#!/usr/bin/python

import sys
import getopt
import shutil
import os
import datetime
import subprocess
import re

from time import gmtime, strftime, mktime


def isset(variable):
    return variable in locals() or variable in globals()


def list_directory(path):
    fichier = []
    for root, dirs, files in os.walk(path):
        for i in files:
            fichier.append(os.path.join(root, i))
    return fichier


def get_tags(fh):
    line = fh.readline()
    while "@tags=" not in line:
        line = fh.readline()
    if "@tags" not in line:
        return []

    line = line.strip()  # Delete \n at the end of the line
    tag_pos = line.find("@tags=")
    tags = [x.strip() for x in line[tag_pos+6:].split(",")]
    return tags


def latest_articles(directory, number):
    now = datetime.datetime.now()
    counter = 0
    latest_articles = []

    for i in range(int(now.strftime('%Y')), 0, -1):
        if counter >= number:
            break

        if os.path.isdir(directory+"/"+str(i)):
            for j in range(12, 0, -1):
                if j < 10:
                    j = "0"+str(j)

                if os.path.isdir(directory+"/"+str(i)+"/"+str(j)):
                    articles_list = list_directory(directory+str(i)+"/"+str(j))
                    # Sort by date the articles
                    articles_list.sort(key=lambda x: os.stat(x).st_mtime)

                    latest_articles += articles_list[:number-counter]
                    if len(latest_articles) < number-counter:
                        counter += len(articles_list)
                    else:
                        counter = number

    #Delete directory in file names
    return latest_articles


def auto_dir(path):
    directory = os.path.dirname(path)
    try:
        if not os.path.exists(directory):
            os.makedirs(directory)
    except IOError:
        sys.exit("[ERROR] An error occured while creating "+path+" file \
          and parent dirs.")


def replace_tags(article, search_list, replace_list):
    return_string = article
    for search, replace in zip(search_list, replace_list):
        return_string = re.sub(search, replace, article)
    return return_string


try:
    opts, args = getopt.gnu_getopt(sys.argv, "hf", ["help", "force-regen"])
except getopt.GetoptError:
    sys.exit("Error while parsing command line arguments. See pre-commit -h for more infos on how to use.")

force_regen = False
for opt, arg in opts:
    if opt in ("-h", "--help"):
        print("Usage :")
        print("This should be called automatically as a git hook when commiting. You can also launch it manually.\n")
        print("This script generates static pages ready to be served behind your webserver.\n")
        print("Usage :")
        print("-h \t --help \t displays this help message.")
        print("-f \t --force-regen \t force the regeneration of all the pages.")
        sys.exit(0)
    elif opt in ("-f", "--force-regen"):
        force_regen = True

#Set parameters
search_list = []
replace_list = []
with open("raw/params", "r") as params_fh:
    params = {}
    for line in params_fh.readlines():
        if line.strip() == "" or line.strip().startswith("#"):
            continue
        option, value = line.split("=", 1)
        if option == "SEARCH":
            search_list = value.strip().split(",")
        elif option == "REPLACE":
            replace_list = value.strip().split(",")
        else:
            params[option.strip()] = value.strip()

#Fill lists for modified, deleted and added files
modified_files = []
deleted_files = []
added_files = []

if not force_regen:
    #Find the changes to be committed
    try:
        changes = subprocess.check_output(["git", "diff", "--cached", "--name-status"], universal_newlines=True)
    except:
        sys.exit("[ERROR] An error occured when running git diff.")

    changes = changes.strip().split("\n")
    if changes == [""]:
        sys.exit("[ERROR] Nothing to do...")

    for changed_file in changes:
        if changed_file[0].startswith("A"):
            added_files.append(changed_file[changed_file.index("\t")+1:])
        elif changed_file[0].startswith("M"):
            modified_files.append(changed_file[changed_file.index("\t")+1:])
        elif changed_file[0].startswith("D"):
            deleted_files.append(changed_file[changed_file.index("\t")+1:])
        else:
            sys.exit("[ERROR] An error occured when running git diff.")
else:
    shutil.rmtree("blog/")
    shutil.rmtree("gen/")
    added_files = list_directory("raw")

if not added_files and not modified_files and not deleted_files:
    sys.exit("[ERROR] Nothing to do...")

