#!/usr/bin/env bash

APP_NAME=Gitea
DEFAULT_PORT=3000
GITEA_BINARY=$HOME/gitea/gitea
TMP_LOCATION=$HOME/tmp
PGP_KEY_FINGERPRINT=7C9E68152594688862D62AF62D9AE806EC1592E2
ORG=go-gitea # Organisation or GitHub user
REPO=gitea
GITHUB_API_URL=https://api.github.com/repos/$ORG/$REPO/releases/latest
# simply get the first password string from ~/.my.cnf
MYSQL_PASSWORD_STR=$(grep --max-count=1 password= ~/.my.cnf)
# using bash substring syntax to remove the 9 characters "password="
MYSQL_PASSWORD=${MYSQL_PASSWORD_STR:9}

function install_gitea
{
  echo "Please set your $APP_NAME login credentials."
  read -r -p "$APP_NAME admin user: " ADMIN_USER
  ask_for_password
  echo "Download $APP_NAME $INSTALL_VERSION"
  curl --location --progress-bar --output "$TMP_LOCATION"/gitea "$DOWNLOAD_URL"
  verify_file
  mkdir --parents ~/gitea/custom/conf/
  mv --verbose "$TMP_LOCATION"/gitea "$GITEA_BINARY"
  chmod u+x --verbose "$GITEA_BINARY"
  #ln --symbolic --verbose "$GITEA_BINARY" ~/bin/gitea
  ## gitea does not recognize its real path, maybe use a wrapper for this
  install_gitea_wrapper
  ln --symbolic --verbose ~/.ssh ~/gitea/.ssh
  create_app_ini
  mysql --verbose --execute="CREATE DATABASE ${USER}_gitea"
  echo "The database initialisation may take a while ..."
  $GITEA_BINARY migrate 1>/dev/null
  create_gitea_daemon_config
  supervisorctl reread
  supervisorctl update gitea
  supervisorctl status gitea
  echo "waiting 30 seconds ..."
  sleep 30
  supervisorctl status gitea
  $GITEA_BINARY admin user create \
    --username "${ADMIN_USER}" \
    --password "${ADMIN_PASS}" \
    --email "${USER}"@uber.space \
    --admin \
    --config "/home/${USER}/gitea/custom/conf/app.ini" \
    1>/dev/null
  uberspace web backend set / --http --port $DEFAULT_PORT
  uberspace web backend list
  install_update_script
  echo "This is the file structure for this app"
  echo_tree
  printf "You can now access your $APP_NAME by directing your browser to: \n https://%s.uber.space \n" "$USER"
}

function uninstall_gitea
{
  # If some files do not exist there may be some errors
  unset_critical_section
  fix_stop_signal
  $GITEA_BINARY manager flush-queues
  supervisorctl stop gitea
  sleep 30
  mysql --verbose --execute="DROP DATABASE ${USER}_gitea"
  rm ~/etc/services.d/gitea.ini
  rm -r ~/gitea
  rm ~/bin/gitea
  rm ~/bin/gitea-update
  supervisorctl reread
  supervisorctl update gitea
  uberspace web backend set / --apache
  set_critical_section
}

function ask_for_password
{
  echo "Note: Your password input will not be visible."
  read -s -r -p "$APP_NAME admin password: " ADMIN_PASS
  echo
  read -s -r -p "$APP_NAME admin password confirmation: " ADMIN_PASS_CONFIRMATION
  echo
  while [ -z "$ADMIN_PASS" ] || [ "$ADMIN_PASS" != "$ADMIN_PASS_CONFIRMATION" ]
  do
    echo That was not correct, try again
    ask_for_password
  done
}

