import asyncio
import json

import pytest
import httpx

from src import gitea_proxy
from src import main


@pytest.fixture(autouse=True)
def reset_available_issue_snapshot():
    main._available_issue_snapshot_task = None
    main._available_issue_snapshot_value = None
    main._available_issue_snapshot_created_at = None
    main._available_issue_snapshot_retry_at = None
    yield
    task = main._available_issue_snapshot_task
    if task is not None and not task.done():
        task.cancel()
    main._available_issue_snapshot_task = None
    main._available_issue_snapshot_value = None
    main._available_issue_snapshot_created_at = None
    main._available_issue_snapshot_retry_at = None


@pytest.mark.anyio
async def test_work_page_preserves_total_and_reason_without_loading_other_pages():
    requests = []

    def upstream(request):
        requests.append(str(request.url))
        return httpx.Response(
            200,
            headers={"X-Total-Count": "84"},
            json=[{
                "id": 51,
                "number": 51,
                "title": "Older review",
                "state": "open",
                "repository": {"full_name": "stackchain/api"},
                "html_url": "https://forge.example/stackchain/api/pulls/51",
            }],
        )

    gitea_proxy.start_client(transport=httpx.MockTransport(upstream))
    try:
        result = await gitea_proxy.work_page("review", page=2)
    finally:
        await gitea_proxy.stop_client()

    assert requests == [
        "http://127.0.0.1:3000/api/v1/repos/issues/search?state=open&review_requested=true&type=pulls&limit=50&page=2"
    ]
    assert result["page"] == 2
    assert result["total"] == 84
    assert result["has_more"] is False
    assert result["items"][0]["work_reasons"] == ["review_requested"]


@pytest.mark.anyio
async def test_available_issue_page_filters_assigned_and_pull_items_then_ranks_priority():
    requests = []

    def upstream(request):
        requests.append(str(request.url))
        return httpx.Response(
            200,
            headers={"X-Total-Count": "4"},
            json=[
                {"id": 1, "number": 1, "title": "Ordinary", "state": "open",
                 "updated_at": "2026-08-07T12:00:00Z", "assignees": None,
                 "pull_request": None,
                 "labels": [], "repository": {"full_name": "stackchain/api"}},
                {"id": 2, "number": 2, "title": "Claimed", "state": "open",
                 "assignees": [{"login": "alex"}], "repository": {"full_name": "stackchain/api"}},
                {"id": 3, "number": 3, "title": "A pull", "state": "open",
                 "assignees": [], "pull_request": {"merged": False},
                 "repository": {"full_name": "stackchain/api"}},
                {"id": 4, "number": 4, "title": "Critical", "state": "open",
                 "updated_at": "2026-08-07T10:00:00Z", "assignees": [],
                 "pull_request": None,
                 "labels": [{"name": "critical"}],
                 "repository": {"full_name": "stackchain/web"}},
            ],
        )

    gitea_proxy.start_client(transport=httpx.MockTransport(upstream))
    try:
        result = await gitea_proxy.available_issue_page(page=1)
    finally:
        await gitea_proxy.stop_client()

    assert requests == [
        "http://127.0.0.1:3000/api/v1/repos/issues/search?state=open&type=issues&limit=50&page=1"
    ]
    assert [item["title"] for item in result["items"]] == ["Critical", "Ordinary"]
    assert result == {
        "items": result["items"], "page": 1, "total": 2, "has_more": False,
    }


@pytest.mark.anyio
async def test_available_issue_page_ranks_all_upstream_pages_before_logical_pagination():
    requests = []

    def issue(number, *, assigned=True, critical=False, updated_at="2026-08-07T12:00:00Z"):
        return {
            "id": number, "number": number, "title": f"Issue {number}", "state": "open",
            "updated_at": updated_at, "assignees": [{"login": "alex"}] if assigned else None,
            "pull_request": None,
            "labels": [{"name": "critical"}] if critical else [],
            "repository": {"full_name": "stackchain/api"},
        }

    first_page = [issue(number) for number in range(1, 51)]
    first_page[0] = issue(1, assigned=False, updated_at="2026-08-07T13:00:00Z")