#Only keep modified raw articles files
for filename in list(added_files):
    if not filename.startswith("raw/"):
        added_files.remove(filename)
        continue

    try:
        int(filename[4:8])
    except ValueError:
        added_files.remove(filename)
        continue

    if not filename.endswith("html") and not filename.endswith("ignore"):
        print("[INFO] (Not HTML file) Copying directly not html file "+filename[4:]+" to blog dir.")

        auto_dir("blog/"+filename[4:])
        shutil.copy(filename, "blog/"+filename[4:])
        added_files.remove(filename)
        continue

    if filename.endswith("ignore"):
        print("[INFO] (Not published) Found not published article "+filename[4:-7]+".")
        added_files.remove(filename)
        continue

for filename in list(modified_files):
    if not filename.startswith("raw/"):
        modified_files.remove(filename)
        continue

    try:
        int(filename[4:6])
    except ValueError:
        modified_files.remove(filename)
        continue

    if not filename.endswith("html") and not filename.endswith("ignore"):
        print("[INFO] (Not HTML file) Updating directly not html file "+filename[4:]+" to blog dir.")
        auto_dir("blog/"+filename[4:])
        shutil.copy(filename, "blog/"+filename[4:])
        modified_files.remove(filename)
        continue

    if filename.endswith("ignore"):
        print("[INFO] (Not published) Found not published article "+filename[4:-7]+".")
        added_files.remove(filename)
        continue

for filename in list(deleted_files):
    if not filename.startswith("raw/"):
        deleted_files.remove(filename)
        continue

    try:
        int(filename[4:6])
    except ValueError:
        deleted_files.remove(filename)
        continue

    if not filename.endswith("html") and not filename.endswith("ignore"):
        print("[INFO] (Not HTML file) Copying directly not html file "+filename[4:]+" to blog dir.")
        auto_dir("blog/"+filename[4:])
        shutil.copy(filename, "blog/"+filename[4:])
        deleted_files.remove(filename)
        continue

    if filename.endswith("ignore"):
        print("[INFO] (Not published) Found not published article "+filename[4:-7]+".")
        added_files.remove(filename)
        continue


print("[INFO] Added files : "+", ".join(added_files))
print("[INFO] Modified files : "+", ".join(modified_files))
print("[INFO] Deleted filed : "+", ".join(deleted_files))

print("[INFO] Updating tags for added and modified files")
for filename in added_files:
    try:
        with open(filename, 'r') as fh:
            tags = get_tags(fh)
            if tags:
                for tag in tags:
                    try:
                        auto_dir("gen/tags/"+tag+".tmp")
                        with open("gen/tags/"+tag+".tmp", 'a+') as tag_file:
                            tag_file.seek(0)
                            if filename[4:] not in tag_file.read():
                                tag_file.write(filename[4:]+"\n")
                            print("[INFO] (TAGS) Found tag "+tag+" for article "+filename[4:])
                    except IOError:
                        sys.exit("[ERROR] (TAGS) New tag found but error occured in article "+filename[4:]+": "+tag+".")
            else:
                sys.exit("[ERROR] (TAGS) In added article "+filename[4:]+" : No tags found !")
    except IOError:
        sys.exit("[ERROR] Unable to open file "+filename+".")

for filename in modified_files:
    try:
        with open(filename, 'r') as fh:
            tags = get_tags(fh)
            if tags:
                for tag in list_directory("gen/tags/"):
                    try:
                        with open(tag, 'r+') as tag_file:
                            if tag[tag.index("tags/") + 5:tag.index(".tmp")] in tags and filename[4:] not in tag_file.read():
                                    tag_file.seek(0, 2)  # Append to end of file
                                    tag_file.write(filename[4:]+"\n")
                                    print("[INFO] (TAGS) Found new tag "+tag[:tag.index(".tmp")]+" for modified article "+filename[4:])
                                    tags.remove(tag_file[9:])
                            if tag[tag.index("tags/") + 5:tag.index(".tmp")] not in tags and filename[4:] in tag_file.read():
                                    old_tag_file_content = tag_file.read()
                                    tag_file.truncate()
                                    tag_file.write(old_tag_file_content.replace(filename[4:]+"\n", ""))
                                    print("[INFO] (TAGS) Deleted tag "+tag[:tag.index(".tmp")]+" in modified article "+filename[4:])
                                    tags.remove(tag_file[9:])
                    except IOError:
                        sys.exit("[ERROR] (TAGS) An error occured when parsing tags of article "+filename[4:]+".")

                for tag in tags:  # New tags added
                    try:
                        auto_dir("gen/tags/"+tag+".tmp")
                        with open("gen/tags/"+tag+".tmp", "a+") as tag_file:
                            tag_file.write(filename[4:]+"\n")
                            print("[INFO] (TAGS) Found new tag "+tag+" for modified article "+filename[4:])
                    except IOError:
                        sys.exit("[ERROR] (TAGS) An error occured when parsing tags of article "+filename[4:]+".")
            else:
                sys.exit("[ERROR] (TAGS) In modified article "+filename[4:]+" : No tags found !")
    except IOError:
        sys.exit("[ERROR] Unable to open file "+filename+".")

