# SPDX-License-Identifier: GPL-3.0-or-later
#
# Copyright (C) 2025 The Project Authors
# See pyproject.toml for authors/maintainers.
# See LICENSE for license details.
"""
Utilities for managing structured Markdown notes.

This module provides a lightweight framework for creating, loading, and managing
Markdown-based notes with structured metadata. It supports templated note
creation, automated refactoring of note names and links, reference notes with
BibTeX integration, and utilities for working with collections of notes.

Quick start
===========

This section demonstrates common operations for working with Markdown-based notes.


Load a note


.. code-block:: python

    from losalamos.notes import Note

    note = Note(name="Example", alias="Nt1")
    note.load("path/to/note.md")

    print(note.metadata)
    print(note.data)


Create a new note from a template

.. code-block:: python

    from losalamos.notes import NoteBasic

    note = NoteBasic()
    note.load_new("path/to/new_note.md")

    note.metadata["abstract"] = '"Short description of the note."'
    note.update()
    note.save()


Refactor a note and update links

.. code-block:: python

    from losalamos.notes import Note

    note = Note()
    note.load("path/to/old_name.md")

    note.refactor(
        new_name="new_name",
        scope="path/to/notes_folder"
    )


Create a reference note

.. code-block:: python

    from losalamos.notes import NoteReference

    note = NoteReference()

    metadata = {
        "entry_type": "article",
        "name": "smith2022",
        "author": "Smith, John and Doe, Jane",
        "title": "Example Article",
        "year": "2022",
        "journal": "Journal of Examples",
        "doi": "10.1000/example"
    }

    note.load_new(
        file_note="path/to/smith2022.md",
        metadata=metadata
    )

    note.save()


Export BibTeX from a reference note

.. code-block:: python

    from losalamos.notes import NoteReference

    note = NoteReference()
    note.load("path/to/smith2022.md")

    note.to_bib("path/to/file.bib")


Load a collection of notes

.. code-block:: python

    from losalamos.notes import NoteCollection

    coll = NoteCollection()

    coll.load_folder("path/to/notes")

    print(len(coll))


Search notes using a glob pattern

.. code-block:: python

    from losalamos.notes import NoteCollection

    coll = NoteCollection()

    coll.load_pattern("path/to/notes/**/*.md")

    for note in coll:
        print(note.name)


"""
# IMPORTS
# ***********************************************************************
# import modules from other libs

# Native imports
# =======================================================================
import glob, re
from pathlib import Path
from datetime import datetime

# ... {develop}

# External imports
# =======================================================================
import pandas as pd

# ... {develop}

# Project-level imports
# =======================================================================
from losalamos.root import MbaE, Collection
from losalamos.references import Reference, REFERENCE_DISPATCHER
from losalamos.paths import FOLDER_TEMPLATES_NOTES

# ... {develop}


# CONSTANTS
# ***********************************************************************
# define constants in uppercase

# CONSTANTS -- Project-level
# =======================================================================
# ... {develop}


# list of fields that needs harmonization
HARMONIZE_TEXT_FIELDS = [
    "name",
    "title",
    "subtitle",
    "subject",
    "abstract",
    "contract",
    "client",
    "project",
    "comment",
    "caption",
    "alttext",
    "source",
    "document",
    "file",
    "pdf",
    "file_draft",
    "publisher",
    "booktitle",
    "cite_bibli",
]
HARMONIZE_DATE_FIELDS = [
    "timestamp",
    "date",
    "datetime",
    "date_start",
    "date_end",
]
# Subsubsection example
# -----------------------------------------------------------------------

# CONSTANTS -- Module-level
# =======================================================================
# ... {develop}


# FUNCTIONS
# ***********************************************************************

# FUNCTIONS -- Project-level
# =======================================================================


def search_markdown_files(paths: list[Path]) -> list[Path]:
    """
    Recursively scans the provided paths to identify and collect all files with a ``.md`` extension.