    def upstream(request):
        requests.append(str(request.url))
        page = int(request.url.params["page"])
        payload = first_page if page == 1 else [
            issue(51, assigned=False, critical=True, updated_at="2026-08-07T10:00:00Z"),
            issue(52, assigned=False, updated_at="2026-08-07T11:00:00Z"),
        ]
        return httpx.Response(200, headers={"X-Total-Count": "52"}, json=payload)

    gitea_proxy.start_client(transport=httpx.MockTransport(upstream))
    try:
        result = await gitea_proxy.available_issue_page(page=1, limit=2)
    finally:
        await gitea_proxy.stop_client()

    assert len(requests) == 2
    assert [item["number"] for item in result["items"]] == [51, 1]
    assert result == {
        "items": result["items"], "page": 1, "total": 3, "has_more": True,
    }


@pytest.mark.anyio
async def test_available_issue_snapshot_loads_known_remaining_pages_concurrently():
    active = 0
    peak_active = 0
    remaining_started = asyncio.Event()
    release = asyncio.Event()

    async def upstream(request):
        nonlocal active, peak_active
        page = int(request.url.params["page"])
        if page == 1:
            return httpx.Response(
                200, headers={"X-Total-Count": "200"},
                json=[{
                    "id": number, "number": number, "title": f"Issue {number}",
                    "state": "open", "assignees": [], "pull_request": None,
                    "labels": [], "repository": {"full_name": "stackchain/api"},
                } for number in range(1, 51)],
            )
        active += 1
        peak_active = max(peak_active, active)
        if peak_active == 3:
            remaining_started.set()
        await release.wait()
        active -= 1
        start = (page - 1) * 50 + 1
        return httpx.Response(200, headers={"X-Total-Count": "200"}, json=[{
            "id": number, "number": number, "title": f"Issue {number}",
            "state": "open", "assignees": [], "pull_request": None,
            "labels": [], "repository": {"full_name": "stackchain/api"},
        } for number in range(start, start + 50)])

    gitea_proxy.start_client(transport=httpx.MockTransport(upstream))
    task = asyncio.create_task(gitea_proxy.available_issue_snapshot())
    try:
        await asyncio.wait_for(remaining_started.wait(), timeout=1)
        assert peak_active == 3
        release.set()
        result = await asyncio.wait_for(task, timeout=1)
    finally:
        release.set()
        await gitea_proxy.stop_client()

    assert len(result) == 200
    assert peak_active == 3


@pytest.mark.anyio
async def test_available_issue_endpoint_is_bounded_retryable_and_no_store(monkeypatch):
    calls = []

    async def available():
        calls.append(True)
        return [{"number": number} for number in range(1, 52)]

    monkeypatch.setattr(main.gitea_proxy, "available_issue_snapshot", available)
    transport = httpx.ASGITransport(app=main.app)
    async with httpx.AsyncClient(transport=transport, base_url="http://test") as client:
        response = await client.get("/api/v1/available-issues?page=1")

    assert response.status_code == 200
    assert response.headers["cache-control"] == "no-store"
    assert response.json() == {
        "items": [{"number": number} for number in range(1, 51)],
        "page": 1, "total": 51, "has_more": True,
    }
    assert calls == [True]


@pytest.mark.anyio
async def test_available_issue_endpoint_coalesces_cold_scan_and_reuses_it_for_pages(monkeypatch):
    calls = 0
    started = asyncio.Event()
    release = asyncio.Event()

    async def available():
        nonlocal calls
        calls += 1
        started.set()
        await release.wait()
        return [{"number": number} for number in range(1, 64)]

    monkeypatch.setattr(main.gitea_proxy, "available_issue_snapshot", available)
    transport = httpx.ASGITransport(app=main.app)
    async with httpx.AsyncClient(transport=transport, base_url="http://test") as client:
        first = asyncio.create_task(client.get("/api/v1/available-issues?page=1"))
        second = asyncio.create_task(client.get("/api/v1/available-issues?page=2"))
        await asyncio.wait_for(started.wait(), timeout=1)
        release.set()
        first_response, second_response = await asyncio.gather(first, second)
        repeated_response = await client.get("/api/v1/available-issues?page=1")

    assert calls == 1
    assert len(first_response.json()["items"]) == 50
    assert len(second_response.json()["items"]) == 13
    assert second_response.json()["total"] == 63
    assert second_response.json()["has_more"] is False
    assert repeated_response.status_code == 200


