#!/bin/bash
#
# This source file is part of the Swift.org open source project
#
# Copyright (c) 2022 Apple Inc. and the Swift project authors
# Licensed under Apache License v2.0 with Runtime Library Exception
#
# See https://swift.org/LICENSE.txt for license information
# See https://swift.org/CONTRIBUTORS.txt for Swift project authors
#

# This script performs code checks such as verifying that source files
# use the correct license header. Its contents are largely copied from
# https://github.com/apple/swift-nio/blob/main/scripts/soundness.sh

set -eu
here="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"

function replace_acceptable_years() {
    # this needs to replace all acceptable forms with 'YEARS'
    sed -e 's/20[12][789012]-20[12][89012]/YEARS/' -e 's/20[12][89012]/YEARS/'
}

printf "=> Checking for unacceptable language… "
# This greps for unacceptable terminology. The square bracket[s] are so that
# "git grep" doesn't find the lines that greps :).
unacceptable_terms=(
    -e blacklis[t]
    -e whitelis[t]
    -e slav[e]
)
# Ignore the NonInclusiveLangeChecker source and tests
if git grep --color=never -i "${unacceptable_terms[@]}" -- :/**/^NonInclusiveLanguageChecker*.swift > /dev/null; then
    printf "\033[0;31mUnacceptable language found.\033[0m\n"
    git grep -i "${unacceptable_terms[@]}"
    exit 1
fi
printf "\033[0;32mokay.\033[0m\n"

printf "=> Checking license headers… "
tmp=$(mktemp /tmp/.docc-check-source_XXXXXX)

for language in swift-or-c bash md-or-tutorial; do
  declare -a matching_files
  declare -a exceptions
  declare -a reader
  matching_files=( -name '*' )
  reader=head
  case "$language" in
      swift-or-c)
        exceptions=( -name Package.swift )
        matching_files=( -name '*.swift' -o -name '*.c' -o -name '*.h' )
        cat > "$tmp" <<"EOF"
// This source file is part of the Swift.org open source project
//
// Copyright (c) YEARS Apple Inc. and the Swift project authors
// Licensed under Apache License v2.0 with Runtime Library Exception
//
// See https://swift.org/LICENSE.txt for license information
// See https://swift.org/CONTRIBUTORS.txt for Swift project authors
EOF
        ;;
      bash)
        matching_files=( -name '*.sh' )
        cat > "$tmp" <<"EOF"
#!/bin/bash
#
# This source file is part of the Swift.org open source project
#
# Copyright (c) YEARS Apple Inc. and the Swift project authors
# Licensed under Apache License v2.0 with Runtime Library Exception
#
# See https://swift.org/LICENSE.txt for license information
# See https://swift.org/CONTRIBUTORS.txt for Swift project authors
#
EOF
      ;;
      md-or-tutorial)
        exceptions=( -path "./.github/*.md")
        matching_files=( -name '*.md' -o -name '*.tutorial' )
        reader=tail
        cat > "$tmp" <<"EOF"
<!-- Copyright (c) YEARS Apple Inc and the Swift Project authors. All Rights Reserved. -->
EOF
      ;;
    *)
      echo >&2 "ERROR: unknown language '$language'"
      ;;
  esac

  # Determine which SHA command to use; not all platforms support shasum, but they
  # likely either support shasum or sha256sum.
  SHA_CMD=""
  if [ -x "$(command -v shasum)" ]; then
    SHA_CMD="shasum"
  elif [ -x "$(command -v sha256sum)" ]; then
    SHA_CMD="sha256sum"
  else
    echo >&2 "No sha command found; install shasum or sha256sum or submit a PR that supports another platform"
  fi

  expected_lines=$(cat "$tmp" | wc -l)
  expected_sha=$(cat "$tmp" | "$SHA_CMD")

  (
    cd "$here/.."
    find . \
      \( \! -path '*/.build/*' -a \
      \! -name '.' -a \
      \( "${matching_files[@]}" \) -a \
      \( \! -path './swift-docc/*' \) -a \
      \( \! -path './swift-docc-render-artifact/*' \) -a \
      \( \! \( "${exceptions[@]}" \) \) \) | while read line; do
      if [[ "$(cat "$line" | replace_acceptable_years | $reader -n $expected_lines | $SHA_CMD)" != "$expected_sha" ]]; then
        printf "\033[0;31mmissing headers in file '$line'!\033[0m\n"
        diff -u <(cat "$line" | replace_acceptable_years | $reader -n $expected_lines) "$tmp"
        exit 1
      fi
    done
  )
done

printf "\033[0;32mokay.\033[0m\n"
rm "$tmp"
