import pytest
from fastapi.testclient import TestClient
import sys
from pathlib import Path

# Add parent directory to path for imports
sys.path.insert(0, str(Path(__file__).parent.parent.parent.parent))

from backend.main import app


class TestValidationAPI:
    
    @pytest.fixture
    def client(self):
        return TestClient(app)
    
    def test_validate_url_success_standard(self, client):
        """Test successful validation of standard YouTube URL."""
        response = client.post(
            "/api/validate-url",
            json={"url": "https://youtube.com/watch?v=dQw4w9WgXcQ"}
        )
        assert response.status_code == 200
        data = response.json()
        assert data["is_valid"] is True
        assert data["video_id"] == "dQw4w9WgXcQ"
        assert data["video_url"] == "https://youtube.com/watch?v=dQw4w9WgXcQ"
        assert data["error"] is None
    
    def test_validate_url_success_short(self, client):
        """Test successful validation of short YouTube URL."""
        response = client.post(
            "/api/validate-url",
            json={"url": "https://youtu.be/dQw4w9WgXcQ"}
        )
        assert response.status_code == 200
        data = response.json()
        assert data["is_valid"] is True
        assert data["video_id"] == "dQw4w9WgXcQ"
    
    def test_validate_url_success_embed(self, client):
        """Test successful validation of embed YouTube URL."""
        response = client.post(
            "/api/validate-url",
            json={"url": "https://youtube.com/embed/dQw4w9WgXcQ"}
        )
        assert response.status_code == 200
        data = response.json()
        assert data["is_valid"] is True
        assert data["video_id"] == "dQw4w9WgXcQ"
    
    def test_validate_url_invalid_format(self, client):
        """Test validation failure for invalid URL format."""
        response = client.post(
            "/api/validate-url",
            json={"url": "https://vimeo.com/123456789"}
        )
        assert response.status_code == 200
        data = response.json()
        assert data["is_valid"] is False
        assert data["video_id"] is None
        assert data["video_url"] is None
        assert data["error"] is not None
        assert data["error"]["code"] == "INVALID_URL"
        assert "supported_formats" in data["error"]["details"]
    
    def test_validate_url_playlist(self, client):
        """Test validation failure for playlist URLs."""
        response = client.post(
            "/api/validate-url",
            json={"url": "https://youtube.com/playlist?list=PLrAXtmErZgOeiKm4sgNOknGvNjby9efdf"}
        )
        assert response.status_code == 200
        data = response.json()
        assert data["is_valid"] is False
        assert data["error"] is not None
        assert data["error"]["code"] == "UNSUPPORTED_FORMAT"
        assert "playlist" in data["error"]["message"].lower()
        assert "suggestion" in data["error"]["details"]
    
    def test_validate_url_empty(self, client):
        """Test validation failure for empty URL."""
        response = client.post(
            "/api/validate-url",
            json={"url": ""}
        )
        # FastAPI will validate this at the request model level
        assert response.status_code == 422  # Unprocessable Entity
    
    def test_validate_url_with_timestamp(self, client):
        """Test validation of URL with timestamp parameter."""
        response = client.post(
            "/api/validate-url",
            json={"url": "https://youtube.com/watch?v=dQw4w9WgXcQ&t=30s"}
        )
        assert response.status_code == 200
        data = response.json()
        assert data["is_valid"] is True
        assert data["video_id"] == "dQw4w9WgXcQ"
    
    def test_validate_url_mobile(self, client):
        """Test validation of mobile YouTube URL."""
        response = client.post(
            "/api/validate-url",
            json={"url": "https://m.youtube.com/watch?v=dQw4w9WgXcQ"}
        )
        assert response.status_code == 200
        data = response.json()
        assert data["is_valid"] is True
        assert data["video_id"] == "dQw4w9WgXcQ"
    
    def test_validate_url_invalid_video_id_length(self, client):
        """Test validation failure for invalid video ID length."""
        response = client.post(
            "/api/validate-url",
            json={"url": "https://youtube.com/watch?v=short"}
        )
        assert response.status_code == 200
        data = response.json()
        assert data["is_valid"] is False
        assert data["error"]["code"] == "INVALID_URL"
    
    def test_get_supported_formats(self, client):
        """Test getting supported URL formats."""
        response = client.get("/api/supported-formats")
        assert response.status_code == 200
        data = response.json()
        assert "supported_formats" in data
        assert isinstance(data["supported_formats"], list)
        assert len(data["supported_formats"]) > 0
        assert "examples" in data
        assert "notes" in data