# SPDX-FileCopyrightText: Copyright 2024 Damon Lynch <damonlynch@gmail.com>
# SPDX-License-Identifier: GPL-3.0-or-later

import re
from email.utils import parseaddr
import shlex
import shutil
import subprocess
import sys
from pathlib import Path
from typing import Any, Iterator, NamedTuple, Union

import argparse_manpage.tooling  # type:ignore[import-untyped]
import argparse_manpage.manpage  # type:ignore[import-untyped]
from hatchling.builders.hooks.plugin.interface import BuildHookInterface
from rich.console import Console

ManpageOptions = dict[str, Union[str, list[tuple[str, str]], list[str]]]


class ManpageToBuildOptions(NamedTuple):
    manpage: str
    manpage_dir: Path
    options: ManpageOptions


ManpageOptionsCollection = list[ManpageToBuildOptions]


class ArgparseManpageBuildHook(BuildHookInterface):
    """
    Compile GNU gettext translation files from po-format into
    mo-format using the GNU gettext utility msgfmt, and optionally translate files
    using the GNU gettext utility intltool-merge.

    Cleans up any files that it creates, and any resulting directories, but
    only if the directories are empty.
    """

    PLUGIN_NAME = "argparse-manpage"

    MANPAGE_OPTIONS = (
        "authors",
        "description",
        "long_description",
        "project_name",
        "prog",
        "url",
        "version",
        "format",
        "manual_section",
        "manual_title",
        "include",
        "manfile",
    )

    AUTHOR_PAIR = "authors_tuple"

    def config_name(self) -> str:
        return f"[tool.hatch.build.hooks.{self.PLUGIN_NAME}]"

    @staticmethod
    def _assemble_command(cmd: str) -> Union[list[str], str]:
        if sys.platform == "win32":
            return cmd
        return shlex.split(cmd)

    def _create_man_page_using_cmdline(self, args: str) -> None:
        """
        Create a manual page using the utility argparse-manpage

        """

        cmd_str = f"argparse-manpage {args}"
        self.console_output(
            f"{cmd_str}", level=2, style=self._style_level_debug, highlight=False
        )
        cmd = self._assemble_command(cmd_str)
        process = subprocess.run(cmd, text=True, capture_output=True)
        if process.returncode:
            raise Exception(
                "Error while invoking argparse-manpage:\n"
                f"{process.stderr}\n{process.stdout}"
            )

    def _clean_files(self, relative_file_paths: Iterator[str]) -> None:
        project_root: Path = Path(self.root)
        for p in relative_file_paths:
            full_path = project_root / p
            if full_path.exists():
                self.console_output(
                    f"Removing {full_path}", level=2, style=self._style_level_debug
                )
                full_path.unlink()

    def _has_only_subdirectories(self, path: Path) -> bool:
        """
        Checks if a directory has only subdirectories and no files.

        :param path: the full path to the directory to check
        :return: True if the directory has only subdirectories and no files
        """

        for entry in path.iterdir():
            if entry.is_file():
                return False
            # Recursively check subdirectories
            if entry.is_dir() and not self._has_only_subdirectories(entry):
                return False
        return True

    def _clean_directory_tree_only_if_has_empty_subdirectories(
        self, folder: Path
    ) -> None:
        """
        Removes a directory tree only if it contains no files and any of its
        subdirectories in its tree likewise contain no files

        :param folder: full path of the directory
        """

        if folder.is_dir() and self._has_only_subdirectories(folder):
            self.console_output(
                f"Removing {folder}", level=2, style=self._style_level_debug
            )
            shutil.rmtree(folder)

    def clean(self, versions: list[str]) -> None:
        """
        Remove all files created by this plug-in, if they exist.

        Remove all their directories only they contain no other files,
        with the same being true of their subdirectories.