@pytest.mark.anyio
async def test_available_issue_endpoint_retains_last_snapshot_on_refresh_failure(monkeypatch):
    async def unavailable():
        raise httpx.ConnectError("offline")

    main._available_issue_snapshot_value = [{"number": 7}]
    main._available_issue_snapshot_created_at = 0.0
    monkeypatch.setattr(main.gitea_proxy, "available_issue_snapshot", unavailable)
    transport = httpx.ASGITransport(app=main.app)
    async with httpx.AsyncClient(transport=transport, base_url="http://test") as client:
        response = await client.get("/api/v1/available-issues?page=1")

    assert response.status_code == 200
    assert response.json() == {
        "items": [{"number": 7}], "page": 1, "total": 1,
        "has_more": False, "stale": True, "revalidating": True,
    }


@pytest.mark.anyio
async def test_available_issue_endpoint_serves_expired_snapshot_while_one_refresh_runs(monkeypatch):
    calls = 0
    started = asyncio.Event()
    release = asyncio.Event()

    async def refresh():
        nonlocal calls
        calls += 1
        started.set()
        await release.wait()
        return [{"number": 8}]

    main._available_issue_snapshot_value = [{"number": 7}]
    main._available_issue_snapshot_created_at = 0.0
    monkeypatch.setattr(main.gitea_proxy, "available_issue_snapshot", refresh)
    transport = httpx.ASGITransport(app=main.app)
    async with httpx.AsyncClient(transport=transport, base_url="http://test") as client:
        first, second = await asyncio.gather(
            client.get("/api/v1/available-issues?page=1"),
            client.get("/api/v1/available-issues?page=1"),
        )
        await asyncio.wait_for(started.wait(), timeout=1)

    assert calls == 1
    assert first.json() == second.json() == {
        "items": [{"number": 7}], "page": 1, "total": 1,
        "has_more": False, "stale": True, "revalidating": True,
    }
    release.set()
    await asyncio.wait_for(main._available_issue_snapshot_task, timeout=1)
    assert main._available_issue_snapshot_value == [{"number": 8}]


@pytest.mark.anyio
async def test_available_issue_endpoint_backs_off_after_background_refresh_failure(monkeypatch):
    calls = 0

    async def unavailable():
        nonlocal calls
        calls += 1
        raise httpx.ConnectError("offline")

    main._available_issue_snapshot_value = [{"number": 7}]
    main._available_issue_snapshot_created_at = 0.0
    monkeypatch.setattr(main.gitea_proxy, "available_issue_snapshot", unavailable)
    transport = httpx.ASGITransport(app=main.app)
    async with httpx.AsyncClient(transport=transport, base_url="http://test") as client:
        first = await client.get("/api/v1/available-issues?page=1")
        await asyncio.gather(main._available_issue_snapshot_task, return_exceptions=True)
        second = await client.get("/api/v1/available-issues?page=1")

    assert calls == 1
    assert first.json()["revalidating"] is True
    assert second.json() == {
        "items": [{"number": 7}], "page": 1, "total": 1,
        "has_more": False, "stale": True, "refresh_failed": True,
    }


@pytest.mark.anyio
async def test_confirmed_claim_is_removed_from_retained_available_snapshot(monkeypatch):
    main._available_issue_snapshot_value = [
        {"number": 7, "repository": "stackchain/api"},
        {"number": 8, "repository": "stackchain/web"},
    ]
    main._available_issue_snapshot_created_at = 10**12

    async def claim(repository, number):
        return {"repository": repository, "number": number, "assignees": ["timmy"]}

    monkeypatch.setattr(main.gitea_proxy, "claim_available_issue", claim)
    transport = httpx.ASGITransport(app=main.app)
    async with httpx.AsyncClient(transport=transport, base_url="http://test") as client:
        claimed = await client.patch("/api/v1/repos/stackchain/api/issues/7/claim")
        available = await client.get("/api/v1/available-issues?page=1")

    assert claimed.status_code == 200
    assert available.json() == {
        "items": [{"number": 8, "repository": "stackchain/web"}],
        "page": 1, "total": 1, "has_more": False,
    }


