package main

import "C"
import (
	"errors"
	"io/ioutil"
	"os"
	"path"

	"github.com/mitchellh/go-homedir"
	"github.com/planetscale/planetscale-go/planetscale"
)

const accessTokenDir string = "~/.config/planetscale"

//export startfromenv
func startfromenv(org, database, branch, listenAddr *C.char) (*C.char, *C.char) {
	client, err := newClientFromEnv()
	if err != nil {
		return nil, nilOrError(err)
	}

	opts := []controllerOpt{withClient(client)}

	if a := C.GoString(listenAddr); a != "" {
		opts = append(opts, withListen(a))
	}

	return startproxy(org, database, branch, opts...)
}

//export startfromtoken
func startfromtoken(tokenName, token, org, database, branch, listenAddr *C.char) (*C.char, *C.char) {
	client, err := newClientFromServiceToken(C.GoString(tokenName), C.GoString(token))
	if err != nil {
		return nil, nilOrError(err)
	}

	opts := []controllerOpt{withClient(client)}

	if a := C.GoString(listenAddr); a != "" {
		opts = append(opts, withListen(a))
	}

	return startproxy(org, database, branch, opts...)
}

//export startfromstatic
func startfromstatic(org, database, branch, privKey, cert, addr, port, listenAddr *C.char) (*C.char, *C.char) {
	certSource := &localCertSource{
		privKey:     C.GoString(privKey),
		certificate: C.GoString(cert),
		remoteAddr:  C.GoString(addr),
		port:        C.GoString(port),
	}

	opts := []controllerOpt{withLocalCertSource(certSource)}

	if a := C.GoString(listenAddr); a != "" {
		opts = append(opts, withListen(a))
	}

	return startproxy(org, database, branch, opts...)
}

func startproxy(org, database, branch *C.char, opts ...controllerOpt) (*C.char, *C.char) {
	cntrlr, err := newController(C.GoString(org), C.GoString(database), C.GoString(branch), opts...)
	if err != nil {
		return nil, nilOrError(err)
	}

	addr, err := cntrlr.start()
	return C.CString(addr), nilOrError(err)
}

func newClientFromEnv() (*planetscale.Client, error) {
	opts := []planetscale.ClientOption{
		planetscale.WithBaseURL(planetscale.DefaultBaseURL),
	}

	token, err := accessToken()
	if err != nil {
		return nil, err
	}

	opts = append(opts, planetscale.WithAccessToken(token))

	return planetscale.NewClient(opts...)
}

func newClientFromServiceToken(name, token string) (*planetscale.Client, error) {
	opts := []planetscale.ClientOption{
		planetscale.WithBaseURL(planetscale.DefaultBaseURL),
		planetscale.WithServiceToken(name, token),
	}

	return planetscale.NewClient(opts...)
}

func accessToken() (string, error) {
	cfgDir, err := homedir.Expand(accessTokenDir)
	if err != nil {
		return "", err
	}
	tFile := path.Join(cfgDir, "access-token")
	if _, err := os.Stat(tFile); err != nil {
		return "", errors.New("unable to find access token file")
	}

	t, err := ioutil.ReadFile(tFile)
	if err != nil {
		return "", errors.New("unable to read access token file")
	}

	return string(t), nil
}

func nilOrError(err error) *C.char {
	if err == nil {
		return nil
	}

	return C.CString(err.Error())
}