        :param versions: see Hatch documentation for details
        """

        self.setup_console()
        self.console_output(
            "Cleaning manual pages", level=1, style=self._style_level_waiting
        )

        self.load_argparse_manpage_config(full_spec=False)

        # Remove individual manpages, irrespective of folder
        self._clean_files(self.manpages_to_build)

        # Remove manpage build folders
        project_root: Path = Path(self.root)
        build_folders = (
            manpage.manpage_dir
            for manpage in self._manpages_to_build
            if manpage.manpage_dir != project_root
        )

        for folder in build_folders:
            self._clean_directory_tree_only_if_has_empty_subdirectories(folder)

        self.console_output(
            "Finished cleaning manual pages",
            level=1,
            style=self._style_level_success,
        )

    def _build_command_line_options(self, build_options: ManpageToBuildOptions) -> str:
        options = build_options.options
        manpage = f"--output {build_options.manpage_dir / build_options.manpage}"
        object = (
            f"--{options['object_type']} {options['object_name']}"
            if options.get("object_type") in ("function", "object")
            else ""
        )
        import_from = (
            f"--{options['import_type']} {options['import_from']}"
            if options.get("import_type") in ("pyfile", "module")
            else ""
        )
        format = f"--format {options['format']}" if "format" in options else ""

        # argparse-manpage expects pairs of --author --author-email
        authors = ""
        if self.AUTHOR_PAIR in options:
            authors = " ".join(
                f'--author "{author[0]}" --author-email "<{author[1]}>"'
                for author in options[self.AUTHOR_PAIR]
            )

        # Wrap command line values in double quotes
        other_options = " ".join(
            (
                f"--{key.replace('_', '-')} \"{options[key]}\""
                for key in self.MANPAGE_OPTIONS
                if key in options and key != self.AUTHOR_PAIR
            )
        )

        args = " ".join([manpage, object, import_from, format, authors, other_options])
        # Remove extraneous whitespace before returning string
        return re.sub(r"\s+", r" ", args)

    def _build_using_cmdline(self, build_options: ManpageToBuildOptions) -> None:
        cmd_str = self._build_command_line_options(build_options)
        self._create_man_page_using_cmdline(cmd_str)

    def _build_manpage(self, build_options: ManpageToBuildOptions) -> None:
        """
        Build manpage by directly calling argparse code, obviously using the data
        structures it expects. If those structures change, this code will break.
        """

        options = build_options.options
        page = str(build_options.manpage_dir / build_options.manpage)
        parser = argparse_manpage.tooling.get_parser(
            options["import_type"],
            options["import_from"],
            options["object_name"],
            options["object_type"],
            options.get("prog", None),
        )
        format = options.get("format", "pretty")
        assert format in ("pretty", "single-commands-section")

        # Convert tuple of author and author email into a string with email
        # surrounded by angle brackets
        if self.AUTHOR_PAIR in options:
            options["authors"] = [
                f"{author[0]} <{author[1]}>" for author in options[self.AUTHOR_PAIR]
            ]
            del options[self.AUTHOR_PAIR]

        manpage = argparse_manpage.manpage.Manpage(parser, format=format, _data=options)
        argparse_manpage.tooling.write_to_filename(str(manpage), page)

    def apply_config_options(self, build_options: ManpageToBuildOptions) -> None:
        """
        Applies any custom configuration options unique to this plugin that
        can be used to manipulate a manpage's appearance
        """

        if not self._include_url and "url" in build_options.options:
            del build_options.options["url"]

    def build_manpages(self) -> None:
        """
        Builds the manpages by either calling argparse-manpage Python classes directly
        or via the command line.