    :param paths: A list of file or directory paths to search.
    :type paths: list[:class:`pathlib.Path`]
    :return: A list of paths pointing to the discovered markdown files.
    :rtype: list[:class:`pathlib.Path`]
    """
    files = []
    for p in paths:
        if p.is_file() and p.suffix == ".md":
            files.append(p)
        elif p.is_dir():
            files.extend(p.rglob("*.md"))
    return files


# FUNCTIONS -- Module-level
# =======================================================================
# ... {develop}


# CLASSES
# ***********************************************************************

# CLASSES -- Project-level
# =======================================================================

# NOTES
# -----------------------------------------------------------------------


class Note(MbaE):
    # todo major docstring

    STR_HEAD = "Head"
    STR_BODY = "Body"
    STR_TAIL = "Tail"

    def __init__(self, name="MyNote", alias="Nt1"):
        # set attributes
        self.file_note = None
        self.metadata = None
        self.data = None
        super().__init__(name=name, alias=alias)
        # ... continues in downstream objects ... #

    def _set_fields(self):
        super()._set_fields()
        # Attribute fields
        self.field_name_note = "note_name"
        self.field_alias_note = "note_alias"
        self.field_file_note = "note_file"

        # Metadata fields

        # ... continues in downstream objects ... #

    def get_metadata(self):
        """
        This method returns all objects metadata, incluiding selected
        attributes beyond the metadata of the file
        """
        # set object metadata
        dc_main = {
            self.field_name_note: self.name,
            self.field_alias_note: self.alias,
            self.field_file_note: str(self.file_note),
        }

        # include file metadata
        if self.metadata is not None:
            dc_main.update(self.metadata)

        return dc_main

    def load_metadata(self, file_note=None):

        if file_note is not None:
            self.file_note = Path(file_note)

        dc = Note.parse_metadata(self.file_note)

        self.setup_metadata(metadata=dc)

        return None

    def setup_metadata(self, metadata):
        dc = metadata.copy()

        # TEXT
        # ---------------------
        for k in dc:
            if k in HARMONIZE_TEXT_FIELDS:
                dc[k] = Note.harmonize_entry_text(dc[k])

        # DATE
        # ---------------------
        for k in dc:
            if k in HARMONIZE_DATE_FIELDS:
                dc[k] = Note.harmonize_entry_date(dc[k], key=k)

        if self.metadata is None:
            self.metadata = dc.copy()
        else:
            self.metadata.update(dc)

        return None

    def load_data(self, file_note=None):

        if file_note is not None:
            self.file_note = Path(file_note)

        self.data = Note.parse_note(self.file_note)

    def load(self, file_note=None):
        self.load_metadata(file_note=file_note)
        self.load_data(file_note=file_note)

    def save(self):
        self.to_file(file_path=self.file_note)

    def export(self, folder, filename, export_metadata=False):
        """
        Export to a markdown file with optional metadata handling.

        :param folder: The directory path where the file will be saved.
        :type folder: str
        :param filename: The name of the file without the extension.
        :type filename: str
        :param export_metadata: Toggle to trigger the parent class metadata export. Default value = ``False``
        :type export_metadata: bool
        :return: Path to the exported file
        :rtype: Path

        .. note::

            This method constructs a file path using ``pathlib.Path`` and appends the
            ``.md`` extension. It calls the internal ``to_file`` method with ``cleanup``
            enabled to finalize the document. If ``export_metadata`` is set to ``True``,
            it invokes the ``export`` method of the superclass before proceeding.

        """
        if export_metadata:
            super().export(folder=folder, filename=filename)
        fpath = Path(folder) / f"{filename}.md"
        self.to_file(fpath, cleanup=True)

        return fpath.absolute()

    def to_file(self, file_path, cleanup=True):
        """
        Write the note object's metadata and data content to a specified file.

        :param file_path: The destination path where the note will be written.
        :type file_path: str
        :param cleanup: Toggle to remove excessive blank lines after writing. Default value = ``True``
        :type cleanup: bool
        :return: None
        :rtype: NoneType

        .. note::

            This method aggregates metadata and data by calling ``metadata_to_list`` and
            ``data_to_list``. It sanitizes the output by replacing ``None`` string
            occurrences with empty strings and ensures each entry ends with a newline
            character. If ``cleanup`` is enabled, it post-processes the file using
            ``remove_excessive_blank_lines`` to maintain consistent formatting.

        """
        # metadata
        # ------------------------------------
        ls_metadata = Note.metadata_to_list(self.metadata)

        for i in range(len(ls_metadata)):
            # clear "None" values
            ls_metadata[i] = ls_metadata[i].replace("None", "")

        # data
        # ------------------------------------
        ls_data = Note.data_to_list(self.data)
        # append to metadata list
        for l in ls_data:
            ls_metadata.append(l[:])
        ls_all = [line + "\n" for line in ls_metadata]

        with open(file_path, "w", encoding="utf-8") as file:
            file.writelines(ls_all)

        # clean up excessive lines
        if cleanup:
            Note.remove_excessive_blank_lines(file_path)

        return None

    def refactor(self, new_name, scope):
        """
        Renames the current file note and updates all internal markdown
        links within a specified scope.