# This is only relevant for the uninstaller for broken old installations
function fix_stop_signal
{
  if (grep --quiet HUP "$HOME"/etc/services.d/gitea.ini)
  then
    sed --in-place '/HUP/d' "$HOME"/etc/services.d/gitea.ini
    supervisorctl reread
    supervisorctl update
  fi
}

function process_parameters
{
  while test $# -gt 0
	do
    local next_parameter=$1
    case $next_parameter in
      use )
        shift
        USE_VERSION="$1"
        if [[ -n $USE_VERSION ]]
        then GITHUB_API_URL=https://api.github.com/repos/$ORG/$REPO/releases/tags/v$USE_VERSION
        fi
        shift
      ;;
      uninstall )
        echo "This command tries to revert the $APP_NAME installation, it will delete all of its scripts, service config, ~/gitea directory with all contents and drop the database"
        if yes_no_question "Do you really want to do this?"
        then uninstall_gitea
        fi
        exit 0
      ;;
      * )
        echo "$1 can not be processed, exiting script"
        exit 1
      ;;
    esac
  done
}

function install_gitea_wrapper
{
  cat << 'end_of_content' > ~/bin/gitea
#!/usr/bin/env bash

## No linking to the gitea binary as that would not recognize its real path,
## so it would set the wrong working directory settings. We just use a wrapper script instead.
export GITEA_WORK_DIR=$HOME/gitea

FIRST_PARAMETER="$1"
GITEA_BINARY=$HOME/gitea/gitea

case $FIRST_PARAMETER in
  start | stop | restart | status )
    supervisorctl $FIRST_PARAMETER gitea
    exit $?
  ;;
  update | upgrade )
    gitea-update
    exit $?
  ;;
  log | logs )
    less ~/logs/supervisord.log
    exit $?
  ;;
  backup )
    ## this command creates a backup zip file with db, repos, config, log, data
    ## restoring the backup is more difficult
    ## read: https://docs.gitea.io/en-us/backup-and-restore/#restore-command-restore
    $GITEA_BINARY dump --tempdir $HOME/tmp
    exit $?
  ;;
esac

$GITEA_BINARY "$@"
exit $?
end_of_content
  chmod u+x --verbose ~/bin/gitea
}

function create_app_ini
{
  SECRET_KEY=$($GITEA_BINARY generate secret SECRET_KEY)
  cat << end_of_content > ~/gitea/custom/conf/app.ini
[server]
DOMAIN               = $USER.uber.space
ROOT_URL             = https://%(DOMAIN)s
OFFLINE_MODE         = true ; Disables use of CDN for static files and Gravatar for profile pictures.
LANDING_PAGE         = explore ; possible options are [home, explore, organizations, login, custom like /org/repo or url]
LFS_START_SERVER     = true ; Enables Git LFS support

[database]
DB_TYPE  = mysql
NAME     = ${USER}_gitea
USER     = $USER
PASSWD   = $MYSQL_PASSWORD

[security]
INSTALL_LOCK        = true ; disables the installation web page
MIN_PASSWORD_LENGTH = 8
PASSWORD_COMPLEXITY = lower
SECRET_KEY          = $SECRET_KEY

[session]
COOKIE_SECURE = true

[service]
DISABLE_REGISTRATION       = true ; security option, only admins can create new users.
SHOW_REGISTRATION_BUTTON   = false
REGISTER_EMAIL_CONFIRM     = true
DEFAULT_ORG_VISIBILITY     = private ; [public, limited, private]
DEFAULT_KEEP_EMAIL_PRIVATE = true
NO_REPLY_ADDRESS           = noreply.${USER}.uber.space

[mailer]
ENABLED     = true
MAILER_TYPE = sendmail
FROM        = ${USER}@uber.space

