#!/bin/bash

set -ex  # Exit on error; debugging enabled.
set -o pipefail  # Fail a pipe if any sub-command fails.

# not makes sure the command passed to it does not exit with a return code of 0.
not() {
  # This is required instead of the earlier (! $COMMAND) because subshells and
  # pipefail don't work the same on Darwin as in Linux.
  ! "$@"
}

die() {
  echo "$@" >&2
  exit 1
}

fail_on_output() {
  tee /dev/stderr | not read
}

# Check to make sure it's safe to modify the user's git repo.
git status --porcelain | fail_on_output

# Undo any edits made by this script.
cleanup() {
  git reset --hard HEAD
}
trap cleanup EXIT

PATH="${GOPATH}/bin:${GOROOT}/bin:${PATH}"

if [[ "$1" = "-install" ]]; then
  # Check for module support
  if go help mod >& /dev/null; then
    # Install the pinned versions as defined in module tools.
    pushd ./test/tools
    go install \
      golang.org/x/lint/golint \
      golang.org/x/tools/cmd/goimports \
      honnef.co/go/tools/cmd/staticcheck \
      github.com/client9/misspell/cmd/misspell \
      github.com/golang/protobuf/protoc-gen-go
    popd
  else
    # Ye olde `go get` incantation.
    # Note: this gets the latest version of all tools (vs. the pinned versions
    # with Go modules).
    go get -u \
      golang.org/x/lint/golint \
      golang.org/x/tools/cmd/goimports \
      honnef.co/go/tools/cmd/staticcheck \
      github.com/client9/misspell/cmd/misspell \
      github.com/golang/protobuf/protoc-gen-go
  fi
  if [[ -z "${VET_SKIP_PROTO}" ]]; then
    if [[ "${TRAVIS}" = "true" ]]; then
      PROTOBUF_VERSION=3.3.0
      PROTOC_FILENAME=protoc-${PROTOBUF_VERSION}-linux-x86_64.zip
      pushd /home/travis
      wget https://github.com/google/protobuf/releases/download/v${PROTOBUF_VERSION}/${PROTOC_FILENAME}
      unzip ${PROTOC_FILENAME}
      bin/protoc --version
      popd
    elif not which protoc > /dev/null; then
      die "Please install protoc into your path"
    fi
  fi
  exit 0
elif [[ "$#" -ne 0 ]]; then
  die "Unknown argument(s): $*"
fi

# - Ensure all source files contain a copyright message.
not git grep -L "\(Copyright [0-9]\{4,\} gRPC authors\)\|DO NOT EDIT" -- '*.go'

# - Make sure all tests in grpc and grpc/test use leakcheck via Teardown.
not grep 'func Test[^(]' *_test.go
not grep 'func Test[^(]' test/*.go

# - Do not import x/net/context.
not git grep -l 'x/net/context' -- "*.go"

# - Do not import math/rand for real library code.  Use internal/grpcrand for
#   thread safety.
git grep -l '"math/rand"' -- "*.go" 2>&1 | not grep -v '^examples\|^stress\|grpcrand\|^benchmark\|wrr_test'

# - Ensure all ptypes proto packages are renamed when importing.
not git grep "\(import \|^\s*\)\"github.com/golang/protobuf/ptypes/" -- "*.go"

# - Check imports that are illegal in appengine (until Go 1.11).
# TODO: Remove when we drop Go 1.10 support
go list -f {{.Dir}} ./... | xargs go run test/go_vet/vet.go

# - gofmt, goimports, golint (with exceptions for generated code), go vet.
gofmt -s -d -l . 2>&1 | fail_on_output
goimports -l . 2>&1 | not grep -vE "(_mock|\.pb)\.go"
golint ./... 2>&1 | not grep -vE "(_mock|\.pb)\.go:"
go vet -all ./...

misspell -error .

# - Check that generated proto files are up to date.
if [[ -z "${VET_SKIP_PROTO}" ]]; then
  PATH="/home/travis/bin:${PATH}" make proto && \
    git status --porcelain 2>&1 | fail_on_output || \
    (git status; git --no-pager diff; exit 1)
fi

# - Check that our module is tidy.
if go help mod >& /dev/null; then
  go mod tidy && \
    git status --porcelain 2>&1 | fail_on_output || \
    (git status; git --no-pager diff; exit 1)
fi

# - Collection of static analysis checks
#
# TODO(dfawley): don't use deprecated functions in examples or first-party
# plugins.
SC_OUT="$(mktemp)"
staticcheck -go 1.9 -checks 'inherit,-ST1015' ./... > "${SC_OUT}" || true
# Error if anything other than deprecation warnings are printed.
not grep -v "is deprecated:.*SA1019" "${SC_OUT}"
# Only ignore the following deprecated types/fields/functions.
not grep -Fv '.HandleResolvedAddrs
.HandleSubConnStateChange
.HeaderMap
.NewAddress
.NewServiceConfig
.Metadata is deprecated: use Attributes
.Type is deprecated: use Attributes
.UpdateBalancerState
balancer.Picker
grpc.CallCustomCodec
grpc.Code
grpc.Compressor
grpc.Decompressor
grpc.MaxMsgSize
grpc.MethodConfig
grpc.NewGZIPCompressor
grpc.NewGZIPDecompressor
grpc.RPCCompressor
grpc.RPCDecompressor
grpc.RoundRobin
grpc.ServiceConfig
grpc.WithBalancer
grpc.WithBalancerName
grpc.WithCompressor
grpc.WithDecompressor
grpc.WithDialer
grpc.WithMaxMsgSize
grpc.WithServiceConfig
grpc.WithTimeout
http.CloseNotifier
info.SecurityVersion
naming.Resolver
naming.Update
naming.Watcher
resolver.Backend
resolver.GRPCLB' "${SC_OUT}"

echo SUCCESS