#!/usr/bin/env bash
set -eo pipefail

#######################################################################
# Init arguments parser
# Arguments:
#   script_dir - absolute path to hook dir location
#######################################################################
function common::initialize {
  local -r script_dir=$1
  # source getopt function
  # shellcheck source=../lib_getopt
  . "$script_dir/../lib_getopt"
}

#######################################################################
# Parse args and filenames passed to script and populate respective
# global variables with appropriate values
# Globals (init and populate):
#   ARGS (array) arguments that configure wrapped tool behavior
#   HOOK_CONFIG (array) arguments that configure hook behavior
#   FILES (array) filenames to check
# Arguments:
#   $@ (array) all specified in `hooks.[].args` in
#     `.pre-commit-config.yaml` and filenames.
#######################################################################
function common::parse_cmdline {
  # common global arrays.
  # Populated via `common::parse_cmdline` and can be used inside hooks' functions
  declare -g -a ARGS=() HOOK_CONFIG=() FILES=() ENV_PASSTHRU=()

  local argv
  argv=$(getopt -o a:,h: --long args:,hook-config:,env-passthrough: -- "$@") || return
  eval "set -- $argv"

  for argv; do
    case $argv in
      -a | --args)
        shift
        ARGS+=("$1")
        shift
        ;;
      -h | --hook-config)
        shift
        HOOK_CONFIG+=("$1;")
        shift
        ;;
      --env-passthrough)
        shift
        ENV_PASSTHRU+=("$1")
        shift
        ;;
      --)
        shift
        # shellcheck disable=SC2034 # Variable is used
        FILES=("$@")
        break
        ;;
    esac
  done
}

# Iterates through each value in ${ENV_PASSTHRU} and replaces the
# placeholder value __ENV_<value>__ with the value of the environment
# variable <value>
#
# Example usage:
# - FOO=one
# - __ENV_FOO__ becomes "one"

function common::passthrough_env_vars {
  local var
  for var in "${ENV_PASSTHRU[@]}"; do
    # shellcheck disable=SC2178
    ARGS=${ARGS[*]/__ENV_${var}__/${!var}}
  done
}

#######################################################################
# This is a workaround to improve performance when all files are passed
# See: https://github.com/antonbabenko/pre-commit-terraform/issues/309
# Arguments:
#   hook_id (string) hook ID, see `- id` for details in .pre-commit-hooks.yaml file
#   files (array) filenames to check
# Outputs:
#   Return 0 if `-a|--all` arg was passed to `pre-commit`
#######################################################################
function common::is_hook_run_on_whole_repo {
  local -r hook_id="$1"
  shift 1
  local -a -r files=("$@")
  # get directory containing `.pre-commit-hooks.yaml` file
  local -r root_config_dir="$(dirname "$(dirname "$(realpath "${BASH_SOURCE[0]}")")")"
  # get included and excluded files from .pre-commit-hooks.yaml file
  local -r hook_config_block=$(sed -n "/^- id: $hook_id$/,/^$/p" "$root_config_dir/.pre-commit-hooks.yaml")
  local -r included_files=$(awk '$1 == "files:" {print $2; exit}' <<< "$hook_config_block")
  local -r excluded_files=$(awk '$1 == "exclude:" {print $2; exit}' <<< "$hook_config_block")
  # sorted string with the files passed to the hook by pre-commit
  local -r files_to_check=$(printf '%s\n' "${files[@]}" | sort | tr '\n' ' ')
  # git ls-files sorted string
  local all_files_that_can_be_checked

  if [ -z "$excluded_files" ]; then
    all_files_that_can_be_checked=$(git ls-files | sort | grep -e "$included_files" | tr '\n' ' ')
  else
    all_files_that_can_be_checked=$(git ls-files | sort | grep -e "$included_files" | grep -v -e "$excluded_files" | tr '\n' ' ')
  fi

  if [ "$files_to_check" == "$all_files_that_can_be_checked" ]; then
    return 0
  else
    return 1
  fi
}

#######################################################################
# Hook execution boilerplate logic which is common to hooks, that run
# on per dir basis.
# 1. Because hook runs on whole dir, reduce file paths to uniq dir paths
# 2. Run for each dir `per_dir_hook_unique_part`, on all paths
# 2.1. If at least 1 check failed - change exit code to non-zero
# 3. Complete hook execution and return exit code
# Arguments:
#   args (string with array) arguments that configure wrapped tool behavior
#   hook_id (string) hook ID, see `- id` for details in .pre-commit-hooks.yaml file
#   files (array) filenames to check
#######################################################################
function common::per_dir_hook {
  local -r args="$1"
  local -r hook_id="$2"
  shift 2
  local -a -r files=("$@")

  # check is (optional) function defined
  if [ "$(type -t run_hook_on_whole_repo)" == function ] &&
    # check is hook run via `pre-commit run --all`
    common::is_hook_run_on_whole_repo "$hook_id" "${files[@]}"; then
    run_hook_on_whole_repo "$args"
    exit 0
  fi

  # consume modified files passed from pre-commit so that
  # hook runs against only those relevant directories
  local index=0
  for file_with_path in "${files[@]}"; do
    file_with_path="${file_with_path// /__REPLACED__SPACE__}"

    dir_paths[index]=$(dirname "$file_with_path")

    ((index += 1))
  done

  # preserve errexit status
  shopt -qo errexit && ERREXIT_IS_SET=true
  # allow hook to continue if exit_code is greater than 0
  set +e
  local final_exit_code=0

  # run hook for each path
  for dir_path in $(echo "${dir_paths[*]}" | tr ' ' '\n' | sort -u); do
    dir_path="${dir_path//__REPLACED__SPACE__/ }"
    pushd "$dir_path" > /dev/null || continue

    per_dir_hook_unique_part "$args" "$dir_path"

    local exit_code=$?
    if [ $exit_code -ne 0 ]; then
      final_exit_code=$exit_code
    fi

    popd > /dev/null
  done

  # restore errexit if it was set before the "for" loop
  [[ $ERREXIT_IS_SET ]] && set -e
  # return the hook final exit_code
  exit $final_exit_code
}

#######################################################################
# Colorize provided string and print it out to stdout
# Environment variables:
#   PRE_COMMIT_COLOR (string) If set to `never` - do not colorize output
# Arguments:
#   COLOR (string) Color name that will be used to colorize
#   TEXT (string)
# Outputs:
#   Print out provided text to stdout
#######################################################################
function common::colorify {
  # shellcheck disable=SC2034
  local -r red="\e[0m\e[31m"
  # shellcheck disable=SC2034
  local -r green="\e[0m\e[32m"
  # shellcheck disable=SC2034
  local -r yellow="\e[0m\e[33m"
  # Color reset
  local -r RESET="\e[0m"

  # Params start #
  local COLOR="${!1}"
  local -r TEXT=$2
  # Params end #

  if [ "$PRE_COMMIT_COLOR" = "never" ]; then
    COLOR=$RESET
  fi

  echo -e "${COLOR}${TEXT}${RESET}"
}