        The default behavior is to call the code directly.
        """

        for build_options in self._manpages_to_build:
            self.console_output(
                f"Building manpage {build_options.manpage_dir / build_options.manpage}",
                level=2,
                style=self._style_level_info,
                highlight=False,
            )
            self.apply_config_options(build_options)

            if self._force_command_line:
                self._build_using_cmdline(build_options)
            else:
                try:
                    self._build_manpage(build_options)
                except Exception as e:
                    message = (
                        f"Exception: {e}\n"
                        f"Manpage {build_options.manpage_dir / build_options.manpage} "
                        "failed to build when directly calling argparse-manpage "
                        "Python code. Will retry using the command line program..."
                    )
                    self.console_output(
                        message=message,
                        level=0,
                        style=self._style_level_error,
                    )
                    self._build_using_cmdline(build_options)
                    self.console_output(
                        message="...generating using the command line succeeded",
                        level=0,
                        style=self._style_level_error,
                    )

    def _load_manpage_options(
        self, options: ManpageOptions, defn_components: list[str]
    ) -> None:
        """
        Parse the manpage configuration options, and build a ManpageOptions object.
        Load any missing values from pyproject.toml.
        """

        self._project_config = self.metadata.config.get("project")
        basename = ""

        for defn in defn_components:
            option, value = defn.split("=")
            if option in ("function", "object"):
                try:
                    assert "object_type" not in options
                except AssertionError:
                    raise ValueError(
                        f"'{option}' is invalid: object type "
                        f"'{options['object_type']}' is already configured"
                    )
                options["object_type"] = option
                options["object_name"] = value

            elif option in ("pyfile", "module"):
                try:
                    assert "import_type" not in options
                except AssertionError:
                    raise ValueError(
                        f"'{option}' is invalid: import type "
                        f"'{options['import_type']}' is already configured"
                    )
                options["import_type"] = option
                options["import_from"] = value
                if option == "pyfile":
                    basename = Path(value).name

            elif option == "format":
                try:
                    assert "format" not in options
                except AssertionError:
                    raise ValueError(
                        f"'{option}' is invalid: format is already configured "
                        f"'{options['format']}' is already configured"
                    )
                options["format"] = value

            elif option == "author":
                if self.AUTHOR_PAIR not in options:
                    options[self.AUTHOR_PAIR] = []
                assert isinstance(options[self.AUTHOR_PAIR], list)
                options[self.AUTHOR_PAIR].append(extract_name_email(value))  # type: ignore

            elif option in self.MANPAGE_OPTIONS:
                try:
                    assert option not in options
                except AssertionError:
                    raise ValueError(
                        f"'{option}' is invalid: the option "
                        f"'{options[option]}' is already configured"
                    )
                options[option] = value

        # Load any missing values using pyproject.toml
        if self._project_config is not None:
            if "url" not in options and "urls" in self._project_config:
                urls: dict[str, str] = self._project_config["urls"]
                url: str = ""
                # If there is only one URL, use it
                if len(urls) == 1:
                    url = list(urls.values())[0]
                else:
                    # If there is more than one URL, use the homepage
                    # Make dictionary keys lowercase
                    urls_lowercase = {k.lower(): v for k, v in urls.items()}
                    for key in ("homepage", "home-page"):
                        if key in urls_lowercase:
                            url = urls_lowercase[key]
                            break
                if url:
                    options["url"] = url

            if self.AUTHOR_PAIR not in options and "authors" in self._project_config:
                options[self.AUTHOR_PAIR] = []
                for author in self._project_config["authors"]:
                    name = author.get("name", "")
                    email = author.get("email", "")
                    if name or email:
                        options[self.AUTHOR_PAIR].append((name, email))  # type: ignore

            if "project_name" not in options and "name" in self._project_config:
                options["project_name"] = self._project_config["name"]

            if "version" not in options and self.metadata.version:
                options["version"] = self.metadata.version

        if "prog" not in options:
            options["prog"] = basename

    def load_argparse_manpage_config(self, full_spec: bool) -> None:
        """
        Load the argparse-manpage config from pyproject.toml using hatch's interface
        and assign the values to private class variables.

        Parsing the manual page configuration options (the full specification)
        is needed only if actually building the manual pages.

