#!/bin/bash
#
# QaD script to wrap blog posting with IkiWiki
#
# TODO: get some settings from ikiwiki.setup?
# TODO: split RcsSubmit.  add files to the RCS always (catches drafts)

# Settings
AUTHOR="Daniel Quinlan"
WIKI_SRC=$HOME/src/wiki
POST_SUFFIX=.mdwn
DRAFT_PREFIX=DRAFT

# Don't mess with these
SETUP_FILE=ikiwiki.setup.$(hostname)
POST_BASE="wiki-src/blog/posts"
TAG_BASE="wiki-src/blog/tags"
DRAFT_BASE="drafts"
POST_LAYOUT="%Y/%m/%d"
DIR_PATTERN="$POST_BASE/$POST_LAYOUT"
DATE=$(date "+%Y-%m-%d %H:%M:%S")
OP=POST
COMMIT_FILES=
EDIT_FILE=
DEBUG=

function EditFileCheckForChanges() { # {{{
  # edit a file, return true if it was changed

  md5sum=$(md5sum $1)

  # edit tempfile
  ${EDITOR:-vim} $1

  if [ "$md5sum" == "$(md5sum $1)" ] ; then
    return 1
  else
    return 0
  fi
} # }}}

function InitialCase() { # {{{

  LOWER='abcdefghijklmnopqrstuvwxyz'
  UPPER='ABCDEFGHIJKLMNOPQRSTUVWXYZ'

  echo "$@" | sed -n '

# if first char is not a lowercase letter
# jump to end and print
/^[^a-z]/bEND

# save word
h

# keep just the first letter
s/^\([a-z]\).*/\1/

# translate to upper case
y/'$LOWER'/'$UPPER'/

# swap hold/pattern space
x

# append hold space to pattern space
G

# replace old first letter with new first letter
s/^[a-z]\(.*\)\n\([A-Z]\)/\2\1/p
t

: END
p
'

} # }}}

function CreateTagsIfNotExist() { # {{{

  # $1 - file to search for tags

  local TAGS TAG_FILE tag TAG_TITLE

  TAGS=$(grep '\[\[tag' $1 | sed -n 's/^.*\[\[tag *\([^]]*\)\]\].*$/\1/p')

  for tag in $TAGS ; do
    TAG_FILE=$TAG_BASE/$(echo "$tag$POST_SUFFIX" | tr '[A-Z]' '[a-z]')
    TAG_FILE_ABS=$WIKI_SRC/$TAG_FILE
    TAG_TITLE=$(InitialCase "$tag")
    if [ ! -e $TAG_FILE_ABS ] ; then
      if [ -z "$DEBUG" ] ; then
	cat <<EOF > $TAG_FILE_ABS

This feed contains pages with the tag "$TAG_TITLE".

[[inline pages="link($tag) and *blog/posts/* and !*/Discussion" show="10"]]
	

EOF
      fi
      echo ${TAG_FILE}
    fi
  done

} # }}}

function GetMetaDataFromPost() { # {{{

  # $1 = path to post file
  # $2 = meta data to get

  if [ ! -r "$1" ] ; then
    echo "Error: $1 not found" >&2
    exit 1
  fi

  grep "\[\[meta $2=" $1 | sed -e 's/^\[\[meta [a-z]*="\([^"]*\)".*$/\1/'
} # }}}

function MakeSlugFromTitle() { # {{{

  echo "$1" | tr -dc '[a-zA-Z0-9 _\-]' | sed -e 's/  / /g' | tr '[A-Z] ' '[a-z]-'

} # }}}

function NewPost() { # {{{

  local TEMP_FILE=$1
  local NEW_FILE=false

  if [ -z "$TEMP_FILE" ] ; then
    TEMP_FILE=$(tempfile -p$DRAFT_PREFIX -d$WIKI_SRC/$DRAFT_BASE)
    NEW_FILE=true

    # cat post template into tempfile
    cat <<__END__ > $TEMP_FILE

[[meta title="I_FORGOT_TO_ADD_A_TITLE"]]
[[meta date="$DATE"]]
[[meta author="$AUTHOR"]]

drivel goes here

[[tag uncategorised ]]
__END__
  fi
  echo $TEMP_FILE

  if ! EditFileCheckForChanges $TEMP_FILE ; then
    echo $TEMP_FILE not modified, aborting...
    [ "$NEW_FILE" == "true" ] && rm $TEMP_FILE
    exit 0
  fi  