        .. note::

             This function performs a regex-based search across the provided scope to find and replace
             Obsidian-style internal links (e.g., ``[[OldName]]`` or ``[[OldName|Alias]]``) with the
             newly defined name.

        :param new_name: The new filename (without extension) to be applied.
        :type new_name: str
        :param scope: The directories or file paths where link references should be updated.
        :type scope: :class:`pathlib.Path`, str, or Iterable
        :return: None
        :rtype: None
        """
        from typing import Iterable, Union

        def _normalize_scope(scope):
            if scope is None:
                return [source]  # only self

            if isinstance(scope, (str, Path)):
                return [Path(scope)]

            if isinstance(scope, Iterable):
                return [Path(p) for p in scope]

            raise ValueError("Invalid scope for refactoring")

        source = Path(self.file_note)
        old_name = source.stem

        if old_name == new_name:
            return None

        # Rename file itself
        new_path = source.with_name(f"{new_name}.md")
        source.rename(new_path)
        self.file_note = new_path

        # determine scope
        scope_paths = _normalize_scope(scope)

        # search files
        md_files = search_markdown_files(scope_paths)

        # Build regex
        pattern = re.compile(rf"\[\[{re.escape(old_name)}(\|[^\]]+)?\]\]")

        # Replace in files
        for file in md_files:
            text = file.read_text(encoding="utf-8")

            new_text = pattern.sub(rf"[[{new_name}\1]]", text)

            if new_text != text:
                file.write_text(new_text, encoding="utf-8")

        return None

    @staticmethod
    def harmonize_entry_text(entry):
        if entry is not None:
            new_entry_bulk = entry[:]
            new_entry_bulk = new_entry_bulk.replace("'", "`")
            new_entry_bulk = new_entry_bulk.replace('"', "``")

            new_entry = '"' + new_entry_bulk + '"'
            s_start = new_entry[:2].replace("`", "")
            s_end = new_entry[-2:].replace("`", "")
            s_bulk = new_entry[2:-2]

            return s_start + s_bulk + s_end
        else:
            return None

    @staticmethod
    def harmonize_entry_date(entry, key="date"):
        if entry is None:
            return None

        if "datetime" in key or "timestamp" in key:
            format_mask = "%Y-%m-%d %H:%M:%S"
        else:
            format_mask = "%Y-%m-%d"

        dt = pd.to_datetime(entry, errors="coerce")

        if pd.isna(dt):
            return None

        return dt.strftime(format_mask)

    @staticmethod
    def harmonize_entry_date_old(entry, key="date"):
        if entry is not None:

            format_mask = "%Y-%m-%d"

            if "datetime" in key:
                format_mask = "%Y-%m-%d %H:%M:%S"
            if "timestamp" in key:
                format_mask = "%Y-%m-%d %H:%M:%S"

            # Convert string back into a Python object
            dt_object = pd.to_datetime([entry])

            # return string
            return str(dt_object.strftime(format_mask).values[0])
        else:
            return None

    @staticmethod
    def remove_excessive_blank_lines(file_path):
        """
        Remove consecutive blank lines from a file to ensure only single blank lines remain.

        :param file_path: The path to the target text file to be processed.
        :type file_path: str
        :return: None
        :rtype: NoneType

        .. note::

            This method performs an in-place modification of the file. It iterates through
            the content and suppresses any sequence of empty lines that exceeds a
            single occurrence, effectively "squeezing" the vertical whitespace.

        """
        with open(file_path, "r", encoding="utf-8") as file:
            lines = file.readlines()

        cleaned_lines = []
        previous_line_blank = False

        for line in lines:
            if line.strip() == "":
                if not previous_line_blank:
                    cleaned_lines.append(line)
                    previous_line_blank = True
            else:
                cleaned_lines.append(line)
                previous_line_blank = False

        with open(file_path, "w", encoding="utf-8") as file:
            file.writelines(cleaned_lines)

    @staticmethod
    def parse_metadata(note_file):
        """
        Extracts YAML metadata from the header of a Markdown file.

        :param note_file: str, path to the Markdown file
        :return: dict, extracted YAML metadata
        """
        with open(note_file, "r", encoding="utf-8") as file:
            content = file.read()

        # Regular expression to match the YAML header
        yaml_header_regex = r"^---\s*\n(.*?)\n---\s*\n"

        # Search for the YAML header in the content
        match = re.search(yaml_header_regex, content, re.DOTALL)

        if match:
            yaml_content = match.group(1)
            return Note.parse_yaml(yaml_content)
        else:
            return None

    @staticmethod
    def parse_yaml(yaml_content):
        """
        Parses YAML content into a dictionary.

