rustdoc_processor 0.1.1

use std::fmt::{Display, Formatter};

use anyhow::Context;
use guppy::graph::{PackageGraph, PackageMetadata, PackageSource};
use guppy::{PackageId, Version};

/// A selector that follows the [package ID specification](https://doc.rust-lang.org/cargo/reference/pkgid-spec.html).
/// It is used as argument to the `-p`/`--package` flag in `cargo`'s commands.
#[derive(Debug, PartialEq, Hash, Eq, Clone)]
pub(crate) struct PackageIdSpecification {
    pub(crate) source: Option<String>,
    pub(crate) name: String,
    pub(crate) version: Option<Version>,
}

impl PackageIdSpecification {
    pub fn from_package_id(
        package_id: &PackageId,
        package_graph: &PackageGraph,
    ) -> Result<Self, anyhow::Error> {
        let package_metadata = package_graph.metadata(package_id).with_context(|| {
            format!(
                "`{}` doesn't appear in the package graph",
                package_id.repr()
            )
        })?;

        Ok(Self::from_package_metadata(&package_metadata))
    }

    pub fn from_package_metadata(metadata: &PackageMetadata) -> Self {
        let source = match metadata.source() {
            PackageSource::Workspace(source) | PackageSource::Path(source) => {
                let source = source.strip_prefix("path+").unwrap_or(source);
                if source.as_str().is_empty() {
                    source.to_string()
                } else {
                    let source = if source.is_relative() {
                        metadata.graph().workspace().root().join(source).to_string()
                    } else {
                        source.to_string()
                    };
                    format!("file://{source}")
                }
            }
            PackageSource::External(source) => {
                let s = if let Some(source) = source.strip_prefix("git+") {
                    source
                } else if let Some(source) = source.strip_prefix("registry+") {
                    source
                } else {
                    source
                };
                // The source URL for the `git` repository can sometimes contain query parameters,
                // e.g. `?rev=abcdef`. We need to strip them away, since the specification requires
                // "hostname+path", no query params (see https://doc.rust-lang.org/cargo/reference/pkgid-spec.html).
                s.split('?').next().unwrap().to_owned()
            }
        };
        let source = if source.is_empty() {
            None
        } else {
            Some(source)
        };
        let name = metadata.name().to_owned();
        let version = Some(metadata.version().to_owned());
        Self {
            source,
            name,
            version,
        }
    }
}

impl Display for PackageIdSpecification {
    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
        if let Some(source) = &self.source {
            // The source URL for the `git` repository can sometimes contain a fragment,
            // e.g. `#<commit-sha>`.
            // We need to strip that away, otherwise there is ambiguity in the package ID.
            let source = source.split('#').next().unwrap();
            write!(f, "{source}#")?;
        }
        write!(f, "{}", &self.name)?;
        if let Some(version) = &self.version {
            write!(f, "@{version}")?;
        }
        Ok(())
    }
}