fs = require 'fs'
path = require 'path'

class Task
  constructor: (@task) ->

  # Returns the priority, if any.
  priority: () ->
    @task.match(Task.priority_regex)?.toString()?.trim()

  # Retrieves an array of all the @context annotations.
  contexts: () ->
    ctx = @task.match(Task.contexts_regex)
    if ctx
      c.trim() for c in ctx

  # Retrieves an array of all the +project annotations.
  projects: () ->
    proj = @task.match(Task.projects_regex)
    if proj
      p.trim() for p in proj

  # returns properties
  properties: () ->
    propsList = {}
    props = @task.match(Task.props_regex)
    for p in props
      [key, value] = p.split(':')
      propsList[key] = value

    return propsList

  # Retrieves the date.
  date: () ->
    try
      return @task.match(Task.date_regex)[1]
    catch err
    return 
    
  # Returns text of task
  raw: ->
    @task
    
  overdue: () ->
    if @date is undefined
      return
    else if @date < new Date()
      true
    else false

  # Gets text of todo without priorities, contexts, projects, or dates
  text: () ->
    @task.replace(Task.priority_regex, "").
      replace(Task.contexts_regex, "").
      replace(Task.date_regex, "").
      replace(Task.projects_regex, "").
      replace(Task.property_regex, "")

  # TODO Compare to other task priority

  # The regular expression used to match contexts.
  @contexts_regex = /(?:\s+|^)@\w+/g

  # The regex used to match projects.
  @projects_regex = /(?:\s+|^)\+\w+/g

  # The regex used to match priorities.
  @priority_regex = /^\([A-Za-z]\)\s+/

  # The regex used to match dates.
  @date_regex = /([0-9]{4}-[0-9]{2}-[0-9]{2})/

  # The regex used to match properties.
  @props_regex = /\w+:\w+/g

root = exports ? this
root.Task = Task

class TodoList
  constructor: (args) ->
    @list = []
    if args instanceof Array
      @path = null
      
      for item in args
        if (item.constructor.name is 'String')
          @list.push(new Task(item))
        else if (item instanceof Task)
          @list.push(item)
    else if args.constructor.name is 'String'
      @path = args
      # If path doesn't end in .txt, default to todo.txt
      @path=path.join(@path,'todo.txt') if @path.substr(-4) isnt '.txt'

      # Read list of files, create todos from them
      lines = fs.readFileSync(@path).toString().split '\n'
      for line in lines
        if (line isnt '')
          @list.push(new Task(line))


  path: () ->
    @path

  byPriority: (priority) ->
    task for task in @list when task.priority() == "("+priority+")"

  byContext: (context) ->
    l = []
    for task in @list
      ctx = task.contexts()
      if (ctx and context in ctx)
        l.push task
    l

  byProject: (project) ->
    l = []
    for task in @list
      proj = task.projects()
      if (proj and project in proj)
        l.push task
    l


root = exports ? this
root.TodoList = TodoList