[other]
SHOW_FOOTER_VERSION = false
end_of_content
}

function create_gitea_daemon_config
{
  cat << end_of_content > ~/etc/services.d/gitea.ini
[program:gitea]
directory=%(ENV_HOME)s/gitea
command=%(ENV_HOME)s/gitea/gitea web
startsecs=30
autorestart=true
end_of_content
}

function set_install_version
{
  curl --silent "$GITHUB_API_URL" > "$TMP_LOCATION"/github_api_response.json
  TAG_NAME=$(jq --raw-output '.tag_name' "$TMP_LOCATION"/github_api_response.json)
  INSTALL_VERSION=${TAG_NAME:1}
}

function set_download_url
{
  DOWNLOAD_URL=$(jq --raw-output '.assets[].browser_download_url' "$TMP_LOCATION"/github_api_response.json |
    grep --max-count=1 "linux-amd64")
}

function download_signature_file
{
  SIGNATURE_FILE_URL=$(jq --raw-output '.assets[].browser_download_url' "$TMP_LOCATION"/github_api_response.json |
    grep "linux-amd64.asc")
  rm "$TMP_LOCATION"/github_api_response.json
  wget --quiet --progress=bar:force --output-document "$TMP_LOCATION"/gitea.asc "$SIGNATURE_FILE_URL"
}

function verify_file
{
  download_signature_file

  ## downloading public key if it does NOT already exist OR if it is expired
  if ! (gpg --fingerprint $PGP_KEY_FINGERPRINT) ||
    (gpg --fingerprint $PGP_KEY_FINGERPRINT | grep expired)
  then
    ## currently the key download via gpg does not work on Uberspace
    #gpg --keyserver keys.openpgp.org --recv $PGP_KEY_FINGERPRINT
    curl --silent https://keys.openpgp.org/vks/v1/by-fingerprint/$PGP_KEY_FINGERPRINT | gpg --import
  fi

  if ! gpg --export-ownertrust | grep --quiet $PGP_KEY_FINGERPRINT:6:
  then echo "$PGP_KEY_FINGERPRINT:6:" | gpg --import-ownertrust
  fi

  if gpg --verify "$TMP_LOCATION"/gitea.asc "$TMP_LOCATION"/gitea
  then rm "$TMP_LOCATION"/gitea.asc; return 0
  else echo "gpg verification results in a BAD signature"; exit 1
  fi
}

function install_update_script
{
  cat << 'end_of_content' > ~/bin/gitea-update
#!/usr/bin/env bash

APP_NAME=Gitea
GITEA_BINARY=$HOME/gitea/gitea
TMP_LOCATION=$HOME/tmp
PGP_KEY_FINGERPRINT=7C9E68152594688862D62AF62D9AE806EC1592E2

ORG=go-gitea # Organisation or GitHub user
REPO=gitea
GITHUB_API_URL=https://api.github.com/repos/$ORG/$REPO/releases/latest

function do_update_procedure
{
  curl --location --progress-bar --output "$TMP_LOCATION"/gitea "$DOWNLOAD_URL"
  verify_file
  $GITEA_BINARY manager flush-queues
  supervisorctl stop gitea
  mv --verbose "$TMP_LOCATION"/gitea "$GITEA_BINARY"
  chmod u+x --verbose "$GITEA_BINARY"
  echo "$APP_NAME service takes 30 seconds to start"
  supervisorctl start gitea
  supervisorctl status gitea
}

function set_local_version
{
  LOCAL_VERSION=$($GITEA_BINARY --version |
    awk '{print $3}')
}

function set_latest_version
{
  curl --silent $GITHUB_API_URL > "$TMP_LOCATION"/github_api_response.json
  TAG_NAME=$(jq --raw-output '.tag_name' "$TMP_LOCATION"/github_api_response.json)
  LATEST_VERSION=${TAG_NAME:1}
  DOWNLOAD_URL=$(jq --raw-output '.assets[].browser_download_url' "$TMP_LOCATION"/github_api_response.json |
    grep --max-count=1 "linux-amd64")
}

function download_signature_file
{
  SIGNATURE_FILE_URL=$(jq --raw-output '.assets[].browser_download_url' "$TMP_LOCATION"/github_api_response.json |
    grep "linux-amd64.asc")
  rm "$TMP_LOCATION"/github_api_response.json
  wget --quiet --progress=bar:force --output-document "$TMP_LOCATION"/gitea.asc "$SIGNATURE_FILE_URL"
}