        :param full_spec: Whether to load the full specification from pyproject.toml.
         If running the clean operation, loading the full specification is unnecessary.
        """

        project_root: Path = Path(self.root)

        try:
            manpage_specs: list[str] = self.config["manpages"]
        except KeyError:
            raise ValueError(
                f'Configure "manpages" in "{self.config_name()}" in '
                "pyproject.toml to specify the manpages to generate"
            )
        try:
            assert isinstance(manpage_specs, list)
        except AssertionError:
            raise ValueError(
                f'Configure "manpages" in "{self.config_name()}" in '
                "pyproject.toml as a list of manpages to generate"
            )

        self._manpages_to_build: ManpageOptionsCollection = []

        # Custom config options optionally located in the pyproject.toml section
        # [tool.hatch.build.hooks.argparse-manpage]
        self._include_url = True
        self._force_command_line = False

        for spec in manpage_specs:
            options: ManpageOptions = {}

            components = spec.strip().split(":")
            manpage_path = Path(components[0])

            manpage: str = manpage_path.name
            manpage_dir = manpage_path.parent

            if manpage_dir == project_root:
                raise ValueError(
                    "The directory storing the generated man page must be within the "
                    "project's base directory, and not equal to the project's base "
                    "directory"
                )

            if full_spec:
                self._load_manpage_options(
                    options=options, defn_components=components[1:]
                )
                self._include_url = self.config.get("include-url", True)
                self._force_command_line = self.config.get("force-command-line", False)

            self._manpages_to_build.append(
                ManpageToBuildOptions(
                    manpage=manpage, manpage_dir=manpage_dir, options=options
                )
            )

    @property
    def manpages_to_build(self) -> Iterator[str]:
        return (
            str(manpage.manpage_dir / manpage.manpage)
            for manpage in self._manpages_to_build
        )

    def do_work(self, build_data: dict[str, Any]) -> None:
        self.load_argparse_manpage_config(full_spec=True)
        build_data["artifacts"].extend(self.manpages_to_build)
        self.build_manpages()

    def setup_console(self) -> None:
        if self.app.verbosity < 0:
            return
        self.console = Console(force_terminal=True, force_interactive=False)

        # Match default Hatch color config:
        self._style_level_success = "bold cyan"
        self._style_level_error = "bold red"
        self._style_level_warning = "bold yellow"
        self._style_level_waiting = "bold magenta"
        self._style_level_info = "bold"
        self._style_level_debug = "bold"

    def console_output(
        self, message: str, level: int = 0, style: str = "", highlight=True
    ) -> None:
        if self.app.verbosity < level:
            return
        self.console.print(message, style=style, highlight=highlight)

    def initialize(self, version: str, build_data: dict[str, Any]) -> None:
        if self.target_name not in ["wheel", "sdist"]:
            return

        self.setup_console()
        self.console_output(
            "Building manual pages", level=1, style=self._style_level_waiting
        )
        self.do_work(build_data)
        self.console_output(
            "Finished building manual pages",
            level=1,
            style=self._style_level_success,
        )


def extract_name_email(text: str) -> tuple[str, str]:
    """
    Parse a line of text to extract the name and/or email from it

    :param text: the line containing the name and/or email
    :return: a tuple containing the name and email

    >>> extract_name_email("Damon Lynch <damonlynch@gmail.com>")
    ('Damon Lynch', 'damonlynch@gmail.com')
    >>> extract_name_email("Damon Lynch damonlynch@gmail.com")
    ('Damon Lynch', 'damonlynch@gmail.com')
    >>> extract_name_email("Damon Lynch")
    ('Damon Lynch', '')
    >>> extract_name_email("damonlynch@gmail.com")
    ('', 'damonlynch@gmail.com')
    >>> extract_name_email("")
    ('', '')
    >>> extract_name_email(" ")
    ('', '')
    """

    text = text.strip()
    if "@" not in text:
        return text, ""

    name, email = parseaddr(text)
    if name and email:
        return name, email

    # Wrap the email address with angle brackets and try again
    text = re.sub(r"^(.+)\s(.+@.+)$", r"\g<1> <\g<2>>", text)
    return parseaddr(text)
