#!/bin/bash
# Copyright 2020 The Fuchsia Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

#### CATEGORY=Build
### Locally replicate the result of infra builds and tests
##
## This command attempts to replicate the result of an infra builder by reading
## build information and translating to corresponding local 'fx' commands.
##
## usage: fx repro [-h|--help] <BUILD_ID>|<BUILD_URL>|<FINT_PARAMS_FILE>
##
##  BUILD_ID: the id of a build, prefixed or not by "b". For example:
##       b8860637037546448224 or 8860637037546448224
##
##  BUILD_URL: the URL you are redirected to when you click on a box in the
##       "Tryjob" section of a Gerrit CL. For example:
##       https://ci.chromium.org/p/fuchsia/builders/try/fuchsia-x64-release/b8860637037546448224?
##
##  FINT_PARAMS_FILE: a local path to a fint params file, usually a *.textproto file
##       in //integration/infra/config/generated/*/fint_params/. For example:
##       integration/infra/config/generated/fuchsia/fint_params/try/core.x64-release.textproto
##
## Please provide feedback on go/fx-repro-feedback

source "${FUCHSIA_DIR}/tools/devshell/lib/style.sh" || exit $?
source "$(cd "$(dirname "${BASH_SOURCE[0]}")" >/dev/null 2>&1 && pwd)"/lib/vars.sh || exit $?

set -e -o pipefail

function create_builddir_name {
  if [[ -n "$build_id" ]]; then
    echo "out/repro_${build_id}"
  else
    echo "out/repro_${project}_${bucket}_${builder}"
  fi
}

function repro {
  local project="$1"
  local bucket="$2"
  local builder="$3"
  local build_id="$4"

  local fint_params_file build_dir_name
  local fint_params_file_relative
  local fint_params_file_relative_legacy

  local instructions_file

  local can_sync_to=true
  local no_sync_to_reason

  if ! fx-command-exists "sync-to"; then
    can_sync_to=false
    no_sync_to_reason="\`fx sync-to\` is not available in a public checkout."
  fi

  if [[ -z "$build_id" ]]; then
    can_sync_to=false
  else
    check_bb_auth
    build=$(get_build "$build_id")
    if [[ -z "$build" ]]; then
      fx-error "Could not retrieve build from buildbucket."
      return 1
    fi

    project="$(get_builder_field project)"
    bucket="$(get_builder_field bucket)"
    builder="$(get_builder_field builder)"

    if [ "$project" == "fuchsia" ]; then
      # `sync-to` doesn't support public builds, so `repro` can't support them either.
      can_sync_to=false
      no_sync_to_reason="\`fx sync-to\` only supports internal builds (see https://fxbug.dev/66019)."
    elif [[ "$bucket" = *try ]]; then
      # `sync-to` can't resolve the commit hashes that result from patching
      # changes in CQ builds.
      can_sync_to=false
      no_sync_to_reason="\`fx sync-to\` doesn't work on tryjobs (see https://fxbug.dev/72533)."
    fi

    build_url="https://luci-milo.appspot.com/p/${project}/builders/${bucket}/${builder}/b${build_id}"
  fi

  fint_params_file_relative="$(get_fint_params_path)"
  # Older builds don't emit the fint params path as an output property, so we
  # have to fall back to a more fragile approach for constructing the path.
  # TODO(olivernewman): Delete this more fragile logic after we no longer need
  # to reproduce any builds from before fxrev.dev/573872 landed.
  if [[ -z "$fint_params_file_relative" ]]; then
    # Note that it's not a strict requirement that a fint params file have the
    # same name as its builder; it just happens to be the case for most builders
    # (except the builders that do multiple builds and thus have multiple fint
    # params files).
    fint_params_file_relative="integration/infra/config/generated/${project}/fint_params/${bucket}/${builder}.textproto"
    # Older revisions used the following pattern:
    fint_params_file_relative_legacy="integration/infra/config/generated/${project}/specs/${bucket}/${builder}.fint.textproto"
  fi
  fint_params_file="${FUCHSIA_DIR}/${fint_params_file_relative}"
  fint_params_file_legacy="${FUCHSIA_DIR}/${fint_params_file_relative_legacy}"

