// Copyright 2018-2023 the Deno authors. All rights reserved. MIT license.

//! Code for global npm cache resolution.

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

use async_trait::async_trait;
use deno_ast::ModuleSpecifier;
use deno_core::error::AnyError;
use deno_core::url::Url;
use deno_runtime::deno_node::NodePermissions;
use deno_runtime::deno_node::NodeResolutionMode;

use crate::npm::cache::NpmPackageCacheFolderId;
use crate::npm::resolution::NpmResolution;
use crate::npm::resolvers::common::cache_packages;
use crate::npm::NpmCache;
use crate::npm::NpmPackageId;
use crate::npm::NpmResolutionPackage;

use super::common::ensure_registry_read_permission;
use super::common::types_package_name;
use super::common::NpmPackageFsResolver;

/// Resolves packages from the global npm cache.
#[derive(Debug, Clone)]
pub struct GlobalNpmPackageResolver {
  cache: NpmCache,
  resolution: NpmResolution,
  registry_url: Url,
}

impl GlobalNpmPackageResolver {
  pub fn new(
    cache: NpmCache,
    registry_url: Url,
    resolution: NpmResolution,
  ) -> Self {
    Self {
      cache,
      resolution,
      registry_url,
    }
  }

  fn package_folder(&self, id: &NpmPackageId) -> PathBuf {
    let folder_id = self
      .resolution
      .resolve_package_cache_folder_id_from_id(id)
      .unwrap();
    self
      .cache
      .package_folder_for_id(&folder_id, &self.registry_url)
  }

  fn resolve_types_package(
    &self,
    package_name: &str,
    referrer_pkg_id: &NpmPackageCacheFolderId,
  ) -> Result<NpmResolutionPackage, AnyError> {
    let types_name = types_package_name(package_name);
    self
      .resolution
      .resolve_package_from_package(&types_name, referrer_pkg_id)
  }
}

#[async_trait]
impl NpmPackageFsResolver for GlobalNpmPackageResolver {
  fn resolve_package_folder_from_deno_module(
    &self,
    id: &NpmPackageId,
  ) -> Result<PathBuf, AnyError> {
    Ok(self.package_folder(id))
  }

  fn resolve_package_folder_from_package(
    &self,
    name: &str,
    referrer: &ModuleSpecifier,
    mode: NodeResolutionMode,
  ) -> Result<PathBuf, AnyError> {
    let referrer_pkg_id = self
      .cache
      .resolve_package_folder_id_from_specifier(referrer, &self.registry_url)?;
    let pkg = if mode.is_types() && !name.starts_with("@types/") {
      // attempt to resolve the types package first, then fallback to the regular package
      match self.resolve_types_package(name, &referrer_pkg_id) {
        Ok(pkg) => pkg,
        Err(_) => self
          .resolution
          .resolve_package_from_package(name, &referrer_pkg_id)?,
      }
    } else {
      self
        .resolution
        .resolve_package_from_package(name, &referrer_pkg_id)?
    };
    Ok(self.package_folder(&pkg.pkg_id))
  }

  fn resolve_package_folder_from_specifier(
    &self,
    specifier: &ModuleSpecifier,
  ) -> Result<PathBuf, AnyError> {
    let pkg_folder_id = self.cache.resolve_package_folder_id_from_specifier(
      specifier,
      &self.registry_url,
    )?;
    Ok(
      self
        .cache
        .package_folder_for_id(&pkg_folder_id, &self.registry_url),
    )
  }

  fn package_size(&self, id: &NpmPackageId) -> Result<u64, AnyError> {
    let package_folder = self.package_folder(id);
    Ok(crate::util::fs::dir_size(&package_folder)?)
  }

  async fn cache_packages(&self) -> Result<(), AnyError> {
    cache_packages_in_resolver(self).await
  }

  fn ensure_read_permission(
    &self,
    permissions: &mut dyn NodePermissions,
    path: &Path,
  ) -> Result<(), AnyError> {
    let registry_path = self.cache.registry_folder(&self.registry_url);
    ensure_registry_read_permission(permissions, &registry_path, path)
  }
}

async fn cache_packages_in_resolver(
  resolver: &GlobalNpmPackageResolver,
) -> Result<(), AnyError> {
  let package_partitions = resolver.resolution.all_packages_partitioned();

  cache_packages(
    package_partitions.packages,
    &resolver.cache,
    &resolver.registry_url,
  )
  .await?;

  // create the copy package folders
  for copy in package_partitions.copy_packages {
    resolver.cache.ensure_copy_package(
      &copy.get_package_cache_folder_id(),
      &resolver.registry_url,
    )?;
  }

  Ok(())
}