package main

import (
	"bytes"
	"encoding/base64"
	"errors"
	"fmt"
	"os"
	"path/filepath"

	cmds "github.com/jbenet/go-ipfs/commands"
	config "github.com/jbenet/go-ipfs/config"
	core "github.com/jbenet/go-ipfs/core"
	ci "github.com/jbenet/go-ipfs/crypto"
	imp "github.com/jbenet/go-ipfs/importer"
	chunk "github.com/jbenet/go-ipfs/importer/chunk"
	peer "github.com/jbenet/go-ipfs/peer"
	u "github.com/jbenet/go-ipfs/util"
)

var initCmd = &cmds.Command{
	Helptext: cmds.HelpText{
		Tagline:          "Initializes IPFS config file",
		ShortDescription: "Initializes IPFS configuration files and generates a new keypair.",
	},

	Options: []cmds.Option{
		cmds.IntOption("bits", "b", "Number of bits to use in the generated RSA private key (defaults to 4096)"),
		cmds.StringOption("passphrase", "p", "Passphrase for encrypting the private key"),
		cmds.BoolOption("force", "f", "Overwrite existing config (if it exists)"),
		cmds.StringOption("datastore", "d", "Location for the IPFS data store"),
	},
	Run: func(req cmds.Request) (interface{}, error) {

		dspathOverride, _, err := req.Option("d").String() // if !found it's okay. Let == ""
		if err != nil {
			return nil, err
		}

		force, _, err := req.Option("f").Bool() // if !found, it's okay force == false
		if err != nil {
			return nil, err
		}

		nBitsForKeypair, bitsOptFound, err := req.Option("b").Int()
		if err != nil {
			return nil, err
		}
		if !bitsOptFound {
			nBitsForKeypair = 4096
		}

		return nil, doInit(req.Context().ConfigRoot, dspathOverride, force, nBitsForKeypair)
	},
}

// TODO add default welcome hash: eaa68bedae247ed1e5bd0eb4385a3c0959b976e4
// NB: if dspath is not provided, it will be retrieved from the config
func doInit(configRoot string, dspathOverride string, force bool, nBitsForKeypair int) error {

	u.POut("initializing ipfs node at %s\n", configRoot)

	configFilename, err := config.Filename(configRoot)
	if err != nil {
		return errors.New("Couldn't get home directory path")
	}

	fi, err := os.Lstat(configFilename)
	if fi != nil || (err != nil && !os.IsNotExist(err)) {
		if !force {
			// TODO multi-line string
			return errors.New("ipfs configuration file already exists!\nReinitializing would overwrite your keys.\n(use -f to force overwrite)")
		}
	}

	ds, err := datastoreConfig(dspathOverride)
	if err != nil {
		return err
	}

	identity, err := identityConfig(nBitsForKeypair)
	if err != nil {
		return err
	}

	conf := config.Config{

		// setup the node addresses.
		Addresses: config.Addresses{
			Swarm: "/ip4/0.0.0.0/tcp/4001",
			API:   "/ip4/127.0.0.1/tcp/5001",
		},

		Bootstrap: []*config.BootstrapPeer{
			&config.BootstrapPeer{ // Use these hardcoded bootstrap peers for now.
				// mars.i.ipfs.io
				PeerID:  "QmaCpDMGvV2BGHeYERUEnRQAwe3N8SzbUtfsmvsqQLuvuJ",
				Address: "/ip4/104.131.131.82/tcp/4001",
			},
		},

		Datastore: ds,

		Identity: identity,

		// setup the node mount points.
		Mounts: config.Mounts{
			IPFS: "/ipfs",
			IPNS: "/ipns",
		},

		// tracking ipfs version used to generate the init folder and adding
		// update checker default setting.
		Version: config.VersionDefaultValue(),
	}

	err = config.WriteConfigFile(configFilename, conf)
	if err != nil {
		return err
	}

	nd, err := core.NewIpfsNode(&conf, false)
	if err != nil {
		return err
	}
	defer nd.Close()

	// Set up default file
	msg := `Hello and Welcome to IPFS!
If you're seeing this, that means that you have successfully
installed ipfs and are now interfacing with the wonderful
world of DAGs and hashes!
`
	reader := bytes.NewBufferString(msg)

	defnd, err := imp.BuildDagFromReader(reader, nd.DAG, nd.Pinning.GetManual(), chunk.DefaultSplitter)
	if err != nil {
		return err
	}

	k, _ := defnd.Key()
	fmt.Printf("Default file key: %s\n", k)

	return nil
}

func datastoreConfig(dspath string) (config.Datastore, error) {
	ds := config.Datastore{}
	if len(dspath) == 0 {
		var err error
		dspath, err = config.DataStorePath("")
		if err != nil {
			return ds, err
		}
	}
	ds.Path = dspath
	ds.Type = "leveldb"

	// Construct the data store if missing
	if err := os.MkdirAll(dspath, os.ModePerm); err != nil {
		return ds, err
	}

	// Check the directory is writeable
	if f, err := os.Create(filepath.Join(dspath, "._check_writeable")); err == nil {
		os.Remove(f.Name())
	} else {
		return ds, errors.New("Datastore '" + dspath + "' is not writeable")
	}

	return ds, nil
}

func identityConfig(nbits int) (config.Identity, error) {
	// TODO guard higher up
	ident := config.Identity{}
	if nbits < 1024 {
		return ident, errors.New("Bitsize less than 1024 is considered unsafe.")
	}

	fmt.Println("generating key pair...")
	sk, pk, err := ci.GenerateKeyPair(ci.RSA, nbits)
	if err != nil {
		return ident, err
	}

	// currently storing key unencrypted. in the future we need to encrypt it.
	// TODO(security)
	skbytes, err := sk.Bytes()
	if err != nil {
		return ident, err
	}
	ident.PrivKey = base64.StdEncoding.EncodeToString(skbytes)

	id, err := peer.IDFromPubKey(pk)
	if err != nil {
		return ident, err
	}
	ident.PeerID = id.Pretty()

	return ident, nil
}