil {
			return err
		}

		fmt.Printf("%s\n", decrypted)

		return nil
	},
}

var encryptCredentialsCmd = &cobra.Command{
	Use:     "encrypt-creds <keyfile> <login> <password>",
	Aliases: []string{"encrypt-credentials"},
	Short:   "Encrypt the given credentials with the specified decryption keyfile.",
	RunE: func(cmd *cobra.Command, args []string) error {
		if len(args) != 3 {
			return cmd.Usage()
		}

		credsEncryptor, err := readKeyFromFile(args[0])
		if err != nil {
			return err
		}

		encryptedCreds, err := account.EncryptCredentialsWithKey(credsEncryptor, args[1], args[2])
		if err != nil {
			return err
		}
		fmt.Printf("Encrypted credentials: %s\n", encryptedCreds)
		return nil
	},
}

var decryptCredentialsCmd = &cobra.Command{
	Use:     "decrypt-creds <keyfile> <ciphertext>",
	Aliases: []string{"decrypt-credentials"},
	Short:   "Decrypt the given credentials cipher text with the specified decryption keyfile.",
	RunE: func(cmd *cobra.Command, args []string) error {
		if len(args) != 2 {
			return cmd.Usage()
		}

		credsDecryptor, err := readKeyFromFile(args[0])
		if err != nil {
			return err
		}

		credentialsEncrypted, err := base64.StdEncoding.DecodeString(args[1])
		if err != nil {
			return fmt.Errorf("Cipher text is not properly base64 encoded: %s", err)
		}

		login, password, err := account.DecryptCredentialsWithKey(credsDecryptor, credentialsEncrypted)
		if err != nil {
			return fmt.Errorf("Could not decrypt cipher text: %s", err)
		}

		fmt.Printf(`Decrypted credentials:
login:    %q
password: %q
`, login, password)
		return nil
	},
}

func writeFile(filename string, data []byte, perm os.FileMode) error {
	f, err := os.OpenFile(filename, os.O_WRONLY|os.O_CREATE|os.O_EXCL, perm)
	if err != nil {
		return err
	}
	n, err := f.Write(data)
	if err == nil && n < len(data) {
		err = io.ErrShortWrite
	}
	if err1 := f.Close(); err == nil {
		err = err1
	}
	return err
}

func readKeyFromFile(filepath string) (*keymgmt.NACLKey, error) {
	keyBytes, err := ioutil.ReadFile(filepath)
	if err != nil {
		return nil, err
	}

	return keymgmt.UnmarshalNACLKey(keyBytes)
}

var insertAssetCmd = &cobra.Command{
	Use:   "insert-asset --url <url> --name <name> --shasum <shasum> --context <context>",
	Short: "Inserts an asset",
	Long: `Inserts a custom asset in a specific context

Deprecated: please use the command cozy-stack assets add.
`,
	RunE: func(cmd *cobra.Command, args []string) error {
		errPrintfln("Please use cozy-stack assets add, this command has been deprecated")
		return addAsset(cmd, args)
	},
}

var removeAssetCmd = &cobra.Command{
	Use:   "rm-asset [context] [name]",
	Short: "Removes an asset",
	Long: `Removes a custom asset in a specific context

Deprecated: please use the command cozy-stack assets rm.
`,
	RunE: func(cmd *cobra.Command, args []string) error {
		errPrintfln("Please use cozy-stack assets rm, this command has been deprecated")
		return rmAsset(cmd, args)
	},
}

var listAssetCmd = &cobra.Command{
	Use:   "ls-assets",
	Short: "List assets",
	Long: `List assets currently served by the stack

Deprecated: please use the command cozy-stack assets ls.
`,
	RunE: func(cmd *cobra.Command, args []string) error {
		errPrintfln("Please use cozy-stack assets ls, this command has been deprecated")
		return lsAssets(cmd, args)
	},
}

var showContextCmd = &cobra.Command{
	Use:     "show-context",
	Short:   "Show a context",
	Example: "$ cozy-stack config show-context cozy_demo",
	RunE: func(cmd *cobra.Command, args []string) error {
		if len(args) < 1 {
			return cmd.Usage()
		}
		c := newAdminClient()
		req := &request.Options{
			Method: "GET",
			Path:   "instances/contexts/" + args[0],
		}
		res, err := c.Req(req)
		if err != nil {
			return err
		}
		defer res.Body.Close()

		var v interface{}

		err = json.NewDecoder(res.Body).Decode(&v)
		if err != nil {
			return err
		}

		json, err := json.MarshalIndent(v, "", "  ")
		if err != nil {
			return err
		}

		fmt.Println(string(json))
		return nil
	},
}

var listContextsCmd = &cobra.Command{
	Use:     "ls-contexts",
	Aliases: []string{"list-contexts"},
	Short:   "List contexts",
	Long:    "List contexts currently used by the stack",
	Example: "$ cozy-stack config ls-contexts",
	RunE: func(cmd *cobra.Command, args []string) error {
		c := newAdminClient()
		req := &request.Options{
			Method: "GET",
			Path:   "instances/contexts",
		}
		res, err := c.Req(req)
		if err != nil {
			return err
		}
		defer res.Body.Close()

		var v interface{}

		err = json.NewDecoder(res.Body).Decode(&v)
		if err != nil {
			return err
		}

		json, err := json.MarshalIndent(v, "", "  ")
		if err != nil {
			return err
		}

		fmt.Println(string(json))
		return nil
	},
}

func init() {
	configCmdGroup.AddCommand(adminPasswdCmd)
	configCmdGroup.AddCommand(genKeysCmd)
	configCmdGroup.AddCommand(encryptCredentialsDataCmd)
	configCmdGroup.AddCommand(decryptCredentialsDataCmd)
	configCmdGroup.AddCommand(encryptCredentialsCmd)
	configCmdGroup.AddCommand(decryptCredentialsCmd)
	configCmdGroup.AddCommand(insertAssetCmd)
	configCmdGroup.AddCommand(listAssetCmd)
	configCmdGroup.AddCommand(removeAssetCmd)
	configCmdGroup.AddCommand(showContextCmd)
	configCmdGroup.AddCommand(listContextsCmd)
	RootCmd.AddCommand(configCmdGroup)
	insertAssetCmd.Flags().StringVar(&flagURL, "url", "", "The URL of the asset")
	insertAssetCmd.Flags().StringVar(&flagName, "name", "", "The name of the asset")
	insertAssetCmd.Flags().StringVar(&flagShasum, "shasum", "", "The shasum of the asset")
	insertAssetCmd.Flags().StringVar(&flagContext, "context", "", "The context of the asset")
}
