(.module:
  [lux (#- Module)
   [abstract
    ["." monad (#+ Monad do)]]
   [control
    ["." try (#+ Try)]
    ["." exception (#+ exception:)]
    [concurrency
     ["." promise (#+ Promise) ("#\." monad)]]
    [security
     ["!" capability]]
    ["<>" parser
     ["<b>" binary]]]
   [data
    [binary (#+ Binary)]
    ["." text
     ["%" format (#+ format)]]
    [collection
     ["." dictionary (#+ Dictionary)]
     ["." row]]
    [format
     ["." tar]]]
   [tool
    [compiler
     [meta
      [archive
       [descriptor (#+ Module)]]]]]
   [world
    ["." file (#+ Path File)]]]
  [//
   [cli (#+ Library)]])

(def: Action
  (type (All [a] (Promise (Try a)))))

(exception: #export useless_tar_entry)

(exception: #export (duplicate {library Library} {module Module})
  (exception.report
   ["Module" (%.text module)]
   ["Library" (%.text library)]))

(type: #export Import
  (Dictionary Path Binary))

(def: (import_library system library import)
  (-> (file.System Promise) Library Import (Action Import))
  (do (try.with promise.monad)
    [file (: (Action (File Promise))
             (!.use (\ system file) [library]))
     binary (!.use (\ file content) [])]
    (promise\wrap
     (do {! try.monad}
       [tar (<b>.run tar.parser binary)]
       (monad.fold ! (function (_ entry import)
                       (case entry
                         (#tar.Normal [path instant mode ownership content])
                         (let [path (tar.from_path path)]
                           (case (dictionary.try_put path (tar.data content) import)
                             (#try.Success import)
                             (wrap import)
                             
                             (#try.Failure error)
                             (exception.throw ..duplicate [library path])))
                         
                         _
                         (exception.throw ..useless_tar_entry [])))
                   import
                   (row.to_list tar))))))

(def: #export (import system libraries)
  (-> (file.System Promise) (List Library) (Action Import))
  (monad.fold (: (Monad Action)
                 (try.with promise.monad))
              (..import_library system)
              (dictionary.new text.hash)
              libraries))