package com.rssuper.integration

import android.content.Context
import androidx.room.Room
import androidx.test.core.app.ApplicationProvider
import androidx.test.ext.junit.runners.AndroidJUnit4
import com.rssuper.database.RssDatabase
import com.rssuper.parsing.FeedParser
import com.rssuper.parsing.ParseResult
import com.rssuper.services.FeedFetcher
import com.rssuper.services.HTTPAuthCredentials
import okhttp3.mockwebserver.MockResponse
import okhttp3.mockwebserver.MockWebServer
import okhttp3.mockwebserver.RecordedRequest
import org.junit.Assert.*
import org.junit.After
import org.junit.Before
import org.junit.Test
import org.junit.runner.RunWith
import java.io.File
import java.io.FileReader
import java.util.concurrent.TimeUnit
import kotlinx.coroutines.test.runTest

/**
 * Integration tests for cross-platform feed functionality.
 * 
 * These tests verify the complete feed fetch → parse → store flow
 * across the Android platform using real network calls and database operations.
 */
@RunWith(AndroidJUnit4::class)
class FeedIntegrationTest {
    
    private lateinit var context: Context
    private lateinit var database: RssDatabase
    private lateinit var feedFetcher: FeedFetcher
    private lateinit var feedParser: FeedParser
    private lateinit var mockServer: MockWebServer
    
    // Sample RSS feed content embedded directly
    private val sampleRssContent = """
        <?xml version="1.0" encoding="UTF-8"?>
        <rss version="2.0">
          <channel>
            <title>Test RSS Feed</title>
            <link>https://example.com</link>
            <description>Test feed</description>
            <item>
              <title>Article 1</title>
              <link>https://example.com/1</link>
              <description>Content 1</description>
              <pubDate>Mon, 31 Mar 2026 10:00:00 GMT</pubDate>
            </item>
            <item>
              <title>Article 2</title>
              <link>https://example.com/2</link>
              <description>Content 2</description>
              <pubDate>Mon, 31 Mar 2026 11:00:00 GMT</pubDate>
            </item>
            <item>
              <title>Article 3</title>
              <link>https://example.com/3</link>
              <description>Content 3</description>
              <pubDate>Mon, 31 Mar 2026 12:00:00 GMT</pubDate>
            </item>
          </channel>
        </rss>
    """.trimIndent()

    @Before
    fun setUp() {
        context = ApplicationProvider.getApplicationContext()
        
        // Use in-memory database for isolation
        database = Room.inMemoryDatabaseBuilder(context, RssDatabase::class.java)
            .allowMainThreadQueries()
            .build()
        
        feedFetcher = FeedFetcher(timeoutMs = 10000)
        feedParser = FeedParser()
        mockServer = MockWebServer()
        mockServer.start(8080)
    }
    
    @After
    fun tearDown() {
        database.close()
        mockServer.shutdown()
    }
    
    @Test
    fun testFetchParseAndStoreFlow() = runBlockingTest {
        // Setup mock server to return sample RSS feed
        mockServer.enqueue(MockResponse().setBody(sampleRssContent).setResponseCode(200))
        
        val feedUrl = mockServer.url("/feed.xml").toString()
        
        // 1. Fetch the feed
        val fetchResult = feedFetcher.fetch(feedUrl)
        assertTrue("Fetch should succeed", fetchResult.isSuccess())
        assertNotNull("Fetch result should not be null", fetchResult.getOrNull())
        
        // 2. Parse the feed
        val parseResult = feedParser.parse(fetchResult.getOrNull()!!.feedXml, feedUrl)
        assertNotNull("Parse result should not be null", parseResult)
        
        // 3. Store the subscription
        database.subscriptionDao().insert(parseResult.feed.subscription)
        
        // 4. Store the feed items
        parseResult.feed.items.forEach { item ->
            database.feedItemDao().insert(item)
        }
        
        // 5. Verify items were stored
        val storedItems = database.feedItemDao().getAll()
        assertEquals("Should have 3 feed items", 3, storedItems.size)
        
        val storedSubscription = database.subscriptionDao().getAll().first()
        assertEquals("Subscription title should match", parseResult.feed.subscription.title, storedSubscription.title)
    }
    
    @Test
    fun testSearchEndToEnd() = runBlockingTest {
        // Create test subscription
        val subscription = database.subscriptionDao().insert(
            com.rssuper.database.entities.SubscriptionEntity(
                id = "test-search-sub",
                url = "https://example.com/feed.xml",
                title = "Test Search Feed"
            )
        )
        
        // Create test feed items with searchable content
        val item1 = com.rssuper.database.entities.FeedItemEntity(
            id = "test-item-1",
            title = "Hello World Article",
            content = "This is a test article about programming",
            subscriptionId = subscription.id,
            publishedAt = System.currentTimeMillis()
        )
        
        val item2 = com.rssuper.database.entities.FeedItemEntity(
            id = "test-item-2",
            title = "Another Article",
            content = "This article is about technology and software",
            subscriptionId = subscription.id,
            publishedAt = System.currentTimeMillis()
        )
        
        database.feedItemDao().insert(item1)
        database.feedItemDao().insert(item2)
        
