"""Tests for dotfiles link planning."""

from pathlib import Path
from typing import Optional

from flow.domain.dotfiles.models import (
    LinkTarget,
    LinkedState,
)
from flow.domain.dotfiles.planning import plan_link, plan_unlink


def _lt(target, source="/a", pkg="_shared/zsh", module=False, sudo=False):
    return LinkTarget(
        source=Path(source), target=Path(target),
        package=pkg, from_module=module, needs_sudo=sudo,
    )


def _fs_check_none(path: Path) -> Optional[str]:
    """Fake filesystem_check: nothing exists."""
    return None


def _fs_check_file(path: Path) -> Optional[str]:
    """Fake: everything is a file."""
    return "file"


def _no_link_target(path: Path) -> Optional[Path]:
    """Default fake link_target: no symlink anywhere."""
    return None


class TestPlanLink:
    def test_new_target_creates_link(self):
        desired = [_lt("/home/x/.zshrc")]
        plan = plan_link(desired, LinkedState(), _fs_check_none, _no_link_target)
        assert len(plan.operations) == 1
        assert plan.operations[0].type == "create_link"
        assert plan.summary.added == 1

    def test_existing_correct_link_unchanged(self):
        lt = _lt("/home/x/.zshrc")
        current = LinkedState(links={Path("/home/x/.zshrc"): lt})
        plan = plan_link([lt], current, _fs_check_none, _no_link_target)
        assert len(plan.operations) == 0
        assert plan.summary.unchanged == 1

    def test_stale_link_removed(self):
        old = _lt("/home/x/.old")
        current = LinkedState(links={Path("/home/x/.old"): old})
        plan = plan_link([], current, _fs_check_none, _no_link_target)
        assert len(plan.operations) == 1
        assert plan.operations[0].type == "remove_link"
        assert plan.summary.removed == 1

    def test_changed_source_produces_remove_then_create(self):
        old = _lt("/home/x/.zshrc", source="/old")
        new = _lt("/home/x/.zshrc", source="/new")
        current = LinkedState(links={Path("/home/x/.zshrc"): old})
        plan = plan_link([new], current, _fs_check_none, _no_link_target)
        types = [op.type for op in plan.operations]
        assert types == ["remove_link", "create_link"]
        assert plan.summary.updated == 1
        assert plan.summary.added == 0
        assert plan.summary.removed == 0

    def test_unmanaged_file_at_target_is_conflict(self):
        desired = [_lt("/home/x/.zshrc")]
        plan = plan_link(desired, LinkedState(), _fs_check_file, _no_link_target)
        assert len(plan.conflicts) == 1
        assert ".zshrc" in plan.conflicts[0]

    def test_module_targets_counted(self):
        desired = [_lt("/home/x/.config/nvim/init.lua", module=True)]
        plan = plan_link(desired, LinkedState(), _fs_check_none, _no_link_target)
        assert plan.summary.from_modules == 1


    def test_broken_symlink_is_repaired(self):
        lt = _lt("/home/x/.zshrc")
        current = LinkedState(links={Path("/home/x/.zshrc"): lt})
        plan = plan_link(
            [lt], current, lambda p: "broken_symlink", _no_link_target,
        )
        types = [op.type for op in plan.operations]
        assert types == ["remove_link", "create_link"]
        assert plan.summary.updated == 1
        assert plan.summary.unchanged == 0

    def test_orphan_symlink_matching_source_is_adopted(self):
        """Untracked symlink that already points at the desired source counts
        as unchanged, not a conflict. Enables partial-failure rerun."""
        desired = [_lt("/home/x/.zshrc", source="/dots/.zshrc")]
        plan = plan_link(
            desired,
            LinkedState(),
            lambda p: "symlink",
            lambda p: Path("/dots/.zshrc"),
        )
        assert plan.conflicts == ()
        assert plan.operations == ()
        assert plan.summary.unchanged == 1
        assert plan.summary.added == 0

    def test_orphan_symlink_pointing_elsewhere_is_conflict(self):
        """Untracked symlink that points at the wrong source is still a
        conflict -- we don't silently retarget unmanaged links."""
        desired = [_lt("/home/x/.zshrc", source="/dots/.zshrc")]
        plan = plan_link(
            desired,
            LinkedState(),
            lambda p: "symlink",
            lambda p: Path("/elsewhere/.zshrc"),
        )
        assert len(plan.conflicts) == 1
        assert plan.summary.added == 0
        assert plan.summary.unchanged == 0

    def test_orphan_module_symlink_counts_as_module(self):
        """Adopted orphan symlinks for module files still count toward
        from_modules in the summary."""
        desired = [
            _lt("/home/x/.config/nvim/init.lua", source="/cache/init.lua", module=True),
        ]
        plan = plan_link(
            desired,
            LinkedState(),
            lambda p: "symlink",
            lambda p: Path("/cache/init.lua"),
        )
        assert plan.summary.unchanged == 1
        assert plan.summary.from_modules == 1


class TestPlanUnlink:
    def test_unlink_all(self):
        lt = _lt("/home/x/.zshrc")
        current = LinkedState(links={Path("/home/x/.zshrc"): lt})
        plan = plan_unlink(current, packages=None)
        assert len(plan.operations) == 1
        assert plan.operations[0].type == "remove_link"

    def test_unlink_specific_package(self):
        zsh = _lt("/home/x/.zshrc", pkg="_shared/zsh")
        git = _lt("/home/x/.gitconfig", pkg="_shared/git")
        current = LinkedState(links={
            Path("/home/x/.zshrc"): zsh,
            Path("/home/x/.gitconfig"): git,
        })
        plan = plan_unlink(current, packages=["_shared/zsh"])
        assert len(plan.operations) == 1
        assert plan.operations[0].target == Path("/home/x/.zshrc")

    def test_unlink_by_basename(self):
        zsh = _lt("/home/x/.zshrc", pkg="_shared/zsh")
        current = LinkedState(links={Path("/home/x/.zshrc"): zsh})
        plan = plan_unlink(current, packages=["zsh"])
        assert len(plan.operations) == 1