"""
Renders Jinja2 & Sass templates for use by the front end application
"""
# Standard Imports
from pathlib import Path

# Module Imports
import sass
import toml
import jinja2
import logzero
from logzero import logger
from markdown2 import Markdown
from flask import render_template

# Project Imports
from hyperglass.exceptions import HyperglassError
from hyperglass.configuration import params, devices, logzero_config

# Module Directories
working_directory = Path(__file__).resolve().parent
hyperglass_root = working_directory.parent
file_loader = jinja2.FileSystemLoader(str(working_directory))
env = jinja2.Environment(loader=file_loader)

default_details = {
    "footer": (
        "---\n"
        "By using {{ branding.site_name }}, you agree to be bound by the following "
        "terms of use: All queries executed on this page are logged for analysis and "
        "troubleshooting. Users are prohibited from automating queries, or attempting "
        "to process queries in bulk. This service is provided on a best effort basis, "
        "and {{ general.org_name }} makes no availability or performance warranties "
        "or guarantees whatsoever."
    ),
    "bgp_aspath": (
        "title: Supported AS Path Patterns\n"
        "---\n"
        "{{ branding.site_name }} accepts the following `AS_PATH` regular expression "
        "patterns:\n"
        "| Expression           | Match                                         |\n"
        "| :------------------- | :-------------------------------------------- |\n"
        "| `_65000$`            | Originated by 65000                           |\n"
        "| `^65000_`            | Received from 65000                           |\n"
        "| `_65000_`            | Via 65000                                     |\n"
        "| `_65000_65001_`      | Via 65000 and 65001                           |\n"
        "| `_65000(_.+_)65001$` | Anything from 65001 that passed through 65000 |\n"
    ),
    "bgp_community": (
        "title: BGP Communities\n"
        "---\n"
        "{{ branding.site_name }} makes use of the following BGP communities:\n"
        "| Community | Description |\n"
        "| :-------- | :---------- |\n"
        "| `65000:1` | Example 1   |\n"
        "| `65000:2` | Example 2   |\n"
        "| `65000:3` | Example 3   |\n"
    ),
}

default_info = {
    "bgp_route": """
---
Performs BGP table lookup based on IPv4/IPv6 prefix.
""",
    "bgp_community": (
        'link: <a href="#" id="help_link_bgpc">{{ general.org_name }} '
        "BGP Communities</a>\n"
        "---\n"
        "Performs BGP table lookup based on "
        "[Extended](https://tools.ietf.org/html/rfc4360) "
        "or [Large](https://tools.ietf.org/html/rfc8195) community value."
        '<br>{{ info["bgp_community"]["link"] }}'
    ),
    "bgp_aspath": (
        'link: <a href="#" id="help_link_bgpa">Supported BGP AS Path Expressions</a>\n'
        "---\n"
        "Performs BGP table lookup based on `AS_PATH` regular expression."
        '<br>{{ info["bgp_aspath"]["link"] }}'
    ),
    "ping": ("---\n", "Sends 5 ICMP echo requests to the target."),
    "traceroute": (
        "---\n"
        "Performs UDP Based traceroute to the target.<br>For information about how to"
        "interpret traceroute results, [click here]"
        "(https://hyperglass.readthedocs.io/en/latest/assets/traceroute_nanog.pdf)."
    ),
}


def info(file_name):
    """
    Converts Markdown documents to HTML, renders Jinja2 variables,
    renders TOML frontmatter variables, returns dictionary of variables
    and HTML content.
    """
    html_classes = {"table": "table"}
    markdown = Markdown(
        extras={
            "break-on-newline": True,
            "code-friendly": True,
            "tables": True,
            "html-classes": html_classes,
        }
    )
    file = working_directory.joinpath(f"templates/info/{file_name}.md")
    frontmatter_dict = {}
    if file.exists():
        with file.open(mode="r") as file_raw:
            file_read = file_raw.read()
            frontmatter, content = file_read.split("---")
            frontmatter_dict[file_name] = toml.loads(frontmatter)
        md_template_fm = jinja2.Environment(loader=jinja2.BaseLoader).from_string(
            frontmatter
        )
        md_template_content = jinja2.Environment(loader=jinja2.BaseLoader).from_string(
            content
        )
    else:
        _, frontmatter, content = default_info[file_name].split("+++")
        md_template_fm = jinja2.Environment(loader=jinja2.BaseLoader).from_string(
            frontmatter
        )
        md_template_content = jinja2.Environment(loader=jinja2.BaseLoader).from_string(
            content
        )
    frontmatter_rendered = md_template_fm.render(params)
    frontmatter_dict[file_name] = toml.loads(frontmatter_rendered)
    content_rendered = md_template_content.render(params, info=frontmatter_dict)
    frontmatter_dict[file_name]["content"] = markdown.convert(content_rendered)
    return frontmatter_dict


