#!/bin/bash
set -euo pipefail
shopt -s extglob

DEBUG=${DEBUG:-''}

declare HOOK_SCRIPT='pre-commit'
if [[ $# -gt 0 && $1 =~ pre-push.* ]]; then
  HOOK_SCRIPT='pre-push'
fi

function run() {
  # Arguments: $1 = 'pre-commit' or 'pre-push'. whether to set talisman up as pre-commit or pre-push hook : TODO: not implemented yet
  # Environment variables:
  #    DEBUG="any-non-emply-value": verbose output for debugging the script
  #    INSTALL_ORG_REPO="..."     : the github org/repo to install from (default thoughtworks/talisman)
  #
  # Download the script needed for uninstalling the repo level hooks
  # For each git repo found in the search root (default $HOME)
  #     Run the repo level uninstall hook. This will remove the symlink from .git/hooks/pre-<commit/push> to the central $TALISMAN_SETUP_DIR
  #     The script will only remove talisman hook, not a pre-commit.com script or some other non-talisman hook
  #     Write exceptions to a file for manual action
  #     Look in the uninstall_git_repo_hook.bash script for more details on what it does
  # Remove the talisman_hook_script in .git-template/hooks/pre-<commit/push>
  # Remove talisman binary and talisman_hook_script from $TALISMAN_SETUP_DIR ($HOME/.talisman/bin)

  function echo_error() {
    echo -ne $(tput setaf 1) >&2
    echo "$1" >&2
    echo -ne $(tput sgr0) >&2
  }
  export -f echo_error

  function echo_debug() {
    [[ -z "${DEBUG}" ]] && return
    echo -ne $(tput setaf 3) >&2
    echo "$1" >&2
    echo -ne $(tput sgr0) >&2
  }
  export -f echo_debug

  function echo_success() {
    echo -ne $(tput setaf 2)
    echo "$1" >&2
    echo -ne $(tput sgr0)
  }
  export -f echo_success

  TALISMAN_SETUP_DIR=${HOME}/.talisman/bin
  TEMPLATE_DIR=$(git config --global init.templatedir) || true
  INSTALL_ORG_REPO=${INSTALL_ORG_REPO:-'thoughtworks/talisman'}
  SCRIPT_BASE="https://raw.githubusercontent.com/${INSTALL_ORG_REPO}/master/global_install_scripts"

  TEMP_DIR=$(mktemp -d 2>/dev/null || mktemp -d -t 'talisman_uninstall')
  trap "rm -r ${TEMP_DIR}" EXIT
  chmod 0700 ${TEMP_DIR}

  DELETE_REPO_HOOK_SCRIPT=${TEMP_DIR}/uninstall_git_repo_hook.bash
  function get_dependent_scripts() {
    curl --silent "${SCRIPT_BASE}/uninstall_git_repo_hook.bash" >${DELETE_REPO_HOOK_SCRIPT}
    chmod +x ${DELETE_REPO_HOOK_SCRIPT}
  }

  function remove_git_talisman_hooks() {
    if [[ ! -x ${DELETE_REPO_HOOK_SCRIPT} ]]; then
      echo_error "Couldn't find executable script ${DELETE_REPO_HOOK_SCRIPT}"
      exit 1
    fi

    echo "Removing talisman hooks recursively in git repos"
    read -e -p "Please enter root directory to search for git repos (Default: ${HOME}): " SEARCH_ROOT
    SEARCH_ROOT=${SEARCH_ROOT:-$HOME}
    SEARCH_CMD="find"
    EXTRA_SEARCH_OPTS=""
    echo -e "\tSearching ${SEARCH_ROOT} for git repositories"

    SUDO_PREFIX=""
    if [[ "${SEARCH_ROOT}" == "/" ]]; then
      echo -e "\tPlease enter your password when prompted to enable script to search as root user:"
      SUDO_PREFIX="sudo"
      EXTRA_SEARCH_OPTS="-xdev \( -path '/private/var' -prune \) -o"
    fi
    EXCEPTIONS_FILE=${TEMP_DIR}/repos_with_multiple_hooks.paths
    touch ${EXCEPTIONS_FILE}

    TALISMAN_PATH=${TALISMAN_SETUP_DIR}/talisman_hook_script
    CMD_STRING="${SUDO_PREFIX} ${SEARCH_CMD} ${SEARCH_ROOT} ${EXTRA_SEARCH_OPTS} -name .git -type d -exec ${DELETE_REPO_HOOK_SCRIPT} ${TALISMAN_PATH} ${EXCEPTIONS_FILE} {} ${HOOK_SCRIPT} \;"
    echo_debug "EXECUTING: ${CMD_STRING}"
    eval "${CMD_STRING}" || true

    NUMBER_OF_EXCEPTION_REPOS=$(cat ${EXCEPTIONS_FILE} | wc -l)

    if [ ${NUMBER_OF_EXCEPTION_REPOS} -gt 0 ]; then
      EXCEPTIONS_FILE_HOME_PATH="${HOME}/repos_to_remove_talisman_from.paths"
      mv ${EXCEPTIONS_FILE} ${EXCEPTIONS_FILE_HOME_PATH}
      echo_error ""
      echo_error "Please see ${EXCEPTIONS_FILE_HOME_PATH} for a list of repositories"
      echo_error "that talisman couldn't be automatically removed from"
      echo_error "This is likely because these repos are using pre-commit (https://pre-commit.com)"
      echo_error "Remove lines related to talisman from the .pre-commit-config.yaml manually"
    fi
  }

  function remove_talisman_env_variables() {
    FILE_PATH="$1"
    if [ -f $FILE_PATH ] && grep -q "TALISMAN_HOME" $FILE_PATH; then
      sed -i'-talisman.bak' '/# >>> talisman >>>/,/# <<< talisman <<</d' $FILE_PATH
    fi
  }

  get_dependent_scripts
  remove_git_talisman_hooks

  echo_debug "Removing talisman hooks from .git-template"
  echo_debug "${TEMPLATE_DIR}/hooks/${HOOK_SCRIPT}"
  if [[ -n $TEMPLATE_DIR && -e ${TEMPLATE_DIR}/hooks/${HOOK_SCRIPT} && ${TALISMAN_SETUP_DIR}/talisman_hook_script -ef ${TEMPLATE_DIR}/hooks/${HOOK_SCRIPT} ]] \
    ; then
    rm -f "${TEMPLATE_DIR}/hooks/${HOOK_SCRIPT}" &&
      echo_success "Removed ${HOOK_SCRIPT} from ${TEMPLATE_DIR}"
  fi

  echo_debug "Removing talisman from $TALISMAN_SETUP_DIR"
  rm -rf $TALISMAN_SETUP_DIR &&
    echo_success "Removed global talisman install from ${TALISMAN_SETUP_DIR}"

  if [ -n "${TALISMAN_HOME:-}" ]; then
    remove_talisman_env_variables ~/.bash_profile
    remove_talisman_env_variables ~/.bashrc
    remove_talisman_env_variables ~/.profile
    echo "Please remember to remove TALISMAN_HOME from your environment variables if you have setup manually"
  fi

}

run $0 $@