#!/bin/bash

# Globals
usage="Usage: ${0##*/} [-n] [-r repeat] databasedir"
newlinebetween="false"
oldifs="$IFS"
repeat="1"
aoran="0"
upper="0"

# Functions
function parse_template {
  local object max word i

  if [[ -z "$1" ]]; then return; fi

  local IFS=" "
  for object in $1; do
    case "${object:0:1}" in
    \_)
      # Ignore spaces when doing an aoran
      if [[ "$aoran" -eq "0" ]]; then
        # Echo a space
        echo -n " "
      fi
      ;;
    \\)
      # Echo a newline
      echo
      ;;
    \|)
      # Echo an "a" or an "an", depending on the next raw word
      ((aoran++))
      parse_template "${object:1}"
      ;;
    \^)
      # Capitalize the next letter
      ((upper++))
      parse_template "${object:1}"
      ;;
    \()
      # Repeat the following n times
      number="${object:1}"
      number="${number%%)*}"
      while [[ "$i" -lt "$number" ]]; do
        parse_template "${object##*)}"
	((i++))
      done
      ;;
    \:)
      # Choose an entry from the object database and parse it as a template
      eval max=\$dbmax${object:1}
      if [[ -z "$max" ]]; then
        echo "Error, db object $object not found, aborting"
	exit 1
      fi
      rand=$(($RANDOM % $max))
      eval word=\${db${object:1}[\$rand]}
      parse_template "$word"
      ;;
    *)
      object=${object# }
      # Assume a raw word
      if [[ "$aoran" -gt "0" ]]; then
	((aoran--))
        if [[ "${object:0:1}" == [aeiou] ]]; then
	  parse_template "an _"
	else
	  parse_template "a _"
	fi
      fi
      if [[ "$upper" -gt "0" ]]; then
        ((upper--))
        echo -n "${object:0:1}" | tr [a-z] [A-Z]
	parse_template "${object:1}"
      else
        echo -n "$object"
      fi
      ;;
    esac
  done
}

# Parse command line
while [[ "${1:0:1}" == "-" ]]; do
  case "$1" in
  -n)
    newlinebetween="true";
    shift;
    ;;
  -r)
    if [[ -z "$2" ]]; then
      echo "$usage"
      exit 1
    fi
    repeat="$2"
    shift 2;
    ;;
  *)
    echo "$usage"
    exit 1
    ;;
  esac
done

# Sanity check
if [[ -z "$1" ]]; then
  echo $usage
  exit 1
fi

# Load the wordlists and templates
for file in "$1"/*; do
  basename=${file##*/}
  IFS=$'\n'

  if [[ "$basename" == "template" ]]; then
    dbmaxtemplate="0"
    for word in $(<"$file"); do
      dbtemplate[$dbmaxtemplate]=$word
      ((dbmaxtemplate++))
    done
  else
    for word in $(<"$file"); do
      i=0
      syl=0
      dbname="$basename"
      while [[ "${word:$i:1}" == "+" ]]; do
        ((syl++))
	((i++))
      done
      if [[ "$syl" != "0" ]]; then dbname="${dbname}${syl}"; fi
      if eval [[ -z dbmax${dbname} ]]; then
        eval dbmax${dbname}="0"
      fi
      eval db${dbname}[dbmax${dbname}]=\${word:i}
      ((dbmax${dbname}++))
    done
  fi

  IFS="$oldifs"
done

# Sanity check, we need a template
if [[ -z "$dbmaxtemplate" ]]; then
  echo "Template file not parsed, aborting"
  exit 1
fi

while [[ "$repeat" -gt "0" ]]; do
  # Choose a random template
  template=$(($RANDOM % $dbmaxtemplate))
  parse_template "${dbtemplate[$template]}"
  ((repeat--))

  if [[ "$newlinebetween" == "true" && "$repeat" -gt "0" ]]; then
    echo
  fi

done

# Put a final newline
echo