From 862a42ab2327154db21befa0838a25191c582b31 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Abigail=20Magalh=C3=A3es?= <me@abby.how>
Date: Wed, 27 Oct 2021 11:50:28 -0300
Subject: [PATCH] Initial commit

---
 .gitignore                |  4 +++
 LICENSE                   | 30 ++++++++++++++++++
 README.md                 |  1 +
 Setup.hs                  |  2 ++
 agda-unused-imports.cabal | 25 +++++++++++++++
 src/Main.hs               | 67 +++++++++++++++++++++++++++++++++++++++
 stack.yaml                | 67 +++++++++++++++++++++++++++++++++++++++
 stack.yaml.lock           | 13 ++++++++
 8 files changed, 209 insertions(+)
 create mode 100644 .gitignore
 create mode 100644 LICENSE
 create mode 100644 README.md
 create mode 100644 Setup.hs
 create mode 100644 agda-unused-imports.cabal
 create mode 100755 src/Main.hs
 create mode 100644 stack.yaml
 create mode 100644 stack.yaml.lock

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..72f8cf6
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,4 @@
+/.stack-work
+/html
+/*.agda
+/*.agdai
diff --git a/LICENSE b/LICENSE
new file mode 100644
index 0000000..ca46626
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,30 @@
+Copyright Abigail Magalhães (c) 2021
+
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+    * Redistributions of source code must retain the above copyright
+      notice, this list of conditions and the following disclaimer.
+
+    * Redistributions in binary form must reproduce the above
+      copyright notice, this list of conditions and the following
+      disclaimer in the documentation and/or other materials provided
+      with the distribution.
+
+    * Neither the name of Abigail Magalhães nor the names of other
+      contributors may be used to endorse or promote products derived
+      from this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
\ No newline at end of file
diff --git a/README.md b/README.md
new file mode 100644
index 0000000..42eb705
--- /dev/null
+++ b/README.md
@@ -0,0 +1 @@
+# agda-unused-imports
diff --git a/Setup.hs b/Setup.hs
new file mode 100644
index 0000000..9a994af
--- /dev/null
+++ b/Setup.hs
@@ -0,0 +1,2 @@
+import Distribution.Simple
+main = defaultMain
diff --git a/agda-unused-imports.cabal b/agda-unused-imports.cabal
new file mode 100644
index 0000000..5e234d2
--- /dev/null
+++ b/agda-unused-imports.cabal
@@ -0,0 +1,25 @@
+name:                agda-unused-imports
+version:             0.1.0.0
+-- synopsis:
+-- description:
+homepage:            https://github.com/plt-hokusai/agda-unused-imports#readme
+license:             BSD3
+license-file:        LICENSE
+author:              Abigail Magalhães
+maintainer:          me@abby.how
+copyright:           2021 Abigail Magalhães
+category:            Web
+build-type:          Simple
+cabal-version:       >=1.10
+extra-source-files:  README.md
+
+executable agda-unused-imports
+  hs-source-dirs:      src
+  main-is:             Main.hs
+  default-language:    Haskell2010
+  build-depends:       base >= 4.7 && < 5
+                     , text
+                     , tagsoup
+                     , hashable
+                     , filepath
+                     , unordered-containers
diff --git a/src/Main.hs b/src/Main.hs
new file mode 100755
index 0000000..9b5d0d8
--- /dev/null
+++ b/src/Main.hs
@@ -0,0 +1,67 @@
+#!/usr/bin/env stack
+{- stack --resolver lts-18.14 script
+         --package text
+         --package unordered-containers
+         --package tagsoup
+         --package filepath
+         --package hashable
+-}
+{-# LANGUAGE OverloadedStrings #-}
+module Main where
+
+import qualified Data.Text.Lazy.IO as Text
+import qualified Data.HashSet as HashSet
+import qualified Data.Text.Lazy as Text
+import Data.HashSet (HashSet)
+import Data.Text.Lazy (Text)
+import Data.Hashable
+
+import System.Environment
+
+import Text.HTML.TagSoup
+import Data.Function
+import Data.Int
+import Data.Foldable
+import System.FilePath
+import Control.Monad
+
+main :: IO ()
+main = do
+  args <- getArgs
+  for_ args $ \mod -> do
+    contents <- Text.readFile mod
+    let unused = findUnusedImports mempty (parseTags contents)
+    unless (null unused) $ do
+      putStrLn $ "Potentially unused imports for: \x1b[1m" <> dropExtension (takeFileName mod) <> "\x1b[0m"
+      Text.putStrLn $ " * " <> Text.intercalate ", " (toList unused)
