refactor: move packages to mason-registry (#27)

1 files changed, 90 insertions, 0 deletions

diff --git a/lua/mason-registry/init.lua b/lua/mason-registry/init.lua
new file mode 100644
index 00000000..1c87735e
--- /dev/null
+++ b/lua/mason-registry/init.lua
@@ -0,0 +1,90 @@
+local log = require "mason.log"
+local fs = require "mason.core.fs"
+local _ = require "mason.core.functional"
+local Optional = require "mason.core.optional"
+local path = require "mason.core.path"
+local EventEmitter = require "mason.core.EventEmitter"
+
+local index = require "mason-registry.index"
+
+local M = setmetatable({}, { __index = EventEmitter })
+EventEmitter.init(M)
+
+local scan_install_root
+
+do
+    ---@type table<string, true>
+    local cached_dirs
+
+    local get_directories = _.compose(
+        _.set_of,
+        _.filter_map(function(entry)
+            if entry.type == "directory" and index[entry.name] then
+                return Optional.of(entry.name)
+            else
+                return Optional.empty()
+            end
+        end)
+    )
+
+    ---@return table<string, true>
+    scan_install_root = function()
+        if cached_dirs then
+            return cached_dirs
+        end
+        log.trace "Scanning installation root dir"
+        ---@type string[]
+        local ok, entries = pcall(fs.sync.readdir, path.package_prefix())
+        if not ok then
+            log.debug("Failed to scan installation root dir", entries)
+            -- presume installation root dir has not been created yet (i.e., no packages installed)
+            return {}
+        end
+        cached_dirs = get_directories(entries)
+        vim.schedule(function()
+            cached_dirs = nil
+        end)
+        log.trace("Resolved installation root dirs", cached_dirs)
+        return cached_dirs
+    end
+end
+
+---@param package_name string
+function M.is_installed(package_name)
+    return scan_install_root()[package_name] == true
+end
+
+---@param package_name string
+---@return Package
+function M.get_package(package_name)
+    local ok, pkg = pcall(require, index[package_name])
+    if not ok then
+        log.error(pkg)
+        error(("Cannot find package %q."):format(package_name))
+    end
+    return pkg
+end
+
+local get_packages = _.map(M.get_package)
+
+---@return string[]
+function M.get_installed_package_names()
+    return _.keys(scan_install_root())
+end
+
+---@return Package[]
+function M.get_installed_packages()
+    return get_packages(M.get_installed_package_names())
+end
+
+---@return string[]
+function M.get_all_package_names()
+    return _.keys(index)
+end
+
+---@return Package[]
+function M.get_all_packages()
+    return get_packages(M.get_all_package_names())
+end
+
+return M