import locale
import os.path
import re
from datetime import datetime
from pathlib import Path

from markdown.preprocessors import Preprocessor
from pelican import signals
from pelican.readers import Markdown, MarkdownReader, pelican_open
from pelican.utils import get_date, slugify

locale.setlocale(locale.LC_TIME, "fr_FR")


class WorklogPreprocessor(Preprocessor):
    pattern = re.compile(
        r"""
        (\w+)\s+                      # Day name
        (\d{1,2})\s+                  # Day number
        ([\wéû]+)\s+                  # Month name
        (\d{4})\s+                    # Year
        \(
        (\d{1,2})h                    # Hours (mandatory)
        (?:\s+facturées)?             # Optionally 'facturées', if not present, assume hours are 'facturées'
        (?:,\s*(\d{1,2})h\s*bénévoles)? # Optionally 'volunteer hours 'bénévoles'
        ,?                            # An optional comma
        \s*                           # Optional whitespace
        (?:fun\s+)?                   # Optionally 'fun' (text) followed by whitespace
        (\d)/5                        # Happiness rating (mandatory, always present)
        \)                            # Closing parenthesis
        """,
        re.VERBOSE | re.UNICODE,
    )

    def __init__(self, *args, **kwargs):
        self.data = {}
        super().__init__(*args, **kwargs)

    def run(self, lines):
        new_lines = []
        for line in lines:
            if line.startswith("##"):
                match = re.search(self.pattern, line)
                if not match:
                    raise ValueError("Unable to parse worklog title", line)
                (
                    day_of_week,
                    day,
                    month,
                    year,
                    payed_hours,
                    volunteer_hours,
                    happiness,
                ) = match.groups()

                volunteer_hours = int(volunteer_hours) if volunteer_hours else 0
                payed_hours = int(payed_hours)
                happiness = int(happiness)

                date = datetime.strptime(f"{day} {month} {year}", "%d %B %Y")
                self.data[date.strftime("%Y-%m-%d")] = {
                    "payed_hours": payed_hours,
                    "volunteer_hours": volunteer_hours,
                    "happyness": happiness,
                }

                # Replace the line with just the date
                new_lines.append(f"## 🗓️ {day_of_week} {day} {month} {year}")
            else:
                new_lines.append(line)
        return new_lines

    def compute_data(self, metadata):
        done_hours = sum([item["payed_hours"] for item in self.data.values()])

        data = dict(
            data=self.data,
            done_hours=done_hours,
            template="worklog",
        )

        if "total_days" in metadata:
            total_hours = int(metadata["total_days"]) * 7
            data.update(
                dict(
                    total_hours=total_hours,
                    percentage=round(done_hours / total_hours * 100),
                )
            )

        return data


class SimpleReader(MarkdownReader):
    enabled = True

    file_extensions = ["md"]

    def __init__(self, *args, **kwargs):
        super(SimpleReader, self).__init__(*args, **kwargs)
        self.settings["MARKDOWN"]["extensions"].append("markdown.extensions.toc")

    def read(self, source_path):
        self._source_path = source_path
        self._md = Markdown(**self.settings["MARKDOWN"])

        is_worklog = Path(source_path).parent.match("pages/worklog")

        if is_worklog:
            worklog = WorklogPreprocessor(self._md)
            self._md.preprocessors.register(worklog, "worklog", 20)

        with pelican_open(source_path) as text:
            content = self._md.convert(text)

        if hasattr(self._md, "Meta"):
            metadata = self._parse_metadata(self._md.Meta)
        else:
            metadata = {}

        # Add the worklog info to the metadata
        if is_worklog:
            metadata["worklog"] = worklog.compute_data(metadata)

        # Add the TOC to the metadata.
        if len(self._md.toc) > 300:
            metadata["table_of_contents"] = self._md.toc

        # Get the title from the first title
        if "title" not in metadata and len(self._md.toc_tokens):
            first_title = self._md.toc_tokens[0]
            metadata["title"] = first_title["name"]
            content = content.replace(
                '<h1 id="{id}">{name}</h1>'.format(**first_title), ""
            )

        # Get the date from the filename, if possible.
        parts = os.path.splitext(os.path.basename(source_path))[0].split("-")
        if len(parts) > 3:
            metadata["date"] = get_date("-".join(parts[:3]))

        if "slug" not in metadata:
            metadata["slug"] = slugify(
                metadata["title"], self.settings.get("SLUG_REGEX_SUBSTITUTIONS", [])
            )

        category = os.path.basename(
            os.path.abspath(os.path.join(source_path, os.pardir))
        )
        metadata["category"] = self.process_metadata("category", category)
        return content, metadata


def add_reader(readers):
    readers.reader_classes["md"] = SimpleReader


# This is how pelican works.
def register():
    signals.readers_init.connect(add_reader)