#!/usr/bin/env python
import argparse
import os
import sys
import xml.etree.ElementTree as ET
from io import StringIO
from datetime import datetime

import markdown
import yaml

from bs4 import BeautifulSoup
from jinja2 import Environment, FunctionLoader


def _load_sitemap(path, current_path):
    by_name = dict()
    flattened = []
    with open(path, "r") as fp:
        _sitemap = yaml.safe_load(fp.read())

    if not _sitemap["enabled"]:
        return None

    variables = dict()
    if "variables" in _sitemap:
        variables = _sitemap["variables"]

    def _filter_entries(entries):
        entries = list(
            filter(
                lambda entry: "enabled" not in entry or entry["enabled"] is True,
                entries,
            )
        )
        for entry in entries:
            if "others" in entry:
                entry["others"] = _filter_entries(entry["others"])
        return entries

    entries = _filter_entries(_sitemap["entries"])

    def _link(entries, parent=None):
        for entry in entries:
            flattened.append(entry)
            entry["parent"] = parent
            if "others" in entry:
                _link(entry["others"], parent=entry)

    def _make_url(link):
        path = [link["name"]]
        parent = link["parent"]
        while parent is not None:
            path.append(parent["name"])
            parent = parent["parent"]
        path.reverse()
        return "/".join(path)

    _link(entries, parent=None)

    for entry in flattened:
        target = "/" + _make_url(entry)
        if target == current_path:
            entry["active"] = True
        else:
            entry["active"] = False
        entry["url"] = target
        by_name[target] = entry

    return dict(by_name=by_name, variables=variables, links=entries)


def _make_tree(links):
    def _populate(root, links):
        for link in links:
            elm = ET.Element("li")
            if "directory" in link and link["directory"]:
                elm.text = link["name"]
            else:
                lref = ET.Element("a", href=link["url"])
                link_text = link["name"]
                if "date" in link:
                    link_text = link_text + " [" + str(link["date"]) + "]"
                lref.text = link_text
                if link["active"]:
                    lref.text = lref.text + "  <"
                elm.append(lref)
            if "others" in link:
                others = link["others"]
                ul = ET.Element("ul")
                elm.append(ul)
                _populate(root=ul, links=others)
            root.append(elm)

    params = {"class": "tree"}

    root = ET.Element("ul", **params)
    _populate(root=root, links=links)
    return ET.tostring(root).decode()


def load_content(path):
    with open(path) as fp:
        text = fp.read()
        content = markdown.markdown(
            text,
            extensions=["fenced_code", "tables"],
        )
        return content


def generate(template, content_path, stylesheet, link, sitemap, devmode=False):
    tree = _make_tree(sitemap["links"])
    with open(template, "r") as fp:
        template = fp.read()
    env = Environment(loader=FunctionLoader(lambda name: template))
    base = env.get_template(template)
    with open(stylesheet) as fp:
        style = fp.read()
    content = load_content(content_path)
    env_content = Environment(loader=FunctionLoader(lambda name: content))
    out = base.render(
        {
            "content": env_content.get_template("").render(
                {
                    "sitemap": sitemap,
                    "tree": tree,
                    "variables": sitemap["variables"]
                }
            ),
            "variables": sitemap["variables"],
            "is_index": False,
            "link": link,
            "style": style,
            "sitemap": sitemap,
            "tree": tree,
            "devmode": devmode,
            "current_time": datetime.now(),
        }
    )
    sys.stdout.write(out)


def generate_rss(sitemap):
    sitemap = _load_sitemap(sitemap, "/")

    rss = ET.Element("rss", attrib={"version": "2.0", "encoding": "UTF-8"})
    channel = ET.SubElement(rss, "channel")

    title = ET.SubElement(channel, "title")
    title.text = "Blog of Kevin Schoon"
    link = ET.SubElement(channel, "link")
    link.attrib["href"] = "https://kevinschoon.com"
    description = ET.SubElement(channel, "description")
    description.text = "Blog of Kevin Schoon"

    for entry in sitemap["by_name"]["/blog"]["others"]:
        absolute_url = "https://kevinschoon.com/blog/" + entry["name"]
        item = ET.SubElement(channel, "item")
        title_item = ET.SubElement(item, "title")
        link_item = ET.SubElement(item, "link")
        guid_item = ET.SubElement(item, "guid")
        guid_item.text = absolute_url
        description_item = ET.SubElement(item, "description")
        title_item.text = entry["name"]
        link_item.attrib["href"] = absolute_url 
        description_item.text = entry["tagline"]

    xml_str = ET.tostring(rss, xml_declaration=True, encoding="utf-8", method="xml")
    sys.stdout.buffer.write(xml_str)


if __name__ == "__main__":
    parser = argparse.ArgumentParser(description="static renderer")
    parser.add_argument("-rss", help="if rendering the rss feed", action="store_true")
    parser.add_argument("-content", help="markdown file with content")
    parser.add_argument(
        "-template", default="index.html.jinja", help="jinja template file"
    )
    parser.add_argument("-stylesheet", default="./assets/main.css", help="style sheet")
    parser.add_argument("-sitemap", default="sitemap.yaml", help="sitemap")
    parser.add_argument("-link", default="/", help="current url")
    parser.add_argument(
        "-devmode", action="store_true", help="developer mode (websocket page refresh)"
    )
    args = parser.parse_args()
    sitemap = _load_sitemap(args.sitemap, args.link)
    if args.rss:
        generate_rss(args.sitemap)
    else:
        generate(
            template=args.template,
            content_path=args.content,
            stylesheet=args.stylesheet,
            link=args.link,
            sitemap=sitemap,
            devmode=args.devmode,
        )