from __future__ import annotations

from typing import TYPE_CHECKING

from cleo.helpers import argument
from cleo.helpers import option
from packaging.utils import canonicalize_name

from poetry.console.commands.env_command import EnvCommand
from poetry.console.commands.group_command import GroupCommand


if TYPE_CHECKING:
    from cleo.io.io import IO
    from cleo.ui.table import Rows
    from packaging.utils import NormalizedName
    from poetry.core.packages.dependency import Dependency
    from poetry.core.packages.package import Package
    from poetry.core.packages.project_package import ProjectPackage

    from poetry.repositories.repository import Repository


def reverse_deps(pkg: Package, repo: Repository) -> dict[str, str]:
    required_by = {}
    for locked in repo.packages:
        dependencies = {d.name: d.pretty_constraint for d in locked.requires}

        if pkg.name in dependencies:
            required_by[locked.pretty_name] = dependencies[pkg.name]

    return required_by


class ShowCommand(GroupCommand, EnvCommand):
    name = "show"
    description = "Shows information about packages."

    arguments = [argument("package", "The package to inspect", optional=True)]
    options = [
        *GroupCommand._group_dependency_options(),
        option(
            "no-dev",
            None,
            "Do not list the development dependencies. (<warning>Deprecated</warning>)",
        ),
        option("tree", "t", "List the dependencies as a tree."),
        option(
            "why",
            None,
            (
                "When showing the full list, or a <info>--tree</info> for a single"
                " package, also display why it's included."
            ),
        ),
        option("latest", "l", "Show the latest version."),
        option(
            "outdated",
            "o",
            "Show the latest version but only for packages that are outdated.",
        ),
        option(
            "all",
            "a",
            "Show all packages (even those not compatible with current system).",
        ),
        option("top-level", "T", "Show only top-level dependencies."),
    ]

    help = """The show command displays detailed information about a package, or
lists all packages available."""

    colors = ["cyan", "yellow", "green", "magenta", "blue"]

    def handle(self) -> int:
        package = self.argument("package")

        if self.option("tree"):
            self.init_styles(self.io)

        if self.option("top-level"):
            if self.option("tree"):
                self.line_error(
                    "<error>Error: Cannot use --tree and --top-level at the same"
                    " time.</error>"
                )
                return 1
            if package is not None:
                self.line_error(
                    "<error>Error: Cannot use --top-level when displaying a single"
                    " package.</error>"
                )
                return 1

        if self.option("why"):
            if self.option("tree") and package is None:
                self.line_error(
                    "<error>Error: --why requires a package when combined with"
                    " --tree.</error>"
                )

                return 1

            if not self.option("tree") and package:
                self.line_error(
                    "<error>Error: --why cannot be used without --tree when displaying"
                    " a single package.</error>"
                )

                return 1

        if self.option("outdated"):
            self.io.input.set_option("latest", True)

        if not self.poetry.locker.is_locked():
            self.line_error(
                "<error>Error: poetry.lock not found. Run `poetry lock` to create"
                " it.</error>"
            )
            return 1

        locked_repo = self.poetry.locker.locked_repository()

        if package:
            return self._display_single_package_information(package, locked_repo)

        root = self.project_with_activated_groups_only()

        # Show tree view if requested
        if self.option("tree"):
            return self._display_packages_tree_information(locked_repo, root)

        return self._display_packages_information(locked_repo, root)

    def _display_single_package_information(
        self, package: str, locked_repository: Repository
    ) -> int:
        locked_packages = locked_repository.packages
        canonicalized_package = canonicalize_name(package)
        pkg = None

        for locked in locked_packages:
            if locked.name == canonicalized_package:
                pkg = locked
                break

        if not pkg:
            raise ValueError(f"Package {package} not found")

        required_by = reverse_deps(pkg, locked_repository)

        if self.option("tree"):
            if self.option("why"):
                # The default case if there's no reverse dependencies is to query
                # the subtree for pkg but if any rev-deps exist we'll query for each
                # of them in turn
                packages = [pkg]
                if required_by:
                    packages = [
                        p for p in locked_packages for r in required_by if p.name == r
                    ]
                else:
                    # if no rev-deps exist we'll make this clear as it can otherwise
                    # look very odd for packages that also have no or few direct
                    # dependencies
                    self.io.write_line(f"Package {package} is a direct dependency.")

                for p in packages:
                    self.display_package_tree(
                        self.io, p, locked_packages, why_package=pkg
                    )

            else:
                self.display_package_tree(self.io, pkg, locked_packages)

            return 0

        rows: Rows = [
            ["<info>name</>", f" : <c1>{pkg.pretty_name}</>"],
            ["<info>version</>", f" : <b>{pkg.pretty_version}</b>"],
            ["<info>description</>", f" : {pkg.description}"],
        ]

        self.table(rows=rows, style="compact").render()

        if pkg.requires:
            self.line("")
            self.line("<info>dependencies</info>")
            for dependency in pkg.requires:
                self.line(
                    f" - <c1>{dependency.pretty_name}</c1>"
                    f" <b>{dependency.pretty_constraint}</b>"
                )