        :param yaml_content: str, YAML content as string
        :return: dict,  parsed YAML content
        """
        metadata = {}
        lines = yaml_content.split("\n")
        current_key = None
        current_list = None

        for line in lines:
            if line.strip() == "":
                continue
            if ":" in line:
                key, value = line.split(":", 1)
                key = key.strip()
                value = value.strip()
                if value == "":  # start of a list
                    current_key = key
                    current_list = []
                    metadata[current_key] = current_list
                else:
                    if key == "tags":
                        metadata[key] = [
                            v.strip() for v in value.split("-") if v.strip()
                        ]
                    else:
                        metadata[key] = value
            elif current_list is not None and line.strip().startswith("-"):
                current_list.append(line.strip()[1:].strip())

        # fix empty lists
        for e in metadata:
            if len(metadata[e]) == 0:
                metadata[e] = None

        # fix text fields
        for e in metadata:
            if metadata[e]:
                size = len(metadata[e]) - 1
                if metadata[e][0] == '"' and metadata[e][size] == '"':
                    # slice it
                    metadata[e] = metadata[e][1:size]

        return metadata

    @staticmethod
    def metadata_to_list(metadata_dict):
        """
        Convert a dictionary of metadata into a formatted list of strings.

        :param metadata_dict: A dictionary containing metadata keys and values to be formatted.
        :type metadata_dict: dict
        :return: A list of strings formatted with YAML-like syntax, enclosed by dashed separators.
        :rtype: list

        .. note::

            The method processes dictionary entries into a human-readable list format. It
            handles list values by creating indented bullet points and converts ``None``
            values into empty strings. The resulting list starts and ends with a ``---``
            delimiter string.

        """
        ls_metadata = []
        ls_metadata.append("---")
        for e in metadata_dict:
            if isinstance(metadata_dict[e], list):
                ls_metadata.append("{}:".format(e))
                for i in metadata_dict[e]:
                    ls_metadata.append(" - {}".format(i))
            else:
                aux0 = metadata_dict[e]
                if aux0 is None:
                    aux0 = ""
                aux1 = "{}: {}".format(e, aux0)
                ls_metadata.append(aux1)
        ls_metadata.append("---")

        return ls_metadata

    @staticmethod
    def data_to_list(data_dict):
        """
        Flatten a dictionary of lists into a single list separated by blank lines and delimiters.

        :param data_dict: A dictionary where each key maps to a list of strings to be aggregated.
        :type data_dict: dict
        :return: A concatenated list of all values with added structural spacing and separators.
        :rtype: list

        .. note::

            This function iterates through the top-level keys of ``data_dict`` and appends
            the contents of each list to a master list. After each group of data, it
            inserts an empty string, a ``---`` separator, and another empty string to
            visually distinguish different levels or sections.

        """
        ls_out = []
        for level in data_dict:
            ls_out = ls_out + data_dict[level][:]
            if level != Note.STR_TAIL:
                ls_out.append("")
                ls_out.append("---")
        return ls_out

    @staticmethod
    def parse_note(file_path):
        """
        Extract and categorize note content into head, body, and tail sections based on separators.

        :param file_path: The path to the note file to be parsed.
        :type file_path: str
        :return: A dictionary containing the cleaned lines for ``Head``, ``Body``, and ``Tail``.
        :rtype: dict

        .. note::

            The function first identifies and skips an initial YAML frontmatter block if it
            starts with ``---``. It then uses the ``---`` string as a delimiter to
            segment the remaining text. If multiple separators exist, the first and last
            act as boundaries for the ``Body``, while everything before the first is
            ``Head`` and everything after the last is ``Tail``. All extracted lines
            undergo a ``strip()`` operation to remove leading/trailing whitespace.


