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("No tasks") == 3


def test_stats_renders_tasks_in_all_kanban_columns(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 title" in response.text
    assert "In progress title" in response.text
    assert "Done title" in response.text
    assert "Backlog" in response.text
    assert "In Progress" in response.text
    assert "Done" in response.text


def test_stats_preselects_first_task_in_details_block(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 "First task" in response.text
    assert first.created_at.isoformat() 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" in response.text
    assert ">—<" not in response.text.split('id="selected-cycle-time"', 1)[1].split("</div>", 2)[1]


def test_stats_embeds_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='" in response.text
    assert str(task.id) in response.text
    assert '"title": "Payload task"' in response.text
    assert '"status": "done"' in response.text
    assert '"created_at":' in response.text
    assert '"started_at":' in response.text
    assert '"done_at":' in response.text
    assert '"cycle_time":' 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 "JSON.parse(card.dataset.task)" 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" 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;" 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_renders_created_started_and_done_values_for_completed_task(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() in response.text
    assert task.started_at.isoformat() in response.text
    assert task.done_at.isoformat() in response.text