import logging
import os
from importlib import metadata as _M
from pathlib import Path
from types import MappingProxyType
from typing import TYPE_CHECKING, Dict, Mapping, Optional, Sequence, Union

import fastjsonschema as FJS

from .. import api, dist_name, types

if TYPE_CHECKING:  # pragma: no cover
    from ..plugins import PluginProtocol


_logger = logging.getLogger(__name__)


TEXT_REPLACEMENTS = MappingProxyType(
    {
        "from fastjsonschema import": "from .fastjsonschema_exceptions import",
    }
)


def pre_compile(  # noqa: PLR0913
    output_dir: Union[str, os.PathLike] = ".",
    main_file: str = "__init__.py",
    original_cmd: str = "",
    plugins: Union[api.AllPlugins, Sequence["PluginProtocol"]] = api.ALL_PLUGINS,
    text_replacements: Mapping[str, str] = TEXT_REPLACEMENTS,
    *,
    extra_plugins: Sequence["PluginProtocol"] = (),
) -> Path:
    """Populate the given ``output_dir`` with all files necessary to perform
    the validation.
    The validation can be performed by calling the ``validate`` function inside the
    the file named with the ``main_file`` value.
    ``text_replacements`` can be used to
    """
    out = Path(output_dir)
    out.mkdir(parents=True, exist_ok=True)
    replacements = {**TEXT_REPLACEMENTS, **text_replacements}

    validator = api.Validator(plugins, extra_plugins=extra_plugins)
    header = "\n".join(NOCHECK_HEADERS)
    code = replace_text(validator.generated_code, replacements)
    _write(out / "fastjsonschema_validations.py", header + code)

    copy_fastjsonschema_exceptions(out, replacements)
    copy_module("extra_validations", out, replacements)
    copy_module("formats", out, replacements)
    copy_module("error_reporting", out, replacements)
    write_main(out / main_file, validator.schema, replacements)
    write_notice(out, main_file, original_cmd, replacements)
    (out / "__init__.py").touch()

    return out


def replace_text(text: str, replacements: Dict[str, str]) -> str:
    for orig, subst in replacements.items():
        text = text.replace(orig, subst)
    return text


def copy_fastjsonschema_exceptions(
    output_dir: Path, replacements: Dict[str, str]
) -> Path:
    code = replace_text(api.read_text(FJS.__name__, "exceptions.py"), replacements)
    return _write(output_dir / "fastjsonschema_exceptions.py", code)


def copy_module(name: str, output_dir: Path, replacements: Dict[str, str]) -> Path:
    code = api.read_text(api.__package__, f"{name}.py")
    return _write(output_dir / f"{name}.py", replace_text(code, replacements))


def write_main(
    file_path: Path, schema: types.Schema, replacements: Dict[str, str]
) -> Path:
    code = api.read_text(__name__, "main_file.template")
    return _write(file_path, replace_text(code, replacements))


def write_notice(
    out: Path, main_file: str, cmd: str, replacements: Dict[str, str]
) -> Path:
    if cmd:
        opening = api.read_text(__name__, "cli-notice.template")
        opening = opening.format(command=cmd)
    else:
        opening = api.read_text(__name__, "api-notice.template")
    notice = api.read_text(__name__, "NOTICE.template")
    notice = notice.format(notice=opening, main_file=main_file, **load_licenses())
    notice = replace_text(notice, replacements)

    return _write(out / "NOTICE", notice)


def load_licenses() -> Dict[str, str]:
    return {
        "fastjsonschema_license": _find_and_load_licence(_M.files("fastjsonschema")),
        "validate_pyproject_license": _find_and_load_licence(_M.files(dist_name)),
    }


NOCHECK_HEADERS = (
    "# noqa",
    "# ruff: noqa",
    "# flake8: noqa",
    "# pylint: skip-file",
    "# mypy: ignore-errors",
    "# yapf: disable",
    "# pylama:skip=1",
    "\n\n# *** PLEASE DO NOT MODIFY DIRECTLY: Automatically generated code *** \n\n\n",
)


def _find_and_load_licence(files: Optional[Sequence[_M.PackagePath]]) -> str:
    if files is None:  # pragma: no cover
        raise ImportError("Could not find LICENSE for package")
    try:
        return next(f for f in files if f.stem.upper() == "LICENSE").read_text("UTF-8")
    except FileNotFoundError:  # pragma: no cover
        msg = (
            "Please make sure to install `validate-pyproject` and `fastjsonschema` "
            "in a NON-EDITABLE way. This is necessary due to the issue #112 in "
            "python/importlib_metadata."
        )
        _logger.warning(msg)
        raise


def _write(file: Path, text: str) -> Path:
    file.write_text(text.rstrip() + "\n", encoding="utf-8")  # POSIX convention
    return file