#!/bin/bash
# Copyright 2019 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.

### Creates a CL in an integration repository suitable for testing other CLs
### using the global integration commit queue.

## usage: fx make-integration-patch
##
## The command prints instructions and prompts the user for input. Once
## all input has been collected, it creates a patches.json file in
## integration/, creates a changelist and pushes it to Gerrit.

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

function print-instructions {
  echo "INSTRUCTIONS:"
  echo
  echo "For each change you wish to test with global integration:"
  echo "  1) Navigate to the change in Gerrit's web UI"
  echo "  2) Click on Download Patch (in the menu at the top right)"
  echo "  3) Copy any of the download options"
  echo "  4) Paste it here followed by a newline"
  echo
  echo "When all changes have been added, type ^D"
  echo
  echo "... GO!"
  echo
}

function print-help {
  echo "usage: fx make-integration-patch [OPTIONS]"
  echo "  -h, --help      this help message"
  echo "  -m, --message   commit message"
  echo
  print-instructions
}

function print-after-instructions {
  echo
  echo "The URL for your change is above. You can now navigate there and"
  echo "CQ+1 (dry run) the CL to test global integration with your patches."
}

function abort-if-unclean {
  local dir="$1"
  if ! git -C "${dir}" status --porcelain; then
    echo "ERROR: git repo at ${dir} must be clean." > /dev/stderr
    exit 1
  fi
}

function write-patches-json {
  local file="$1/patches.json"
  local contents="$2"

  echo "$contents" > "$file"
}

function prompt-or-exit {
  local prompt="$1"
  read -p "${prompt} [yN] " -n 1 -r yesno
  echo
  if [[ ! "$yesno" =~ ^[Yy]$ ]]; then
    exit 0
  fi
}

function create-git-commit-and-upload {
  local dir="$1"
  local message="$2"
  git -C "$dir" add -A
  if [[ "$message" = "" ]]; then
    git -C "$dir" commit -m "DO NOT SUBMIT - testing unsubmitted changes in GI"
  else
    git -C "$dir" commit -m "$message"
  fi
  git -C "$dir" push origin "HEAD:refs/for/master%wip"
  return $?
}

function read-patches-from-stdin {
  local line host project ref first=true
  declare -A seen_projects
  while read line; do
    local url=$(echo "$line" | cut -d " " -f 3 | sed 's/"//g')
    host=$(echo "$url" | cut -d / -f 3)
    project=$(echo "$url" | cut -d / -f 4-)
    ref=$(echo "$line" | cut -d " " -f 4)

    if [[ ${seen_projects[$project]} ]]; then
      fx-error "You are limited to one patch per project. Project '${project}' saw two patches."
      fx-error "Please collapse all changes in one project into a single change."
      return 1
    fi
    seen_projects[$project]=1

    # The patches.json requires host-review.googlesource.com, while Gerrit's download
    # commands vend host.googlesource.com.
    host=$(echo "$host" | sed "s/\.googlesource/-review\.googlesource/")

    if [[ ${first} = false ]]; then
      printf ',\n'
    fi
    printf '  {\n    "ref": "%s",\n    "host": "%s",\n    "project": "%s"\n  }' "$ref" "$host" "$project"
    first=false
  done < /dev/stdin
}

function main {
  local integration_dir="${FUCHSIA_DIR}/integration"

  local message=

  while [[ $# -gt 0 ]]; do
    case "$1" in
      -h|--help)
        print-help
        exit 0
        ;;
      -m|--message)
        shift
        message="$1"
        ;;
      *)
        echo "Invalid flag $1"
        print-help
        exit 1
    esac
    shift
  done

  abort-if-unclean "$integration_dir"
  print-instructions

  # Track seen projects. We are limited to a single patch per project.
  local patches
  patches=$(read-patches-from-stdin)
  local result=$?
  if [[ $result -ne 0 ]]; then
    exit 1
  fi

  local patch_file_contents=$(printf '[\n%s\n]' "$patches")

  echo
  echo "I'm about to write ${integration_dir}/patches.json with the following contents"
  echo "and then upload the patch file to Gerrit:"
  echo
  echo "$patch_file_contents"
  echo

  prompt-or-exit "Do you want to continue?"
  write-patches-json "$integration_dir" "$patch_file_contents"
  if create-git-commit-and-upload "$integration_dir" "$message"; then
    print-after-instructions
  else
    echo
    echo "ERROR: could not push your patch change to Gerrit. See details above."
    echo "Once you have resolve the error, you can push the change to Gerrit "
    echo "manually by invoking: "
    echo
    echo "git -C integration push origin HEAD:refs/for/master"
  fi
}

main "$@"