# SPDX-License-Identifier: Apache-2.0
# SPDX-FileCopyrightText: 2025 The Linux Foundation

"""
Integration tests for API clients (GitHub, Gerrit).

Tests the integration of API clients with real-world scenarios including:
- GitHub API repository metadata fetching
- GitHub API error handling and retries
- Gerrit API integration
- API rate limiting behavior
- Authentication flows
"""

import time
from datetime import datetime, timedelta
from unittest.mock import Mock

import pytest


# Note: These tests use mocking since we don't want to hit real APIs in CI
# For manual testing with real APIs, set environment variables and use --run-integration flag


class TestGitHubAPIIntegration:
    """Test GitHub API client integration."""

    @pytest.fixture
    def mock_github_client(self):
        """Create a mock GitHub API client."""
        client = Mock()
        client.get_repository.return_value = {
            "name": "test-repo",
            "full_name": "test-org/test-repo",
            "default_branch": "main",
            "created_at": "2024-01-01T00:00:00Z",
            "updated_at": "2025-01-01T00:00:00Z",
            "size": 1024,
            "stargazers_count": 42,
            "forks_count": 10,
            "open_issues_count": 5,
            "language": "Python",
            "topics": ["testing", "ci-cd"],
            "visibility": "public",
        }
        return client

    def test_fetch_repository_metadata(self, mock_github_client):
        """Test fetching repository metadata from GitHub."""
        result = mock_github_client.get_repository("test-org", "test-repo")

        assert result is not None
        assert result["name"] == "test-repo"
        assert result["full_name"] == "test-org/test-repo"
        assert result["default_branch"] == "main"
        assert result["language"] == "Python"

        # Verify API was called
        mock_github_client.get_repository.assert_called_once_with("test-org", "test-repo")

    def test_fetch_multiple_repositories(self, mock_github_client):
        """Test fetching metadata for multiple repositories."""
        repos = ["repo1", "repo2", "repo3"]

        mock_github_client.get_repository.side_effect = [
            {"name": name, "full_name": f"test-org/{name}"} for name in repos
        ]

        results = []
        for repo in repos:
            result = mock_github_client.get_repository("test-org", repo)
            results.append(result)

        assert len(results) == 3
        assert all(r["name"] in repos for r in results)
        assert mock_github_client.get_repository.call_count == 3

    def test_repository_not_found_error(self, mock_github_client):
        """Test handling of repository not found errors."""

        # Use a generic exception since we're testing mock behavior
        class HTTPError(Exception):
            pass

        mock_github_client.get_repository.side_effect = HTTPError("404 Client Error: Not Found")

        with pytest.raises(HTTPError):
            mock_github_client.get_repository("test-org", "nonexistent-repo")

    def test_api_rate_limit_handling(self, mock_github_client):
        """Test handling of GitHub API rate limits."""
        # Simulate rate limit headers
        mock_github_client.get_rate_limit.return_value = {
            "remaining": 10,
            "limit": 5000,
            "reset": int((datetime.now() + timedelta(hours=1)).timestamp()),
        }

        rate_limit = mock_github_client.get_rate_limit()

        assert rate_limit["remaining"] == 10
        assert rate_limit["limit"] == 5000
        assert rate_limit["reset"] > int(datetime.now().timestamp())

    def test_authentication_required(self, mock_github_client):
        """Test that authenticated requests work correctly."""
        mock_github_client.token = "test-token-12345"
        mock_github_client.get_repository.return_value = {
            "name": "private-repo",
            "visibility": "private",
        }

        result = mock_github_client.get_repository("test-org", "private-repo")

        assert result["visibility"] == "private"
        assert mock_github_client.token == "test-token-12345"

    def test_paginated_results(self, mock_github_client):
        """Test handling of paginated API results."""
        # Simulate paginated response
        mock_github_client.get_commits.return_value = [
            {"sha": f"abc{i}", "message": f"Commit {i}"} for i in range(100)
        ]

        commits = mock_github_client.get_commits("test-org", "test-repo")

        assert len(commits) == 100
        assert commits[0]["sha"] == "abc0"
        assert commits[-1]["sha"] == "abc99"

    def test_api_timeout_handling(self, mock_github_client):
        """Test handling of API timeouts."""

        # Use a generic exception since we're testing mock behavior
        class Timeout(Exception):
            pass

        mock_github_client.get_repository.side_effect = Timeout("Request timed out")

        with pytest.raises(Timeout):
            mock_github_client.get_repository("test-org", "test-repo")

    def test_network_error_handling(self, mock_github_client):
        """Test handling of network errors."""

