import pytest
import os
import base64
from pathlib import Path
from unittest.mock import patch, MagicMock
from app.services.ai_vision import (
    _read_image, _extract_json, _usage_tokens_gemini, 
    _generate_gemini, _generate_openrouter, _generate,
    extract_text_with_ai, analyze_image
)
from app.config import settings

def test_read_image_variants(tmp_path):
    img_file = tmp_path / "test.png"
    img_file.write_bytes(b"fake_png_data")
    
    data, mime = _read_image(str(img_file))
    assert data == b"fake_png_data"
    assert mime == "image/png"

def test_extract_json_bad_cases():
    assert _extract_json(None) is None
    assert _extract_json("No JSON here") is None
    assert _extract_json("Broken { json : 1") is None

def test_usage_tokens_gemini_none():
    assert _usage_tokens_gemini(None) == (None, None)
    
    mock_resp = MagicMock()
    mock_resp.usage_metadata = None
    assert _usage_tokens_gemini(mock_resp) == (None, None)

@pytest.mark.asyncio
@patch("app.services.ai_vision._get_client")
@patch("app.services.ai_vision.settings")
async def test_generate_gemini_no_key(mock_settings, mock_get_client):
    mock_settings.GEMINI_API_KEY = None
    res = await _generate_gemini("test prompt")
    assert res["text"] is None

@pytest.mark.asyncio
@patch("httpx.AsyncClient.post")
@patch("app.services.ai_vision.settings")
async def test_generate_openrouter_success(mock_settings, mock_post):
    mock_settings.OPENROUTER_API_KEY = "test_key"
    mock_settings.OPENROUTER_MODEL = "test_model"
    
    mock_response = MagicMock()
    mock_response.status_code = 200
    mock_response.json.return_value = {
        "choices": [{"message": {"content": "openrouter test response"}}],
        "usage": {"prompt_tokens": 10, "completion_tokens": 5}
    }
    mock_post.return_value = mock_response
    
    res = await _generate_openrouter("test prompt")
    assert res["text"] == "openrouter test response"
    assert res["usage"] == (10, 5)

@pytest.mark.asyncio
@patch("app.services.ai_vision._generate_openrouter")
@patch("app.services.ai_vision.settings")
async def test_generate_dispatcher_openrouter(mock_settings, mock_gen_or):
    mock_settings.AI_PROVIDER = "openrouter"
    await _generate("test")
    mock_gen_or.assert_called_once()

@pytest.mark.asyncio
@patch("app.services.ai_vision._generate")
@patch("app.services.ai_vision._read_image")
@patch("app.services.ai_vision.settings")
async def test_extract_text_with_ai(mock_settings, mock_read_image, mock_generate):
    mock_settings.AI_ENABLED = True
    mock_settings.AI_PROVIDER = "gemini"
    mock_read_image.return_value = (b"fake", "image/jpeg")
    mock_generate.return_value = {
        "text": '{"text": "Extracted text", "language": "en", "confidence": 0.9}'
    }
    
    res = await extract_text_with_ai("fake/path.jpg")
    assert res["text"] == "Extracted text"
    assert res["language"] == "en"

@pytest.mark.asyncio
@patch("app.services.ai_vision._generate")
@patch("app.services.ai_vision._read_image")
@patch("app.services.ai_vision.settings")
async def test_analyze_image_failure(mock_settings, mock_read_image, mock_generate):
    mock_settings.AI_ENABLED = True
    mock_read_image.return_value = (b"fake", "image/jpeg")
    mock_generate.return_value = {"text": "Invalid JSON", "usage": (None, None)}
    
    res = await analyze_image("fake/path.jpg")
    assert res["description"] is None