@pytest.mark.anyio
async def test_initial_work_collections_expose_independent_pagination(monkeypatch):
    async def fake_page(stream, page=1, limit=50):
        assert page == 1
        totals = {"issue": 84, "pull": 61, "review": 73}
        return {
            "items": [], "page": 1, "total": totals[stream],
            "has_more": True, "stream": stream,
        }

    monkeypatch.setattr(gitea_proxy, "work_page", fake_page)

    assigned_issues = await gitea_proxy.issues()
    pulls = await gitea_proxy.pull_requests()

    assert assigned_issues.pagination == {
        "issue": {"page": 1, "total": 84, "has_more": True}
    }
    assert pulls.pagination == {
        "pull": {"page": 1, "total": 61, "has_more": True},
        "review": {"page": 1, "total": 73, "has_more": True},
    }


@pytest.mark.anyio
async def test_work_collections_include_supported_review_request_search(monkeypatch):
    requested_streams = []

    async def fake_page(stream, page=1, limit=50):
        requested_streams.append((stream, page, limit))
        return {"stream": stream, "items": [], "page": page, "total": 0, "has_more": False}

    monkeypatch.setattr(gitea_proxy, "work_page", fake_page)

    assert await gitea_proxy.issues() == []
    assert await gitea_proxy.pull_requests() == []
    assert requested_streams == [
        ("issue", 1, 50),
        ("pull", 1, 50),
        ("review", 1, 50),
    ]


@pytest.mark.anyio
async def test_pull_requests_merge_assignment_and_review_responsibilities(monkeypatch):
    assigned = {
        "id": 11,
        "number": 7,
        "title": "Review API",
        "repository": {"full_name": "stackchain/api"},
    }
    review_only = {
        "id": 12,
        "number": 8,
        "title": "Review mobile",
        "repository": {"full_name": "stackchain/mobile"},
    }

    async def fake_page(stream, page=1, limit=50):
        items = [assigned] if stream == "pull" else [assigned.copy(), review_only]
        reason = "assigned_to_me" if stream == "pull" else "review_requested"
        return {
            "stream": stream,
            "items": [{**item, "work_reasons": [reason]} for item in items],
            "page": page, "total": len(items), "has_more": False,
        }

    monkeypatch.setattr(gitea_proxy, "work_page", fake_page)

    pulls = await gitea_proxy.pull_requests()

    assert [pull["id"] for pull in pulls] == [11, 12]
    assert pulls[0]["work_reasons"] == ["assigned_to_me", "review_requested"]
    assert pulls[1]["work_reasons"] == ["review_requested"]


@pytest.mark.anyio
async def test_pull_request_searches_start_concurrently(monkeypatch):
    started = [asyncio.Event(), asyncio.Event()]
    release = asyncio.Event()

    async def fake_page(stream, page=1, limit=50):
        index = 0 if stream == "pull" else 1
        started[index].set()
        await release.wait()
        return {"stream": stream, "items": [], "page": page, "total": 0, "has_more": False}

    monkeypatch.setattr(gitea_proxy, "work_page", fake_page)
    task = asyncio.create_task(gitea_proxy.pull_requests())
    try:
        await asyncio.wait_for(
            asyncio.gather(*(event.wait() for event in started)), timeout=1
        )
    finally:
        release.set()

    assert await task == []


@pytest.mark.anyio
async def test_requested_review_guard_uses_direct_pull_and_current_user(monkeypatch):
    requested = []

    async def fake_fetch(path):
        requested.append(path)
        if path == "user":
            return {"login": "timmy"}
        assert path == "repos/stackchain/api/pulls/77"
        return {
            "state": "open",
            "requested_reviewers": [{"login": "timmy"}],
        }

    async def reject_search(*args, **kwargs):
        raise AssertionError("authorization must not scan review search pages")

    monkeypatch.setattr(gitea_proxy, "fetch", fake_fetch)
    monkeypatch.setattr(gitea_proxy, "work_page", reject_search)

    assert await gitea_proxy.is_requested_review("stackchain/api", 77) is True
    assert sorted(requested) == ["repos/stackchain/api/pulls/77", "user"]


