CMSgov/dpc-app

package dpc

import (
    "bytes"
    "crypto/rsa"
    "fmt"
    "io/ioutil"
    "net/url"
)

func templateBodyGenerator(templateFile string, replacementMap map[string]func() string) func() []byte {
    body, err := ioutil.ReadFile(templateFile)
    if err != nil {
        panic(err)
    }
    return func() []byte {
        output := body

        for k, v := range replacementMap {
            keyCount := bytes.Count(body, []byte(k))
            for i := 0; i < keyCount; i++ {
                value := v()
                output = bytes.Replace(output, []byte(k), []byte(value), i+1)
            }

        }
        return output
    }
}

func keyBodyGenerator(n int, fn func() (string, *rsa.PrivateKey, string)) func() []byte {
    var bodies [][]byte
    for i := 0; i < n; i++ {
        pubKeyStr, _, signature := fn()
        bodies = append(bodies, []byte(fmt.Sprintf(`{ "key": "%s", "signature": "%s"}`, pubKeyStr, signature)))
    }

    return byteArrayGenerator(bodies)
}

func authBodyGenerator(authTokens [][]byte) func() []byte {
    var bodies [][]byte
    for _, authToken := range authTokens {
        bodies = append(bodies, []byte(
            url.Values{
                "scope":                 {"system/*.*"},
                "grant_type":            {"client_credentials"},
                "client_assertion_type": {"urn:ietf:params:oauth:client-assertion-type:jwt-bearer"},
                "client_assertion":      {string(authToken)},
            }.Encode()),
        )
    }

    return byteArrayGenerator(bodies)
}

func byteArrayGenerator(arrayOfBytes [][]byte) func() []byte {
    numOfBytes := len(arrayOfBytes)
    if numOfBytes == 0 {
        return func() []byte { return []byte{} }
    }
    i := 0
    return func() []byte {
        if i >= numOfBytes {
            return []byte{}
        }

        bytes := arrayOfBytes[i]
        i++
        return bytes
    }
}