  # parse tempfile for title
  POST_TITLE="$(GetMetaDataFromPost $TEMP_FILE title)"
  if [ -z "$POST_TITLE" ] ; then
    # TODO: add some logic for a default title (based on date?)
    echo no title found in $TEMP_FILE >&2
    exit 1
  fi

  # parse tempfile for date
  POST_DATE="$(GetMetaDataFromPost $TEMP_FILE date)"
  POST_DATE_DIR=$(date "+$DIR_PATTERN" -d "$POST_DATE")

  # create slug from title
  SLUG=$(MakeSlugFromTitle "$POST_TITLE")

  POST_FILE=$WIKI_SRC/$POST_DATE_DIR/$SLUG$POST_SUFFIX

  # check if post already exists
  if [ -e $POST_FILE ] ; then
    echo $POST_FILE exists
    while : ; do
      read -p 'Edit existing file, Merge, Overwrite or Quit? [emoq]' 
      case $REPLY in
	e|E)
	  EditPost $POST_FILE
	  exit 0
	  ;;
	m|M)
	  echo Doing a simple merge...
	  cat $TEMP_FILE >> $POST_FILE
	  EditPost $POST_FILE
	  exit 0
	  ;;
        o|O)
	  break
	  ;;
        q|Q)
	  exit 0
	  ;;
      esac
    done
  fi

  # makepath and 
  # make any missing year/month/day indexes
  CREATED_FILES=$(MakePath $WIKI_SRC/$POST_BASE $POST_LAYOUT $(date "+%Y/%m/%d" -d "$POST_DATE"))
	  
  # create files for any new tags
  CREATED_FILES="$CREATED_FILES $(CreateTagsIfNotExist $TEMP_FILE)"

  # move to wikisrc
  $DEBUG mv -v $TEMP_FILE $POST_FILE && CREATED_FILES="$CREATED_FILES ${POST_FILE##$WIKI_SRC/}"

  while read -p 'Commit post? [yn] ' ; do
    case $REPLY in
      Y|y)
	break
	;;
      N|n)
        echo Created files:
	echo $CREATED_FILES | tr ' ' '\n'
	exit 0
	;;
    esac
  done

  RcsSubmit "$CREATED_FILES" "Blog post on $DATE"
} # }}}

function MakePath() { #{{{

  # $1 = POST_BASE
  # $2 = POST_LAYOUT
  # $3 = optional, date -d

  local DATE CREATED_FILES ABS_PATH

  [ -n "$3" ] && DATE="-d $3"

  cd $1 || return 1

  for part in $(echo $2 | tr / ' ') ; do
    dir=$(date "+$part" $DATE) 
    case $part in
      %Y)
        pages="./$dir/*/*/*"
	title=$dir
	;;
      %m)
        pages="./$dir/*/*"
	title="$(date '+%B %Y' $DATE)"
	;;
      %d)
        pages="./*"
	title="$(date '+%A %B %d %Y' $DATE)"
	;;
    esac

    [ -d $dir ] || mkdir $dir

    ABS_PATH=$(pwd)/${dir}$POST_SUFFIX
    CREATED_FILES="$CREATED_FILES ${ABS_PATH##$WIKI_SRC/}"
    if [ -n "$DEBUG" ] ; then
      echo "Creating $ABS_PATH" >&2
    else
      cat <<__END__ > $ABS_PATH
[[meta title="$title"]]

Here is a full list of posts for $title

[[inline pages="$pages and !*/Discussion" archive="yes"]]
__END__
    fi
   
    cd $dir
  done
  
  cd $WIKI_SRC

  echo $CREATED_FILES
    
} # }}}

function EditPost() { # {{{
  cd $WIKI_SRC
  if EditFileCheckForChanges $1 ; then
    RcsSubmit $1 "Edit post $(basename -- $1)"
  fi
} # }}}

function RcsSubmit() { # {{{

  # $1 list of files to submit
  # $2 commit message

  cd $WIKI_SRC && \
  $DEBUG git add $1 && \
  $DEBUG git commit -m "$2" -o $1
} # }}}

function UpdateIndexes() { # {{{

  local CREATED_FILES

  # TODO: fix the grep pattern in next 90 or so years
  find $WIKI_SRC/$POST_BASE -type d | grep '20../../..$' | while read dir ; do
    echo "$(MakePath $WIKI_SRC/$POST_BASE $POST_LAYOUT ${dir##$WIKI_SRC/$POST_BASE/})"
    cd $WIKI_SRC 
  done

