import XCTest
@testable import RSSuper

final class FeedParserTests: XCTestCase {
    func testParsesRSS20Feed() throws {
        let parser = FeedParser()
        let result = try parser.parse(
            data: Data(rssSample.utf8),
            sourceURL: "https://example.com/rss.xml"
        )

        XCTAssertEqual(result.feedType, .rss)
        XCTAssertEqual(result.feed.title, "Example Podcast")
        XCTAssertEqual(result.feed.subtitle, "Weekly iOS and Swift updates")
        XCTAssertEqual(result.feed.items.count, 2)
        XCTAssertEqual(result.feed.ttl, 60)

        let firstItem = try XCTUnwrap(result.feed.items.first)
        XCTAssertEqual(firstItem.title, "Episode 1")
        XCTAssertEqual(firstItem.author, "Host Name")
        XCTAssertEqual(firstItem.guid, "episode-1")
        XCTAssertEqual(firstItem.categories, ["Swift"])
        XCTAssertEqual(firstItem.enclosure?.url, "https://example.com/audio/ep1.mp3")
        XCTAssertEqual(firstItem.enclosure?.type, "audio/mpeg")
        XCTAssertEqual(firstItem.enclosure?.length, 12345)
        XCTAssertEqual(firstItem.content, "<p>Full content for episode 1.</p>")
    }

    func testParsesAtom10Feed() throws {
        let parser = FeedParser()
        let result = try parser.parse(
            data: Data(atomSample.utf8),
            sourceURL: "https://example.com/atom.xml"
        )

        XCTAssertEqual(result.feedType, .atom)
        XCTAssertEqual(result.feed.title, "Example Atom Feed")
        XCTAssertEqual(result.feed.subtitle, "Recent engineering posts")
        XCTAssertEqual(result.feed.link, "https://example.com")
        XCTAssertEqual(result.feed.items.count, 2)

        let firstItem = try XCTUnwrap(result.feed.items.first)
        XCTAssertEqual(firstItem.guid, "urn:uuid:1225c695-cfb8-4ebb-aaaa-80da344efa6a")
        XCTAssertEqual(firstItem.link, "https://example.com/posts/1")
        XCTAssertEqual(firstItem.author, "Jane Author")
        XCTAssertEqual(firstItem.enclosure?.url, "https://example.com/audio/post1.mp3")
        XCTAssertEqual(firstItem.enclosure?.type, "audio/mpeg")
        XCTAssertEqual(firstItem.enclosure?.length, 2048)
    }

    func testHandlesITunesNamespace() throws {
        let parser = FeedParser()
        let result = try parser.parse(
            data: Data(rssWithITunesSample.utf8),
            sourceURL: "https://example.com/itunes.xml"
        )

        XCTAssertEqual(result.feed.subtitle, "Podcast subtitle")
        XCTAssertEqual(result.feed.description, "Feed-level summary")

        let item = try XCTUnwrap(result.feed.items.first)
        XCTAssertEqual(item.author, "Podcast Author")
        XCTAssertEqual(item.description, "Item-level summary")
    }

    func testThrowsForMalformedXML() {
        let parser = FeedParser()
        XCTAssertThrowsError(
            try parser.parse(
                data: Data("<rss><channel><title>Broken".utf8),
                sourceURL: "https://example.com/broken.xml"
            )
        ) { error in
            XCTAssertEqual(error as? FeedParsingError, .malformedXML)
        }
    }

    func testParsesRealWorldStyleFeeds() throws {
        let parser = FeedParser()
        let rssResult = try parser.parse(
            data: Data(realWorldRSSSample.utf8),
            sourceURL: "https://feeds.example.com/news.xml"
        )
        XCTAssertEqual(rssResult.feedType, .rss)
        XCTAssertGreaterThan(rssResult.feed.items.count, 0)

        let atomResult = try parser.parse(
            data: Data(realWorldAtomSample.utf8),
            sourceURL: "https://feeds.example.com/engineering.xml"
        )
        XCTAssertEqual(atomResult.feedType, .atom)
        XCTAssertGreaterThan(atomResult.feed.items.count, 0)
    }
}

