# -*- coding: utf-8 -*-
"""
  Copyright 2012-2014 Grégory Soutadé

  This file is part of Dynastie.

  Dynastie 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.

  Dynastie 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 Dynastie.  If not, see <http://www.gnu.org/licenses/>.
"""
import os
import shutil
import hashlib
import inspect
import gzip
from unicodedata import normalize
from re import sub
from datetime import datetime
from django.db import models
from django.contrib.auth.models import User
from django.db.models.signals import pre_init, post_init, pre_delete, post_delete
from django.db.models.signals import pre_save, post_save
from django.dispatch import receiver
from dynastie.generators import *

def slugify(name):
    name = name.strip()
    name = normalize('NFKD', name).replace(' ', '-').lower()
        #remove `other` characters
    name = sub('[^a-zA-Z0-9_-]', '', name)
        #nomalize dashes
    name = sub('-+', '-', name)
    return name

class Blog(models.Model):
    name = models.CharField(max_length=255, unique=True)
    title = models.CharField(max_length=255)
    description = models.TextField(max_length=255, blank=True)
    keywords = models.TextField(blank=True)
    writers = models.ManyToManyField(User)
    
    engines = list()

    src_path = ''
    output_path = ''
    report = ''

    def create_paths(self):
        self.src_path = os.environ['DYNASTIE_ROOT'] + 'sites/' + self.name
        self.output_path = os.environ['DYNASTIE_ROOT'] + 'sites/' + self.name + '_output'
        
    def create(self):
        self.create_paths()
        if not os.path.exists(os.environ['DYNASTIE_ROOT'] + 'sites'):
            os.mkdir(os.environ['DYNASTIE_ROOT'] + 'sites')

        if not os.path.exists(self.src_path):
            os.mkdir(self.src_path)

        if not os.path.exists(self.output_path):
            os.mkdir(self.output_path)
        
    def remove(self):
        if os.path.exists(self.src_path):
            shutil.rmtree(self.src_path)
        if os.path.exists(self.output_path):
            shutil.rmtree(self.output_path)

    def load_generators(self):
        if os.path.exists(self.src_path + '/_generators'):
            f = open(self.src_path + '/_generators', 'r')
            for line in f:
                if line.startswith("#"):
                    continue
                engine = line.strip()
                if not engine in globals():
                    print('Engine ' + engine + ' doesn\'t exists')
                else:
                    self.engines.append(globals()[engine])
            f.close()
        else:
            self.engines.append(globals()['post'])
            self.engines.append(globals()['index'])
            self.engines.append(globals()['category'])
            self.engines.append(globals()['tag'])
            self.engines.append(globals()['archive'])
            self.engines.append(globals()['atom'])
            self.engines.append(globals()['rss'])
            self.engines.append(globals()['all_posts'])

    def get_engines(self):
        return self.engines
            
    def copytree(self, src, dst):
        names = os.listdir(src)

        errors = []
        for name in names:
            if name.startswith('_') or name.endswith('~'):
                continue
            srcname = os.path.join(src, name)
            dstname = os.path.join(dst, name)
            try:
                if os.path.islink(srcname) and not os.path.exists(dstname):
                    linkto = os.readlink(srcname)
                    os.symlink(linkto, dstname)
                if os.path.isdir(srcname):
                    if not os.path.exists(dstname):
                        os.makedirs(dstname)
                        self.copytree(srcname, dstname, ignore=True)
                    else:
                        return self.copytree(srcname, dstname)
                else:
                    copied = False
                    if os.path.exists(dstname):
                        src_md5 = hashlib.md5()
                        f = open(srcname,'rb') 
                        src_md5.update(f.read())
                        f.close()

                        dst_md5 = hashlib.md5()
                        f = open(dstname,'rb') 
                        dst_md5.update(f.read())
                        f.close()

