#!/bin/bash
# shellcheck disable=SC2034 # false flags nameref params

# =====================
# Require shell options
# =====================

# Necessary for piping to "send" funciton
shopt -s lastpipe

# ===============
# Setup Functions
# ===============

# $1: Log file to redirect output
function redirectStdout() {
  local output="$1";
  [ -z "$output" ] && output="/dev/null";

  exec 5<&1;
  _exprashRedirectStdout="$1";
  exec 1>>"$_exprashRedirectStdout";
  printf '%s: %s\n' "${REQUEST_METHOD:-UNKNOWN}" "${PATH_INFO:-/}"
}

# =============
# Route Function
# =============

# $1: path
function get() {
  [ "$REQUEST_METHOD" != "GET" ] && return 1;
  all "$1";
}

# $1: path
function post() {
  [ "$REQUEST_METHOD" != "POST" ] && return 1;
  all "$1";
}

# $1: path
function put() {
  [ "$REQUEST_METHOD" != "PUT" ] && return 1;
  all "$1";
}

# $1: path
function delete() {
  [ "$REQUEST_METHOD" != "DELETE" ] && return 1;
  all "$1";
}

# $1: path
function all() {
  [ "$_exprashRouteHandled" -eq 1 ] && return 1;
  [ -n "$_exprashErrorMessage" ] && return 1;

  # Reset params
  _exprashParams=();

  pathMatch "$1" _exprashParams || return 1;
  _exprashRouteHandled=1;

  return 0;
}

function use() {
  [ "$_exprashRouteHandled" -eq 1 ] && return 1;
  [ -n "$_exprashErrorMessage" ] && return 1;

  _exprashRouteHandled=1;
  return 0;
}

# =====================
# Error Route Functions
# =====================

# $1: path
function getError() {
  [ "$REQUEST_METHOD" != "GET" ] && return 1;
  allError "$1";
}

# $1: path
function postError() {
  [ "$REQUEST_METHOD" != "POST" ] && return 1;
  allError "$1";
}

# $1: path
function putError() {
  [ "$REQUEST_METHOD" != "PUT" ] && return 1;
  allError "$1";
}

# $1: path
function deleteError() {
  [ "$REQUEST_METHOD" != "DELETE" ] && return 1;
  allError "$1";
}

# $1: path
function allError() {
  [ "$_exprashRouteHandled" -eq 1 ] && return 1;
  [ -z "$_exprashErrorMessage" ] && return 1;

  # Reset params
  _exprashParams=();

  pathMatch "$1" _exprashParams || return 1;
  _exprashRouteHandled=1;

  return 0;
}

function useError() {
  [ "$_exprashRouteHandled" -eq 1 ] && return 1;
  [ -z "$_exprashErrorMessage" ] && return 1;

  _exprashRouteHandled=1;
  return 0;
}

# ====
# Next
# ====

# $1 (optional): error message
function next() {
  _exprashRouteHandled=0;
  [ -n "$1" ] && _exprashErrorMessage="$1";
}

# =============
# App Functions
# =============

function errorMessage() {
  printf '%s' "$_exprashErrorMessage";
}

function hasErrorMessage() {
  [ -n "$_exprashErrorMessage" ];
}

# =================
# Request Functions
# =================

# $1: param name
function param() {
  printf '%s\n' "${_exprashParams[$1]}";
}

function hasParam() {
  [[ -v "_exprashParams[$1]" ]];
}

# ==================
# Response Functions
# ==================

function send() {
  if [ "$_exprashHeadersSent" -eq 0 ]; then
    sendHeaders
    _exprashHeadersSent=1
  fi

  sendRaw
}

# $1: Header Name
# $2: Header Value
function setHeader() {
  _exprashHeaders["$1"]="$2";
}

function sendHeaders() {
  printf '%s\n' "Content-Type: ${_exprashHeaders['Content-Type']}" | sendRaw
  for key in "${!_exprashHeaders[@]}"; do
    [ "$key" == 'Content-Type' ] && continue
    printf '%s\n' "${key}: ${_exprashHeaders[$key]}" | sendRaw
  done;
  printf '\n' | sendRaw
}

# =========
# Internals
# =========

function sendRaw() {
  [ -n "$_exprashRedirectStdout" ] && exec >&5;
  cat;
  [ -n "$_exprashRedirectStdout" ] && exec 1>>"$_exprashRedirectStdout";
}

# $1: path
# $2: (nameref) array
function pathToArray() {
  readarray -t "$2" < <(printf '%s\n' "$1" | tr '/' '\n' | grep .);
}

# $1: route
# $2: (nameref) associative array for params
function pathMatch() {
  [ -z ${PATH_INFO+x} ] && return 1;
  [ -z ${1+x} ] && return 1;

  local path="$PATH_INFO";
  local route="$1";

  # Params associative array
  local -n routeParams="$2";

  local pathArr;
  pathToArray "$path" pathArr;

  local routeArr;
  pathToArray "$route" routeArr;

  # Get max path length
  local routeLen=${#routeArr[@]};
  local pathLen=${#pathArr[@]};
  local maxLen=$(( routeLen >= pathLen ? routeLen : pathLen ));

  for ((i=0; i<maxLen; i++)); do
    local routeComponent="${routeArr[$i]}";
    local pathComponent="${pathArr[$i]}";

    # If route component starts with ":"
    if [[ "$routeComponent" == :* ]]; then
      routeParams["${routeComponent:1}"]="$pathComponent";
    elif [[ "$routeComponent" == '*' ]] && [ -n "$pathComponent" ]; then
      continue;
    elif [[ "$routeComponent" == '**' ]] && [ -n "$pathComponent" ]; then
      break;
    else
      # Confirm paths match
      [ "$routeComponent" != "$pathComponent" ] && return 1;
    fi;
  done;

  return 0;
}

# =======
# Globals
# =======

# Route globals
function _exprashResetRouteGlobals() {
  _exprashRouteHandled=0
  _exprashErrorMessage=''
  declare -gA _exprashParams
  
  _exprashHeadersSent=0
  declare -gA _exprashHeaders
  _exprashHeaders['Content-Type']='text/html'
}
_exprashResetRouteGlobals

# Setup globals
_exprashRedirectStdout=''