        if required_by:
            self.line("")
            self.line("<info>required by</info>")
            for parent, requires_version in required_by.items():
                self.line(f" - <c1>{parent}</c1> <b>{requires_version}</b>")

        return 0

    def _display_packages_information(
        self, locked_repository: Repository, root: ProjectPackage
    ) -> int:
        import shutil

        from cleo.io.null_io import NullIO

        from poetry.puzzle.solver import Solver
        from poetry.repositories.installed_repository import InstalledRepository
        from poetry.repositories.repository_pool import RepositoryPool
        from poetry.utils.helpers import get_package_version_display_string

        locked_packages = locked_repository.packages
        pool = RepositoryPool(ignore_repository_names=True)
        pool.add_repository(locked_repository)
        solver = Solver(
            root,
            pool=pool,
            installed=[],
            locked=locked_packages,
            io=NullIO(),
        )
        solver.provider.load_deferred(False)
        with solver.use_environment(self.env):
            ops = solver.solve().calculate_operations()

        required_locked_packages = {op.package for op in ops if not op.skipped}

        show_latest = self.option("latest")
        show_all = self.option("all")
        show_top_level = self.option("top-level")
        width = shutil.get_terminal_size().columns
        name_length = version_length = latest_length = required_by_length = 0
        latest_packages = {}
        latest_statuses = {}
        installed_repo = InstalledRepository.load(self.env)

        # Computing widths
        for locked in locked_packages:
            if locked not in required_locked_packages and not show_all:
                continue

            current_length = len(locked.pretty_name)
            if not self.io.output.is_decorated():
                installed_status = self.get_installed_status(
                    locked, installed_repo.packages
                )

                if installed_status == "not-installed":
                    current_length += 4

            if show_latest:
                latest = self.find_latest_package(locked, root)
                if not latest:
                    latest = locked

                latest_packages[locked.pretty_name] = latest
                update_status = latest_statuses[locked.pretty_name] = (
                    self.get_update_status(latest, locked)
                )

                if not self.option("outdated") or update_status != "up-to-date":
                    name_length = max(name_length, current_length)
                    version_length = max(
                        version_length,
                        len(
                            get_package_version_display_string(
                                locked, root=self.poetry.file.parent
                            )
                        ),
                    )
                    latest_length = max(
                        latest_length,
                        len(
                            get_package_version_display_string(
                                latest, root=self.poetry.file.parent
                            )
                        ),
                    )

                    if self.option("why"):
                        required_by = reverse_deps(locked, locked_repository)
                        required_by_length = max(
                            required_by_length,
                            len(" from " + ",".join(required_by.keys())),
                        )
            else:
                name_length = max(name_length, current_length)
                version_length = max(
                    version_length,
                    len(
                        get_package_version_display_string(
                            locked, root=self.poetry.file.parent
                        )
                    ),
                )

                if self.option("why"):
                    required_by = reverse_deps(locked, locked_repository)
                    required_by_length = max(
                        required_by_length, len(" from " + ",".join(required_by.keys()))
                    )

        write_version = name_length + version_length + 3 <= width
        write_latest = name_length + version_length + latest_length + 3 <= width

        why_end_column = (
            name_length + version_length + latest_length + required_by_length
        )
        write_why = self.option("why") and (why_end_column + 3) <= width
        write_description = (why_end_column + 24) <= width

        requires = root.all_requires

        for locked in locked_packages:
            color = "cyan"
            name = locked.pretty_name
            install_marker = ""

            if show_top_level and not any(
                locked.is_same_package_as(r) for r in requires
            ):
                continue

            if locked not in required_locked_packages:
                if not show_all:
                    continue

                color = "black;options=bold"
            else:
                installed_status = self.get_installed_status(
                    locked, installed_repo.packages
                )
                if installed_status == "not-installed":
                    color = "red"

                    if not self.io.output.is_decorated():
                        # Non installed in non decorated mode
                        install_marker = " (!)"

            if (
                show_latest
                and self.option("outdated")
                and latest_statuses[locked.pretty_name] == "up-to-date"
            ):
                continue

            line = (
                f"<fg={color}>"
                f"{name:{name_length - len(install_marker)}}{install_marker}</>"
            )
            if write_version:
                version = get_package_version_display_string(
                    locked, root=self.poetry.file.parent
                )
                line += f" <b>{version:{version_length}}</b>"
            if show_latest:
                latest = latest_packages[locked.pretty_name]
                update_status = latest_statuses[locked.pretty_name]

                if write_latest:
                    color = "green"
                    if update_status == "semver-safe-update":
                        color = "red"
                    elif update_status == "update-possible":
                        color = "yellow"

                    version = get_package_version_display_string(
                        latest, root=self.poetry.file.parent
                    )
                    line += f" <fg={color}>{version:{latest_length}}</>"

            if write_why:
                required_by = reverse_deps(locked, locked_repository)
                if required_by:
                    content = ",".join(required_by.keys())
                    # subtract 6 for ' from '
                    line += f" from {content:{required_by_length - 6}}"
                else:
                    line += " " * required_by_length

            if write_description:
                description = locked.description
                remaining = (
                    width - name_length - version_length - required_by_length - 4
                )

                if show_latest:
                    remaining -= latest_length

                if len(locked.description) > remaining:
                    description = description[: remaining - 3] + "..."