        """
        with open(file_path, "r", encoding="utf-8") as file:
            lines = file.readlines()

        # Skip YAML header if present
        if lines[0].strip() == "---":
            yaml_end_index = lines.index("---\n", 1) + 1
            lines = lines[yaml_end_index:]

        # Find all separator positions (lines with "---")
        separator_indices = [i for i, line in enumerate(lines) if line.strip() == "---"]

        # Default values for Head, Body, and Tail
        head, body, tail = [], [], []

        if len(separator_indices) == 0:
            # No separators, the whole content is the Body
            body = lines
        elif len(separator_indices) == 1:
            # One separator: Head is before, Body is between, Tail is after
            head = lines[: separator_indices[0]]
            body = lines[separator_indices[0] + 1 :]
        elif len(separator_indices) == 2:
            # Two separators: Head, Body, and Tail
            head = lines[: separator_indices[0]]
            body = lines[separator_indices[0] + 1 : separator_indices[1]]
            tail = lines[separator_indices[1] + 1 :]
        else:
            # More than two separators: Head is before the first, Body is between the first and last, Tail is after the last
            head = lines[: separator_indices[0]]
            body = lines[separator_indices[0] + 1 : separator_indices[-1]]
            tail = lines[separator_indices[-1] + 1 :]

        # Clean up any extra newlines from the content
        head = [line.strip() for line in head]
        body = [line.strip() for line in body]
        tail = [line.strip() for line in tail]

        return {Note.STR_HEAD: head, Note.STR_BODY: body, Note.STR_TAIL: tail}

    @staticmethod
    def list_by_pattern(md_dict, patt_type="tag"):
        """
        Retrieve a list of patterns from the note dictionary.

        :param md_dict: Dictionary containing note sections.
        :type md_dict: dict
        :param patt_type: Type of pattern to search for, either "tag" or "related". Defaults to "tag".
        :type patt_type: str
        :return: List of found patterns or None if no patterns are found.
        :rtype: list or None
        """

        if patt_type == "tag":
            pattern = re.compile(r"#\w+")
        elif patt_type == "related":
            pattern = re.compile(r"\[\[.*?\]\]")
        else:
            pattern = re.compile(r"#\w+")

        patts = []
        # run over all sections
        for s in md_dict:
            content = md_dict[s]["Content"]
            for line in content:
                patts.extend(pattern.findall(line))

        if len(patts) == 0:
            patts = None

        return patts


class NoteBasic(Note):

    TEMPLATE_FILE = FOLDER_TEMPLATES_NOTES / "_basic.md"
    THUMBNAIL_SIZE = None
    PATTERN_ABSTRACT = "[!Abstract]"

    def __init__(self, name="MyNote", alias="Nt1"):
        super().__init__(name=name, alias=alias)
        self.file_note_template = self.get_template_file()
        self.metadata_standard = self.load_metadata_standard()
        self.data_standard = self.load_data_standard()

    @classmethod
    def get_template_file(cls):
        """
        Retrieves the filesystem path of the template file associated with the class.

        :return: The path to the template file.
        :rtype: :class:`pathlib.Path`
        """
        return Path(cls.TEMPLATE_FILE)

    def load_new(self, file_note):
        """
        Initializes a new note instance using a template and assigns it a new file path.

        :param file_note: The destination path where the new note will be saved.
        :type file_note: str or :class:`pathlib.Path`
        """
        self.file_note = self.file_note_template
        self.load()
        self.file_note = Path(file_note)
        self.update()
        self.update_timestamp()

    def load_data_standard(self):
        """
        Parses and returns the standard data content from the template file.

        :return: A dictionary containing the parsed data from the template.
        :rtype: dict
        """
        dc = Note.parse_note(file_path=self.file_note_template)
        return dc

    def load_metadata_standard(self):
        """
        Retrieves the metadata structure from the template and initializes all values to ``None``.

        :return: A dictionary of metadata keys with cleared values.
        :rtype: dict
        """
        dc = Note.parse_metadata(note_file=self.file_note_template)
        for k in dc:
            dc[k] = None
        return dc

    def load_metadata(self, file_note=None):
        """
        Loads metadata and synchronizes it against the standard template schema.

        .. important::

            This method filters the current metadata to ensure only keys present in
            ``metadata_standard`` are kept, filling missing keys with ``None``.

        :return: No value is returned.
        :rtype: None
        """
        super().load_metadata(file_note=file_note)
        # filter standard entries
        dc = {}
        for k in self.metadata_standard:
            # filter standard entry
            if k in self.metadata:
                dc[k] = self.metadata[k]
            # add standard entry
            else:
                dc[k] = None

        self.metadata = dc.copy()
        return None

    def reset_data(self):
        """
        Resets all data segments including ``Head``, ``Body`` and ``Tail`` to their standard values.

        .. danger::

            This action will erase all current data in the instance.

        """
        self.reset_data_head()
        self.reset_data_body()
        self.reset_data_tail()

    def reset_data_segment(self, segment):
        """
        Resets a specific data segment to its standard default state.

