#!/usr/bin/env python

import logging
import argparse
import os
import subprocess
import warnings
import re
from pathlib import Path
from multiprocessing import Pool, cpu_count
from itertools import product
from typing import Union, Sequence, Optional

from jinja2 import Environment, PackageLoader

from dungeonsheets import character as _char, exceptions, readers, latex, monsters
from dungeonsheets.stats import mod_str, findattr
from dungeonsheets.fill_pdf_template import (
    create_character_pdf_template,
    create_spells_pdf_template,
)
from dungeonsheets.character import Character
from dungeonsheets.entity import Entity

"""Program to take character definitions and build a PDF of the
character sheet."""

log = logging.getLogger(__name__)

ORDINALS = {
    1: "1st",
    2: "2nd",
    3: "3rd",
    4: "4th",
    5: "5th",
    6: "6th",
    7: "7th",
    8: "8th",
    9: "9th",
}

jinja_env = Environment(
    loader=PackageLoader("dungeonsheets", "forms"),
    block_start_string="[%",
    block_end_string="%]",
    variable_start_string="[[",
    variable_end_string="]]",
)
jinja_env.filters["rst_to_latex"] = latex.rst_to_latex
jinja_env.filters["mod_str"] = mod_str


PDFTK_CMD = "pdftk"


# Custom types
File = Union[Path, str]


def create_subclasses_tex(
    character: Character,
    use_dnd_decorations: bool = False,
) -> str:
    template = jinja_env.get_template("subclasses_template.tex")
    return template.render(character=character, use_dnd_decorations=use_dnd_decorations)


def create_features_tex(
    character: Character,
    use_dnd_decorations: bool = False,
) -> str:
    template = jinja_env.get_template("features_template.tex")
    return template.render(character=character, use_dnd_decorations=use_dnd_decorations)


def create_magic_items_tex(
    character: Character,
    use_dnd_decorations: bool = False,
) -> str:
    template = jinja_env.get_template("magic_items_template.tex")
    return template.render(character=character, use_dnd_decorations=use_dnd_decorations)


def create_monsters_tex(
    monsters: Sequence[Union[monsters.Monster, str]],
    use_dnd_decorations: bool = False,
) -> str:
    # Convert strings to Monster objects
    template = jinja_env.get_template("monsters_template.tex")
    return template.render(monsters=monsters, use_dnd_decorations=use_dnd_decorations)


def create_party_summary_tex(
        party: Sequence[Entity],
        use_dnd_decorations: bool = False,
) -> str:
    template = jinja_env.get_template("party_summary_template.tex")
    return template.render(party=party, use_dnd_decorations=use_dnd_decorations)


def create_spellbook_tex(
    character: Character,
    use_dnd_decorations: bool = False,
) -> str:
    template = jinja_env.get_template("spellbook_template.tex")
    return template.render(
        character=character, ordinals=ORDINALS, use_dnd_decorations=use_dnd_decorations
    )


def create_infusions_tex(
    character: Character,
    use_dnd_decorations: bool = False,
) -> str:
    template = jinja_env.get_template("infusions_template.tex")
    return template.render(character=character, use_dnd_decorations=use_dnd_decorations)


def create_druid_shapes_tex(
    character: Character,
    use_dnd_decorations: bool = False,
) -> str:
    template = jinja_env.get_template("druid_shapes_template.tex")
    return template.render(character=character, use_dnd_decorations=use_dnd_decorations)


def make_sheet(
    sheet_file: File,
    flatten: bool = False,
    fancy_decorations: bool = False,
    debug: bool = False,
):
    """Make a character or GM sheet into a PDF.
    Parameters
    ----------
    sheet_file
      File (.py) to load character from. Will save PDF using same name
    flatten : bool, optional
      If true, the resulting PDF will look better and won't be
      fillable form.
    fancy_decorations : bool, optional
      Use fancy page layout and decorations for extra sheets, namely
      the dnd style file: https://github.com/rpgtex/DND-5e-LaTeX-Template.
    debug : bool, optional
      Provide extra info and preserve temporary files.

    """
    # Parse the file
    sheet_file = Path(sheet_file)
    sheet_props = readers.read_sheet_file(sheet_file)
    # Create the sheet
    if sheet_props.get("sheet_type", "") == "gm":
        ret = make_gm_sheet(
            gm_file=sheet_file,
            fancy_decorations=fancy_decorations,
            debug=debug,
        )
    else:
        ret = make_character_sheet(
            char_file=sheet_file,
            flatten=flatten,
            fancy_decorations=fancy_decorations,
            debug=debug,
        )
    return ret


def make_gm_sheet(
    gm_file: Union[str, Path],
    fancy_decorations: bool = False,
    debug: bool = False,
):
    """Prepare a PDF character sheet from the given character file.