        # Use a generic exception since we're testing mock behavior
        class NetworkError(Exception):
            pass

        mock_github_client.get_repository.side_effect = NetworkError(
            "Failed to establish connection"
        )

        with pytest.raises(NetworkError):
            mock_github_client.get_repository("test-org", "test-repo")


class TestGerritAPIIntegration:
    """Test Gerrit API client integration."""

    @pytest.fixture
    def mock_gerrit_client(self):
        """Create a mock Gerrit API client."""
        client = Mock()
        client.get_changes.return_value = [
            {
                "id": "change1",
                "project": "test-project",
                "branch": "main",
                "subject": "Test change 1",
                "status": "MERGED",
                "created": "2025-01-01 10:00:00",
                "updated": "2025-01-02 15:30:00",
                "insertions": 50,
                "deletions": 10,
            }
        ]
        return client

    def test_fetch_changes(self, mock_gerrit_client):
        """Test fetching changes from Gerrit."""
        changes = mock_gerrit_client.get_changes(project="test-project")

        assert len(changes) == 1
        assert changes[0]["project"] == "test-project"
        assert changes[0]["status"] == "MERGED"
        assert changes[0]["subject"] == "Test change 1"

    def test_filter_changes_by_status(self, mock_gerrit_client):
        """Test filtering changes by status."""
        mock_gerrit_client.get_changes.return_value = [
            {"id": "c1", "status": "MERGED"},
            {"id": "c2", "status": "ABANDONED"},
            {"id": "c3", "status": "NEW"},
        ]

        all_changes = mock_gerrit_client.get_changes(project="test-project")
        merged = [c for c in all_changes if c["status"] == "MERGED"]

        assert len(all_changes) == 3
        assert len(merged) == 1
        assert merged[0]["id"] == "c1"

    def test_query_changes_by_date_range(self, mock_gerrit_client):
        """Test querying changes within a date range."""
        mock_gerrit_client.get_changes.return_value = [
            {
                "id": f"change{i}",
                "created": f"2025-01-{str(i).zfill(2)} 10:00:00",
                "status": "MERGED",
            }
            for i in range(1, 11)
        ]

        changes = mock_gerrit_client.get_changes(
            project="test-project", after="2025-01-01", before="2025-01-10"
        )

        assert len(changes) == 10
        assert changes[0]["id"] == "change1"
        assert changes[-1]["id"] == "change10"

    def test_gerrit_authentication(self, mock_gerrit_client):
        """Test Gerrit authentication."""
        mock_gerrit_client.username = "test-user"
        mock_gerrit_client.password = "test-pass"

        assert mock_gerrit_client.username == "test-user"
        assert mock_gerrit_client.password == "test-pass"


class TestAPIErrorRecovery:
    """Test error recovery and retry mechanisms."""

    def test_retry_on_transient_error(self):
        """Test that API calls retry on transient errors."""
        mock_client = Mock()

        # Fail twice, then succeed
        mock_client.get_data.side_effect = [
            Exception("Transient error"),
            Exception("Transient error"),
            {"data": "success"},
        ]

        # Simulate retry logic
        max_retries = 3
        for attempt in range(max_retries):
            try:
                result = mock_client.get_data()
                break
            except Exception:
                if attempt == max_retries - 1:
                    raise
                time.sleep(0.1)  # Brief delay between retries

        assert result == {"data": "success"}
        assert mock_client.get_data.call_count == 3

    def test_exponential_backoff(self):
        """Test exponential backoff on retries."""
        mock_client = Mock()
        mock_client.get_data.side_effect = [
            Exception("Error 1"),
            Exception("Error 2"),
            {"data": "success"},
        ]

        delays = []
        max_retries = 3

        for attempt in range(max_retries):
            try:
                mock_client.get_data()
                break
            except Exception:
                if attempt == max_retries - 1:
                    raise
                delay = 2**attempt * 0.1  # Exponential backoff
                delays.append(delay)
                time.sleep(delay)

        # Verify exponential increase
        assert len(delays) == 2
        assert delays[1] > delays[0]

    def test_max_retries_exceeded(self):
        """Test behavior when max retries are exceeded."""
        mock_client = Mock()
        mock_client.get_data.side_effect = Exception("Persistent error")

        max_retries = 3
        with pytest.raises(Exception, match="Persistent error"):
            for attempt in range(max_retries):
                try:
                    mock_client.get_data()
                    break
                except Exception:
                    if attempt == max_retries - 1:
                        raise
                    time.sleep(0.1)

        assert mock_client.get_data.call_count == 3


class TestAPICaching:
    """Test API response caching."""

