#!/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
### manage Goma distributed compilation client

## Usage: fx goma [--browser] [--update]
##
## This makes sure that both initial setup tasks are complete and that
## periodic maintenance actions are done.  It's probably only really
## necessary to run it once, but it should be harmless (and reasonably
## fast) to run it again any time, such as after a `jiri update`.  It's
## just not a good idea to run it while you have a build running in the
## background, since it may result in restarting the local Goma client
## service and causing all new compilation commands to fail for a moment.
##
## See also `fx goma_auth` and `fx goma_ctl`.  This mostly just runs those.
##
## The `fx goma_auth` command is usually only needed once at setup time to
## run `fx goma_auth login`, which is done by `fx goma` if needed.  Use `fx
## goma_auth help` for details on `fx goma_auth` subcommands.  If something
## seems to be wrong, you can run the command `fx goma_auth logout` and
## then repeat `fx goma`.
##
## The `fx goma_ctl` command controls the Goma client service on your local
## machine.  Use `fx goma_ctl help` for details.  The common subcommand used
## every day is `fx goma_ctl ensure_start` to make sure your local client
## service is running.  (`fx goma` does this for you but only after a few other
## checks that might be somewhat slower than `fx goma_ctl ensure_start` alone.)
##
## The `--browser` switch is passed along to `fx goma_auth login` so that
## it attempts to launch a browser window to perform authentication.  This
## may or may not work, depending on your desktop and command-line setup.
## Without that switch, it will print out a URL you need to visit in your
## browser to (authenticate and) copy a token to paste into a prompt.
##
## **NOTE:** _The following features are temporary for the transition._
##
## `fx goma` checks for an old Goma installation and recommends commands to
## update to the current recommended style managed by `fx goma`.
##
## It also checks the current Fuchsia build directory's Goma configuration.
## This is the only aspect of `fx goma` that refers to a build directory
## (as controlled by the `--dir` switch to `fx` or the most recent `fx set`
## or `fx use` command).  It will report whether the build is set to use
## the recommended Goma setup managed by `fx goma`.  If given the
## `--update` switch, it will modify the existing `args.gn` and then re-run
## `fx gen` to enable Goma with the standard setup.  This results in the
## same configuration that a fresh `fx set` will with the `--goma` switch
## (or without the switch, once `fx goma` has been done once).
##

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

set -e

readonly GOMA_AUTH="$PREBUILT_GOMA_DIR/goma_auth.py"
readonly GOMA_CTL="$PREBUILT_GOMA_DIR/goma_ctl.py"

if [[ ! -x "$GOMA_AUTH" || ! -x "$GOMA_CTL" ]]; then
  echo "*** $PREBUILT_GOMA_DIR is not current."
  echo "*** Be sure to run \`jiri fetch-packages\` or \`jiri update\`."
  exit 1
fi

function main {
  local login_args=() update=false

  while [ $# -gt 0 ]; do
    case "$1" in
    --browser)
      login_args+=("$1")
      shift
      ;;
    --update)
      update=true
      shift
      ;;
    *)
      fx-command-help
      return 1
      ;;
    esac
  done

  # TODO(mcgrathr): Remove these after some period when old installs are gone.
  check
  check-build $update

  "$GOMA_AUTH" info || "$GOMA_AUTH" login "$@"
  if "$GOMA_CTL" status; then
    "$GOMA_CTL" update_hook
  else
    "$GOMA_CTL" ensure_start
  fi
}

# TODO(mcgrathr): Remove this after some period when old installs are gone.
function check {
  if [[ -n "$GOMA_DIR" ]]; then
    echo "*** Detected GOMA_DIR environment variable."
    echo "*** Remove GOMA_DIR from the environment and run \`fx goma\` again."
    echo "*** \`unset GOMA_DIR\` will remove it from the running shell."
    echo "*** But check your dot files to make sure it's not set at login."
  fi

  local goma_dir="$("$GOMA_CTL" goma_dir 2> /dev/null)"
  if [[ -d "$goma_dir" && \
        "$(cd "$goma_dir" && /bin/pwd)" = "$(cd "$PREBUILT_GOMA_DIR" && /bin/pwd)" ]]; then
    return 0
  fi
  echo "*** Detected old Goma installed in $goma_dir"
  echo "*** Recommend \`fx goma_ctl stop\` and \`rm -rf '$goma_dir'\`."
  echo "*** It may still be necessary to run \`fx goma\` separately in each old build."
  return 1
}

# TODO(mcgrathr): Remove this after some period when old installs are gone.
function check-build {
  local update=$1

  unset USE_GOMA GOMA_DIR # Just in case it's in the environment.
  fx-config-read || return

  if [[ -z "$USE_GOMA" ]]; then
    echo "*** Run \`fx gen\` and then try \`fx goma\` again."
    echo "*** Or else just do a fresh \`fx set\` to get the right defaults!"
    return 1
  fi

  local status=0
  local gen=false

  if [[ "$USE_GOMA" = true ]]; then
    echo "$FUCHSIA_BUILD_DIR has Goma enabled."
  elif $update; then
    echo "*** Enabling Goma in $FUCHSIA_BUILD_DIR..."
    sed -e /use_goma/d "$FUCHSIA_BUILD_DIR/args.gn" > "$FUCHSIA_BUILD_DIR/args.gn.new"
    mv -f "$FUCHSIA_BUILD_DIR/args.gn.new" "$FUCHSIA_BUILD_DIR/args.gn"
    echo "use_goma = true" >> "$FUCHSIA_BUILD_DIR/args.gn"
    echo "*** Make sure that Goma has been set up via \`fx goma bootstrap\`!"
    gen=true
  else
    echo "$FUCHSIA_BUILD_DIR has Goma disabled."
    status=1
  fi

  if [[ -z "$GOMA_DIR" ]]; then
    echo "$FUCHSIA_BUILD_DIR uses prebuilt Goma client."
  elif $update; then
    echo "*** $FUCHSIA_BUILD_DIR was using non-default goma_dir=\"$GOMA_DIR\"."
    sed -i /goma_dir/d "$FUCHSIA_BUILD_DIR/args.gn"
    echo "*** Reset to default prebuilt Goma client."
    gen=true
  else
    echo "$FUCHSIA_BUILD_DIR uses non-default goma_dir=\"$GOMA_DIR\"."
    status=1
  fi

  if $gen; then
    echo "*** Running \`fx gen\` after $FUCHSIA_BUILD_DIR/args.gn updates..."
    fx-command-run gen
  fi

  if [[ $status -ne 0 ]]; then
    echo "*** Run \`fx goma --update\` to reset this build to defaults."
    echo "*** Or else just do a fresh \`fx set\` to get the right defaults!"
  fi
  return $status
}

main "$@"