'''
Task Coach - Your friendly task manager
Copyright (C) 2011 Task Coach developers <developers@taskcoach.org>

Task Coach is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

Task Coach is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>.
'''

from taskcoachlib.domain.category import Category
from taskcoachlib.domain.date import DateTime, TimeDelta
from taskcoachlib.domain.task import Task
from taskcoachlib.i18n import _
from taskcoachlib.thirdparty.dateutil import parser as dparser
import csv
import tempfile
import StringIO
import re
import math


class CSVReader(object):
    def __init__(self, taskList, categoryList):
        self.taskList = taskList
        self.categoryList = categoryList
        
    def createReader(self, fp, dialect, hasHeaders):
        reader = csv.reader(fp, dialect=dialect)
        if hasHeaders:
            reader.next()
        return reader
        
    def read(self, **kwargs):
        fp = tempfile.TemporaryFile()
        fp.write(file(kwargs['filename'], 'rb').read().decode(kwargs['encoding']).encode('UTF-8'))
        fp.seek(0)
        
        rx1 = re.compile(r'^(\d+):(\d+)$')
        rx2 = re.compile(r'^(\d+):(\d+):(\d+)$')

        reader = self.createReader(fp, kwargs['dialect'], kwargs['hasHeaders'])
        dayfirst = kwargs['dayfirst']
        tasksById = dict()
        tasks = []

        for index, line in enumerate(reader):
            if kwargs['importSelectedRowsOnly'] and index not in kwargs['selectedRows']:
                continue
            subject = _('No subject')
            id_ = None
            description = StringIO.StringIO()
            categories = []
            priority = 0
            actualStartDateTime = None
            plannedStartDateTime = None
            dueDateTime = None
            completionDateTime = None
            reminderDateTime = None
            budget = TimeDelta()
            fixedFee = 0.0
            hourlyFee = 0.0
            percentComplete = 0

            for idx, fieldValue in enumerate(line):
                if kwargs['mappings'][idx] == _('ID'):
                    id_ = fieldValue.decode('UTF-8')
                elif kwargs['mappings'][idx] == _('Subject'):
                    subject = fieldValue.decode('UTF-8')
                elif kwargs['mappings'][idx] == _('Description'):
                    description.write(fieldValue.decode('UTF-8'))
                    description.write(u'\n')
                elif kwargs['mappings'][idx] == _('Category') and fieldValue:
                    name = fieldValue.decode('UTF-8')
                    if name.startswith('(') and name.endswith(')'):
                        continue  # Skip categories of subitems
                    cat = self.categoryList.findCategoryByName(name)
                    if not cat:
                        cat = self.createCategory(name)
                    categories.append(cat)
                elif kwargs['mappings'][idx] == _('Priority'):
                    try:
                        priority = int(fieldValue)
                    except ValueError:
                        pass
                elif kwargs['mappings'][idx] == _('Actual start date'):
                    actualStartDateTime = self.parseDateTime(fieldValue, dayfirst=dayfirst)
                elif kwargs['mappings'][idx] == _('Planned start date'):
                    plannedStartDateTime = self.parseDateTime(fieldValue, dayfirst=dayfirst)
                elif kwargs['mappings'][idx] == _('Due date'):
                    dueDateTime = self.parseDateTime(fieldValue, 23, 59, 59, dayfirst=dayfirst) 
                elif kwargs['mappings'][idx] == _('Completion date'):
                    completionDateTime = self.parseDateTime(fieldValue, 12, 0, 0, dayfirst=dayfirst) 
                elif kwargs['mappings'][idx] == _('Reminder date'):
                    reminderDateTime = self.parseDateTime(fieldValue, dayfirst=dayfirst)
                elif kwargs['mappings'][idx] == _('Budget'):
                    try:
                        value = float(fieldValue)
                        hours = int(math.floor(value))
                        minutes = int(60 * (value - hours))
                        budget = TimeDelta(hours=hours, minutes=minutes, seconds=0)
                    except ValueError:
                        mt = rx1.search(fieldValue)
                        if mt:
                            budget = TimeDelta(hours=int(mt.group(1)), minutes=int(mt.group(2)), seconds=0)
                        else:
                            mt = rx2.search(fieldValue)
                            if mt:
                                budget = TimeDelta(hours=int(mt.group(1)), minutes=int(mt.group(2)), seconds=int(mt.group(3)))
                elif kwargs['mappings'][idx] == _('Fixed fee'):
                    try:
                        fixedFee = float(fieldValue)
                    except ValueError:
                        pass
                elif kwargs['mappings'][idx] == _('Hourly fee'):
                    try:
                        hourlyFee = float(fieldValue)
                    except ValueError:
                        pass
                elif kwargs['mappings'][idx] == _('Percent complete'):
                    try:
                        percentComplete = max(0, min(100, int(fieldValue)))
                    except ValueError:
                        pass

            task = Task(subject=subject,
                        description=description.getvalue(),
                        priority=priority,
                        actualStartDateTime=actualStartDateTime,
                        plannedStartDateTime=plannedStartDateTime,
                        dueDateTime=dueDateTime,
                        completionDateTime=completionDateTime,
                        reminder=reminderDateTime,
                        budget=budget,
                        fixedFee=fixedFee,
                        hourlyFee=hourlyFee,
                        percentageComplete=percentComplete)

            if id_ is not None:
                tasksById[id_] = task

            for category in categories:
                category.addCategorizable(task)
                task.addCategory(category)

            tasks.append(task)

        # OmniFocus uses the task's ID to keep track of hierarchy: 1 => 1.1 and 1.2, etc...

        if tasksById:
            ids = []
            for id_, task in tasksById.items():
                try:
                    ids.append(tuple(map(int, id_.split('.'))))
                except ValueError:
                    self.taskList.append(task)

            ids.sort()
            ids.reverse()

            for id_ in ids:
                sid = '.'.join(map(str, id_))
                if len(id_) >= 2:
                    pid = '.'.join(map(str, id_[:-1]))
                    if pid in tasksById:
                        tasksById[pid].addChild(tasksById[sid])
                else:
                    self.taskList.append(tasksById[sid])
        else:
            self.taskList.extend(tasks)

    def createCategory(self, name):
        if ' -> ' in name:
            parentName, childName = name.rsplit(' -> ', 1)
            parent = self.categoryList.findCategoryByName(parentName)
            if not parent:
                parent = self.createCategory(parentName)
            newCategory = Category(subject=childName)
            parent.addChild(newCategory)
            newCategory.setParent(parent)
        else:
            newCategory = Category(subject=name)
        self.categoryList.append(newCategory)
        return newCategory

    def parseDateTime(self, fieldValue, defaultHour=0, defaultMinute=0, 
                      defaultSecond=0, dayfirst=False):
        if not fieldValue:
            return None
        try:
            dateTime = dparser.parse(fieldValue.decode('UTF-8'), 
                                     dayfirst=dayfirst, fuzzy=True).replace(tzinfo=None)
            hour, minute, second = dateTime.hour, dateTime.minute, dateTime.second
            if 0 == hour == minute == second:
                hour = defaultHour
                minute = defaultMinute
                second = defaultSecond
            return DateTime(dateTime.year, dateTime.month, dateTime.day,
                            hour, minute, second)
        except:  # pylint: disable=W0702
            return None  