#Delete tags for deleted files and delete all generated files
for filename in deleted_files:
    try:
        with open(filename, 'r') as fh:
            tags = get_tags(fh)
            if tags:
                for tag in tags:
                    try:
                        with open("gen/tags/"+tag+".tmp", 'r+') as tag_file:
                            old_tag_file_content = tag_file.read()
                            tag_file.truncate()
                            #Delete file in tag
                            tag_file.write(old_tag_file_content.replace(filename[4:]+"\n", ""))
                    except IOError:
                        sys.exit("[ERROR] An error occured while deleting article "+filename[4:]+" from tags files.")
            else:
                sys.exit("[ERROR] (TAGS) In deleted article "+filename[4:]+" : No tags found !")
    except IOError:
        sys.exit("[ERROR] Unable to open file "+filename+".")

    #Delete generated files
    try:
        os.unlink("gen/"+filename[4:-5]+".gen")
        os.unlink("blog/"+filename[4:])
    except FileNotFoundError:
        print("[INFO] Article "+filename[4:]+" was not already generated. You should check manually.")

    print("[INFO] Deleted article "+filename[4:]+" in both gen and blog directories")

#Delete empty tags files
for tag in list_directory("gen/tags"):
    try:
        with open(tag, 'r') as tag_file:
            content = tag_file.read().strip()
        if content == '':
            try:
                os.unlink(tag)
                os.unlink(tag.replace("gen", "blog"))
            except FileNotFoundError:
                print("[INFO] "+tag+" was found to be empty but there was an error during deletion. You should check manually.")
            print("[INFO] (TAGS) No more article with tag "+tag[8:-4]+", deleting it.")
    except IOError:
        sys.exit("[ERROR] Unable to open "+tag+".")

#(Re)Generate HTML files
for filename in added_files+modified_files:
    try:
        with open(filename, 'r') as fh:
            #Generate HTML for the updated articles
            for line in fh.readlines():
                if "@title=" in line:
                    line = line.strip()
                    title_pos = line.find("@title=")
                    title = line[title_pos+7:].strip()
                    continue

                if "@date=" in line:
                    line = line.strip()
                    date_pos = line.find("@date=")
                    date = line[date_pos+6:].strip()
                    continue

                if isset("date") and isset("title"):
                    break

            fh.seek(0)
            article = fh.read()
            article = replace_tags(article, search_list, replace_list)
            date = "Le "+date[0:2]+"/"+date[2:4]+"/"+date[4:8]+" à "+date[9:11]+":"+date[11:13]

            try:
                auto_dir("gen/"+filename[4:-5]+".gen")
                with open("gen/"+filename[4:-5]+".gen", 'w') as article_file:
                    article_file.write("<article><nav class=\"aside_article\"></nav><div class=\"article\"><h1>"+title+"</h1>"+article+"<p class=\"date\">"+date+"</p></div>\n")
                    print("[GEN ARTICLES] Article "+filename[4:]+" generated")
            except IOError:
                print("[GEN ARTICLES ERROR] An error occurred while generating article "+filename[4:])
    except IOError:
        sys.exit("[ERROR] Unable to open file "+filename+".")

#Generate headers file (except title)
try:
    with open("raw/header.html", "r") as header_fh:
        #Tags
        tags = list_directory("gen/tags")
        header = header_fh.read()
        tags_header = "<ul>"
        for tag in tags:
            tags_header += "<li><a href=\""+params["BLOG_URL"]+tag[4:-4]+".html\">"+tag[9:-4]+"</a></li>"
        tags_header += "</ul>"
        header = header.replace("@categories", tags_header, 1)

        header = header.replace("@blog_url", params["BLOG_URL"], 1)