                line += " " + description

            self.line(line)

        return 0

    def _display_packages_tree_information(
        self, locked_repository: Repository, root: ProjectPackage
    ) -> int:
        packages = locked_repository.packages

        for p in packages:
            for require in root.all_requires:
                if p.name == require.name:
                    self.display_package_tree(self.io, p, packages)
                    break

        return 0

    def display_package_tree(
        self,
        io: IO,
        package: Package,
        installed_packages: list[Package],
        why_package: Package | None = None,
    ) -> None:
        io.write(f"<c1>{package.pretty_name}</c1>")
        description = ""
        if package.description:
            description = " " + package.description

        io.write_line(f" <b>{package.pretty_version}</b>{description}")

        if why_package is not None:
            dependencies = [p for p in package.requires if p.name == why_package.name]
        else:
            dependencies = package.requires
            dependencies = sorted(
                dependencies,
                key=lambda x: x.name,
            )

        tree_bar = "├"
        total = len(dependencies)
        for i, dependency in enumerate(dependencies, 1):
            if i == total:
                tree_bar = "└"

            level = 1
            color = self.colors[level]
            info = (
                f"{tree_bar}── <{color}>{dependency.name}</{color}>"
                f" {dependency.pretty_constraint}"
            )
            self._write_tree_line(io, info)

            tree_bar = tree_bar.replace("└", " ")
            packages_in_tree = [package.name, dependency.name]

            self._display_tree(
                io,
                dependency,
                installed_packages,
                packages_in_tree,
                tree_bar,
                level + 1,
            )

    def _display_tree(
        self,
        io: IO,
        dependency: Dependency,
        installed_packages: list[Package],
        packages_in_tree: list[NormalizedName],
        previous_tree_bar: str = "├",
        level: int = 1,
    ) -> None:
        previous_tree_bar = previous_tree_bar.replace("├", "│")

        dependencies = []
        for package in installed_packages:
            if package.name == dependency.name:
                dependencies = package.requires

                break

        dependencies = sorted(
            dependencies,
            key=lambda x: x.name,
        )
        tree_bar = previous_tree_bar + "   ├"
        total = len(dependencies)
        for i, dependency in enumerate(dependencies, 1):
            current_tree = packages_in_tree
            if i == total:
                tree_bar = previous_tree_bar + "   └"

            color_ident = level % len(self.colors)
            color = self.colors[color_ident]

            circular_warn = ""
            if dependency.name in current_tree:
                circular_warn = "(circular dependency aborted here)"

            info = (
                f"{tree_bar}── <{color}>{dependency.name}</{color}>"
                f" {dependency.pretty_constraint} {circular_warn}"
            )
            self._write_tree_line(io, info)

            tree_bar = tree_bar.replace("└", " ")

            if dependency.name not in current_tree:
                current_tree.append(dependency.name)

                self._display_tree(
                    io,
                    dependency,
                    installed_packages,
                    current_tree,
                    tree_bar,
                    level + 1,
                )

    def _write_tree_line(self, io: IO, line: str) -> None:
        if not io.output.supports_utf8():
            line = line.replace("└", "`-")
            line = line.replace("├", "|-")
            line = line.replace("──", "-")
            line = line.replace("│", "|")

        io.write_line(line)

    def init_styles(self, io: IO) -> None:
        from cleo.formatters.style import Style

        for color in self.colors:
            style = Style(color)
            io.output.formatter.set_style(color, style)
            io.error_output.formatter.set_style(color, style)

    def find_latest_package(
        self, package: Package, root: ProjectPackage
    ) -> Package | None:
        from cleo.io.null_io import NullIO

        from poetry.puzzle.provider import Provider
        from poetry.version.version_selector import VersionSelector

        # find the latest version allowed in this pool
        requires = root.all_requires
        if package.is_direct_origin():
            for dep in requires:
                if dep.name == package.name and dep.source_type == package.source_type:
                    provider = Provider(root, self.poetry.pool, NullIO())
                    return provider.search_for_direct_origin_dependency(dep)

        allow_prereleases = False
        for dep in requires:
            if dep.name == package.name:
                allow_prereleases = dep.allows_prereleases()
                break

        name = package.name
        selector = VersionSelector(self.poetry.pool)

        return selector.find_best_candidate(
            name, f">={package.pretty_version}", allow_prereleases
        )

    def get_update_status(self, latest: Package, package: Package) -> str:
        from poetry.core.constraints.version import parse_constraint

        if latest.full_pretty_version == package.full_pretty_version:
            return "up-to-date"

        constraint = parse_constraint("^" + package.pretty_version)

        if constraint.allows(latest.version):
            # It needs an immediate semver-compliant upgrade
            return "semver-safe-update"

        # it needs an upgrade but has potential BC breaks so is not urgent
        return "update-possible"

    def get_installed_status(
        self, locked: Package, installed_packages: list[Package]
    ) -> str:
        for package in installed_packages:
            if locked.name == package.name:
                return "installed"

        return "not-installed"