                        if src_md5.digest() != dst_md5.digest():
                            self.report = self.report + 'Update ' + dstname + '<br/>\n'
                            shutil.copy2(srcname, dstname)
                            copied = True
                            
                    else:
                        self.report = self.report + 'Add ' + dstname + '<br/>\n'
                        shutil.copy2(srcname, dstname)
                        copied = True

                    if copied:
                        exts = ('css', 'html', 'htm', 'xhtml', 'js')
                        found = False
                        for ext in exts:
                            if srcname.endswith(ext):
                                found = True
                                break
                        if found:
                            dstname = dstname + '.gz'
                            if os.path.exists(dstname):
                                os.unlink(dstname)
                            f = open(srcname)
                            content = f.read()
                            f.close()
                            f = gzip.open(dstname, 'wb')
                            f.write(content)
                            f.close()


        # XXX What about devices, sockets etc.?
            except (IOError, os.error) as why:
                errors.append((srcname, dstname, str(why)))
        # catch the Error from the recursive copytree so that we can
        # continue with other files
            except Exception as err:
                errors.extend(err.args[0])
        if errors:
            raise Exception(errors)

    def generate(self, request):
        start_time = datetime.now()
        self.report = ''
        self.load_generators()
        self.copytree(self.src_path, self.output_path)
        generated = []
        hash_posts = {}
        hash_posts_content = {}
        for engine in self.engines:
            if not inspect.ismodule(engine):
                continue
            for name, obj in inspect.getmembers(engine):
                if inspect.isclass(obj) and obj.__module__.startswith("dynastie.generators"):
                    if obj.__module__ in generated: continue
                    e = obj(hash_posts, hash_posts_content)
                    print('Go for {}'.format(e))
                    r = e.generate(self, self.src_path, self.output_path)
                    generated.append(obj.__module__)
                    if not r is None:
                        self.report = self.report + '<br/>\n' + r

        duration = datetime.now() - start_time
        t = '<br/><br/>Generation of ' + start_time.strftime("%d/%m/%Y at %H:%M:%S") + '<br/>\n'
        t = t + 'Duration ' + str(duration) + '<br/><br/>\n'
        return t + self.report

    def generate_post(self, request, post):
        from dynastie.generators import post as PostGenerator
        start_time = datetime.now()
        self.report = ''
        self.load_generators()
        self.copytree(self.src_path, self.output_path)
        post_list = [post]
        hash_posts = {}
        hash_posts_content = {}
        engine = globals()['post']
        for name, obj in inspect.getmembers(engine):
            if inspect.isclass(obj) and obj.__module__.startswith("dynastie.generators") \
               and obj.__module__.endswith("post"):
                e = obj(request, hash_posts, hash_posts_content)
                self.report = e._generate(self, self.src_path, self.output_path, post_list)
                break
        # report = PostGenerator()._generate(self, self.src_path, self.output_path, post_list)

        duration = datetime.now() - start_time
        t = '<br/><br/>Generation of ' + start_time.strftime("%d/%m/%Y at %H:%M:%S") + ' post ' + str(post.id) + '<br/>\n'
        t = t + 'Duration ' + str(duration) + '<br/><br/>\n'
        return t + self.report

class Editor(models.Model):
    name = models.CharField(max_length=255, unique=True)

class Category(models.Model):
    name = models.CharField(max_length=255, unique=True)
    name_slug = models.CharField(max_length=255)
    parent = models.ForeignKey('self', blank=True, null=True, on_delete=models.CASCADE)
    description = models.TextField(max_length=255, blank=True)
    blog = models.ForeignKey(Blog, on_delete=models.CASCADE)

    def save(self):
        self.name_slug = slugify(self.name)
        super(Category, self).save()

    def remove(self):
        blog = Blog.objects.get(pk=self.blog.id)
        output = blog.output_path + '/category/' + self.name_slug
        if os.path.exists(output):
            shutil.rmtree(output)


class Tag(models.Model):
    name = models.CharField(max_length=255, unique=True)
    name_slug = models.CharField(max_length=255)
    blog = models.ForeignKey(Blog, on_delete=models.CASCADE)
    