        :param segment: The name of the data segment to reset (e.g., ``Head``, ``Body``, or ``Tail``).
        :type segment: str

        .. danger::

            This action will erase the current data for the specified segment.

        """
        dc = self.load_data_standard()
        self.data[segment] = dc[segment][:]
        ### self.update()

    def reset_data_head(self):
        """
        Resets the ``Head`` data segment to its standard default state.

        .. danger::

            This action will erase the current data segment.

        """
        self.reset_data_segment(self.STR_HEAD)

    def reset_data_body(self):
        """
        Resets the ``Body`` data segment to its standard default state.

        .. danger::

            This action will erase the current data segment.

        """
        self.reset_data_segment(self.STR_BODY)

    def reset_data_tail(self):
        """
        Resets the ``Tail`` data segment to its standard default state.

        .. danger::

            This action will erase the current data segment.

        """
        self.reset_data_segment(self.STR_TAIL)

    def refactor(self, new_name, scope):
        """
        Performs a full refactor operation by renaming the resource and
        refreshing its local data state.

        :param new_name: The new filename to be assigned to the resource.
        :type new_name: str
        :param scope: The scope of files where references to this resource should be updated.
        :type scope: :class:`pathlib.Path`, str, or Iterable
        :return: None
        :rtype: None
        """
        super().refactor(new_name=new_name, scope=scope)
        self.load()
        self.update()
        self.save()

    def update(self):
        """
        Triggers a sequence of internal updates to synchronize the note's name, abstract, and thumbnail.

        .. note::

            This method acts as a base update sequence; additional update
            logic may be implemented in downstream classes.

        """
        self.update_name()
        self.update_abstract()
        self.update_thumbnail()
        # -- continues in downstream classes

    def update_name(self):
        """
        Updates the note metadata and the first line of the Head segment with the current file stem.

        .. warning::

            This method assumes the first item in the ``Head`` data segment is the title and will overwrite it.

        """
        current_name = Path(self.file_note).stem
        self.metadata["name"] = current_name
        # always the first item
        self.data[self.STR_HEAD][0] = f"# {current_name}"

    def update_abstract(self):
        """
        Synchronizes the abstract from metadata into the Head data segment block.

        .. note::

            The method searches for the ``self.PATTERN_ABSTRACT`` identifier within the ``Head``
            segment and replaces the subsequent line with the formatted abstract string.

        """
        if self.metadata["abstract"] is not None:
            current_abstract = self.metadata["abstract"][1:-1]
            n = 0
            for line in self.data[self.STR_HEAD]:
                n = n + 1
                if self.PATTERN_ABSTRACT in line:
                    break
            if n > 0:
                self.data[self.STR_HEAD][n] = f"> {current_abstract}\n"

    def update_thumbnail(self, image_name=None):
        """
        Updates the thumbnail image link in the Head data segment based
        on the current file name and predefined size.

        .. note::

            The method searches for an existing Wikilink image pattern
            (``![[``) within the ``Head`` segment to perform the replacement.

        """
        size = self.THUMBNAIL_SIZE

        if image_name is None:
            image_name = self.file_note.stem

        if size is not None:
            n = 0
            for line in self.data[self.STR_HEAD]:
                if "![[" in line[:3]:
                    break
                n = n + 1
            if n > 0:
                self.data[self.STR_HEAD][n] = f"![[{image_name}.jpeg|{size}]]"

    def update_timestamp(self):
        """
        Records the current local date and time into the note metadata.

        .. note::

            The timestamp is formatted as a string following
            the ``%Y-%m-%d %H:%M:%S`` pattern.

        """
        from datetime import datetime

        now = datetime.now()
        self.metadata["timestamp"] = now.strftime("%Y-%m-%d %H:%M:%S")

    def update_note(self, file_note=None):
        if file_note is not None:
            self.load(file_note=file_note)
        self.update()
        self.save()


class NoteProject(NoteBasic):

    TEMPLATE_FILE = FOLDER_TEMPLATES_NOTES / "_project.md"
    THUMBNAIL_SIZE = None


class NoteJournal(NoteBasic):

    TEMPLATE_FILE = FOLDER_TEMPLATES_NOTES / "_journal.md"
    THUMBNAIL_SIZE = 300

    def update(self):
        super().update()
        self.update_title()

    def update_title(self):
        name = self.metadata["name"]
        self.metadata["title"] = f'"{name}"'


class NoteFigure(NoteBasic):

    TEMPLATE_FILE = FOLDER_TEMPLATES_NOTES / "_figure.md"
    THUMBNAIL_SIZE = 500


class NoteReference(NoteBasic):

    TEMPLATE_FILE = FOLDER_TEMPLATES_NOTES / "_reference.md"
    THUMBNAIL_SIZE = 200
    PATTERN_ABSTRACT = "[!Info]"

    def __init__(self):
        super().__init__()
        self.cite_style = "apa"

    def get_reference(self):
        """
        Creates and returns a standardized ``Reference`` object based on the current metadata.

