import asyncio
import json
import pytest
from unittest.mock import AsyncMock, MagicMock, patch
from app.services.browser_session_service import BrowserSessionService, BrowserSession, BrowserTab, BrowserSessionError

@pytest.fixture
def service():
    return BrowserSessionService()

@pytest.fixture
def session(service):
    fake_context = AsyncMock()
    fake_page = AsyncMock()
    fake_page.is_closed = MagicMock(return_value=False)
    fake_page.url = "https://initial.test"
    fake_page.title = AsyncMock(return_value="Initial Tab")
    
    tab_id = "tab1"
    tab = BrowserTab(id=tab_id, page=fake_page, created_at=100.0)
    
    sess = BrowserSession(
        id="sess123",
        custom_page_id=1,
        profile_key="profile1",
        context=fake_context,
        tabs={tab_id: tab},
        active_tab_id=tab_id,
        lock=asyncio.Lock(),
    )
    service._sessions[sess.id] = sess
    return sess

@pytest.mark.asyncio
async def test_tab_capture(service, session):
    new_page = AsyncMock()
    new_page.is_closed = MagicMock(return_value=False)
    new_page.url = "https://new.test"
    new_page.title = AsyncMock(return_value="New Tab")
    new_page.bring_to_front = AsyncMock()
    
    # Simulate page capture
    service._handle_new_page(session, new_page)
    
    assert len(session.tabs) == 2
    assert session.active_tab_id != "tab1"
    new_tab_id = session.active_tab_id
    assert session.tabs[new_tab_id].page == new_page
    assert session.tab_revision == 1
    
    # Wait a bit for the background task _init_new_tab to finish if possible, 
    # though it's mocked anyway.
    await asyncio.sleep(0.1)

@pytest.mark.asyncio
async def test_activate_tab(service, session):
    new_page = AsyncMock()
    new_page.is_closed = MagicMock(return_value=False)
    new_page.bring_to_front = AsyncMock()
    tab2_id = "tab2"
    session.tabs[tab2_id] = BrowserTab(id=tab2_id, page=new_page, created_at=200.0)
    
    await service.activate_tab(session.id, tab2_id)
    
    assert session.active_tab_id == tab2_id
    assert new_page.bring_to_front.call_count == 1
    assert session.tab_revision == 1

@pytest.mark.asyncio
async def test_close_tab_safety(service, session):
    # Cannot close last tab
    with pytest.raises(ValueError, match="cannot close the last tab"):
        await service.close_tab(session.id, "tab1")

@pytest.mark.asyncio
async def test_close_active_tab_fallback(service, session):
    # Setup tab2
    page2 = AsyncMock()
    page2.is_closed = MagicMock(return_value=False)
    page2.bring_to_front = AsyncMock()
    tab2_id = "tab2"
    session.tabs[tab2_id] = BrowserTab(id=tab2_id, page=page2, created_at=200.0)
    
    # Active is tab2
    session.active_tab_id = tab2_id
    
    # Close active tab2
    await service.close_tab(session.id, tab2_id)
    
    assert len(session.tabs) == 1
    assert session.active_tab_id == "tab1"
    assert tab2_id not in session.tabs
    assert session.tabs["tab1"].page.bring_to_front.call_count == 1

@pytest.mark.asyncio
async def test_session_state_includes_tabs(service, session):
    # Setup tab2
    page2 = AsyncMock()
    page2.is_closed = MagicMock(return_value=False)
    page2.url = "https://tab2.test"
    page2.title = AsyncMock(return_value="Tab 2")
    tab2_id = "tab2"
    session.tabs[tab2_id] = BrowserTab(id=tab2_id, page=page2, created_at=200.0)
    
    state = await service.state(session.id)
    
    assert state["id"] == session.id
    assert state["active_tab_id"] == "tab1"
    assert len(state["tabs"]) == 2
    
    # Tabs should be sorted by created_at
    assert state["tabs"][0]["id"] == "tab1"
    assert state["tabs"][1]["id"] == "tab2"
    assert state["tabs"][0]["title"] == "Initial Tab"
    assert state["tabs"][1]["url"] == "https://tab2.test"

@pytest.mark.asyncio
async def test_ensure_open_prunes_closed_tab(service, session):
    # Setup tab2 and make it active
    page2 = AsyncMock()
    page2.is_closed = MagicMock(return_value=True) # Page 2 is closed
    tab2_id = "tab2"
    session.tabs[tab2_id] = BrowserTab(id=tab2_id, page=page2, created_at=200.0)
    session.active_tab_id = tab2_id
    
    # Calling any interaction method should trigger _ensure_open
    # and fallback to tab1
    await service.screenshot(session.id)
    
    assert session.active_tab_id == "tab1"
    assert tab2_id not in session.tabs
    assert session.tab_revision == 1

@pytest.mark.asyncio
async def test_ensure_open_discards_session_if_all_tabs_closed(service, session):
    session.tabs["tab1"].page.is_closed = MagicMock(return_value=True)
    
    with pytest.raises(BrowserSessionError, match="all browser pages are closed"):
        await service.screenshot(session.id)
    
    assert session.id not in service._sessions