use-pnpm 0.0.1

#![forbid(unsafe_code)]
#![doc = include_str!("../README.md")]

use core::{fmt, str::FromStr};
use std::error::Error;

macro_rules! text_newtype {
    ($name:ident) => {
        #[derive(Clone, Debug, Eq, Hash, Ord, PartialEq, PartialOrd)]
        pub struct $name(String);

        impl $name {
            /// Creates non-empty pnpm text metadata.
            ///
            /// # Errors
            ///
            /// Returns [`PnpmTextError::Empty`] when `input` is empty after trimming.
            pub fn new(input: &str) -> Result<Self, PnpmTextError> {
                let trimmed = input.trim();
                if trimmed.is_empty() {
                    Err(PnpmTextError::Empty)
                } else {
                    Ok(Self(trimmed.to_string()))
                }
            }

            /// Returns the stored text.
            #[must_use]
            pub fn as_str(&self) -> &str {
                &self.0
            }
        }
    };
}

/// Common pnpm command labels.
#[derive(Clone, Copy, Debug, Eq, Hash, Ord, PartialEq, PartialOrd)]
pub enum PnpmCommand {
    Install,
    Add,
    Run,
    Test,
    Exec,
    Publish,
}

impl FromStr for PnpmCommand {
    type Err = PnpmTextError;

    fn from_str(input: &str) -> Result<Self, Self::Err> {
        match normalized(input)?.as_str() {
            "install" | "i" => Ok(Self::Install),
            "add" => Ok(Self::Add),
            "run" => Ok(Self::Run),
            "test" => Ok(Self::Test),
            "exec" => Ok(Self::Exec),
            "publish" => Ok(Self::Publish),
            _ => Err(PnpmTextError::Unknown),
        }
    }
}

text_newtype!(PnpmWorkspace);
text_newtype!(PnpmFilter);

/// Common pnpm lockfile labels.
#[derive(Clone, Copy, Debug, Eq, Hash, Ord, PartialEq, PartialOrd)]
pub enum PnpmLockfile {
    Workspace,
}

impl PnpmLockfile {
    /// Returns the lockfile label.
    #[must_use]
    pub const fn as_str(self) -> &'static str {
        "pnpm-lock.yaml"
    }
}

/// Error returned when pnpm text metadata is invalid.
#[derive(Clone, Copy, Debug, Eq, PartialEq)]
pub enum PnpmTextError {
    Empty,
    Unknown,
}

impl fmt::Display for PnpmTextError {
    fn fmt(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
        match self {
            Self::Empty => formatter.write_str("pnpm metadata text cannot be empty"),
            Self::Unknown => formatter.write_str("unknown pnpm command"),
        }
    }
}

impl Error for PnpmTextError {}

fn normalized(input: &str) -> Result<String, PnpmTextError> {
    let trimmed = input.trim();
    if trimmed.is_empty() {
        Err(PnpmTextError::Empty)
    } else {
        Ok(trimmed.to_ascii_lowercase())
    }
}

#[cfg(test)]
mod tests {
    use super::{PnpmCommand, PnpmFilter, PnpmLockfile};

    #[test]
    fn models_pnpm_metadata() -> Result<(), Box<dyn std::error::Error>> {
        assert_eq!("install".parse::<PnpmCommand>()?, PnpmCommand::Install);
        assert_eq!(
            PnpmFilter::new("./packages/app")?.as_str(),
            "./packages/app"
        );
        assert_eq!(PnpmLockfile::Workspace.as_str(), "pnpm-lock.yaml");
        Ok(())
    }
}