@pytest.mark.anyio
async def test_assigned_issue_guard_uses_direct_target_and_current_user(monkeypatch):
    requested = []

    async def fake_fetch(path):
        requested.append(path)
        if path == "user":
            return {"login": "timmy"}
        assert path == "repos/stackchain/api/issues/77"
        return {
            "state": "open",
            "assignees": [{"login": "timmy"}],
        }

    async def reject_search(*args, **kwargs):
        raise AssertionError("authorization must not scan work search pages")

    monkeypatch.setattr(gitea_proxy, "fetch", fake_fetch)
    monkeypatch.setattr(gitea_proxy, "work_page", reject_search)

    assert await gitea_proxy.is_assigned_issue("stackchain/api", 77) is True
    assert sorted(requested) == ["repos/stackchain/api/issues/77", "user"]


@pytest.mark.anyio
async def test_assigned_pull_guard_uses_direct_target_and_current_user(monkeypatch):
    requested = []

    async def fake_fetch(path):
        requested.append(path)
        if path == "user":
            return {"login": "timmy"}
        assert path == "repos/stackchain/api/pulls/77"
        return {
            "state": "open",
            "assignees": [{"login": "timmy"}],
        }

    async def reject_search(*args, **kwargs):
        raise AssertionError("authorization must not scan work search pages")

    monkeypatch.setattr(gitea_proxy, "fetch", fake_fetch)
    monkeypatch.setattr(gitea_proxy, "work_page", reject_search)

    assert await gitea_proxy.is_assigned_pull("stackchain/api", 77) is True
    assert sorted(requested) == ["repos/stackchain/api/pulls/77", "user"]


@pytest.mark.anyio
async def test_context_preserves_repository_and_update_time_for_cross_repo_work(monkeypatch):
    async def user():
        return {"id": 1, "login": "timmy"}

    async def repositories():
        return []

    async def issues():
        return [{
            "id": 10,
            "number": 7,
            "title": "Ship mobile flow",
            "state": "open",
            "labels": [{"name": "P0"}],
            "assignees": [{"login": "timmy"}],
            "repository": {"full_name": "stackchain/mobile"},
            "updated_at": "2026-08-06T12:00:00Z",
            "due_date": "2026-08-09T23:59:59Z",
            "html_url": "https://forge.example/stackchain/mobile/issues/7",
        }]

    async def pulls():
        return [{
            "id": 11,
            "number": 7,
            "title": "Review API",
            "state": "open",
            "user": {"login": "alex"},
            "labels": [{"name": "priority-high"}],
            "assignees": [{"login": "timmy"}],
            "work_reasons": ["assigned_to_me", "review_requested"],
            "repository": {"full_name": "stackchain/api"},
            "updated_at": "2026-08-06T11:00:00Z",
            "html_url": "https://forge.example/stackchain/api/pulls/7",
        }]

    monkeypatch.setattr(main, "current_user", user)
    monkeypatch.setattr(main, "repos", repositories)
    monkeypatch.setattr(main, "issues", issues)
    monkeypatch.setattr(main, "pull_requests", pulls)

    payload = json.loads((await main.context()).body)

    assert payload["issues"][0]["repository"] == "stackchain/mobile"
    assert payload["issues"][0]["updated_at"] == "2026-08-06T12:00:00Z"
    assert payload["issues"][0]["due_date"] == "2026-08-09T23:59:59Z"
    assert payload["pull_requests"][0]["repository"] == "stackchain/api"
    assert payload["pull_requests"][0]["updated_at"] == "2026-08-06T11:00:00Z"
    assert payload["pull_requests"][0]["labels"] == ["priority-high"]
    assert payload["pull_requests"][0]["assignees"] == ["timmy"]
    assert payload["pull_requests"][0]["work_reasons"] == [
        "assigned_to_me",
        "review_requested",
    ]


