#compdef task

  #

  # Copyright 2010 - 2016 Johannes Schlatow

  # Copyright 2009 P.C. Shyamshankar
  #
  # Permission is hereby granted, free of charge, to any person obtaining a copy
  # of this software and associated documentation files (the "Software"), to deal
  # in the Software without restriction, including without limitation the rights
  # to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  # copies of the Software, and to permit persons to whom the Software is
  # furnished to do so, subject to the following conditions:
  #
  # The above copyright notice and this permission notice shall be included
  # in all copies or substantial portions of the Software.
  #
  # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  # OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  # FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  # THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  # LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  # OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  # SOFTWARE.
  #
  # http://www.opensource.org/licenses/mit-license.php
  #
  typeset -g _task_cmds _task_projects _task_tags _task_config _task_modifiers
  _task_projects=($(task _projects))
  _task_tags=($(task _tags))

  _task_zshids=( ${(f)"$(task _zshids)"} )

  _task_config=($(task _config))
  _task_columns=($(task _columns))
  _task_modifiers=(

    'before' \
    'after' \
    'none' \
    'any' \
    'is' \
    'isnt' \
    'has' \
    'hasnt' \
    'startswith' \
    'endswith' \
    'word' \
    'noword'

  )
  _task_conjunctions=(

    'and' \
    'or' \
    'xor' \
    '\)' \
    '\(' \
    '<' \
    '<=' \
    '=' \
    '!=' \
    '>=' \
    '>'

  )

  _task_cmds=($(task _commands; task _aliases))
  _task_zshcmds=( ${(f)"$(task _zshcommands)"} sentinel:sentinel:sentinel )
  
  _task_aliases=($(task _aliases))

  
  _task() {
      _arguments -s -S \
          "*::task default:_task_default"
      return 0
  }
  
  local -a reply args word
  word=$'[^\0]#\0'
  
  # priorities
  local -a task_priorities
  _regex_words values 'task priorities' \

    'H:High' \
    'M:Middle' \
    'L:Low'

  task_priorities=("$reply[@]")
  
  # projects
  local -a task_projects
  task_projects=(

    /"$word"/
    ":values:task projects:compadd -a _task_projects"

  )
  
  local -a _task_dates
  _regex_words values 'task dates' \

    'tod*ay:Today' \
    'yes*terday:Yesterday' \
    'tom*orrow:Tomorrow' \
    'sow:Start of week' \
    'soww:Start of work week' \
    'socw:Start of calendar week' \
    'som:Start of month' \
    'soq:Start of quarter' \
    'soy:Start of year' \
    'eow:End of week' \
    'eoww:End of work week' \
    'eocw:End of calendar week' \
    'eom:End of month' \
    'eoq:End of quarter' \
    'eoy:End of year' \
    'mon:Monday' \
    'tue:Tuesday'\
    'wed:Wednesday' \
    'thu:Thursday' \
    'fri:Friday' \
    'sat:Saturday' \
    'sun:Sunday' \
    'good*friday:Good Friday' \
    'easter:Easter' \
    'eastermonday:Easter Monday' \
    'ascension:Ascension' \
    'pentecost:Pentecost' \
    'midsommar:Midsommar' \
    'midsommarafton:Midsommarafton' \
    'later:Later' \
    'someday:Some Day'

  _task_dates=("$reply[@]")
  
  local -a _task_reldates
  _regex_words values 'task reldates' \

    'hrs:n hours' \
    'day:n days' \
    '1st:first' \
    '2nd:second' \
    '3rd:third' \
    'th:4th, 5th, etc.' \
    'wks:weeks'

  _task_reldates=("$reply[@]")
  
  task_dates=(

    \( "$_task_dates[@]" \|

      \( /$'[0-9][0-9]#'/- \( "$_task_reldates[@]" \) \)

    \)

  )

  local -a task_zshids

  if (( $#_task_zshids )); then
    _regex_words values 'task IDs' $_task_zshids
    task_zshids=("$reply[@]")
  fi

  _regex_words values 'task frequencies' \

    'daily:Every day' \
    'day:Every day' \
    'weekdays:Every day skipping weekend days' \
    'weekly:Every week' \
    'biweekly:Every two weeks' \
    'fortnight:Every two weeks' \
    'monthly:Every month' \
    'quarterly:Every three months' \
    'semiannual:Every six months' \
    'annual:Every year' \
    'yearly:Every year' \
    'biannual:Every two years' \
    'biyearly:Every two years'