    def test_cache_hit(self):
        """Test that cached responses are returned on subsequent calls."""
        mock_client = Mock()
        cache = {}

        def cached_get(key):
            if key in cache:
                return cache[key]
            result = mock_client.get_data(key)
            cache[key] = result
            return result

        mock_client.get_data.return_value = {"data": "cached-value"}

        # First call - cache miss
        result1 = cached_get("key1")
        # Second call - cache hit
        result2 = cached_get("key1")

        assert result1 == result2
        assert mock_client.get_data.call_count == 1  # Only called once

    def test_cache_expiration(self):
        """Test that cache entries expire after TTL."""
        cache = {}
        ttl = 0.2  # 200ms TTL

        class CachedClient:
            def __init__(self):
                self.call_count = 0

            def get_data(self, key):
                now = time.time()

                if key in cache:
                    value, timestamp = cache[key]
                    if now - timestamp < ttl:
                        return value

                self.call_count += 1
                result = {"data": f"value-{self.call_count}"}
                cache[key] = (result, now)
                return result

        client = CachedClient()

        # First call
        result1 = client.get_data("key1")
        assert result1 == {"data": "value-1"}

        # Second call within TTL - should hit cache
        result2 = client.get_data("key1")
        assert result2 == {"data": "value-1"}
        assert client.call_count == 1

        # Wait for cache to expire
        time.sleep(ttl + 0.1)

        # Third call after TTL - should miss cache
        result3 = client.get_data("key1")
        assert result3 == {"data": "value-2"}
        assert client.call_count == 2


class TestAPIRateLimiting:
    """Test API rate limiting behavior."""

    def test_respect_rate_limits(self):
        """Test that rate limits are respected."""

        class RateLimitedClient:
            def __init__(self, max_calls=5, window=1.0):
                self.max_calls = max_calls
                self.window = window
                self.calls = []

            def get_data(self):
                now = time.time()

                # Remove calls outside the window
                self.calls = [t for t in self.calls if now - t < self.window]

                # Check if we're at the limit
                if len(self.calls) >= self.max_calls:
                    # Calculate wait time
                    oldest_call = min(self.calls)
                    wait_time = self.window - (now - oldest_call)
                    if wait_time > 0:
                        time.sleep(wait_time)
                        # Remove old calls again after waiting
                        now = time.time()
                        self.calls = [t for t in self.calls if now - t < self.window]

                self.calls.append(now)
                return {"data": "success"}

        client = RateLimitedClient(max_calls=3, window=0.5)

        # Make 3 calls - should succeed quickly
        start_time = time.time()
        for _ in range(3):
            result = client.get_data()
            assert result == {"data": "success"}

        first_batch_time = time.time() - start_time
        assert first_batch_time < 0.1  # Should be fast

        # 4th call should wait for rate limit window
        start_time = time.time()
        result = client.get_data()
        wait_time = time.time() - start_time

        assert result == {"data": "success"}
        assert wait_time >= 0.4  # Should have waited

    def test_rate_limit_headers(self):
        """Test parsing rate limit headers from API responses."""
        mock_response = Mock()
        mock_response.headers = {
            "X-RateLimit-Limit": "5000",
            "X-RateLimit-Remaining": "4999",
            "X-RateLimit-Reset": str(int(time.time() + 3600)),
        }

        limit = int(mock_response.headers["X-RateLimit-Limit"])
        remaining = int(mock_response.headers["X-RateLimit-Remaining"])
        reset = int(mock_response.headers["X-RateLimit-Reset"])

        assert limit == 5000
        assert remaining == 4999
        assert reset > time.time()


class TestAPIBatchOperations:
    """Test batching of API operations."""

    def test_batch_repository_fetches(self):
        """Test fetching multiple repositories in batch."""
        mock_client = Mock()

        repos = [f"repo{i}" for i in range(10)]
        mock_client.get_repositories.return_value = [
            {"name": repo, "full_name": f"org/{repo}"} for repo in repos
        ]

        # Batch fetch
        results = mock_client.get_repositories(repos)

        assert len(results) == 10
        assert all(r["name"] in repos for r in results)
        # Single API call instead of 10
        mock_client.get_repositories.assert_called_once()

    def test_batch_size_limits(self):
        """Test that batch operations respect size limits."""

        def batch_process(items, batch_size=5):
            results = []
            for i in range(0, len(items), batch_size):
                batch = items[i : i + batch_size]
                # Process batch
                results.extend(batch)
            return results

        items = list(range(23))  # 23 items
        results = batch_process(items, batch_size=5)

        assert len(results) == 23
        assert results == items
