"""Fail-closed server gates for autonomous exact-head PR merging."""

from __future__ import annotations

import copy

import pytest

from packages.connector_kit import GiteaError
from tests.test_gitea_connector import connector, context


@pytest.mark.parametrize(
    ("mutate", "code"),
    [
        (lambda fixture: fixture._action_run.update(event="workflow_dispatch"),
         "GITEA_PR_VALIDATION_REQUIRED"),
        (lambda fixture: fixture._action_run.update(head_sha="d" * 40),
         "GITEA_PR_VALIDATION_REQUIRED"),
        (lambda fixture: fixture._statuses[0].update(status="failure"),
         "GITEA_PR_CHECK_FAILED"),
        (lambda fixture: fixture._statuses[0].update(status="pending"),
         "GITEA_PR_CHECK_PENDING"),
        (lambda fixture: fixture._reverse_compare_commits.append({"sha": "b" * 40}),
         "GITEA_BRANCH_OUTDATED"),
        (lambda fixture: fixture._branches[0]["commit"].update(id="b" * 40),
         "GITEA_BASE_CHANGED"),
        (lambda fixture: fixture._reviews.append({
            "id": 12, "state": "REQUEST_CHANGES", "user": {"login": "reviewer"}}),
         "GITEA_BLOCKING_REVIEW"),
        (lambda fixture: fixture._branch_protections["acme/hub"][0].update(
            required_approvals=1), "GITEA_APPROVAL_REQUIRED"),
        (lambda fixture: fixture._branch_protections["acme/hub"][0].update(
            status_check_contexts=[
                "Managed validation / full (pull_request)", "Extra required check"
            ]), "GITEA_REQUIRED_CHECK_BLOCKED"),
        (lambda fixture: fixture._branch_protections["acme/hub"][0].update(
            enable_push=True), "GITEA_PROTECTION_DRIFT"),
        (lambda fixture: fixture._branch_protections["acme/hub"][0].update(
            enable_force_push=True), "GITEA_PROTECTION_DRIFT"),
    ],
)
def test_merge_rejects_specific_blocker(mutate, code: str) -> None:
    connector_instance, fixture = connector()
    mutate(fixture)
    try:
        with pytest.raises(GiteaError) as captured:
            connector_instance.pull_request_merge(
                context(), "hub-repository", 7, "e" * 40, "squash"
            )
        assert captured.value.code == code
        assert fixture._pulls[0].get("merged") is not True
    finally:
        connector_instance.client.close()


def test_zero_required_approvals_and_green_exact_pr_run_merge() -> None:
    connector_instance, fixture = connector()
    try:
        merged = connector_instance.pull_request_merge(
            context(), "hub-repository", 7, "e" * 40, "squash"
        )["data"]
        assert merged["validationRunId"] == 42
        assert merged["merged"] is True
        assert merged["resultingMainSha"] == "6" * 40
        assert merged["auditEvidence"]["validationEvent"] == "pull_request"
        assert merged["auditEvidence"]["resultingMainSha"] == "6" * 40
        assert fixture._pulls[0]["merged"] is True
    finally:
        connector_instance.client.close()


def test_additional_required_context_is_checked_on_exact_head() -> None:
    connector_instance, fixture = connector()
    fixture._branch_protections["acme/hub"][0]["status_check_contexts"].append(
        "Extra required check"
    )
    fixture._statuses.append({
        "context": "Extra required check", "status": "success", "target_url": "",
    })
    try:
        merged = connector_instance.pull_request_merge(
            context(), "hub-repository", 7, "e" * 40, "squash"
        )["data"]
        assert merged["merged"] is True
    finally:
        connector_instance.client.close()


def test_change_status_uses_the_same_pr_gate_as_merge() -> None:
    connector_instance, fixture = connector()
    fixture._branches.append(
        {"name": "codex/workflows", "commit": {"id": "e" * 40}, "protected": False}
    )
    fixture._action_run["event"] = "workflow_dispatch"
    try:
        status = connector_instance.change_status(
            context(), "hub-repository", "codex/workflows"
        )["data"]
        assert status["readyToMerge"] is False
        assert status["validationState"] == "pr_check_missing"
        assert status["mergeEligibility"]["reason"] == "GITEA_PR_VALIDATION_REQUIRED"
        assert "ensure-pr-validation" in status["nextActions"]
    finally:
        connector_instance.client.close()


def test_validation_ensure_reuses_successful_exact_pr_check() -> None:
    connector_instance, _ = connector()
    try:
        result = connector_instance.pull_request_validation_ensure(
            context(), "hub-repository", 7, "e" * 40
        )["data"]
        assert result["state"] == "success"
        assert result["runId"] == 42
        assert result["event"] == "pull_request"
        assert result["reused"] is True
    finally:
        connector_instance.client.close()


def test_validation_ensure_reopens_pr_to_create_real_pr_event() -> None:
    connector_instance, fixture = connector()
    fixture._action_run["event"] = "workflow_dispatch"
    try:
        result = connector_instance.pull_request_validation_ensure(
            context(), "hub-repository", 7, "e" * 40
        )["data"]
        assert result["state"] == "pending"
        assert result["triggerMethod"] == "reopen_pull_request"
        assert result["event"] == "pull_request"
        assert fixture._pulls[0]["state"] == "open"
        assert fixture._action_run["event"] == "pull_request"
    finally:
        connector_instance.client.close()


def test_validation_ensure_reruns_failed_pr_run() -> None:
    connector_instance, fixture = connector()
    fixture._action_run.update(status="completed", conclusion="failure")
    try:
        result = connector_instance.pull_request_validation_ensure(
            context(), "hub-repository", 7, "e" * 40
        )["data"]
        assert result["state"] == "pending"
        assert result["triggerMethod"] == "rerun_pull_request"
        assert fixture._action_run["status"] == "queued"
    finally:
        connector_instance.client.close()


@pytest.mark.parametrize("moving_ref", ["head", "base"])
def test_merge_rechecks_head_and_base_before_write(moving_ref: str) -> None:
    connector_instance, fixture = connector()
    original_pull = connector_instance.client.pull_request
    calls = 0

    def moving_pull(repository, number):
        nonlocal calls
        calls += 1
        result = copy.deepcopy(original_pull(repository, number))
        if calls == 2:
            result[moving_ref]["sha"] = "f" * 40
        return result

    connector_instance.client.pull_request = moving_pull
    try:
        with pytest.raises(GiteaError) as captured:
            connector_instance.pull_request_merge(
                context(), "hub-repository", 7, "e" * 40, "squash"
            )
        assert captured.value.code == "GITEA_CONCURRENT_MODIFICATION"
        assert fixture._pulls[0].get("merged") is not True
    finally:
        connector_instance.client.close()