  _task_freqs=("$reply[@]")
  
  local -a _task_frequencies
  _regex_words values 'task frequencies' \

    'd:days' \
    'w:weeks' \
    'q:quarters' \
    'y:years'

  _task_frequencies=("$reply[@]")
  
  task_freqs=(

    \( "$_task_freqs[@]" \|

       \( /$'[0-9][0-9]#'/- \( "$_task_frequencies[@]" \) \)

    \)

  )
  
  # attributes
  local -a task_attributes
  _regex_words -t ':' default 'task attributes' \

    'des*cription:Task description text' \
    'status:Status of task - pending, completed, deleted, waiting' \
    'pro*ject:Project name:$task_projects' \
    'pri*ority:priority:$task_priorities' \
    'du*e:Due date:$task_dates' \
    're*cur:Recurrence frequency:$task_freqs' \
    'un*til:Expiration date:$task_dates' \
    'li*mit:Desired number of rows in report' \
    'wa*it:Date until task becomes pending:$task_dates' \
    'ent*ry:Date task was created:$task_dates' \
    'end:Date task was completed/deleted:$task_dates' \
    'st*art:Date task was started:$task_dates' \
    'sc*heduled:Date task is scheduled to start:$task_dates' \
    'dep*ends:Other tasks that this task depends upon:$task_zshids'

  task_attributes=("$reply[@]")
  
  args=(

    \( "$task_attributes[@]" \|
    \( /'(project|description|status|entry|end|start|scheduled|depends|due|wait|recur|priority|until|limit).'/- \( /$'[^:]#:'/ ":default:modifiers:compadd -S ':' -a _task_modifiers" \) \) \|
    \( /'(rc).'/- \( /$'[^:]#:'/ ":arguments:config:compadd -S ':' -a _task_config" \) \) \|
    \( /'(+|-)'/- \( /"$word"/ ":values:remove tag:compadd -a _task_tags" \) \) \|
    \( /"$word"/ \)
    \) \#

  )
  _regex_arguments _task_attributes "${args[@]}"
  
  ## task commands
  
  # filter completion
  (( $+functions[_task_filter] )) ||
  _task_filter() {

    _task_attributes "$@"

    # TODO complete conjunctions only if the previous word is a filter expression, i.e. attribute, ID, any non-command
    _describe -t default 'task conjunctions' _task_conjunctions

  }
  
  # execute completion
  (( $+functions[_task_execute] )) ||
  _task_execute() {

    _files

  }
  
  # id-only completion
  (( $+functions[_task_id] )) ||
  _task_id() {

    _describe -t values 'task IDs' _task_zshids
  }
  
  # subcommand-only function
  (( $+functions[_task_subcommands] )) ||
  _task_subcommands() {
    local -a subcommands
    local _zshcmd
    local cmd category desc
    local lastcategory=''
    # The list is sorted by category, in the right order.
    for _zshcmd in "$_task_zshcmds[@]"; do
      # Parse out the three fields
      cmd=${_zshcmd%%:*}
      category=${${_zshcmd#*:}%%:*}
      desc=${_zshcmd#*:*:}
  
      # Present each category as soon as the first entry in the *next* category
      # is seen.
      if [[ $category != $lastcategory && -n $lastcategory ]]; then
        _describe -t ${lastcategory}-commands "task ${lastcategory} command" subcommands
        subcommands=()
      fi
  
      # Log the subcommand; we will process it in some future iteration.
      subcommands+=( "$cmd:$desc" )
  
      lastcategory=$category
    done

  }
  
  ## first level completion => task sub-command completion
  (( $+functions[_task_default] )) ||
  _task_default() {
      local cmd ret=1

    integer i=1
    while (( i < $#words ))
    do
      cmd="${_task_cmds[(r)$words[$i]]}"
      if (( $#cmd )); then
        _call_function ret _task_${cmd} ||
          _call_function ret _task_filter ||
            _message "No command remaining."
        return ret
      fi
      (( i++ ))
    done
  
    # update IDs
    _task_zshids=( ${(f)"$(task _zshids)"} )
  
    _task_subcommands
    _describe -t tasks 'task IDs' _task_zshids
    _describe -t aliases 'task aliases' _task_aliases
    _call_function ret _task_filter
  
    return ret

  }

  _task "$@"