package saml

import (
	"bytes"
	"crypto/x509"
	"encoding/pem"
	"errors"
	"fmt"
	"os"

	"github.com/crewjam/saml"
	"github.com/golang-jwt/jwt/v4"
	"github.com/rs/zerolog/log"
)

func initcert(file string, verify func(interface{}) bool) (key interface{}, err error) {
	var blocks []*pem.Block
	if file == "" {
		err = fmt.Errorf("File %s is empty", file)
		return
	}
	blocks, err = loadcerts(file)
	if err != nil {
		return nil, err
	}
	for _, b := range blocks {
		var key interface{}
		key, err = x509.ParsePKCS8PrivateKey(b.Bytes)
		if err != nil {
			key, err = x509.ParseCertificate(b.Bytes)
			if err != nil {
				log.Warn().AnErr("parsingerror", err).Msgf("could not parse file %s as publickey or as an privatekey", file)
				continue
			}
		}
		if key == nil {
			return nil, fmt.Errorf("Cannot find an Key in %s", file)
		}
		if verify(key) {
			return key, nil
		}
	}
	return nil, errors.New("No key found")
}

func loadcerts(filename string) (blocks []*pem.Block, err error) {
	var file *os.File
	if file, err = os.Open(filename); err != nil {
		return
	}
	var buffer bytes.Buffer
	read, err := buffer.ReadFrom(file)
	log.Debug().Int64("read bytes", read).Err(err).Msgf("Read file %s", filename)
	if err != nil {
		return
	}
	data := buffer.Bytes()
	var block *pem.Block
	for {
		if len(data) == 0 {
			return
		}
		block, data = pem.Decode(data)
		if block != nil {
			blocks = append(blocks, block)
		}
	}
}
func empty(data []string) bool {
	for _, t := range data {
		if t == "" {
			return true
		}
	}
	return false
}

func jwttoken(claim jwt.Claims, privatekey interface{}) (string, error) {
	token := jwt.NewWithClaims(
		jwt.SigningMethodPS512,
		claim,
	)
	return token.SignedString(privatekey)
}

func attributeStatementstomap(a []saml.AttributeStatement) map[string][]string {
	var output = map[string][]string{}
	for _, b := range a {
		for _, c := range b.Attributes {
			if _, ok := output[c.FriendlyName]; !ok {
				output[c.FriendlyName] = []string{}
			}
			for _, d := range c.Values {
				output[c.FriendlyName] = append(output[c.FriendlyName], d.Value)
			}
		}
	}
	return output
}