} # }}}

function SetupBlog() { # {{{
 
  if [ -z "$DEBUG" -a -r $WIKI_SRC ] ; then
    echo "$WIKI_SRC exists.  giving up" >&2
    exit 1
  fi

  $DEBUG mkdir -p $WIKI_SRC/plugins
  $DEBUG mkdir -p $WIKI_SRC/templates
  $DEBUG mkdir -p $WIKI_SRC/$DRAFT_BASE
  $DEBUG mkdir -p $WIKI_SRC/$POST_BASE
  $DEBUG mkdir -p $WIKI_SRC/$TAG_BASE
} # }}}

function IkiwikiBuild() { # {{{
    cd $WIKI_SRC
    if [ "$1" == "REFRESH" ] ; then
      REFRESH=--refresh
    fi
    if [ -r $SETUP_FILE ] ; then
      $DEBUG ikiwiki --setup $SETUP_FILE $REFRESH
    else
      echo $SETUP_FILE not found >&2
      exit 1
    fi
} # }}}

function usage() { # {{{
  cat <<EOF >&2
Usage: `basename -- $0` [option] [operation] 

Operations:
  --post|-p [file]  create/update a blog post (Default)
                    if file is specified update that post
                    should be relative to $WIKI_SRC
  --list-tags|-t    list existing blog tags
  --update-indexes  update blog year/month/day indexes
  --build|-b        run 'ikiwiki --setup ikiwiki.$(hostname)'
  --refresh|-r      run 'ikiwiki --setup ikiwiki.$(hostname) --refresh'
  --setup           setup a new blog

Options:
  --debug     Debug: don't actually run commands which would change state, just
              show what would have been done.
  --help|-h   Help: show this help message

EOF
  exit 1

} # }}}

# process options {{{

RAW_ARGS=`getopt -o h,p::,t,b,r \
          --long help,debug,post::,list-tags,update-indexes,setup,build,refresh \
          -n "$(basename $0)" -- "$@"`

[ $? != 0 ] && usage

eval set -- "$RAW_ARGS"

while true ; do
  case "$1" in
    -p|--post) OP=POST ; EDIT_FILE=$2 ; shift 2;;
    -t|--list-tags) OP=TAGS ; shift ;;
    -r|--refresh) OP=REFRESH ; shift ;;
    -b|--build) OP=BUILD ; shift ;;
    --update-indexes) OP=UPDATE ; shift ;;
    --setup) OP=SETUP ; shift ;;
    --debug) DEBUG=echo ; shift ;;
    -h|--help) usage ;;
    --) shift ; break ;;
    *) echo "unknown option ($1)" ; usage ;;
  esac
done

if [ "$OP" == "POST" ] ; then
  # handle a space separating -p and the filename
  if [ -z "$EDIT_FILE" -a -n "$1" -a -w "$WIKI_SRC/$1" ] ; then
    EDIT_FILE=$1
  fi
fi

if [ -n "$DEBUG" ] ; then
  echo "Vars: $@"
  echo "op: $OP"
  [ "$OP" == "POST" ] && echo "Edit file: x${EDIT_FILE}x"
fi
# }}}

case $OP in
  POST)
    if [ -n "$1" -a -e $WIKI_SRC/$1 ] ; then
      if basename -- "$1" | grep -q ^$DRAFT_PREFIX ; then
	NewPost $1
      else
	EditPost $1
      fi
    else
      NewPost
    fi
    ;;
  TAGS)
    cd $WIKI_SRC/$TAG_BASE
    for tag in *$POST_SUFFIX ; do
      echo ${tag%%$POST_SUFFIX}
    done | fmt -80
    ;;
  UPDATE)
    echo Created files:
    UpdateIndexes
    ;;
  SETUP)
    SetupBlog "$1"
    ;;
  BUILD|REFRESH)
    IkiwikiBuild "$OP"
    ;;
  *)
    echo unknown operation >&2
    echo >&2
    usage
    ;;
esac

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