stellar-xdr 26.0.0

use std::{
    fmt::Debug,
    fs::File,
    io::{stdout, Write},
    path::PathBuf,
    str::FromStr,
};

use clap::{Args, ValueEnum};

use crate::cli::Channel;

#[derive(thiserror::Error, Debug)]
pub enum Error {
    #[error("unknown type {0}, choose one of {1:?}")]
    UnknownType(String, &'static [&'static str]),
    #[error("error decoding XDR: {0}")]
    ReadXdrCurr(#[from] crate::curr::Error),
    #[error("error decoding XDR: {0}")]
    ReadXdrNext(#[from] crate::next::Error),
    #[error("error reading file: {0}")]
    ReadFile(std::io::Error),
    #[error("error writing output: {0}")]
    WriteOutput(std::io::Error),
}

/// Compare two XDR values with each other
///
/// Outputs:
///   `-1` when the left XDR value is less than the right XDR value,
///   `0` when the left XDR value is equal to the right XDR value,
///   `1` when the left XDR value is greater than the right XDR value
#[derive(Args, Debug, Clone)]
#[command()]
pub struct Cmd {
    /// XDR file to decode and compare with the right value
    #[arg()]
    pub left: PathBuf,

    /// XDR file to decode and compare with the left value
    #[arg()]
    pub right: PathBuf,

    /// XDR type of both inputs
    #[arg(long)]
    pub r#type: String,

    // Input format of the XDR
    #[arg(long, value_enum, default_value_t)]
    pub input: InputFormat,
}

#[derive(Clone, Copy, Debug, Eq, Hash, PartialEq, ValueEnum)]
pub enum InputFormat {
    Single,
    SingleBase64,
}

impl Default for InputFormat {
    fn default() -> Self {
        Self::SingleBase64
    }
}

macro_rules! run_x {
    ($f:ident, $m:ident) => {
        fn $f(&self) -> Result<(), Error> {
            let f1 = File::open(&self.left).map_err(Error::ReadFile)?;
            let f2 = File::open(&self.right).map_err(Error::ReadFile)?;
            let r#type = crate::$m::TypeVariant::from_str(&self.r#type).map_err(|_| {
                Error::UnknownType(self.r#type.clone(), &crate::$m::TypeVariant::VARIANTS_STR)
            })?;
            let (t1, t2) = match self.input {
                InputFormat::Single => {
                    let t1 = {
                        let mut l1 = crate::$m::Limited::new(f1, crate::$m::Limits::none());
                        crate::$m::Type::read_xdr_to_end(r#type, &mut l1)?
                    };
                    let t2 = {
                        let mut l = crate::$m::Limited::new(f2, crate::$m::Limits::none());
                        crate::$m::Type::read_xdr_to_end(r#type, &mut l)?
                    };
                    (t1, t2)
                }
                InputFormat::SingleBase64 => {
                    let t1 = {
                        let mut l = crate::$m::Limited::new(f1, crate::$m::Limits::none());
                        crate::$m::Type::read_xdr_base64_to_end(r#type, &mut l)?
                    };
                    let t2 = {
                        let mut l = crate::$m::Limited::new(f2, crate::$m::Limits::none());
                        crate::$m::Type::read_xdr_base64_to_end(r#type, &mut l)?
                    };
                    (t1, t2)
                }
            };
            let cmp = t1.cmp(&t2) as i8;
            writeln!(stdout(), "{cmp}").map_err(Error::WriteOutput)?;
            Ok(())
        }
    };
}

impl Cmd {
    /// Run the CLIs decode command.
    ///
    /// ## Errors
    ///
    /// If the command is configured with state that is invalid.
    pub fn run(&self, channel: &Channel) -> Result<(), Error> {
        let result = match channel {
            Channel::Curr => self.run_curr(),
            Channel::Next => self.run_next(),
        };

        match result {
            Ok(()) => Ok(()),
            Err(Error::WriteOutput(e)) if e.kind() == std::io::ErrorKind::BrokenPipe => Ok(()),
            Err(e) => Err(e),
        }
    }

    run_x!(run_curr, curr);
    run_x!(run_next, next);
}