        :return: A reference instance populated with standardized internal metadata.
        :rtype: :class:`Reference`
        """
        dc = self.metadata.copy()
        ref = Reference.get_by_entry(entry_type=dc["entry_type"])
        ref.data = dc.copy()
        ref.standardize()
        return ref

    def get_str_bib(self, drop_fields=None):
        """
        Generates a BibTeX string representation of the reference with an option to exclude specific fields.

        :param drop_fields: [optional] A list of metadata keys to remove before generating the string.
        :type drop_fields: list
        :return: The formatted BibTeX string.
        :rtype: str
        """
        ref = self.get_reference()

        if drop_fields:
            for drop in drop_fields:
                del ref.data[drop]

        return ref.get_str_bib()

    def load_new(self, file_note, metadata=None):
        """
        Initializes a new note from a file and optionally sets and updates its metadata.

        :param file_note: The path or identifier for the note file.
        :type file_note: str | :class:`pathlib.Path`
        :param metadata: [optional] A dictionary of metadata to apply to the new note.
        :type metadata: dict
        :return: No value is returned.
        :rtype: None
        """

        super().load_new(file_note=file_note)
        if metadata is not None:
            self.setup_metadata(metadata=metadata)
            self.update()

    def update(self):
        """
        Triggers a comprehensive refresh of all derived metadata, citation strings, and document sections.

        :return: No value is returned.
        :rtype: None
        """
        self.update_name()
        self.update_cite_inline()
        self.update_cite_bibli()
        self.update_pdf()

        self.update_data_head()
        self.update_data_tail()

        self.update_abstract()
        self.update_thumbnail()

    def update_cite_inline(self):
        """
        Updates the inline citation string in the metadata using the plain text format.

        :return: No value is returned.
        :rtype: None
        """
        self.metadata["cite_inline"] = Reference.cite_line(
            bib_dict=self.metadata, text_format="plain", embed_link=False
        )

    def update_cite_bibli(self):
        """
        Updates the bibliographic citation string in the metadata according to the defined style.

        :return: No value is returned.
        :rtype: None
        """
        s = Reference.cite_bibli(
            bib_dict=self.metadata, text_format="plain", style=self.cite_style
        )
        self.metadata["cite_bibli"] = f'"{s}"'

    def update_pdf(self):
        """
        Formats and updates the PDF link field in the metadata based on the entry name.

        :return: No value is returned.
        :rtype: None
        """
        self.metadata["pdf"] = '"[[{}.pdf]]"'.format(self.metadata["name"])

    def update_data_head(self):
        """
        Refreshes the header section of the document data, specifically handling journal links for articles.

        :return: No value is returned.
        :rtype: None
        """
        self.reset_data_head()

        self.update_name()

        # Handle article case
        if self.metadata["entry_type"] == "article":
            journal = self.metadata["journal"]
            if journal is None:
                pass
            else:
                old_line = "By `=this.cite_inline`"
                new_line = "By `=this.cite_inline` in [[{}]]".format(journal)
                c = 0
                for line in self.data[self.STR_HEAD]:
                    if old_line in line:
                        self.data[self.STR_HEAD][c] = line.replace(old_line, new_line)
                    c = c + 1

    def update_data_tail(self):
        """
        Refreshes the tail section of the document by injecting formatted metadata and BibTeX strings.

        .. note::

             This method synchronizes the end-of-file data by generating a clean BibTeX entry (excluding
             bloat like PDFs or abstracts) and performing string interpolation on the ``STR_TAIL``
             template list using the current metadata dictionary.

        :return: No value is returned.
        :rtype: None
        """
        self.reset_data_tail()

        # replace inline and bibli
        dc = self.metadata.copy()

        ls_drop = ["pdf", "abstract"]
        dc["bibtex"] = self.get_str_bib(drop_fields=ls_drop)

        ls = []
        for line in self.data[self.STR_TAIL]:
            line = line.format(**dc).strip('"')
            ls.append(line[:])
        self.data[self.STR_TAIL] = ls[:]

    def update_thumbnail(self, image_name=None):
        """
        Updates the document thumbnail, automatically selecting the journal name as the image source for articles.