        // Perform search
        val searchResults = database.feedItemDao().search("%test%", limit = 10)
        
        // Verify results
        assertTrue("Should find at least one result", searchResults.size >= 1)
        assertTrue("Should find items with 'test' in content", 
            searchResults.any { it.content.contains("test", ignoreCase = true) })
    }
    
    @Test
    fun testBackgroundSyncIntegration() = runBlockingTest {
        // Setup mock server with multiple feeds
        mockServer.enqueue(MockResponse().setBody(sampleRssContent).setResponseCode(200))
        mockServer.enqueue(MockResponse().setBody(sampleRssContent).setResponseCode(200))
        
        val feed1Url = mockServer.url("/feed1.xml").toString()
        val feed2Url = mockServer.url("/feed2.xml").toString()
        
        // Insert subscriptions
        database.subscriptionDao().insert(
            com.rssuper.database.entities.SubscriptionEntity(
                id = "sync-feed-1",
                url = feed1Url,
                title = "Sync Test Feed 1"
            )
        )
        
        database.subscriptionDao().insert(
            com.rssuper.database.entities.SubscriptionEntity(
                id = "sync-feed-2",
                url = feed2Url,
                title = "Sync Test Feed 2"
            )
        )
        
        // Simulate sync by fetching and parsing both feeds
        feed1Url.let { url ->
            val result = feedFetcher.fetchAndParse(url)
            assertTrue("First feed fetch should succeed or fail gracefully", 
                result.isSuccess() || result.isFailure())
        }
        
        feed2Url.let { url ->
            val result = feedFetcher.fetchAndParse(url)
            assertTrue("Second feed fetch should succeed or fail gracefully",
                result.isSuccess() || result.isFailure())
        }
        
        // Verify subscriptions exist
        val subscriptions = database.subscriptionDao().getAll()
        assertEquals("Should have 2 subscriptions", 2, subscriptions.size)
    }
    
    @Test
    fun testNotificationDelivery() = runBlockingTest {
        // Create subscription
        val subscription = database.subscriptionDao().insert(
            com.rssuper.database.entities.SubscriptionEntity(
                id = "test-notification-sub",
                url = "https://example.com/feed.xml",
                title = "Test Notification Feed"
            )
        )
        
        // Create feed item
        val item = com.rssuper.database.entities.FeedItemEntity(
            id = "test-notification-item",
            title = "Test Notification Article",
            content = "This article should trigger a notification",
            subscriptionId = subscription.id,
            publishedAt = System.currentTimeMillis()
        )
        database.feedItemDao().insert(item)
        
        // Verify item was created
        val storedItem = database.feedItemDao().getById(item.id)
        assertNotNull("Item should be stored", storedItem)
        assertEquals("Title should match", item.title, storedItem?.title)
    }
    
    @Test
    fun testSettingsPersistence() = runBlockingTest {
        // Test notification preferences
        val preferences = com.rssuper.database.entities.NotificationPreferencesEntity(
            id = 1,
            enabled = true,
            sound = true,
            vibration = true,
            light = true,
            channel = "rssuper_notifications"
        )
        
        database.notificationPreferencesDao().insert(preferences)
        
        val stored = database.notificationPreferencesDao().get()
        assertNotNull("Preferences should be stored", stored)
        assertTrue("Notifications should be enabled", stored.enabled)
    }
    
    @Test
    fun testBookmarkCRUD() = runBlockingTest {
        // Create subscription and feed item
        val subscription = database.subscriptionDao().insert(
            com.rssuper.database.entities.SubscriptionEntity(
                id = "test-bookmark-sub",
                url = "https://example.com/feed.xml",
                title = "Test Bookmark Feed"
            )
        )
        
        val item = com.rssuper.database.entities.FeedItemEntity(
            id = "test-bookmark-item",
            title = "Test Bookmark Article",
            content = "This article will be bookmarked",
            subscriptionId = subscription.id,
            publishedAt = System.currentTimeMillis()
        )
        database.feedItemDao().insert(item)
        
        // Create bookmark
        val bookmark = com.rssuper.database.entities.BookmarkEntity(
            id = "bookmark-1",
            feedItemId = item.id,
            title = item.title,
            link = "https://example.com/article1",
            description = item.content,
            content = item.content,
            createdAt = System.currentTimeMillis()
        )
        
        database.bookmarkDao().insert(bookmark)
        
        // Verify bookmark was created
        val storedBookmarks = database.bookmarkDao().getAll()
        assertEquals("Should have 1 bookmark", 1, storedBookmarks.size)
        assertEquals("Bookmark title should match", bookmark.title, storedBookmarks.first().title)
        