    Parameters
    ----------
    gm_file
      The file with the gm_sheet definitions.
    fancy_decorations
      Use fancy page layout and decorations for extra sheets, namely
      the dnd style file: https://github.com/rpgtex/DND-5e-LaTeX-Template.
    debug
      Provide extra info and preserve temporary files.

    """
    # Parse the GM file and filename
    gm_file = Path(gm_file)
    basename = gm_file.stem
    gm_props = readers.read_sheet_file(gm_file)
    # Create the intro tex
    tex = [
        jinja_env.get_template("preamble.tex").render(
            use_dnd_decorations=fancy_decorations,
            title=gm_props["session_title"],
        )
    ]
    # Add the party stats table
    party = []
    for char_file in gm_props.get("party", []):
        # Resolve the file path
        char_file = Path(char_file)
        if not char_file.is_absolute():
            char_file = gm_file.parent / char_file
        char_file = char_file.resolve()
        # Load the character file
        character_props = readers.read_sheet_file(char_file)
        member = _char.Character.load(character_props)
        party.append(member)
    if len(party) > 0:
        tex.append(
            create_party_summary_tex(party, use_dnd_decorations=fancy_decorations)
        )
    # Add the monsters
    monsters_ = []
    for monster in gm_props.get("monsters", []):
        if isinstance(monster, monsters.Monster):
            # It's already a monster, so just add it
            new_monster = monster
        else:
            try:
                MyMonster = findattr(monsters, monster)
            except AttributeError:
                msg = (
                    f"Monster '{monster}' not found. Please add it to"
                    " ``monsters.py``"
                )
                warnings.warn(msg)
                continue
            else:
                new_monster = MyMonster()
        monsters_.append(new_monster)
    if len(monsters_) > 0:
        tex.append(
            create_monsters_tex(monsters_, use_dnd_decorations=fancy_decorations)
        )
    # Add the closing TeX
    tex.append(
        jinja_env.get_template("postamble.tex").render(
            use_dnd_decorations=fancy_decorations
        )
    )
    # Typeset combined LaTeX file
    try:
        if len(tex) > 2:
            latex.create_latex_pdf(
                tex="".join(tex),
                basename=basename,
                keep_temp_files=debug,
                use_dnd_decorations=fancy_decorations,
            )
    except exceptions.LatexNotFoundError:
        log.warning(f"``pdflatex`` not available. Skipping {basename}")


def make_character_sheet(
    char_file: Union[str, Path],
    character: Optional[Character] = None,
    flatten: bool = False,
    fancy_decorations: bool = False,
    debug: bool = False,
):
    """Prepare a PDF character sheet from the given character file.

    Parameters
    ----------
    basename
      The basename for saving files (PDFs, etc).
    character
      If provided, will not load from the character file, just use
      file for PDF name
    flatten
      If true, the resulting PDF will look better and won't be
      fillable form.
    fancy_decorations
      Use fancy page layout and decorations for extra sheets, namely
      the dnd style file: https://github.com/rpgtex/DND-5e-LaTeX-Template.
    debug
      Provide extra info and preserve temporary files.

    """
    # Load properties from file
    if character is None:
        character_props = readers.read_sheet_file(char_file)
        character = _char.Character.load(character_props)
    # Set the fields in the FDF
    basename = char_file.stem
    char_base = basename + "_char"
    sheets = [char_base + ".pdf"]
    pages = []
    tex = [
        jinja_env.get_template("preamble.tex").render(
            use_dnd_decorations=fancy_decorations,
            title="Features, Magical Items and Spells",
        )
    ]

    # Start of PDF gen
    char_pdf = create_character_pdf_template(
        character=character, basename=char_base, flatten=flatten
    )
    pages.append(char_pdf)
    if character.is_spellcaster:
        # Create spell sheet
        spell_base = "{:s}_spells".format(basename)
        create_spells_pdf_template(
            character=character, basename=spell_base, flatten=flatten
        )
        sheets.append(spell_base + ".pdf")
    # end of PDF gen
    features_base = "{:s}_features".format(basename)
    # Create a list of subcasses
    if character.subclasses:
        tex.append(
            create_subclasses_tex(character, use_dnd_decorations=fancy_decorations)
        )

    # Create a list of features
    if character.features:
        tex.append(
            create_features_tex(character, use_dnd_decorations=fancy_decorations)
        )

    if character.magic_items:
        tex.append(
            create_magic_items_tex(character, use_dnd_decorations=fancy_decorations)
        )

    # Create a list of spells
    if character.is_spellcaster:
        tex.append(
            create_spellbook_tex(character, use_dnd_decorations=fancy_decorations)
        )

    # Create a list of Artificer infusions
    if getattr(character, "infusions", []):
        tex.append(
            create_infusions_tex(character, use_dnd_decorations=fancy_decorations)
        )

