// Copyright 2018-2025 the Deno authors. MIT license.

//! Code for global npm cache resolution.

use std::path::Path;
use std::path::PathBuf;

use async_trait::async_trait;
use deno_npm::NpmPackageCacheFolderId;
use deno_npm::NpmPackageId;
use deno_semver::package::PackageNv;
use deno_semver::StackString;
use deno_semver::Version;
use node_resolver::errors::PackageFolderResolveError;
use node_resolver::errors::PackageNotFoundError;
use node_resolver::errors::ReferrerNotFoundError;
use url::Url;

use super::resolution::NpmResolutionRc;
use super::NpmCacheDirRc;
use super::NpmPackageFsResolver;
use crate::ResolvedNpmRcRc;

/// Resolves packages from the global npm cache.
#[derive(Debug)]
pub struct GlobalNpmPackageResolver {
  cache: NpmCacheDirRc,
  npm_rc: ResolvedNpmRcRc,
  resolution: NpmResolutionRc,
}

impl GlobalNpmPackageResolver {
  pub fn new(
    cache: NpmCacheDirRc,
    npm_rc: ResolvedNpmRcRc,
    resolution: NpmResolutionRc,
  ) -> Self {
    Self {
      cache,
      npm_rc,
      resolution,
    }
  }

  fn resolve_package_cache_folder_id_from_specifier_inner(
    &self,
    specifier: &Url,
  ) -> Option<NpmPackageCacheFolderId> {
    self
      .cache
      .resolve_package_folder_id_from_specifier(specifier)
      .and_then(|cache_id| {
        Some(NpmPackageCacheFolderId {
          nv: PackageNv {
            name: StackString::from_string(cache_id.name),
            version: Version::parse_from_npm(&cache_id.version).ok()?,
          },
          copy_index: cache_id.copy_index,
        })
      })
  }
}

#[async_trait(?Send)]
impl NpmPackageFsResolver for GlobalNpmPackageResolver {
  fn node_modules_path(&self) -> Option<&Path> {
    None
  }

  fn maybe_package_folder(&self, id: &NpmPackageId) -> Option<PathBuf> {
    let folder_copy_index = self
      .resolution
      .resolve_pkg_cache_folder_copy_index_from_pkg_id(id)?;
    let registry_url = self.npm_rc.get_registry_url(&id.nv.name);
    Some(self.cache.package_folder_for_id(
      &id.nv.name,
      &id.nv.version.to_string(),
      folder_copy_index,
      registry_url,
    ))
  }

  fn resolve_package_folder_from_package(
    &self,
    name: &str,
    referrer: &Url,
  ) -> Result<PathBuf, PackageFolderResolveError> {
    use deno_npm::resolution::PackageNotFoundFromReferrerError;
    let Some(referrer_cache_folder_id) =
      self.resolve_package_cache_folder_id_from_specifier_inner(referrer)
    else {
      return Err(
        ReferrerNotFoundError {
          referrer: referrer.clone(),
          referrer_extra: None,
        }
        .into(),
      );
    };
    let resolve_result = self
      .resolution
      .resolve_package_from_package(name, &referrer_cache_folder_id);
    match resolve_result {
      Ok(pkg) => match self.maybe_package_folder(&pkg.id) {
        Some(folder) => Ok(folder),
        None => Err(
          PackageNotFoundError {
            package_name: name.to_string(),
            referrer: referrer.clone(),
            referrer_extra: Some(format!(
              "{} -> {}",
              referrer_cache_folder_id,
              pkg.id.as_serialized()
            )),
          }
          .into(),
        ),
      },
      Err(err) => match *err {
        PackageNotFoundFromReferrerError::Referrer(cache_folder_id) => Err(
          ReferrerNotFoundError {
            referrer: referrer.clone(),
            referrer_extra: Some(cache_folder_id.to_string()),
          }
          .into(),
        ),
        PackageNotFoundFromReferrerError::Package {
          name,
          referrer: cache_folder_id_referrer,
        } => Err(
          PackageNotFoundError {
            package_name: name,
            referrer: referrer.clone(),
            referrer_extra: Some(cache_folder_id_referrer.to_string()),
          }
          .into(),
        ),
      },
    }
  }

  fn resolve_package_cache_folder_id_from_specifier(
    &self,
    specifier: &Url,
  ) -> Result<Option<NpmPackageCacheFolderId>, std::io::Error> {
    Ok(self.resolve_package_cache_folder_id_from_specifier_inner(specifier))
  }
}