        // Update bookmark
        val updatedBookmark = bookmark.copy(description = "Updated description")
        database.bookmarkDao().update(updatedBookmark)
        
        val reloaded = database.bookmarkDao().getById(bookmark.id)
        assertEquals("Bookmark description should be updated", 
            updatedBookmark.description, reloaded?.description)
        
        // Delete bookmark
        database.bookmarkDao().delete(bookmark.id)
        
        val deleted = database.bookmarkDao().getById(bookmark.id)
        assertNull("Bookmark should be deleted", deleted)
    }
    
    @Test
    fun testErrorRecoveryNetworkFailure() = runBlockingTest {
        // Setup mock server to fail
        mockServer.enqueue(MockResponse().setResponseCode(500))
        mockServer.enqueue(MockResponse().setResponseCode(500))
        mockServer.enqueue(MockResponse().setBody("Success").setResponseCode(200))
        
        val feedUrl = mockServer.url("/feed.xml").toString()
        
        // Should fail on first two attempts (mocked in FeedFetcher with retries)
        val result = feedFetcher.fetch(feedUrl)
        
        // After 3 retries, should eventually succeed or fail
        assertTrue("Should complete after retries", result.isSuccess() || result.isFailure())
    }
    
    @Test
    fun testErrorRecoveryParseError() = runBlockingTest {
        // Setup mock server with invalid XML
        mockServer.enqueue(MockResponse().setBody("<invalid xml").setResponseCode(200))
        
        val feedUrl = mockServer.url("/feed.xml").toString()
        
        val fetchResult = feedFetcher.fetch(feedUrl)
        assertTrue("Fetch should succeed", fetchResult.isSuccess())
         
         try {
             feedParser.parse(fetchResult.getOrNull()!!.feedXml, feedUrl)
             fail("Parsing invalid XML should throw exception")
         } catch (e: Exception) {
         }
    }
    
    @Test
    fun testCrossPlatformDataConsistency() = runBlockingTest {
        // Verify data structures are consistent across platforms
        // This test verifies that the same data can be created and retrieved
        
        // Create subscription
        val subscription = database.subscriptionDao().insert(
            com.rssuper.database.entities.SubscriptionEntity(
                id = "cross-platform-test",
                url = "https://example.com/feed.xml",
                title = "Cross Platform Test"
            )
        )
        
        // Create feed item
        val item = com.rssuper.database.entities.FeedItemEntity(
            id = "cross-platform-item",
            title = "Cross Platform Item",
            content = "Testing cross-platform data consistency",
            subscriptionId = subscription.id,
            publishedAt = System.currentTimeMillis()
        )
        database.feedItemDao().insert(item)
        
        // Verify data integrity
        val storedItem = database.feedItemDao().getById(item.id)
        assertNotNull("Item should be retrievable", storedItem)
        assertEquals("Title should match", item.title, storedItem?.title)
        assertEquals("Content should match", item.content, storedItem?.content)
    }
    
    @Test
    fun testHTTPAuthCredentials() = runBlockingTest {
        // Test HTTP authentication integration
        val auth = HTTPAuthCredentials("testuser", "testpass")
        val credentials = auth.toCredentials()
        
        assertTrue("Credentials should start with Basic", credentials.startsWith("Basic "))
        
        // Setup mock server with auth
        mockServer.enqueue(MockResponse().setResponseCode(401))
        mockServer.enqueue(MockResponse().setBody("Success").setResponseCode(200)
            .addHeader("WWW-Authenticate", "Basic realm=\"test\""))
        
        val feedUrl = mockServer.url("/feed.xml").toString()
        
        val result = feedFetcher.fetch(feedUrl, httpAuth = auth)
        assertTrue("Should handle auth", result.isSuccess() || result.isFailure())
    }
    
    @Test
    fun testCacheControl() = runBlockingTest {
        // Test ETag and If-Modified-Since headers
        val etag = "test-etag-123"
        val lastModified = "Mon, 01 Jan 2024 00:00:00 GMT"
        
        // First request
        mockServer.enqueue(MockResponse().setBody("Feed 1").setResponseCode(200)
            .addHeader("ETag", etag)
            .addHeader("Last-Modified", lastModified))
        
        // Second request with If-None-Match
        mockServer.enqueue(MockResponse().setResponseCode(304))
        
        val feedUrl = mockServer.url("/feed.xml").toString()
        
        // First fetch
        val result1 = feedFetcher.fetch(feedUrl)
        assertTrue("First fetch should succeed", result1.isSuccess())
        
        // Second fetch with ETag
        val result2 = feedFetcher.fetch(feedUrl, ifNoneMatch = etag)
        assertTrue("Second fetch should complete", result2.isSuccess() || result2.isFailure())
    }
    
    private suspend fun <T> runBlockingTest(block: suspend () -> T): T {
        return kotlinx.coroutines.test.runTest { block() }
    }
}