import subprocess
from pathlib import Path

import pytest
from pygit2 import Oid, Repository, init_repository

from distgit.tasks import (
	BOARD_REF_PREFIX,
	EMPTY_TREE_OID_HEX,
	TASK_REF_PREFIX,
	Board,
	Comment,
	Task,
	get_board,
	get_comment,
	get_task,
	get_task_by_oid,
)

TAGGER: str = "alice <alice@example.com>"
BOARD_MAIN: str = f"{BOARD_REF_PREFIX}main"


@pytest.fixture
def repo(tmp_path: Path) -> Repository:
	repo_path = tmp_path / "repo"
	repo_path.mkdir()
	return init_repository(str(repo_path), bare=False)


def _empty_tree() -> Oid:
	return Oid(hex=EMPTY_TREE_OID_HEX)


def _task_ref(slug: str) -> str:
	return f"{TASK_REF_PREFIX}{slug}"


def _run_git_gc(repo: Repository) -> None:
	subprocess.run(
		["git", "gc", "--prune=now"],
		cwd=repo.workdir,
		capture_output=True,
		text=True,
		check=True,
	)


def test_board_roundtrip(repo: Repository) -> None:
	board = Board(_empty_tree(), BOARD_MAIN, TAGGER, description="Main board")
	board.write(repo)

	loaded = get_board(repo, BOARD_MAIN)
	assert loaded is not None
	assert loaded.name == BOARD_MAIN
	assert loaded.description == "Main board"
	assert loaded.tasks == []


def test_task_roundtrip_by_ref_and_oid(repo: Repository) -> None:
	task = Task(
		_empty_tree(),
		_task_ref("alpha"),
		TAGGER,
		title="Alpha",
		description="First task",
		status=Task.Status.TODO,
		priority=Task.Priority.HIGH,
		assignee="bob",
	)
	oid = task.write(repo)

	by_ref = get_task(repo, _task_ref("alpha"))
	assert by_ref is not None
	assert by_ref.title == "Alpha"
	assert by_ref.description == "First task"
	assert by_ref.status == Task.Status.TODO
	assert by_ref.priority == Task.Priority.HIGH
	assert by_ref.assignee == "bob"

	by_oid = get_task_by_oid(repo, oid)
	assert by_oid is not None
	assert by_oid.title == "Alpha"
	assert by_oid.status == Task.Status.TODO


def test_comment_roundtrip(repo: Repository) -> None:
	task = Task(_empty_tree(), _task_ref("with-comment"), TAGGER, title="WithComment")
	task_oid = task.write(repo)

	comment = Comment(task_oid, "bob <bob@example.com>", content="Hello there")
	c_oid = comment.write(repo)

	loaded = get_comment(repo, c_oid)
	assert loaded is not None
	assert loaded.content == "Hello there"
	assert loaded.target == task_oid


def test_full_board_flow(repo: Repository) -> None:
	board = Board(_empty_tree(), BOARD_MAIN, TAGGER, description="Main")

	task_a = Task(
		_empty_tree(),
		_task_ref("a"),
		TAGGER,
		title="Task A",
		description="Desc A",
		status=Task.Status.TODO,
		priority=Task.Priority.HIGH,
	)
	task_a_oid = task_a.write(repo)

	task_b = Task(
		_empty_tree(),
		_task_ref("b"),
		TAGGER,
		title="Task B",
		description="Desc B",
		status=Task.Status.IN_PROGRESS,
		priority=Task.Priority.MEDIUM,
	)
	task_b_oid = task_b.write(repo)

	comment_a1 = Comment(task_a_oid, "bob <bob@example.com>", content="A1")
	a1_oid = comment_a1.write(repo)
	comment_a2 = Comment(task_a_oid, "carol <carol@example.com>", content="A2")
	a2_oid = comment_a2.write(repo)

	task_a.comments = [str(a1_oid), str(a2_oid)]
	task_a.update_message()
	task_a_oid = task_a.write(repo)

	comment_b1 = Comment(task_b_oid, "dave <dave@example.com>", content="B1")
	b1_oid = comment_b1.write(repo)

	task_b.comments = [str(b1_oid)]
	task_b.update_message()
	task_b_oid = task_b.write(repo)

	board.tasks = [str(task_a_oid), str(task_b_oid)]
	board.update_message()
	board.write(repo)

	loaded_board = get_board(repo, BOARD_MAIN)
	assert loaded_board is not None
	assert len(loaded_board.tasks) == 2

	loaded_a = get_task_by_oid(repo, Oid(hex=loaded_board.tasks[0]))
	assert loaded_a is not None
	assert loaded_a.title == "Task A"
	assert loaded_a.priority == Task.Priority.HIGH
	assert [get_comment(repo, Oid(hex=c)).content for c in loaded_a.comments] == ["A1", "A2"]

	loaded_b = get_task_by_oid(repo, Oid(hex=loaded_board.tasks[1]))
	assert loaded_b is not None
	assert loaded_b.title == "Task B"
	assert loaded_b.status == Task.Status.IN_PROGRESS
	assert [get_comment(repo, Oid(hex=c)).content for c in loaded_b.comments] == ["B1"]


def test_full_board_flow_survives_git_gc(repo: Repository, tmp_path: Path) -> None:
	board = Board(_empty_tree(), BOARD_MAIN, TAGGER, description="Main")

	task = Task(
		_empty_tree(),
		_task_ref("gc-test"),
		TAGGER,
		title="GC Task",
		description="persists across gc",
		status=Task.Status.TODO,
		priority=Task.Priority.CRITICAL,
	)
	task_oid = task.write(repo)

	c1_oid = Comment(task_oid, "bob <bob@example.com>", content="first").write(repo)
	c2_oid = Comment(task_oid, "carol <carol@example.com>", content="second").write(repo)

	task.comments = [str(c1_oid), str(c2_oid)]
	task.update_message()
	task_oid = task.write(repo)

	board.tasks = [str(task_oid)]
	board.update_message()
	board.write(repo)

	_run_git_gc(repo)

	# Re-open repo to avoid any in-memory odb caches from the pre-gc instance.
	reopened = Repository(repo.path)

	loaded_board = get_board(reopened, BOARD_MAIN)
	assert loaded_board is not None
	assert len(loaded_board.tasks) == 1

	loaded_task = get_task_by_oid(reopened, Oid(hex=loaded_board.tasks[0]))
	assert loaded_task is not None
	assert loaded_task.title == "GC Task"
	assert loaded_task.priority == Task.Priority.CRITICAL
	assert len(loaded_task.comments) == 2

	contents = [get_comment(reopened, Oid(hex=c)).content for c in loaded_task.comments]
	assert contents == ["first", "second"]