@pytest.mark.anyio
async def test_pull_review_detail_combines_pr_files_status_and_reviews(monkeypatch):
    requested_paths = []

    async def fake_fetch(path):
        requested_paths.append(path)
        if path.endswith("/pulls/7"):
            return {
                "title": "Review API",
                "body": "Please check the retry flow.",
                "html_url": "https://forge.example/stackchain/api/pulls/7",
                "user": {"login": "alex"},
                "head": {"sha": "abc123"},
            }
        if path.endswith("/files"):
            return [
                {"filename": "src/api.py", "status": "modified", "additions": 8, "deletions": 2},
                None,
            ]
        if "/commits/abc123/status" in path:
            return {"state": "success"}
        return [
            {"user": {"login": "sam"}, "state": "APPROVED", "body": "Looks good"},
            "malformed",
        ]

    monkeypatch.setattr(gitea_proxy, "fetch", fake_fetch)

    async def fake_fetch_text(path, max_bytes):
        assert path == "repos/stackchain/api/pulls/7.diff"
        assert max_bytes == gitea_proxy.REVIEW_DIFF_MAX_BYTES
        return "", False

    monkeypatch.setattr(gitea_proxy, "fetch_text", fake_fetch_text)

    detail = await gitea_proxy.pull_review_detail("stackchain/api", 7)

    assert requested_paths == [
        "repos/stackchain/api/pulls/7",
        "repos/stackchain/api/pulls/7/files",
        "repos/stackchain/api/commits/abc123/status",
        "repos/stackchain/api/pulls/7/reviews",
    ]
    assert detail["author"] == "alex"
    assert detail["head_sha"] == "abc123"
    assert detail["ci_state"] == "success"
    assert detail["files"][0]["filename"] == "src/api.py"
    assert detail["reviews"][0]["state"] == "APPROVED"
    assert len(detail["files"]) == 1
    assert len(detail["reviews"]) == 1


@pytest.mark.anyio
async def test_pull_review_detail_fetches_independent_head_resources_concurrently(monkeypatch):
    started = {name: asyncio.Event() for name in ("files", "status", "reviews", "diff")}
    release = asyncio.Event()

    async def wait_for_release(name, result):
        started[name].set()
        await release.wait()
        return result

    async def fake_fetch(path):
        if path.endswith("/pulls/7"):
            return {"head": {"sha": "abc123"}, "user": {"login": "alex"}}
        if path.endswith("/files"):
            return await wait_for_release("files", [])
        if path.endswith("/reviews"):
            return await wait_for_release("reviews", [])
        return await wait_for_release("status", {"state": "success"})

    async def fake_fetch_text(path, max_bytes):
        return await wait_for_release("diff", ("", False))

    monkeypatch.setattr(gitea_proxy, "fetch", fake_fetch)
    monkeypatch.setattr(gitea_proxy, "fetch_text", fake_fetch_text)

    detail_task = asyncio.create_task(
        gitea_proxy.pull_review_detail("stackchain/api", 7)
    )
    try:
        await asyncio.wait_for(
            asyncio.gather(*(event.wait() for event in started.values())), timeout=1
        )
    finally:
        release.set()

    detail = await detail_task
    assert detail["head_sha"] == "abc123"


@pytest.mark.anyio
async def test_pull_review_detail_attaches_bounded_per_file_diff_previews(monkeypatch):
    async def fake_fetch(path):
        if path.endswith("/pulls/7"):
            return {
                "title": "Review API",
                "head": {"sha": "abc123"},
                "user": {"login": "alex"},
            }
        if path.endswith("/files"):
            return [
                {"filename": "src/api.py", "status": "modified"},
                {"filename": "assets/logo.png", "status": "modified"},
            ]
        if path.endswith("/reviews"):
            return []
        return {"state": "success"}

    diff = """diff --git a/src/api.py b/src/api.py
index 123..456 100644
--- a/src/api.py
+++ b/src/api.py
@@ -1,2 +1,3 @@
 context
-old <value>
+new <value>
diff --git a/assets/logo.png b/assets/logo.png
Binary files a/assets/logo.png and b/assets/logo.png differ
"""

    async def fake_fetch_text(path, max_bytes):
        assert path == "repos/stackchain/api/pulls/7.diff"
        return diff, True

    monkeypatch.setattr(gitea_proxy, "fetch", fake_fetch)
    monkeypatch.setattr(gitea_proxy, "fetch_text", fake_fetch_text)

    detail = await gitea_proxy.pull_review_detail("stackchain/api", 7)

    source, binary = detail["files"]
    assert source["diff_lines"] == [
        "@@ -1,2 +1,3 @@",
        " context",
        "-old <value>",
        "+new <value>",
    ]
    assert source["diff_truncated"] is True
    assert source["diff_available"] is True
    assert binary["diff_available"] is False
    assert binary["diff_binary"] is True