from __future__ import annotations

from datetime import UTC, datetime, timedelta
from uuid import uuid4

from fastapi.testclient import TestClient

from app.api.tasks import get_task_repository
from app.main import app
from app.storage import JsonFileTaskRepository, StoredTask


def make_repo(tmp_path) -> JsonFileTaskRepository:
    return JsonFileTaskRepository(tmp_path / "tasks.json")


def make_task(
    *,
    title: str = "Task",
    started: bool = False,
    done: bool = False,
) -> StoredTask:
    now = datetime.now(UTC)
    started_at = now - timedelta(minutes=10) if started else None
    done_at = now - timedelta(minutes=1) if done else None
    return StoredTask(
        id=uuid4(),
        title=title,
        created_at=now - timedelta(hours=1),
        started_at=started_at,
        done_at=done_at,
    )


def make_client(tmp_path) -> tuple[TestClient, JsonFileTaskRepository]:
    repo = make_repo(tmp_path)
    app.dependency_overrides[get_task_repository] = lambda: repo
    client = TestClient(app)
    return client, repo


def teardown_function() -> None:
    app.dependency_overrides.clear()


def test_stats_returns_html_page_for_empty_board(tmp_path):
    client, _repo = make_client(tmp_path)

    response = client.get("/stats")

    assert response.status_code == 200
    assert "text/html" in response.headers["content-type"]
    assert "TaskFlow Stats" in response.text
    assert "No task selected" in response.text
    assert "Backlog" in response.text
    assert "In Progress" in response.text
    assert "Done" in response.text
    assert response.text.count("Loading tasks...") == 3


def test_stats_includes_client_side_board_loading_hooks(tmp_path):
    client, repo = make_client(tmp_path)
    backlog = make_task(title="Backlog title", started=False, done=False)
    in_progress = make_task(title="In progress title", started=True, done=False)
    done = make_task(title="Done title", started=True, done=True)
    repo.create_task(backlog)
    repo.create_task(in_progress)
    repo.create_task(done)

    response = client.get("/stats")

    assert response.status_code == 200
    assert "Backlog" in response.text
    assert "In Progress" in response.text
    assert "Done" in response.text
    assert 'id="backlog-list"' in response.text
    assert 'id="in-progress-list"' in response.text
    assert 'id="done-list"' in response.text
    assert 'fetch("/ui_data/stats/board")' in response.text


def test_stats_renders_empty_details_block_until_client_side_fetch(tmp_path):
    client, repo = make_client(tmp_path)
    first = make_task(title="First task", started=False, done=False)
    second = make_task(title="Second task", started=True, done=False)
    repo.create_task(first)
    repo.create_task(second)

    response = client.get("/stats")

    assert response.status_code == 200
    assert 'id="selected-title"' in response.text
    assert 'id="selected-created-at"' in response.text
    assert "No task selected" in response.text
    assert first.created_at.isoformat() not in response.text


def test_stats_shows_placeholders_for_missing_dates(tmp_path):
    client, repo = make_client(tmp_path)
    task = make_task(title="Backlog only", started=False, done=False)
    repo.create_task(task)

    response = client.get("/stats")

    assert response.status_code == 200
    assert 'id="selected-started-at"' in response.text
    assert 'id="selected-done-at"' in response.text
    assert 'id="selected-cycle-time"' in response.text
    assert ">—<" in response.text


def test_stats_renders_cycle_time_for_completed_task(tmp_path):
    client, repo = make_client(tmp_path)
    task = make_task(title="Completed task", started=True, done=True)
    repo.create_task(task)

    response = client.get("/stats")

    assert response.status_code == 200
    assert 'id="selected-cycle-time"' in response.text
    assert "0h 9m" not in response.text
    assert ">—<" in response.text


def test_stats_does_not_embed_task_payload_for_client_side_switching(tmp_path):
    client, repo = make_client(tmp_path)
    task = make_task(title="Payload task", started=True, done=True)
    repo.create_task(task)

    response = client.get("/stats")

    assert response.status_code == 200
    assert "data-task='" not in response.text
    assert str(task.id) not in response.text
    assert "Payload task" not in response.text


def test_stats_includes_js_hooks_for_dynamic_selected_task_update(tmp_path):
    client, repo = make_client(tmp_path)
    repo.create_task(make_task(title="Clickable"))

    response = client.get("/stats")

    assert response.status_code == 200
    assert 'id="selected-title"' in response.text
    assert 'id="selected-status"' in response.text
    assert 'id="selected-started-at"' in response.text
    assert 'id="selected-done-at"' in response.text
    assert 'id="selected-cycle-time"' in response.text
    assert 'id="selected-created-at"' in response.text
    assert 'document.querySelectorAll(".task-card")' in response.text
    assert 'card.addEventListener("click"' in response.text
    assert "fetch(`/ui_data/tasks/${taskId}`)" in response.text


def test_stats_handles_utf8_titles(tmp_path):
    client, repo = make_client(tmp_path)
    repo.create_task(make_task(title="Задача пример"))

    response = client.get("/stats")

    assert response.status_code == 200
    assert "Задача пример" not in response.text


def test_stats_escapes_html_in_task_title(tmp_path):
    client, repo = make_client(tmp_path)
    repo.create_task(make_task(title="<script>alert(1)</script>"))

    response = client.get("/stats")

    assert response.status_code == 200
    assert "<script>alert(1)</script>" not in response.text
    assert "&lt;script&gt;alert(1)&lt;/script&gt;" not in response.text


def test_stats_rejects_unsupported_method(tmp_path):
    client, _repo = make_client(tmp_path)

    response = client.post("/stats")

    assert response.status_code == 405


def test_stats_still_works_after_recovery_from_corrupted_file(tmp_path):
    file_path = tmp_path / "tasks.json"
    file_path.write_text("{broken", encoding="utf-8")

    repo = JsonFileTaskRepository(file_path)
    app.dependency_overrides[get_task_repository] = lambda: repo
    client = TestClient(app)

    response = client.get("/stats")

    assert response.status_code == 200
    assert "text/html" in response.headers["content-type"]
    assert "TaskFlow Stats" in response.text
    assert "No task selected" in response.text


def test_stats_does_not_render_created_started_and_done_values_server_side(tmp_path):
    client, repo = make_client(tmp_path)
    task = make_task(title="Detailed task", started=True, done=True)
    repo.create_task(task)

    response = client.get("/stats")

    assert response.status_code == 200
    assert task.created_at.isoformat() not in response.text
    assert task.started_at.isoformat() not in response.text
    assert task.done_at.isoformat() not in response.text