        #Articles
        latest_articles_list = latest_articles("gen/", 5)
        articles_header = "<ul>"
        for article in latest_articles_list:
            try:
                with open(article, 'r') as fh:
                    line = fh.readline()
                    while "@title" not in line:
                        line = fh.readline()
                    line = line.strip()
                    title_pos = line.find("@title=")
                    title = line[title_pos+7:]

                    articles_header += "<li><a href=\""+params["BLOG_URL"]+article[4:-4]+".html\">"+title+"</a></li>"
            except IOError:
                sys.exit("[ERROR] Unable to open file "+article+".")
        articles_header += "</ul>"
        header = header.replace("@articles", articles_header, 1)

        try:
            auto_dir("gen/header.gen")
            with open("gen/header.gen", "w") as header_gen_fh:
                header_gen_fh.write(header)
                print("[INFO] (HEADER) Header has been generated successfully.")
        except FileNotFoundError:
            sys.exit("[ERROR] (HEADER) An error occured while writing header file.")
        except IOError:
            sys.exit("[ERROR] Unable to open gen/header.gen for writing.")
except IOError:
    sys.exit("[ERROR] Unable to open raw/header.html file.")

#Generate footer file
if not os.path.isfile("raw/footer.html"):
    sys.exit("[ERROR] (FOOTER) Footer file (raw/footer.html) not found.")
try:
    shutil.copy("raw/footer.html", "gen/footer.gen")
    print("[INFO] (FOOTER) Footer has been generated successfully")
except IOError:
    sys.exit("[ERROR] Unable to copy the footer.html file.")

#Copy CSS files
if not os.path.isdir("raw/css") or list_directory("raw/css") == []:
    print("[INFO] (CSS) No CSS files in raw/css folder")
else:
    try:
        shutil.copytree("raw/css", "blog/css")
    except IOError:
        sys.exit("[ERROR] An error occured while copying css files.")


#Regenerate index file
last_articles_index = latest_articles("gen/", int(params["NB_ARTICLES_INDEX"]))
try:
    auto_dir("blog/index.html")
    with open("blog/index.html", "w") as index_fh:
        try:
            with open("gen/header.gen", "r") as header_gen_fh:
                index = header_gen_fh.read()
            for article in last_articles_index:
                with open(article, "r") as article_fh:
                    index += replace_tags(article_fh.read(), search_list, replace_list)
            with open("gen/footer.gen") as footer_gen_fh:
                index += footer_gen_fh.read()

            index = index.replace("@titre", params["BLOG_TITLE"], 1)
            index_fh.write(index)
            print("[INFO] (INDEX) Index page has been generated successfully.")
        except IOError:
            sys.exit("[ERROR] Error while creating index.html file")
except IOError:
    sys.exit("[ERROR] Unable to open index.html file for writing.")

#Regenerate tags pages
for tag in list_directory("gen/tags"):
    try:
        auto_dir(tag.replace("gen/", "blog/"))
        with open(tag.replace("gen/", "blog/")[:-4]+".html", "w") as tag_fh:
            with open(tag, "r") as tag_gen_fh:
                with open("gen/header.gen", "r") as header_fh:
                    tag_content = header_fh.read()
                    tag_content = tag_content.replace("@titre", params["BLOG_TITLE"]+" - "+tag[4:-4], 1)
                tag_gen_fh_lines = tag_gen_fh.readlines()
                for line in tag_gen_fh_lines:
                    line = line.replace(".html", ".gen")
                    with open("gen/"+line.strip(), "r") as article_handler:
                        tag_content += replace_tags(article_handler.read(), search_list, replace_list)
                with open("gen/footer.gen", "r") as footer_handler:
                    tag_content += footer_handler.read()
            tag_fh.write(tag_content)
            print("[INFO] (TAGS) Tag page for "+tag[9:-4]+" has been generated successfully.")
    except IOError:
        sys.exit("[ERROR] An error occured while generating tag page \""+tag[9:-4]+"\"")

#Finish articles pages generation
for filename in added_files+modified_files:

    try:
        auto_dir("blog/"+filename[4:])
        with open("blog/"+filename[4:], "w") as article_fh:
            with open("gen/header.gen", "r") as header_gen_fh:
                article = header_gen_fh.read()
            with open("gen/"+filename[4:-5]+".gen", "r") as article_gen_fh:
                line = article_gen_fh.readline()
                while "@title" not in line:
                    line = article_gen_fh.readline()
                line = line.strip()
                title_pos = line.find("@title=")
                title = line[title_pos+7:]
                article_gen_fh.seek(0)

                article = article.replace("@titre", params["BLOG_TITLE"]+" - "+title, 1)
                article += replace_tags(article_gen_fh.read(), search_list, replace_list)
            with open("gen/footer.gen", "r") as footer_gen_fh:
                article += footer_gen_fh.read()
            article_fh.write(article)
            print("[INFO] (ARTICLES) Article page for "+filename[4:]+" has been generated successfully.")
    except IOError:
        sys.exit("[ERROR] An error occured while generating article "+filename[4:]+" page.")