+
+findUnusedImports :: HashSet Text -> [Tag Text] -> HashSet Text
+findUnusedImports unused (TagOpen "pre" attrs:ts)
+  | Just "Agda" <- lookup "class" attrs
+  = goAgda 0 unused ts
+findUnusedImports unused (_:ts) = findUnusedImports unused ts
+findUnusedImports unused [] = unused
+
+goAgda :: Int64 -> HashSet Text -> [Tag Text] -> HashSet Text
+goAgda line unused (TagOpen "a" attrs:TagText text:TagClose "a":ts)
+  | Just "Module" <- lookup "class" attrs
+  , Just href <- lookup "href" attrs
+  , ".html" `Text.isSuffixOf` href
+  = let
+      imp = Text.take (Text.length href - 5) href
+    in goAgda line (HashSet.insert imp unused) ts
+
+  | Just href <- lookup "href" attrs
+  , let (mod, ident) = Text.break (== '#') href
+  , not (Text.null mod), not (Text.null (Text.drop 1 ident))
+  = let
+      imp = Text.take (Text.length mod - 5) mod
+    in goAgda line (HashSet.delete imp unused) ts
+
+goAgda line unused (TagClose "pre":ts) = findUnusedImports unused ts
+
+goAgda line unused (TagText text:ts)
+  | newlines <- Text.filter (== '\n') text = goAgda (line + Text.length newlines) unused ts
+
+goAgda line unused (t:ts) = goAgda line unused ts
+goAgda line unused [] = error "Unclosed <pre class=Agda> tag"
diff --git a/stack.yaml b/stack.yaml
new file mode 100644
index 0000000..6a69a48
--- /dev/null
+++ b/stack.yaml
@@ -0,0 +1,67 @@
+# This file was automatically generated by 'stack init'
+#
+# Some commonly used options have been documented as comments in this file.
+# For advanced use and comprehensive documentation of the format, please see:
+# https://docs.haskellstack.org/en/stable/yaml_configuration/
+
+# Resolver to choose a 'specific' stackage snapshot or a compiler version.
+# A snapshot resolver dictates the compiler version and the set of packages
+# to be used for project dependencies. For example:
+#
+# resolver: lts-3.5
+# resolver: nightly-2015-09-21
+# resolver: ghc-7.10.2
+#
+# The location of a snapshot can be provided as a file or url. Stack assumes
+# a snapshot provided as a file might change, whereas a url resource does not.
+#
+# resolver: ./custom-snapshot.yaml
+# resolver: https://example.com/snapshots/2018-01-01.yaml
+resolver:
+  url: https://raw.githubusercontent.com/commercialhaskell/stackage-snapshots/master/lts/18/14.yaml
+
+# User packages to be built.
+# Various formats can be used as shown in the example below.
+#
+# packages:
+# - some-directory
+# - https://example.com/foo/bar/baz-0.0.2.tar.gz
+#   subdirs:
+#   - auto-update
+#   - wai
+packages:
+- .
+# Dependency packages to be pulled from upstream that are not in the resolver.
+# These entries can reference officially published versions as well as
+# forks / in-progress versions pinned to a git hash. For example:
+#
+# extra-deps:
+# - acme-missiles-0.3
+# - git: https://github.com/commercialhaskell/stack.git
+#   commit: e7b331f14bcffb8367cd58fbfc8b40ec7642100a
+#
+# extra-deps: []
+
+# Override default flag values for local packages and extra-deps
+# flags: {}
+
+# Extra package databases containing global packages
+# extra-package-dbs: []
+
+# Control whether we use the GHC we find on the path
+# system-ghc: true
+#
+# Require a specific version of stack, using version ranges
+# require-stack-version: -any # Default
+# require-stack-version: ">=2.7"
+#
+# Override the architecture used by stack, especially useful on Windows
+# arch: i386
+# arch: x86_64
+#
+# Extra directories used by stack for building
+# extra-include-dirs: [/path/to/dir]
+# extra-lib-dirs: [/path/to/dir]
+#
+# Allow a newer minor version of GHC than the snapshot specifies
+# compiler-check: newer-minor
diff --git a/stack.yaml.lock b/stack.yaml.lock
new file mode 100644
index 0000000..888b596
--- /dev/null
+++ b/stack.yaml.lock
@@ -0,0 +1,13 @@
+# This file was autogenerated by Stack.
+# You should not edit this file by hand.
+# For more information, please see the documentation at:
+#   https://docs.haskellstack.org/en/stable/lock_files
+
+packages: []
+snapshots:
+- completed:
+    size: 586069
+    url: https://raw.githubusercontent.com/commercialhaskell/stackage-snapshots/master/lts/18/14.yaml
+    sha256: 87842ecbaa8ca9cee59a7e6be52369dbed82ed075cb4e0d152614a627e8fd488
+  original:
+    url: https://raw.githubusercontent.com/commercialhaskell/stackage-snapshots/master/lts/18/14.yaml