import sublime
import sublime_plugin
from . import markdown2
import os.path
import re

from html.parser import HTMLParser

# Main sublime tools function

def md(*t, **kwargs):
    sublime.message_dialog(kwargs.get('sep', '\n').join([str(el) for el in t]))

def sm(*t, **kwargs):
    sublime.status_message(kwargs.get('sep', ' ').join([str(el) for el in t]))

def em(*t, **kwargs):
    sublime.error_message(kwargs.get('sep', ' ').join([str(el) for el in t]))

def mini(val, min):
    if val < min:
        return min
    return val

STYLE_FILE = os.path.join(sublime.packages_path(), 'User', 'MarkdownLivePreview.css')
def get_style():
    """Of course, this is temporal, there will be an option to customize the CSS"""
    if os.path.exists(STYLE_FILE):
        with open(STYLE_FILE) as fp:
            content = fp.read()
            if content:
                return content

    return """
        body {
            padding:10px;
            font-family: "Open Sans", sans-serif;
            background-color: var(--background);
            font-size: 15px;
        }

        blockquote {
            font-style: italic;
            display: block;
            margin-left: 30px;
            border: 1px solid red;
        }

        code {
            padding-left: 0.2rem;
            padding-right: 0.2rem;
            background-color: rgb(244.6,244.6,244.6);
            margin: 0;
            border-radius: 3px;
            margin: 5px;
        }

        pre {
            display: block;
            margin-top: 20px;
            line-height: 2;
            background-color: rgb(244.6,244.6,244.6);
            padding-left: 10px;
        }
        pre code {
            padding-left: 0;
        }
    """

def pre_with_br(html):
    """Because the phantoms of sublime text does not support <pre> blocks
    this function replaces every \n with a <br> in a <pre>"""

    while True:
        obj = re.search(r'<pre>.*?</pre>', html, re.DOTALL)
        if not obj:
            break
        html = list(html)
        html[obj.start(0):obj.end(0)] = ''.join(html[obj.start(0):obj.end(0)]).replace('\n', '<br>').replace('<pre>', '<pre class="pre">')
        html = ''.join(html)
    return html

def close_preview(md_view_settings, preview):
    preview.close()
    md_view_settings.erase('markdown_preview_id')
    md_view_settings.erase('markdown_preview_enabled')

def create_preview(window, md_view):
    focus_group, focus_view = window.get_view_index(md_view)
    preview = window.new_file()
    window.run_command('new_pane') # move the preview to a new group
    preview.set_name(os.path.basename(md_view.file_name()) + ' - Preview')

    preview_settings = preview.settings()
    preview_settings.set('gutter', False)
    preview_settings.set('is_markdown_preview', True)
    preview_settings.set('markdown_view_id', md_view.id())

    md_view.settings().set('markdown_preview_id', preview.id())
    window.focus_group(focus_group)
    window.focus_view(md_view)

    return preview

def show_html(md_view, preview):
    html = ('<style>{}</style>'.format(get_style()) +
            pre_with_br(markdown2.markdown(get_view_content(md_view),
                        extras=['fenced-code-blocks'])))
    html = HTMLParser().unescape(html)
    preview.erase_phantoms('markdown_preview')
    preview.add_phantom('markdown_preview',
                         sublime.Region(0),
                         html,
                         sublime.LAYOUT_INLINE,
                         lambda href: sublime.run_command('open_url', {'url': href}))
    # 0 < y < 1
    y = md_view.text_to_layout(md_view.sel()[0].begin())[1] / md_view.layout_extent()[1]
    # remove half of the viewport_extent.y to center it on the screen (verticaly)
    vector = 0, y * preview.layout_extent()[1] - preview.viewport_extent()[1] / 2
    preview.set_viewport_position(vector, animate=False)

def get_view_content(view):
    return view.substr(sublime.Region(0, view.size()))

def get_view_from_id(window, id):
    for view in window.views():
        if view.id() == id:
            return view

class MarkdownInPopupCommand(sublime_plugin.EventListener):

    def on_load(self, view):
        settings = view.settings()
        if not 'markdown' in settings.get('syntax').lower():
            return
        settings.add_on_change('markdown_preview_enabled', lambda: self.on_modified(view))

    def on_modified(self, md_view):
        window = md_view.window()
        md_view_settings = md_view.settings()

        if not 'markdown' in md_view_settings.get('syntax').lower():
            return

        markdown_preview_enabled = md_view_settings.get('markdown_preview_enabled') is True
        preview_id = md_view_settings.get('markdown_preview_id', None)

        if not markdown_preview_enabled:
            if preview_id is not None:
                preview = get_view_from_id(window, preview_id)
                if preview:
                    close_preview(md_view_settings, preview)
            return

        if preview_id is None:
            preview = create_preview(window, md_view)
        else:
            preview = get_view_from_id(window, preview_id)
            if not preview:
                md_view_settings.erase('markdown_preview_id')
                md_view_settings.erase('markdown_preview_enabled')
                return

        show_html(md_view, preview)

    def on_pre_close(self, view):
        settings = view.settings()
        if settings.get('markdown_preview_enabled') is True:
            preview = get_view_from_id(view.window(), settings.get('markdown_preview_id'))
            if preview:
                sublime.set_timeout_async(lambda: preview.close(), 250)
        elif settings.get('is_markdown_preview') is True:
            md_view = get_view_from_id(view.window(), settings.get('markdown_view_id'))
            if md_view:
                def callback():
                    md_view_settings = md_view.settings()
                    md_view_settings.erase('markdown_preview_enabled')
                    md_view_settings.erase('markdown_preview_id')
                sublime.set_timeout_async(callback, 250)