  if [[ ! -f "${fint_params_file}" ]]; then
    if [[ -f "${fint_params_file_legacy}" ]]; then
      fint_params_file="$fint_params_file_legacy"
    else
      fx-error "Cannot find fint parameters for this build: ${fint_params_file} or ${fint_params_file_legacy}"
      fx-error "If this is an internal builder, make sure your Fuchsia source tree has the internal"
      fx-error "integration repository as described in https://fuchsia.dev/internal/intree/development/get-the-source-code"
      return 1
    fi
  fi

  build_dir_name="$(create_builddir_name)"
  instructions_file="${FUCHSIA_DIR}/${build_dir_name}.instructions"

  fx-config-read
  if [[ "${FUCHSIA_BUILD_DIR}" =~ out/repro_ ]]; then
    fx-error "Build directory is still set to a previous fx repro run: ${FUCHSIA_BUILD_DIR#${FUCHSIA_DIR}/}"
    fx-error "Please restore it to the previous state."
    if [[ -f "${FUCHSIA_BUILD_DIR}.instructions" ]]; then
      fx-error "Instructions in ${FUCHSIA_BUILD_DIR#${FUCHSIA_DIR}/}.instructions"
    else
      fx-error "# fx set-build-dir out/default"
    fi
    exit 1
  fi

  rm -f "${instructions_file}"

  print_comment "Fint params file: //$fint_params_file_relative"
  if [[ -n "$build_id" ]]; then
    print_comment "Build URL: $build_url"
  fi

  print_spacer

  if $can_sync_to; then
    print_comment "Sync the Fuchsia source tree to the same commit:"
    print_cmd "fx sync-to ${build_id}"
    print_spacer
  elif [[ -n "$build_id" ]]; then
    print_comment "WARNING: Can't reproduce this build's checkout state."
    print_comment "$no_sync_to_reason"
    print_comment "Make sure your local checkout corresponds to the code used by the build."
    print_spacer
  fi

  print_comment "Set the build configuration:"
  print_cmd "fx --dir=${build_dir_name} set --fint-params-path '$fint_params_file_relative'"
  print_spacer

  print_comment "Build:"
  print_cmd "fx build --fint-params-path '$fint_params_file_relative'"
  print_spacer

  print_comment "If necessary, start an emulator or connect a device"
  print_spacer

  print_comment "Run tests (use the flag '--e2e' if you also want to run E2E tests):"
  repro_test_commands
  print_spacer

  if [[ -n "$build_id" ]]; then
    print_comment "Run only failed tests:"
    repro_failed_test_commands
    print_spacer
  fi

  if [[ "$(build_has_binary_sizes)" == "true" ]]; then
    print_comment "Check component sizes:"
    print_cmd "fx size_checker -build-dir ${build_dir_name} -sizes-json-out ${FUCHSIA_DIR}/${build_dir_name}.sizes.json"
    print_spacer
  fi

  print_comment "Restore to the previous state:"
  print_cmd "fx set-build-dir ${FUCHSIA_BUILD_DIR#${FUCHSIA_DIR}/}"
  if $can_sync_to; then
    print_cmd "fx sync-to reset"
  fi
  print_spacer
  print_comment "(Optional) Remove the repro build directory:"
  print_cmd "rm -Rf ${FUCHSIA_DIR}/${build_dir_name}"

  # TODO: add instructions to run botanist, for example:
  # "Execute the steps in 'Reproducing the task locally' from https://chrome-swarming.appspot.com/task?id=4d23bde27aab0910"
  # or, to simplify, just print out the botanist command line, e.g.:
  # ./botanist -level trace run -images gs://fuchsia-artifacts-internal/builds/8875967070288043824/images/images.json -timeout 1800s -syslog syslog.txt -repo http://localhost:8080/fuchsia-artifacts-internal/builds/8875967070288043824/packages/repository -blobs http://localhost:8080/fuchsia-artifacts-internal/blobs -ssh private_key -config ./qemu.json ./testrunner -out-dir out -snapshot-output snapshot.zip -per-test-timeout 300s tests.json]
  #

  echo
  echo "*** These instructions are saved to ${instructions_file#${FUCHSIA_DIR}/} in case you need them later."
  echo "*** Please, provide feedback on http://go/fx-repro-feedback"
}

function repro_failed_test_commands {
  local status
  status="$(get_build_status)"
  if [[ "$status" != "FAILURE" ]]; then
    print_comment "Status of this build is $status. Failed tests can only exist in builds with status 'FAILURE'"
    return
  fi