    # Create a list of Druid wild_shapes
    if getattr(character, "wild_shapes", []):
        tex.append(
            create_druid_shapes_tex(character, use_dnd_decorations=fancy_decorations)
        )

    tex.append(
        jinja_env.get_template("postamble.tex").render(
            use_dnd_decorations=fancy_decorations
        )
    )

    # Typeset combined LaTeX file
    try:
        if len(tex) > 2:
            latex.create_latex_pdf(
                tex="".join(tex),
                basename=features_base,
                keep_temp_files=debug,
                use_dnd_decorations=fancy_decorations,
            )
            sheets.append(features_base + ".pdf")
            final_pdf = f"{basename}.pdf"
            merge_pdfs(sheets, final_pdf, clean_up=True)
    except exceptions.LatexNotFoundError:
        log.warning(
            f"``pdflatex`` not available. Skipping features for {character.name}"
        )


def merge_pdfs(src_filenames, dest_filename, clean_up=False):
    """Merge several PDF files into a single final file.

    src_filenames
      Iterable of source PDF file paths to use.
    dest_filename
      Path to requested PDF filename, will be overwritten if it
      exists.
    clean_up : optional
      If truthy, the ``src_filenames`` will be deleted once the
      ``dest_filename`` has been created.

    """
    popenargs = (PDFTK_CMD, *src_filenames, "cat", "output", dest_filename)
    try:
        subprocess.call(popenargs)
    except FileNotFoundError:
        warnings.warn(
            f"Could not run `{PDFTK_CMD}`; skipping file concatenation.", RuntimeWarning
        )
    else:
        # Remove temporary files
        if clean_up:
            for sheet in src_filenames:
                os.remove(sheet)


def _build(filename, args) -> int:
    basename = filename.stem
    print(f"Processing {basename}...")
    try:
        make_sheet(
            sheet_file=filename,
            flatten=(not args.editable),
            debug=args.debug,
            fancy_decorations=args.fancy_decorations,
        )
    except exceptions.CharacterFileFormatError:
        # Only raise the failed exception if this file is explicitly given
        print(f"invalid {basename}")
        if args.filename:
            raise
    except Exception:
        print(f"{basename} failed")
        raise
    else:
        print(f"{basename} done")
    return 1


def main(args=None):
    # Prepare an argument parser
    parser = argparse.ArgumentParser(
        description="Prepare Dungeons and Dragons character sheets as PDFs"
    )
    parser.add_argument(
        "filename",
        type=str,
        nargs="*",
        help="File with character definition, or directory containing such files",
    )
    parser.add_argument(
        "--editable",
        "-e",
        action="store_true",
        help="Keep the PDF fields in place once processed",
    )
    parser.add_argument(
        "--recursive",
        "-r",
        action="store_true",
        help="Descend into subfolders looking for character files",
    )
    parser.add_argument(
        "--fancy-decorations",
        "--fancy",
        "-F",
        action="store_true",
        help=(
            "Render extra pages using fancy decorations "
            "(experimental, requires https://github.com/rpgtex/DND-5e-LaTeX-Template)"
        ),
    )
    parser.add_argument(
        "--debug",
        "-d",
        action="store_true",
        help="Provide verbose logging for debugging purposes.",
    )
    args = parser.parse_args(args)
    # Prepare logging if necessary
    if args.debug:
        logging.basicConfig(level=logging.DEBUG)
    # Build the true list of filenames
    input_filenames = args.filename
    known_extensions = readers.readers_by_extension.keys()
    if input_filenames == []:
        input_filenames = [Path()]
    else:
        input_filenames = [Path(f) for f in input_filenames]

    def get_char_files(fpath, parse_dirs=False):
        valid_files = []
        if fpath.is_dir() and parse_dirs:
            for f in fpath.iterdir():
                valid_files.extend(get_char_files(f, parse_dirs=args.recursive))
        elif fpath.suffix in known_extensions:
            valid_files.append(fpath)
        else:
            log.info(f"Unhandled file: {str(fpath)}")
        return valid_files

    temp_filenames = []
    for fpath in input_filenames:
        temp_filenames.extend(get_char_files(fpath, parse_dirs=True))
    # IMPORANT:
    # Check that the files are valid dungeonsheets files without importing them
    filenames = []
    version_re = re.compile(
        r"^dungeonsheets_version = [\'\"](?P<version>[0-9.]+)[\'\"]\s*$", re.MULTILINE
    )
    for fpath in temp_filenames:
        with open(fpath, mode="r") as fp:
            if version_re.search(fp.read()) or fpath.suffix != ".py":
                filenames.append(fpath)
    # Process the requested files
    if args.debug:
        for filename in filenames:
            print("building")
            _build(filename, args)
    else:
        with Pool(cpu_count()) as p:
            p.starmap(_build, product(filenames, [args]))


if __name__ == "__main__":
    main()