def details(file_name):
    """
    Converts Markdown documents to HTML, renders Jinja2 variables,
    renders TOML frontmatter variables, returns dictionary of variables
    and HTML content.
    """
    html_classes = {"table": "table"}
    markdown = Markdown(
        extras={
            "break-on-newline": True,
            "code-friendly": True,
            "tables": True,
            "html-classes": html_classes,
        }
    )
    file = working_directory.joinpath(f"templates/info/details/{file_name}.md")
    frontmatter_dict = {}
    if file.exists():
        with file.open(mode="r") as file_raw:
            file_read = file_raw.read()
            frontmatter, content = file_read.split("---")
        md_template_fm = jinja2.Environment(loader=jinja2.BaseLoader).from_string(
            frontmatter
        )
        md_template_content = jinja2.Environment(loader=jinja2.BaseLoader).from_string(
            content
        )
    else:
        _, frontmatter, content = default_details[file_name].split("+++")
        frontmatter_dict[file_name] = toml.loads(frontmatter)
        md_template_fm = jinja2.Environment(loader=jinja2.BaseLoader).from_string(
            frontmatter
        )
        md_template_content = jinja2.Environment(loader=jinja2.BaseLoader).from_string(
            content
        )
    frontmatter_rendered = md_template_fm.render(params)
    frontmatter_dict[file_name] = toml.loads(frontmatter_rendered)
    content_rendered = md_template_content.render(params, details=frontmatter_dict)
    frontmatter_dict[file_name]["content"] = markdown.convert(content_rendered)
    return frontmatter_dict


def html(template_name):
    """Renders Jinja2 HTML templates"""
    details_name_list = ["footer", "bgp_aspath", "bgp_community"]
    details_dict = {}
    for details_name in details_name_list:
        details_data = details(details_name)
        details_dict.update(details_data)
    info_list = ["bgp_route", "bgp_aspath", "bgp_community", "ping", "traceroute"]
    info_dict = {}
    for info_name in info_list:
        info_data = info(info_name)
        info_dict.update(info_data)
    try:
        template_file = f"templates/{template_name}.html.j2"
        template = env.get_template(template_file)
        return template.render(
            params, info=info_dict, details=details_dict, networks=devices.networks
        )
    except jinja2.TemplateNotFound as template_error:
        logger.error(
            f"Error rendering Jinja2 template {Path(template_file).resolve()}."
        )
        raise HyperglassError(template_error)


def css():
    """Renders Jinja2 template to Sass file, then compiles Sass as CSS"""
    scss_file = hyperglass_root.joinpath("static/sass/hyperglass.scss")
    css_file = hyperglass_root.joinpath("static/css/hyperglass.css")
    # Renders Jinja2 template as Sass file
    try:
        template_file = "templates/hyperglass.scss.j2"
        template = env.get_template(template_file)
        rendered_output = template.render(params)
        with scss_file.open(mode="w") as scss_output:
            scss_output.write(rendered_output)
    except jinja2.TemplateNotFound as template_error:
        logger.error(
            f"Error rendering Jinja2 template {Path(template_file).resolve()}."
        )
        raise HyperglassError(template_error)
    # Compiles Sass to CSS
    try:
        generated_sass = sass.compile(filename=str(scss_file))
        with css_file.open(mode="w") as css_output:
            css_output.write(generated_sass)
            logger.debug(f"Compiled Sass file {scss_file} to CSS file {css_file}.")
    except:
        logger.error(f"Error compiling Sass in file {scss_file}.")
        raise