"""TDD — fleet pagination: offset/limit, total count, first/last/prev/next state."""
from __future__ import annotations

import math
import pytest
from datetime import datetime, timezone
from sqlalchemy.ext.asyncio import AsyncSession

from musehub.db.musehub_repo_models import MusehubCommit, MusehubCommitRef
from tests.factories import create_repo
from muse.core.types import blob_id


def _utc() -> datetime:
    return datetime.now(tz=timezone.utc)


async def _add_commit(
    session: AsyncSession,
    repo_id: str,
    seed: str,
    agent_id: str = "claude-code",
    model_id: str = "claude-sonnet-4-6",
) -> None:
    row = MusehubCommit(
        commit_id=blob_id(seed.encode()),
        branch="dev",
        parent_ids=[],
        message=f"feat: {seed}",
        author="gabriel",
        timestamp=_utc(),
        agent_id=agent_id,
        model_id=model_id,
    )
    session.add(row)
    session.add(MusehubCommitRef(repo_id=repo_id, commit_id=row.commit_id))
    await session.commit()


_IDENTITY = {
    "handle": "gabriel",
    "type": "human",
    "user_id": None,
}

# ---------------------------------------------------------------------------
# P1 — first page returns up to PAGE_SIZE agents, next_cursor set when more exist
# ---------------------------------------------------------------------------

@pytest.mark.asyncio
async def test_p1_first_page_returns_page_size_and_next_cursor(
    db_session: AsyncSession,
) -> None:
    from musehub.api.routes.musehub.ui_user_profile import _fetch_agent_fleet, _FLEET_PAGE_SIZE

    repo = await create_repo(db_session, owner="gabriel", visibility="public")

    # Create PAGE_SIZE + 1 distinct agents
    for i in range(_FLEET_PAGE_SIZE + 1):
        await _add_commit(db_session, repo.repo_id, f"p1-c{i}", agent_id=f"agent-{i:02d}")

    result = await _fetch_agent_fleet(db_session, _IDENTITY)

    assert len(result["agents"]) == _FLEET_PAGE_SIZE
    assert result["next_cursor"] == _FLEET_PAGE_SIZE


# ---------------------------------------------------------------------------
# P2 — last page has no next_cursor
# ---------------------------------------------------------------------------

@pytest.mark.asyncio
async def test_p2_last_page_has_no_next_cursor(
    db_session: AsyncSession,
) -> None:
    from musehub.api.routes.musehub.ui_user_profile import _fetch_agent_fleet, _FLEET_PAGE_SIZE

    repo = await create_repo(db_session, owner="gabriel", visibility="public")

    for i in range(_FLEET_PAGE_SIZE + 1):
        await _add_commit(db_session, repo.repo_id, f"p2-c{i}", agent_id=f"agent-{i:02d}")

    result = await _fetch_agent_fleet(db_session, _IDENTITY, offset=_FLEET_PAGE_SIZE)

    assert len(result["agents"]) == 1
    assert result["next_cursor"] is None


# ---------------------------------------------------------------------------
# P3 — total_agents count is always the full fleet size regardless of page
# ---------------------------------------------------------------------------

@pytest.mark.asyncio
async def test_p3_total_agents_reflects_full_fleet(
    db_session: AsyncSession,
) -> None:
    from musehub.api.routes.musehub.ui_user_profile import _fetch_agent_fleet, _FLEET_PAGE_SIZE

    repo = await create_repo(db_session, owner="gabriel", visibility="public")
    n = _FLEET_PAGE_SIZE + 3

    for i in range(n):
        await _add_commit(db_session, repo.repo_id, f"p3-c{i}", agent_id=f"agent-{i:02d}")

    page1 = await _fetch_agent_fleet(db_session, _IDENTITY, offset=0)
    page2 = await _fetch_agent_fleet(db_session, _IDENTITY, offset=_FLEET_PAGE_SIZE)

    assert page1["total_agents"] == n
    assert page2["total_agents"] == n


# ---------------------------------------------------------------------------
# P4 — total_pages derived correctly from total_agents and PAGE_SIZE
# ---------------------------------------------------------------------------

@pytest.mark.asyncio
async def test_p4_total_pages_rounds_up(
    db_session: AsyncSession,
) -> None:
    from musehub.api.routes.musehub.ui_user_profile import _fetch_agent_fleet, _FLEET_PAGE_SIZE

    repo = await create_repo(db_session, owner="gabriel", visibility="public")
    n = _FLEET_PAGE_SIZE + 1  # exactly 2 pages

    for i in range(n):
        await _add_commit(db_session, repo.repo_id, f"p4-c{i}", agent_id=f"agent-{i:02d}")

    result = await _fetch_agent_fleet(db_session, _IDENTITY)

    assert result["total_pages"] == math.ceil(n / _FLEET_PAGE_SIZE)


# ---------------------------------------------------------------------------
# P5 — current_page derived from offset
# ---------------------------------------------------------------------------

@pytest.mark.asyncio
async def test_p5_current_page_reflects_offset(
    db_session: AsyncSession,
) -> None:
    from musehub.api.routes.musehub.ui_user_profile import _fetch_agent_fleet, _FLEET_PAGE_SIZE

    repo = await create_repo(db_session, owner="gabriel", visibility="public")

    for i in range(_FLEET_PAGE_SIZE * 3):
        await _add_commit(db_session, repo.repo_id, f"p5-c{i}", agent_id=f"agent-{i:02d}")

    p1 = await _fetch_agent_fleet(db_session, _IDENTITY, offset=0)
    p2 = await _fetch_agent_fleet(db_session, _IDENTITY, offset=_FLEET_PAGE_SIZE)
    p3 = await _fetch_agent_fleet(db_session, _IDENTITY, offset=_FLEET_PAGE_SIZE * 2)

    assert p1["current_page"] == 1
    assert p2["current_page"] == 2
    assert p3["current_page"] == 3


# ---------------------------------------------------------------------------
# P6 — single page: no next_cursor, total_pages == 1
# ---------------------------------------------------------------------------

@pytest.mark.asyncio
async def test_p6_single_page_fleet(
    db_session: AsyncSession,
) -> None:
    from musehub.api.routes.musehub.ui_user_profile import _fetch_agent_fleet, _FLEET_PAGE_SIZE

    repo = await create_repo(db_session, owner="gabriel", visibility="public")

    for i in range(3):
        await _add_commit(db_session, repo.repo_id, f"p6-c{i}", agent_id=f"agent-{i:02d}")

    result = await _fetch_agent_fleet(db_session, _IDENTITY)

    assert len(result["agents"]) == 3
    assert result["next_cursor"] is None
    assert result["total_pages"] == 1
    assert result["current_page"] == 1