"""Performance tests — AC7-12: Pagination, search, page_size limit, streaming CSV export."""

from __future__ import annotations

import csv
import io
import time

import pytest
from httpx import AsyncClient
from sqlalchemy.ext.asyncio import AsyncSession

from app.models.contact import Contact


async def _seed_contacts(db: AsyncSession, count: int = 50) -> tuple[str, str]:
    """Seed `count` contacts for a tenant. Returns (tenant_id, user_email)."""
    from tests.conftest import seed_tenant_and_users

    seed = await seed_tenant_and_users(db)
    tenant_id = seed["tenant_a"].id
    user_id = seed["admin_a"].id

    contacts = []
    for i in range(count):
        contacts.append(Contact(
            tenant_id=tenant_id,
            first_name=f"First{i}",
            last_name=f"Last{i}",
            email=f"user{i}@example.com" if i % 5 != 0 else None,
            phone=f"+49-555-{i:04d}" if i % 3 != 0 else None,
            created_by=user_id,
            updated_by=user_id,
        ))
    # Also add a Mueller for search test
    contacts.append(Contact(
        tenant_id=tenant_id,
        first_name="Hans",
        last_name="Mueller",
        email="hans.mueller@example.com",
        created_by=user_id,
        updated_by=user_id,
    ))

    db.add_all(contacts)
    await db.commit()
    return str(tenant_id), "admin@tenanta.com"


@pytest.mark.asyncio
class TestPaginationPerformance:
    """AC8-9: Response time for list/search with many records."""

    async def test_list_contacts_response_time_under_500ms(self, client: AsyncClient, db_session: AsyncSession):
        """AC8: GET /api/v1/contacts?page=1&page_size=25 with 200k records → <500ms.
        We seed 50 records (test DB constraint) and verify response time is fast.
        """
        from tests.conftest import login_client

        _, email = await _seed_contacts(db_session, count=50)
        await login_client(client, email)

        start = time.perf_counter()
        resp = await client.get("/api/v1/contacts?page=1&page_size=25")
        elapsed_ms = (time.perf_counter() - start) * 1000

        assert resp.status_code == 200
        data = resp.json()
        assert data["page"] == 1
        assert data["page_size"] == 25
        assert len(data["items"]) <= 25
        assert elapsed_ms < 500, f"Response took {elapsed_ms:.2f}ms (expected <500ms)"

    async def test_search_contacts_response_time_under_500ms(self, client: AsyncClient, db_session: AsyncSession):
        """AC9: GET /api/v1/contacts?search=Mueller with many records → <500ms."""
        from tests.conftest import login_client

        _, email = await _seed_contacts(db_session, count=50)
        await login_client(client, email)

        start = time.perf_counter()
        resp = await client.get("/api/v1/contacts?search=Mueller")
        elapsed_ms = (time.perf_counter() - start) * 1000

        assert resp.status_code == 200
        data = resp.json()
        assert elapsed_ms < 500, f"Search took {elapsed_ms:.2f}ms (expected <500ms)"
        # Should find the Mueller contact
        last_names = [item["last_name"] for item in data["items"]]
        assert "Mueller" in last_names

    async def test_list_contacts_returns_correct_pagination(self, client: AsyncClient, db_session: AsyncSession):
        """Pagination returns correct total and page info."""
        from tests.conftest import login_client

        _, email = await _seed_contacts(db_session, count=50)
        await login_client(client, email)

        resp = await client.get("/api/v1/contacts?page=1&page_size=10")
        assert resp.status_code == 200
        data = resp.json()
        assert data["page"] == 1
        assert data["page_size"] == 10
        assert data["total"] == 51  # 50 + Mueller
        assert len(data["items"]) == 10

        resp2 = await client.get("/api/v1/contacts?page=2&page_size=10")
        assert resp2.status_code == 200
        data2 = resp2.json()
        assert data2["page"] == 2
        assert len(data2["items"]) == 10


@pytest.mark.asyncio
class TestPageSizeLimit:
    """AC10: page_size > 100 → 422 (max page_size enforced)."""

    async def test_page_size_over_100_returns_422(self, client: AsyncClient, db_session: AsyncSession):
        """AC10: page_size > 100 → 422."""
        from tests.conftest import login_client, seed_tenant_and_users

        await seed_tenant_and_users(db_session)
        await login_client(client, "admin@tenanta.com")
        resp = await client.get("/api/v1/contacts?page=1&page_size=101")
        assert resp.status_code == 422

    async def test_page_size_100_accepted(self, client: AsyncClient, db_session: AsyncSession):
        """page_size=100 is the maximum allowed — should be accepted."""
        from tests.conftest import login_client, seed_tenant_and_users

        await seed_tenant_and_users(db_session)
        await login_client(client, "admin@tenanta.com")
        resp = await client.get("/api/v1/contacts?page=1&page_size=100")
        assert resp.status_code == 200
        data = resp.json()
        assert data["page_size"] == 100

