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use serde::{Deserialize, Serialize};
use serde_dhall::StaticType;
use serde_json as json;
use std::fs;
use std::io::Write;
use std::path::PathBuf;
use structopt::StructOpt;
use secrecy::ExposeSecret;
use age::x25519::Recipient;
#[derive(Deserialize, Serialize, StaticType, Debug)]
struct Survey {
title: String,
description: String,
questions: Vec<Question>,
pubkey: Option<String>
}
#[derive(Deserialize, Serialize, StaticType, Debug)]
struct Question {
question: String,
name: String,
space: AnswerSpace,
}
#[derive(Deserialize, Serialize, StaticType, Debug)]
enum AnswerSpace {
Single(Vec<String>),
Multiple(Vec<String>),
YesOrNo,
Freeform(String),
}
#[derive(StructOpt, Debug)]
struct Options {
/// a dhall configuration file that describes a survey
#[structopt(long, short, parse(from_os_str))]
config_file: PathBuf,
/// encrypt the survey with a passphrase (will be printed to stderr)
#[structopt(long, short)]
encrypt: bool,
/// file to write the configuration to (will otherwise print to stdout)
#[structopt(long, short)]
out_file: Option<PathBuf>
}
fn main () {
let opt = Options::from_args();
let config_file = std::fs::read_to_string(opt.config_file).unwrap();
// hacky way to get a "prelude" in dhall which doesn't have to be
// imported: just wrap our input code into a dhall "let"-statement.
// Probably doesn't scale very vell, though ...
let code = format!(
"let Question = {} \nlet Answers = {} \nin {}",
Question::static_type(),
AnswerSpace::static_type(),
config_file
);
match serde_dhall::from_str(&code)
.static_type_annotation()
.parse::<Survey>()
{
Err(e) => {
eprintln!("There is an error in your dhall code!\n{}", e);
std::process::exit(1);
},
Ok(data) => {
let json = json::to_string(&data).unwrap();
// if a public key is given to encrypt the survey, ad-hoc typecheck it
// (not sure if the dhall crate allows defining custom types which are
// opaque to dhall ...)
match data.pubkey {
Some (key) => key.parse::<Recipient>().is_err(),
None => false
}.then(|| {
println!("field pubkey is not a valid public key, aborting ...");
std::process::exit(1);
});
// out here to avoid borrowing issues — if it were in the password
// branch below, it would go out of scope at its end, since .as_slice()
// just borrows its argument
let mut encrypted = vec![];
// are we restricting access to the survey? if so, encrypt it with
// the password as passphrase.
let outdata = match opt.encrypt {
false => json.as_bytes(),
true => {
let key = age::x25519::Identity::generate();
let pubkey = key.to_public();
let encryptor = age::Encryptor::with_recipients(vec![Box::new(pubkey)]);
let mut writer = encryptor.wrap_output(&mut encrypted).unwrap();
writer.write_all(&json.as_bytes()).unwrap();
writer.finish().unwrap();
eprintln!("Passphrase for this survey: {}", key.to_string().expose_secret());
encrypted.as_slice()
}
};
match opt.out_file {
Some(file) => fs::write(file.clone(), outdata)
.expect(&format!("cannot write to file {:?}!", file)),
None => {
let mut out = std::io::stdout();
out.write_all(outdata).unwrap();
out.flush().unwrap()
}
};
}
}
}
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