#!/bin/bash

_help() {
  echo 'Convert a folder structure of .md files to a HTML site.
Requires pandoc, rsync, python

Commands:
  autobuild source-folder target-folder (builds at change of content)
  build source-folder target-folder
  serve [target-folder] [port] (defaults to . and 8000)

Note: Files in target-folder will be deleted!
'
  exit
}

_serve() {
  root="$1"
  [[ -z "$1" ]] && root="."
  port="$2"
  [[ -z "$2" ]] && port="8000"
  timeout 7200 "$SELF"/../web/webserver.py -a 127.0.0.1 -p $port "$root"
}

_autobuild() {
  _build "$1" "$2"
  old_hash=$( find "$1" -type f -exec cat \{\} \; | md5sum | awk '{ print $1 }' )
  while true; do
    sleep 3
    new_hash=$( find "$1" -type f -exec cat \{\} \; | md5sum | awk '{ print $1 }' )
    [[ "$old_hash" == "$new_hash" ]] && continue
    old_hash="$new_hash"
    _build "$1" "$2"
  done
}

_build() {
  [[ -z "$2" ]] && _help
  [[ "$1" -ef "$2" ]] && {
    echo source and target folders are the same. Cannot continue.
    exit 1
  }
  [[ -d "$1" ]] || {
    echo source is not a directory
    exit 1
  }
  [[ -f "$2" ]] && {
    echo target is a file
    exit 1
  }
  if [[ -d "$2" ]] && [[ ! -f "$2"/.mdsite ]]; then
    echo Target folder not an mdsite folder, delete first
    exit 1
  fi
  rsync -r "$1"/ "$2"
  touch "$2"/.mdsite
  echo "----"
  shopt -s nullglob
  trap _error_in_recursion 1 6 9 15
  _recursive_gen "$2" root $( basename "$1" )
}

_recursive_gen() {
  pushd "$1" &> /dev/null
  parents=""
  [[ "$2" = "root" ]] && parents="-p"
  title=${3:-$( basename "$1" )}
  rm -f index.html
  for md in *.md; do
    [[ -d "$md" ]] && continue
    pandoc -s -f markdown -H "$SELF"/md-site.css -o "${md%.md}.html" "$md" && { rm "$md"; } || _error_in_recursion "$md"
    echo Generated $1/$md
  done
  [[ -f "index.html" ]] || { SimpleWebPage -f $parents -t "$title"; echo Generated $1/index.html; }
  for dir in *; do
    [[ -d "$dir" ]] && {
      _recursive_gen "$dir"
    }
  done
  popd &> /dev/null
}

_error_in_recursion() {
  echo Error prosessing folder
  pwd
  [[ -n "$1" ]] && echo File: "$1"
  exit 1
}

[[ -z "$1" ]] && _help
for (( i=1; i<=$#; i++ )); do
  [[ "${!i}" = "-h" ]] && _help
  [[ "${!i}" = *"help" ]] && _help
done
SELF=$( dirname $( readlink -f "$0" ) )

[[ "$1" == build ]] && _build "$2" "$3"
[[ "$1" == autobuild ]] && _autobuild "$2" "$3"
[[ "$1" == serve ]] && _serve "$2" "$3"