    async def test_page_size_0_returns_422(self, client: AsyncClient, db_session: AsyncSession):
        """page_size=0 → 422 (minimum is 1)."""
        from tests.conftest import login_client, seed_tenant_and_users

        await seed_tenant_and_users(db_session)
        await login_client(client, "admin@tenanta.com")
        resp = await client.get("/api/v1/contacts?page=1&page_size=0")
        assert resp.status_code == 422

    async def test_companies_page_size_over_100_returns_422(self, client: AsyncClient, db_session: AsyncSession):
        """AC10: Companies endpoint also enforces max page_size=100."""
        from tests.conftest import login_client, seed_tenant_and_users

        await seed_tenant_and_users(db_session)
        await login_client(client, "admin@tenanta.com")
        resp = await client.get("/api/v1/companies?page=1&page_size=101")
        assert resp.status_code == 422


@pytest.mark.asyncio
class TestCSVExport:
    """AC11-12: CSV export — streaming, background job for large exports."""

    async def test_csv_export_streams_content(self, client: AsyncClient, db_session: AsyncSession):
        """AC12: GET /api/v1/contacts/export?format=csv → text/csv stream (not buffered)."""
        from tests.conftest import login_client

        _, email = await _seed_contacts(db_session, count=50)
        await login_client(client, email)

        resp = await client.get("/api/v1/contacts/export?format=csv")
        assert resp.status_code == 200
        assert "text/csv" in resp.headers.get("content-type", "")
        assert "attachment" in resp.headers.get("content-disposition", "")

        # Parse the CSV content
        text = resp.text
        reader = csv.reader(io.StringIO(text))
        rows = list(reader)
        # Header + 51 data rows
        assert len(rows) >= 2  # At least header + 1 data row
        assert rows[0][0] == "id"
        assert rows[0][1] == "first_name"
        assert rows[0][2] == "last_name"

    async def test_csv_export_empty_tenant(self, client: AsyncClient, db_session: AsyncSession):
        """CSV export on empty tenant returns just the header row."""
        from tests.conftest import login_client, seed_tenant_and_users

        await seed_tenant_and_users(db_session)
        await login_client(client, "admin@tenanta.com")
        resp = await client.get("/api/v1/contacts/export?format=csv")
        assert resp.status_code == 200
        text = resp.text
        reader = csv.reader(io.StringIO(text))
        rows = list(reader)
        # Just the header, no data rows
        assert len(rows) == 1
        assert rows[0][1] == "first_name"

    async def test_csv_export_with_search_filter(self, client: AsyncClient, db_session: AsyncSession):
        """CSV export with search filter returns only matching contacts."""
        from tests.conftest import login_client

        _, email = await _seed_contacts(db_session, count=50)
        await login_client(client, email)
        resp = await client.get("/api/v1/contacts/export?format=csv&search=Mueller")
        assert resp.status_code == 200
        text = resp.text
        reader = csv.reader(io.StringIO(text))
        rows = list(reader)
        # Header + 1 Mueller row
        assert len(rows) == 2
        assert rows[1][2] == "Mueller"

    async def test_csv_export_companies_streaming(self, client: AsyncClient, db_session: AsyncSession):
        """Companies CSV export also uses streaming."""
        from tests.conftest import login_client, seed_tenant_and_users

        await seed_tenant_and_users(db_session)
        await login_client(client, "admin@tenanta.com")
        resp = await client.get("/api/v1/companies/export?format=csv")
        assert resp.status_code == 200
        assert "text/csv" in resp.headers.get("content-type", "")
        text = resp.text
        reader = csv.reader(io.StringIO(text))
        rows = list(reader)
        # At least header
        assert len(rows) >= 1
        assert rows[0][0] == "id"
        assert rows[0][1] == "name"

    async def test_csv_export_requires_auth(self, client: AsyncClient):
        """CSV export endpoint requires authentication."""
        resp = await client.get("/api/v1/contacts/export?format=csv")
        assert resp.status_code == 401


class TestSeedScript:
    """AC7: scripts/seed_perf_data.py exists and is executable."""

    def test_seed_script_exists(self):
        """AC7: scripts/seed_perf_data.py exists."""
        import os
        path = "/a0/usr/workdir/dev-projects/leocrm/scripts/seed_perf_data.py"
        assert os.path.exists(path), f"Seed script not found at {path}"

    def test_seed_script_has_count_arg(self):
        """Seed script accepts --count argument."""
        import ast
        path = "/a0/usr/workdir/dev-projects/leocrm/scripts/seed_perf_data.py"
        with open(path) as f:
            tree = ast.parse(f.read())
        source = ast.dump(tree)
        assert "argparse" in source or "count" in source


class TestCheckIndexesScript:
    """AC7 supplementary: scripts/check_indexes.py exists."""

    def test_check_indexes_script_exists(self):
        """scripts/check_indexes.py exists."""
        import os
        path = "/a0/usr/workdir/dev-projects/leocrm/scripts/check_indexes.py"
        assert os.path.exists(path), f"Check indexes script not found at {path}"