    def save(self):
        self.name_slug = slugify(self.name)
        super(Tag, self).save()

    def remove(self):
        blog = Blog.objects.get(pk=self.blog.id)
        output = blog.output_path + '/tag/' + self.name_slug
        if os.path.exists(output):
            shutil.rmtree(output)

class PostOnlyManager(models.Manager):

    def get_queryset(self):
        return super(PostOnlyManager, self).get_queryset().filter(post_type='P')
                                    
class Post(models.Model):

    objects = PostOnlyManager()

    title = models.CharField(max_length=255)
    title_slug = models.CharField(max_length=255)
    category = models.ForeignKey(Category, blank=True, null=True, on_delete=models.SET_NULL)
    published = models.BooleanField()
    creation_date = models.DateTimeField()
    modification_date = models.DateTimeField()
    front_page = models.BooleanField()
    author = models.ForeignKey(User, null=True, on_delete=models.SET_NULL)
    description = models.TextField(max_length=255, blank=True)
    keywords = models.TextField(blank=True)
    tags = models.ManyToManyField(Tag, blank=True, null=True)
    blog = models.ForeignKey(Blog, on_delete=models.CASCADE)
    CONTENT_HTML = 0
    CONTENT_TEXT = 1
    CONTENT_FORMAT = (
        (CONTENT_HTML, 'HTML'),
        (CONTENT_TEXT, 'Text'))
    content_format = models.IntegerField(choices=CONTENT_FORMAT, default=CONTENT_HTML, blank=False, null=False)
    post_type = models.CharField(max_length=1, default='P')

    def getPath(self):
        filename = '/post/' 
        filename = filename + self.creation_date.strftime("%Y") + '/' + self.creation_date.strftime("%m") + '/' 
        filename = filename + self.title_slug + '.html'
        return filename

    def save(self):
        self.title = self.title.strip()
        self.title_slug = slugify(self.title)
        self.modification_date=datetime.now()
        super(Post, self).save()

    def manageTags(self, tags):
        tags_list = Tag.objects.filter(blog_id=self.blog.id)
        my_tags = []
        # Create new tags
        for tag in tags.split(','):
            if tag == '': continue
            tag_slug = slugify(tag)
            found = False
            for t in tags_list:
                if t.name_slug == tag_slug:
                    found = True
                    break
            if not found and not tag in my_tags:
                t = Tag(blog=self.blog, name=tag.strip(), name_slug=tag_slug)
                t.save()
                # print 'Create ' + tag_slug
                my_tags.append(tag)

        # Add new tags
        post_tags_list = Tag.objects.filter(post=self.id)
        for tag in tags.split(','):
            if tag == '': continue
            tag_slug = slugify(tag)
            found = False
            for t in post_tags_list:
                if t.name_slug == tag_slug:
                    found = True
                    break
            if not found:
                for t in tags_list:
                    if t.name_slug == tag_slug:
                        self.tags.add(t)
                        # print 'Add ' + tag_slug 
                        break

        # Remove old tags
        if tags == '':
            for t in post_tags_list:
                self.tags.remove(t)
        else:
            for t in post_tags_list:
                found = False
                for tag in tags.split(','):
                    tag_slug = slugify(tag)
                    if t.name_slug == tag_slug:
                        found = True
                        break
                if not found:
                # print 'Remove ' + t.name_slug
                    self.tags.remove(t)

    def createPost(self, content, tags):
        output = self.blog.src_path
        if not os.path.exists(output + '/_post'):
            os.mkdir(output + '/_post')

        filename = output + '/_post/' + str(self.pk)
        content = content.encode('utf-8')

        f = open(filename, 'wb')
        f.write(content)
        f.close()

        self.manageTags(tags)

    def remove(self):
        b = self.blog

        output = b.src_path
        filename = output + '/_post/' + str(self.pk)
        if os.path.exists(filename):
            os.unlink(filename)