  local failed_tests
  failed_tests="$(get_failed_tests)"
  if [[ -z "$failed_tests" ]]; then
    print_comment "Could not find the failed_test_names property in this build."
    print_comment "Maybe it failed in other stages, e.g. build, or it is an old build. Only recent builds export the names of failed tests as properties."
    print_comment "If this is an old build, you may find failed tests in $build_url"
    return
  fi
  repro_test_commands "$failed_tests"
}

function repro_test_commands {
  local failed_tests=("$@")

  print_cmd "fx test ${failed_tests[*]}"
}

function jq {
  jq_command="$1"
  json_obj="$2"
  fx-command-run jq -r "$jq_command" <<< "$json_obj"
}

function get_build_status {
  jq ".status" "$build"
}

function get_builder_field {
  jq ".builder.$1" "$build"
}

# Returns a space-separated list of all the tests that failed for the build.
function get_failed_tests {
  jq '.output.properties.failed_test_names? // [] | unique | join(" ")' "$build"
}

# Returns the fint params path used by the build. Older builds may not have this
# property set.
function get_fint_params_path {
  jq '.output.properties.fint_params_path? // ""' "$build"
}

# Returns "true" or "false" depending on whether the build exposes a
# "binary_sizes" output property.
function build_has_binary_sizes {
  jq '.output.properties | has("binary_sizes")' "$build"
}

function usage {
  fx-command-help
}

function print {
  if [[ -n "${instructions_file}" ]]; then
    echo -e "$*" >> "${instructions_file}"
  fi
  echo -e "$*"
}

function print_cmd {
  if [[ -n "${instructions_file}" ]]; then
    echo -e "$*" >> "${instructions_file}"
  fi
  style::echo --green "$*"
}

function print_spacer {
  print ""
}

function print_comment {
  print "# $*"
}

function check_bb_auth {
  local bbtool="${FUCHSIA_DIR}/prebuilt/tools/buildbucket/bb"
  while ! "$bbtool" auth-info >/dev/null 2>&1; do
    fx-warn "Please login to Buildbucket first:"
    "$bbtool" auth-login
  done
}

function get_build {
  local build_id="$1"
  "${FUCHSIA_DIR}/prebuilt/tools/buildbucket/bb" get "$build_id" -json -fields "status,builder,output.properties"
}

function main {
  # Expect exactly one state.
  if [[ $# -ne 1 ]]; then
    fx-error "BUILD_URL or FINT_PARAMS_FILE missing."
    usage
    return 1
  fi

  if [[ "$1" =~ ^(-h|--help)$ ]]; then
    usage
    return 0
  fi


  local build_url="$1"
  build_url="${build_url#http://}"
  build_url="${build_url#https://}"

  local project="" bucket="" builder="" build_id=""
  if [[ "${build_url}" =~ ^b?([0-9]+)[?]?$ ]]; then
    build_id="${BASH_REMATCH[1]}"

  elif [[ "${build_url}" =~ ^cr-buildbucket.appspot.com/build/b?([0-9]+) ]]; then
    build_id="${BASH_REMATCH[1]}"

  elif [[ "${build_url}" =~ -subbuild/ ]]; then
    fx-error "The URL you pasted is from a subbuild, which doesn't have enough information"
    fx-error "to reproduce the entire build. Please go back and find the correponding tryjob"
    fx-error "without the '-subbuild' suffix."
    return 1

  elif [[ "${build_url}" =~ ^integration/infra/config/generated/(.+)/fint_params/(.+)/(.+).textproto$ ]] ||
       [[ "${build_url}" =~ ^integration/infra/config/generated/(.+)/specs/(.+)/(.+).fint.textproto$ ]]; then
    local fint_params="${FUCHSIA_DIR}/${build_url}"
    if [[ ! -f "${fint_params}" ]]; then
      fx-error "Cannot find file ${fint_params}"
      usage
      return 1
    fi
    project="${BASH_REMATCH[1]}"
    bucket="${BASH_REMATCH[2]}"
    builder="${BASH_REMATCH[3]}"

  elif [[ "${build_url}" =~ ^(luci-milo.appspot.com|ci.chromium.org)(/ui)?/p/(.+)/builders/(.+)/(.+)/b([0-9]+) ]]; then
    build_id="${BASH_REMATCH[6]}"

  else
    fx-error "Unsupported build ID, build URL or fint params file: ${build_url}"
    usage
    return 1
  fi

  repro "$project" "$bucket" "$builder" "$build_id"
}

main "$@"