#Generate pages for each year and month
with open("gen/header.gen", "r") as header_gen_fh:
    header_gen = header_gen_fh.read()

with open("gen/footer.gen", "r") as footer_gen_fh:
    footer_gen = footer_gen_fh.read()

years_list = os.listdir("blog/")
years_list.sort(reverse=True)
for i in years_list:
    try:
        int(i)
    except ValueError:
        continue

    #Generate page per year
    page_year = header_gen.replace("@titre", params["BLOG_TITLE"]+" - "+i, 1)

    months_list = os.listdir("blog/"+i)
    months_list.sort(reverse=True)
    for j in months_list:
        if not os.path.isdir("blog/"+i+"/"+j):
            continue

        #Generate pages per month
        page_month = header_gen.replace("@titre", params["BLOG_TITLE"]+" - "+i+"/"+j, 1)

        articles_list = list_directory("gen/"+i+"/"+j)
        articles_list.sort(key=lambda x: os.stat(x).st_mtime, reverse=True)
        for article in articles_list:
            try:
                with open(article, "r") as article_fh:
                    article_content = replace_tags(article_fh.read(), search_list, replace_list)
                    page_month += article_content
                    page_year += article_content
            except IOError:
                sys.exit("[ERROR] Error while generating years and months pages. Check your gen folder, you may need to regenerate some articles. The error was due to "+article+".")

        page_month += footer_gen
        try:
            with open("blog/"+i+"/"+j+"/index.html", "w") as page_month_fh:
                page_month_fh.write(page_month)
        except IOError:
            sys.exit("[ERROR] Unable to write index file for "+i+"/"+j+".")

    page_year += footer_gen
    try:
        with open("blog/"+i+"/index.html", "w") as page_year_fh:
            page_year_fh.write(page_year)
    except IOError:
        sys.exit("[ERROR] Unable to write index file for "+i+".")


#Generate RSS
rss = "<?xml version=\"1.0\" encoding=\"UTF-8\"?><rss version=\"2.0\" xmlns:atom=\"http://www.w3.org/2005/Atom\" xmlns:content=\"http://purl.org/rss/1.0/modules/content/\">"
rss += "<channel><atom:link href=\""+params["BLOG_URL"]+"rss.xml\" rel=\"self\" type=\"application/rss+xml\"/><title>"+params["BLOG_TITLE"]+"</title><link>"+params["BLOG_URL"]+"</link>"
rss += "<description>"+params["DESCRIPTION"]+"</description><language>"+params["LANGUAGE"]+"</language><copyright>"+params["COPYRIGHT"]+"</copyright>"
rss += "<webMaster>"+params["WEBMASTER"]+"</webMaster><lastBuildDate>"+strftime("%a, %d %b %Y %H:%M:%S +0000", gmtime())+"</lastBuildDate>"

for article in last_articles_index:
    del date, title
    try:
        with open(article, "r") as article_fh:
            tags = get_tags(article_fh)
            article_fh.seek(0)

            for line in article_fh.readlines():
                if "@title=" in line:
                    line = line.strip()
                    title_pos = line.find("@title=")
                    title = line[title_pos+7:].strip()
                    continue

                if "@date=" in line:
                    line = line.strip()
                    date_pos = line.find("@date=")
                    date = line[date_pos+6:].strip()
                    continue

                if isset("date") and isset("title"):
                    break

            date = strftime("%a, %d %b %Y %H:%M:%S +0000", gmtime(mktime(datetime.datetime.strptime(date, "%d%m%Y-%H%M").timetuple())))
            article_fh.seek(0)

            rss += "<item> \
                        <title>"+title+"</title> \
                        <link>"+params["BLOG_URL"]+article[5:]+"</link> \
                        <guid isPermaLink=\"false\">"+params["BLOG_URL"]+article[5:]+"</guid> \
                        <description><![CDATA["+replace_tags(article_fh.read(), search_list, replace_list)+"]]></description> \
                        <pubDate>"+date+"</pubDate> \
                        <category>"+', '.join(tags)+"</category> \
                        <author>"+params["WEBMASTER"]+"</author> \
                    </item>"
    except IOError:
        sys.exit("[ERROR] Unable to read article "+article+" to generate RSS file.")

rss += "</channel></rss>"

try:
    with open("blog/rss.xml", "w") as rss_fh:
        rss_fh.write(rss)
except IOError:
    sys.exit("[ERROR] An error occured while writing RSS file.")