        output = b.output_path + self.getPath()
        if os.path.exists(filename):
            os.unlink(filename)
        filename = filename + '.gz'
        if os.path.exists(filename):
            os.unlink(filename)

        filename = b.src_path + '/post/'
        filename = filename + self.creation_date.strftime("%Y") + '/' + self.creation_date.strftime("%m") + '/' 
        if os.path.exists(filename) and len(os.listdir(filename)) == 0:
            os.rmdir(filename)

        filename = b.output_path + '/post/' 
        filename = filename + self.creation_date.strftime("%Y") + '/'
        if os.path.exists(filename) and len(os.listdir(filename)) == 0:
            os.rmdir(filename)


    def get_editor(self):
        if self.content_format == Post.CONTENT_HTML:
            return 'html'
        else:
            return 'text'

class Draft(Post):

    objects = models.Manager()

    def createDraft(self, content, tags):
        b = self.blog
        output = b.src_path
        if not os.path.exists(output + '/_draft'):
            os.mkdir(output + '/_draft')

        filename = output + '/_draft/' + str(self.pk)
        content = content.encode('utf-8')
        modif = True

        if os.path.exists(filename):
            f = open(filename, 'rb')
            src_md5 = hashlib.md5()
            src_md5.update(f.read())
            f.close()

            dst_md5 = hashlib.md5()
            dst_md5.update(content)

            if src_md5.digest() == dst_md5.digest():
                modif = False
            else:
                os.unlink(filename)

        if modif:
            f = open(filename, 'wb')
            f.write(content)
            f.close()

        self.manageTags(tags)
        self.save()

    def remove(self):
        b = self.blog

        output = b.src_path
        filename = output + '/_draft/' + str(self.pk)
        if os.path.exists(filename):
            os.unlink(filename)

    def save(self):
        self.published = False
        super(Draft, self).save()

class Comment(models.Model):
    post = models.ForeignKey(Post, on_delete=models.CASCADE)
    parent = models.ForeignKey('self', null=True, blank=True, on_delete=models.CASCADE)
    date = models.DateTimeField()
    author = models.CharField(max_length=255)
    email = models.EmailField(max_length=255, blank=True)
    the_comment = models.TextField(max_length=255)
    ip = models.GenericIPAddressField()

    def _update_line_returns(self):
        self.the_comment = self.the_comment.replace('\n', '<br />')

    def _remove_br(self):
        self.the_comment = self.the_comment.replace('<br />', '\n')

class FileOutputCache(models.Model):
    name = models.CharField(max_length=512)
    hash = models.CharField(max_length=512)

@receiver(post_init, sender=Blog)
def init_blog_signal(sender, **kwargs):
    kwargs['instance'].create_paths()

@receiver(post_delete, sender=Blog)
def delete_blog_signal(sender, **kwargs):
    kwargs['instance'].remove()

@receiver(pre_delete, sender=Category)
def delete_category_signal(sender, **kwargs):
    kwargs['instance'].remove()

@receiver(pre_delete, sender=Tag)
def delete_tag_signal(sender, **kwargs):
    kwargs['instance'].remove()

@receiver(post_delete, sender=Post)
def delete_post_signal(sender, **kwargs):
    kwargs['instance'].remove()

@receiver(post_delete, sender=Draft)
def delete_draft_signal(sender, **kwargs):
    kwargs['instance'].remove()

@receiver(pre_delete, sender=Post)
def pre_delete_post_signal(sender, **kwargs):
    post = kwargs['instance']
    comments = Comment.objects.filter(post=post.id).delete()

# Replace line returns by <br /> for generation
@receiver(pre_save, sender=Comment)
def pre_save_comment_signal(sender, **kwargs):
    kwargs['instance']._update_line_returns()

@receiver(pre_save, sender=Draft)
def pre_save_draft_signal(sender, **kwargs):
    kwargs['instance'].post_type = 'D'