from __future__ import annotations

import pytest
from pygit2 import GitError, Repository

from pygittools.tui.branches import (
    checkout_branch,
    create_branch_from_current,
    current_branch_name,
    list_local_branches,
)


def test_current_branch_name_on_main(committed_repo: Repository) -> None:
    name = current_branch_name(committed_repo)
    assert name in {"main", "master"}


def test_current_branch_name_when_detached(committed_repo: Repository) -> None:
    commit = committed_repo.get(committed_repo.head.target)
    committed_repo.set_head(commit.id)
    assert current_branch_name(committed_repo) == "(detached)"


def test_current_branch_name_when_unborn(repo: Repository) -> None:
    assert repo.head_is_unborn
    target = repo.lookup_reference("HEAD").target
    assert isinstance(target, str)
    assert current_branch_name(repo) == target.removeprefix("refs/heads/")


def test_create_branch_from_unborn_head(repo: Repository) -> None:
    ok, error = create_branch_from_current(repo, "main")
    assert ok is True
    assert error == ""
    assert current_branch_name(repo) == "main"
    assert repo.head_is_unborn
    assert "main" not in list_local_branches(repo)


def test_list_local_branches_sorted(committed_repo: Repository) -> None:
    commit = committed_repo.get(committed_repo.head.target)
    committed_repo.branches.create("feature", commit)
    branches = list_local_branches(committed_repo)
    assert branches == sorted(branches)
    assert "feature" in branches


def test_checkout_branch_switches(committed_repo: Repository) -> None:
    commit = committed_repo.get(committed_repo.head.target)
    committed_repo.branches.create("feature", commit)
    ok, error = checkout_branch(committed_repo, "feature")
    assert ok is True
    assert error == ""
    assert current_branch_name(committed_repo) == "feature"


def test_checkout_branch_returns_error_for_missing_branch(committed_repo: Repository) -> None:
    ok, error = checkout_branch(committed_repo, "missing")
    assert ok is False
    assert error


def test_create_branch_from_current_success(committed_repo: Repository) -> None:
    ok, error = create_branch_from_current(committed_repo, "new-branch")
    assert ok is True
    assert error == ""
    assert "new-branch" in list_local_branches(committed_repo)


def test_create_branch_rejects_empty_name(committed_repo: Repository) -> None:
    ok, error = create_branch_from_current(committed_repo, "   ")
    assert ok is False
    assert error == "Branch name is empty"


def test_create_branch_rejects_invalid_name(committed_repo: Repository) -> None:
    ok, error = create_branch_from_current(committed_repo, "bad..name")
    assert ok is False
    assert "Invalid branch name" in error


def test_create_branch_rejects_duplicate(committed_repo: Repository) -> None:
    ok, _ = create_branch_from_current(committed_repo, "dup")
    assert ok is True
    ok, error = create_branch_from_current(committed_repo, "dup")
    assert ok is False
    assert "already exists" in error


def test_create_branch_surfaces_git_error(monkeypatch: pytest.MonkeyPatch, committed_repo: Repository) -> None:
    def fail_create(_name: str, _commit: object) -> None:
        raise GitError("boom")

    monkeypatch.setattr(committed_repo.branches, "create", fail_create)
    ok, error = create_branch_from_current(committed_repo, "broken")
    assert ok is False
    assert error == "boom"


def test_checkout_branch_empty_git_error_message(committed_repo: Repository, monkeypatch: pytest.MonkeyPatch) -> None:
    def fail_checkout(_ref: str) -> None:
        raise GitError("   ")

    monkeypatch.setattr(committed_repo, "checkout", fail_checkout)
    ok, error = checkout_branch(committed_repo, "main")
    assert ok is False
    assert error == "Checkout failed"