        :param image_name: [optional] The specific image name or key to use for the thumbnail.
        :type image_name: str
        :return: No value is returned.
        :rtype: None
        """
        if self.metadata["entry_type"] == "article":
            image_name = self.metadata["journal"]
        super().update_thumbnail(image_name=image_name)

    def to_bib(self, output, drop_pdf=True):
        """
        Exports the reference metadata to a BibTeX file with an option to exclude the PDF field.

        :param output: The file path or buffer where the BibTeX data should be saved.
        :type output: str | :class:`pathlib.Path`
        :param drop_pdf: Whether to remove the ``pdf`` field from the exported file. Default value = ``True``
        :type drop_pdf: bool
        :return: No value is returned.
        :rtype: None
        """
        ref = self.get_reference()
        if drop_pdf:
            del ref.data["pdf"]
        ref.to_bib(output=output)


class NoteDataset(NoteReference):

    TEMPLATE_FILE = FOLDER_TEMPLATES_NOTES / "_dataset.md"
    THUMBNAIL_SIZE = 200
    PATTERN_ABSTRACT = "[!Info]"

    def update(self):
        super().update()
        self.update_source()
        self.update_alias()
        self.update_version()

    def to_bib(self, output):
        super().to_bib(output=output, drop_pdf=False)

    def update_pdf(self):
        return None

    def update_source(self):
        s = Path(self.file_note).stem.split("_")[0]
        self.metadata["source"] = s

    def update_alias(self):
        s = Path(self.file_note).stem.split("_")[1]
        self.metadata["alias"] = s

    def update_version(self):
        s = Path(self.file_note).stem.split("_")[2]
        self.metadata["version"] = s

    def get_dataset_folder(self, folder_base):
        r = Path(folder_base)
        src = self.metadata["source"]
        als = self.metadata["alias"]
        vrs = self.metadata["version"]
        d = r / f"{src}/{als}/{vrs}"
        return d

    def setup_dataset_folder(self, folder_base):
        d = self.get_dataset_folder(folder_base=folder_base)
        d.mkdir(exist_ok=True, parents=True)
        ls = ["SRC", "T0", "T1", "T2"]
        for i in ls:
            if i == "SRC":
                dsub = d / i
            else:
                dsub = d / f"{i}/ASSETS"
            dsub.mkdir(exist_ok=True, parents=True)


# COLLECTIONS
# -----------------------------------------------------------------------


class NoteCollection(Collection):

    # todo major docstring

    BASE_OBJECT = Note

    def __init__(self, name="MyNoteColl", alias="NtCol0"):

        super().__init__(base_object=self.BASE_OBJECT, name=name, alias=alias)

    def load_list(self, files):
        """
        Iterates through a list of file paths to initialize, load, and append objects to the collection.

        :param files: A list of file paths to be processed.
        :type files: list
        :return: None
        :rtype: None
        """
        for f in files:

            p = Path(f)
            name = p.stem

            n = self.baseobject(name=name, alias=name)
            n.file_note = p
            n.load()

            self.append(n)
        return None

    def load_folder(self, folder):
        """
        Identifies all Markdown files within a specific directory and adds them to the collection.

        :param folder: The directory path to scan for ``.md`` files.
        :type folder: str
        :return: None
        :rtype: None
        """
        ls = glob.glob(str(Path(folder) / "*.md"))

        self.load_list(files=ls)

        return None

    def load_pattern(self, pattern):
        """
        Uses a glob pattern to locate files and load them into the collection.

        :param pattern: The search pattern (e.g., ``path/to/*/*.md``) used to match files.
        :type pattern: str
        :return: None
        :rtype: None

        """
        ls = glob.glob(pattern)
        self.load_list(files=ls)
        return None


class NoteCollBasic(NoteCollection):

    BASE_OBJECT = NoteBasic


class NoteCollProject(NoteCollection):

    BASE_OBJECT = NoteProject


class NoteCollJournal(NoteCollection):

    BASE_OBJECT = NoteJournal


class NoteCollFigure(NoteCollection):

    BASE_OBJECT = NoteFigure


# ... {develop}

# CLASSES -- Module-level
# =======================================================================
# ... {develop}


# SCRIPT
# ***********************************************************************
# standalone behaviour as a script
if __name__ == "__main__":
    # Script section
    # ===================================================================
    print("Hello world!")
    # ... {develop}

    # Script subsection
    # -------------------------------------------------------------------
    # ... {develop}