function verify_file
{
  download_signature_file

  ## downloading public key if it does NOT already exist OR if it is expired
  if ! gpg --fingerprint $PGP_KEY_FINGERPRINT ||
    (gpg --fingerprint $PGP_KEY_FINGERPRINT | grep expired)
  then
    ## currently the key download via gpg does not work on Uberspace
    #gpg --keyserver keys.openpgp.org --recv $PGP_KEY_FINGERPRINT
    curl --silent https://keys.openpgp.org/vks/v1/by-fingerprint/$PGP_KEY_FINGERPRINT | gpg --import
  fi

  if ! gpg --export-ownertrust | grep --quiet $PGP_KEY_FINGERPRINT:6:
  then echo "$PGP_KEY_FINGERPRINT:6:" | gpg --import-ownertrust
  fi

  if gpg --verify "$TMP_LOCATION"/gitea.asc "$TMP_LOCATION"/gitea
  then rm "$TMP_LOCATION"/gitea.asc; return 0
  else echo "gpg verification results in a BAD signature"; exit 1
  fi
}

# version_lower_than A B
# returns whether A < B
function is_version_lower_than
{
  test "$(echo "$@" |                 # get all version arguments
    tr " " "\n" |                     # replace `space` with `new line`
    sed '/alpha/d; /beta/d; /rc/d' |  # remove pre-release versions (version-sort interprets suffixes as patch versions)
    sort --version-sort --reverse |   # latest version will be sorted to line 1
    head --lines=1)" != "$1"          # filter line 1 and compare it to A
}

function fix_stop_signal
{
  if (grep --quiet HUP "$HOME"/etc/services.d/gitea.ini)
  then
    sed --in-place '/HUP/d' "$HOME"/etc/services.d/gitea.ini
    supervisorctl reread
    supervisorctl update
  fi
}

function is_update_available
{
  set_local_version
  set_latest_version
  if is_version_lower_than "$LOCAL_VERSION" "$LATEST_VERSION"
  then return 0
  else return 1
  fi
}

function main
{
  fix_stop_signal

  if is_update_available
  then
    echo "There is a new version available."
    echo "Doing update from $LOCAL_VERSION to $LATEST_VERSION"
    do_update_procedure
  else
    echo "Your $APP_NAME is already up to date."
    echo "You are running $APP_NAME $LOCAL_VERSION"
  fi
}

main "$@"
exit $?
end_of_content
  chmod u+x --verbose ~/bin/gitea-update
}

function echo_tree
{
cat << end_of_content
/home/$USER
├── bin
│   ├── [-rwxrw-r--] gitea (wrapper script)
│   └── [-rwxrw-r--] gitea-update
├── etc
│   ├── services.d
│   │   └── gitea.ini
│   └── ...
├── gitea
│   ├── custom
│   │   └── conf
│   │       └── app.ini (configuration file)
│   ├── data
│   └── [-rwxrw-r--] gitea (binary file)
└── ...
end_of_content
}

function yes_no_question
{
  local question=$1
  while true
  do
  read -r -p "$question (y/n) " ANSWER
  case $ANSWER in
    [Yy]* | [Jj]* )
      return 0
      ;;
    [Nn]* )
      return 1
      ;;
    * ) echo "Please answer yes or no. ";;
  esac
  done
}

function set_critical_section { set -o pipefail -o errexit; }
function unset_critical_section { set +o pipefail +o errexit; }

function main
{
  set_critical_section
  process_parameters "$@"

  set_install_version
  set_download_url

  echo "This script installs $APP_NAME $INSTALL_VERSION"
  echo "and assumes a newly created Uberspace with default settings."
  echo "The following files and directories will be created:"
  echo_tree
  echo "Do not run this script if you already use your Uberspace for other apps!"

  if (lsof -nP -iTCP:3000 -sTCP:LISTEN)
  then echo "Port 3000 is already in use, abbort"; exit 1
  fi

  if yes_no_question "Do you want to execute this installer for $APP_NAME $INSTALL_VERSION?"
  then install_gitea
  fi

  unset_critical_section
}

main "$@"
exit $?