from __future__ import annotations

import contextlib
import os
import re
import urllib.parse

from pathlib import Path
from typing import TYPE_CHECKING
from typing import Dict
from typing import List
from typing import TypeVar
from typing import Union
from typing import cast

from poetry.core.packages.dependency import Dependency
from tomlkit.items import InlineTable

from poetry.packages.direct_origin import DirectOrigin


if TYPE_CHECKING:
    from poetry.core.packages.vcs_dependency import VCSDependency

    from poetry.utils.cache import ArtifactCache
    from poetry.utils.env import Env


DependencySpec = Dict[str, Union[str, bool, Dict[str, Union[str, bool]], List[str]]]
BaseSpec = TypeVar("BaseSpec", DependencySpec, InlineTable)

GIT_URL_SCHEMES = {"git+http", "git+https", "git+ssh"}


def dependency_to_specification(
    dependency: Dependency, specification: BaseSpec
) -> BaseSpec:
    if dependency.is_vcs():
        dependency = cast("VCSDependency", dependency)
        assert dependency.source_url is not None
        specification[dependency.vcs] = dependency.source_url
        if dependency.reference:
            specification["rev"] = dependency.reference
    elif dependency.is_file() or dependency.is_directory():
        assert dependency.source_url is not None
        specification["path"] = dependency.source_url
    elif dependency.is_url():
        assert dependency.source_url is not None
        specification["url"] = dependency.source_url
    elif dependency.pretty_constraint != "*" and not dependency.constraint.is_empty():
        specification["version"] = dependency.pretty_constraint

    if not dependency.marker.is_any():
        specification["markers"] = str(dependency.marker)

    if dependency.extras:
        specification["extras"] = sorted(dependency.extras)

    return specification


class RequirementsParser:
    def __init__(
        self,
        *,
        artifact_cache: ArtifactCache,
        env: Env | None = None,
        cwd: Path | None = None,
    ) -> None:
        self._direct_origin = DirectOrigin(artifact_cache)
        self._env = env
        self._cwd = cwd or Path.cwd()

    def parse(self, requirement: str) -> DependencySpec:
        requirement = requirement.strip()

        specification = self._parse_pep508(requirement)

        if specification is not None:
            return specification

        extras = []
        extras_m = re.search(r"\[([\w\d,-_ ]+)\]$", requirement)
        if extras_m:
            extras = [e.strip() for e in extras_m.group(1).split(",")]
            requirement, _ = requirement.split("[")

        specification = (
            self._parse_url(requirement)
            or self._parse_path(requirement)
            or self._parse_simple(requirement)
        )

        if specification:
            if extras:
                specification.setdefault("extras", extras)
            return specification

        raise ValueError(f"Invalid dependency specification: {requirement}")

    def _parse_pep508(self, requirement: str) -> DependencySpec | None:
        if " ; " not in requirement and re.search(r"@[\^~!=<>\d]", requirement):
            # this is of the form package@<semver>, do not attempt to parse it
            return None

        with contextlib.suppress(ValueError):
            dependency = Dependency.create_from_pep_508(requirement)
            specification: DependencySpec = {}
            specification = dependency_to_specification(dependency, specification)

            if specification:
                specification["name"] = dependency.name
                return specification

        return None

    def _parse_git_url(self, requirement: str) -> DependencySpec | None:
        from poetry.core.vcs.git import Git
        from poetry.core.vcs.git import ParsedUrl

        parsed = ParsedUrl.parse(requirement)
        url = Git.normalize_url(requirement)

        pair = {"name": parsed.name, "git": url.url}

        if parsed.rev:
            pair["rev"] = url.revision

        if parsed.subdirectory:
            pair["subdirectory"] = parsed.subdirectory

        source_root = self._env.path.joinpath("src") if self._env else None
        package = self._direct_origin.get_package_from_vcs(
            "git",
            url=url.url,
            rev=pair.get("rev"),
            subdirectory=parsed.subdirectory,
            source_root=source_root,
        )
        pair["name"] = package.name
        return pair

    def _parse_url(self, requirement: str) -> DependencySpec | None:
        url_parsed = urllib.parse.urlparse(requirement)
        if not (url_parsed.scheme and url_parsed.netloc):
            return None

        if url_parsed.scheme in GIT_URL_SCHEMES:
            return self._parse_git_url(requirement)

        if url_parsed.scheme in ["http", "https"]:
            package = self._direct_origin.get_package_from_url(requirement)
            assert package.source_url is not None
            return {"name": package.name, "url": package.source_url}

        return None

    def _parse_path(self, requirement: str) -> DependencySpec | None:
        if (os.path.sep in requirement or "/" in requirement) and (
            self._cwd.joinpath(requirement).exists()
            or Path(requirement).expanduser().exists()
            and Path(requirement).expanduser().is_absolute()
        ):
            path = Path(requirement).expanduser()
            is_absolute = path.is_absolute()

            if not path.is_absolute():
                path = self._cwd.joinpath(requirement)

            if path.is_file():
                package = self._direct_origin.get_package_from_file(path.resolve())
            else:
                package = self._direct_origin.get_package_from_directory(path.resolve())

            return {
                "name": package.name,
                "path": (
                    path.relative_to(self._cwd).as_posix()
                    if not is_absolute
                    else path.as_posix()
                ),
            }

        return None

    def _parse_simple(
        self,
        requirement: str,
    ) -> DependencySpec | None:
        extras: list[str] = []
        pair = re.sub(
            "^([^@=: ]+)(?:@|==|(?<![<>~!])=|:| )(.*)$", "\\1 \\2", requirement
        )
        pair = pair.strip()

        require: DependencySpec = {}

        if " " in pair:
            name, version = pair.split(" ", 1)
            extras_m = re.search(r"\[([\w\d,-_]+)\]$", name)
            if extras_m:
                extras = [e.strip() for e in extras_m.group(1).split(",")]
                name, _ = name.split("[")

            require["name"] = name
            if version != "latest":
                require["version"] = version
        else:
            m = re.match(
                r"^([^><=!: ]+)((?:>=|<=|>|<|!=|~=|~|\^).*)$", requirement.strip()
            )
            if m:
                name, constraint = m.group(1), m.group(2)
                extras_m = re.search(r"\[([\w\d,-_]+)\]$", name)
                if extras_m:
                    extras = [e.strip() for e in extras_m.group(1).split(",")]
                    name, _ = name.split("[")

                require["name"] = name
                require["version"] = constraint
            else:
                extras_m = re.search(r"\[([\w\d,-_]+)\]$", pair)
                if extras_m:
                    extras = [e.strip() for e in extras_m.group(1).split(",")]
                    pair, _ = pair.split("[")

                require["name"] = pair

        if extras:
            require["extras"] = extras

        return require
