simplicityhl 0.4.0

use base64::display::Base64Display;
use base64::engine::general_purpose::STANDARD;
use clap::{Arg, ArgAction, Command};

use simplicityhl::{Arguments, CompiledProgram};
use std::{env, fmt};

#[cfg_attr(feature = "serde", derive(serde::Serialize))]
/// The compilation output.
struct Output {
    /// Simplicity program result, base64 encoded.
    program: String,
    /// Simplicity witness result, base64 encoded, if the .wit file was provided.
    witness: Option<String>,
}

impl fmt::Display for Output {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        writeln!(f, "Program:\n{}", self.program)?;
        if let Some(witness) = &self.witness {
            writeln!(f, "Witness:\n{}", witness)?;
        }
        Ok(())
    }
}

fn main() -> Result<(), Box<dyn std::error::Error>> {
    let command = {
        Command::new(env!("CARGO_BIN_NAME"))
            .about(
                "\
                Compile the given SimplicityHL program and print the resulting Simplicity base64 string.\n\
                If a SimplicityHL witness is provided, then use it to satisfy the program (requires \
                feature 'serde' to be enabled).\
                ",
            )
            .arg(
                Arg::new("prog_file")
                    .required(true)
                    .value_name("PROGRAM_FILE")
                    .action(ArgAction::Set)
                    .help("SimplicityHL program file to build"),
            )
            .arg(
                Arg::new("wit_file")
                    .value_name("WITNESS_FILE")
                    .action(ArgAction::Set)
                    .help("File containing the witness data"),
            )
            .arg(
                Arg::new("debug")
                    .long("debug")
                    .action(ArgAction::SetTrue)
                    .help("Include debug symbols in the output"),
            )
            .arg(
                Arg::new("json")
                    .long("json")
                    .action(ArgAction::SetTrue)
                    .help("Output in JSON"),
            )
    };

    let matches = command.get_matches();

    let prog_file = matches.get_one::<String>("prog_file").unwrap();
    let prog_path = std::path::Path::new(prog_file);
    let prog_text = std::fs::read_to_string(prog_path).map_err(|e| e.to_string())?;
    let include_debug_symbols = matches.get_flag("debug");
    let output_json = matches.get_flag("json");

    let compiled = CompiledProgram::new(prog_text, Arguments::default(), include_debug_symbols)?;

    #[cfg(feature = "serde")]
    let witness_opt = matches
        .get_one::<String>("wit_file")
        .map(|wit_file| -> Result<simplicityhl::WitnessValues, String> {
            let wit_path = std::path::Path::new(wit_file);
            let wit_text = std::fs::read_to_string(wit_path).map_err(|e| e.to_string())?;
            let witness = serde_json::from_str::<simplicityhl::WitnessValues>(&wit_text).unwrap();
            Ok(witness)
        })
        .transpose()?;
    #[cfg(not(feature = "serde"))]
    let witness_opt = if matches.contains_id("wit_file") {
        return Err(
            "Program was compiled without the 'serde' feature and cannot process .wit files."
                .into(),
        );
    } else {
        None
    };

    let (program_bytes, witness_bytes) = match witness_opt {
        Some(witness) => {
            let satisfied = compiled.satisfy(witness)?;
            let (program_bytes, witness_bytes) = satisfied.redeem().to_vec_with_witness();
            (program_bytes, Some(witness_bytes))
        }
        None => {
            let program_bytes = compiled.commit().to_vec_without_witness();
            (program_bytes, None)
        }
    };

    let output = Output {
        program: Base64Display::new(&program_bytes, &STANDARD).to_string(),
        witness: witness_bytes.map(|bytes| Base64Display::new(&bytes, &STANDARD).to_string()),
    };

    if output_json {
        #[cfg(not(feature = "serde"))]
        return Err(
            "Program was compiled without the 'serde' feature and cannot output JSON.".into(),
        );
        #[cfg(feature = "serde")]
        println!("{}", serde_json::to_string(&output)?);
    } else {
        println!("{}", output);
    }

    Ok(())
}