private let rssSample = """
<?xml version="1.0" encoding="UTF-8"?>
<rss version="2.0" xmlns:content="http://purl.org/rss/1.0/modules/content/" xmlns:itunes="http://www.itunes.com/dtds/podcast-1.0.dtd">
  <channel>
    <title>Example Podcast</title>
    <link>https://example.com</link>
    <description>A sample RSS feed</description>
    <language>en-us</language>
    <lastBuildDate>Mon, 30 Mar 2026 10:00:00 +0000</lastBuildDate>
    <generator>RSSuper Test Suite</generator>
    <ttl>60</ttl>
    <itunes:subtitle>Weekly iOS and Swift updates</itunes:subtitle>
    <item>
      <title>Episode 1</title>
      <link>https://example.com/episodes/1</link>
      <guid>episode-1</guid>
      <pubDate>Mon, 30 Mar 2026 09:00:00 +0000</pubDate>
      <category>Swift</category>
      <description>Episode 1 summary</description>
      <content:encoded><![CDATA[<p>Full content for episode 1.</p>]]></content:encoded>
      <itunes:author>Host Name</itunes:author>
      <enclosure url="https://example.com/audio/ep1.mp3" type="audio/mpeg" length="12345" />
    </item>
    <item>
      <title>Episode 2</title>
      <link>https://example.com/episodes/2</link>
      <guid>episode-2</guid>
      <pubDate>Mon, 30 Mar 2026 08:00:00 +0000</pubDate>
      <description>Episode 2 summary</description>
    </item>
  </channel>
</rss>
"""

private let atomSample = """
<?xml version="1.0" encoding="utf-8"?>
<feed xmlns="http://www.w3.org/2005/Atom">
  <title>Example Atom Feed</title>
  <subtitle>Recent engineering posts</subtitle>
  <link href="https://example.com" rel="alternate" />
  <updated>2026-03-30T10:00:00Z</updated>
  <generator>Atom Test Generator</generator>
  <entry>
    <title>Post One</title>
    <id>urn:uuid:1225c695-cfb8-4ebb-aaaa-80da344efa6a</id>
    <updated>2026-03-30T09:00:00Z</updated>
    <published>2026-03-30T08:59:00Z</published>
    <summary>First post summary</summary>
    <content type="html">&lt;p&gt;First post full content&lt;/p&gt;</content>
    <author><name>Jane Author</name></author>
    <link href="https://example.com/posts/1" rel="alternate" />
    <link href="https://example.com/audio/post1.mp3" rel="enclosure" type="audio/mpeg" length="2048" />
  </entry>
  <entry>
    <title>Post Two</title>
    <id>urn:uuid:7a9b2f0d-65b2-44a7-a2ad-d3c3ff7dd003</id>
    <updated>2026-03-30T08:00:00Z</updated>
    <summary>Second post summary</summary>
    <link href="https://example.com/posts/2" rel="alternate" />
  </entry>
</feed>
"""

private let rssWithITunesSample = """
<?xml version="1.0" encoding="UTF-8"?>
<rss version="2.0" xmlns:itunes="http://www.itunes.com/dtds/podcast-1.0.dtd">
  <channel>
    <title>iTunes Feed</title>
    <itunes:subtitle>Podcast subtitle</itunes:subtitle>
    <itunes:summary>Feed-level summary</itunes:summary>
    <item>
      <title>Episode</title>
      <itunes:author>Podcast Author</itunes:author>
      <itunes:summary>Item-level summary</itunes:summary>
    </item>
  </channel>
</rss>
"""

private let realWorldRSSSample = """
<?xml version="1.0" encoding="UTF-8"?>
<rss version="2.0">
  <channel>
    <title>Daily Tech News</title>
    <link>https://news.example.com</link>
    <description>Latest updates from the tech world</description>
    <lastBuildDate>Mon, 30 Mar 2026 12:00:00 +0000</lastBuildDate>
    <item>
      <title>Apple ships new SDK tools</title>
      <link>https://news.example.com/apple-sdk-tools</link>
      <guid>news-1</guid>
      <pubDate>Mon, 30 Mar 2026 11:00:00 +0000</pubDate>
      <description>Tooling improvements for mobile developers.</description>
    </item>
  </channel>
</rss>
"""

private let realWorldAtomSample = """
<?xml version="1.0" encoding="utf-8"?>
<feed xmlns="http://www.w3.org/2005/Atom">
  <title>Engineering Blog</title>
  <updated>2026-03-30T12:00:00Z</updated>
  <link rel="alternate" href="https://engineering.example.com" />
  <entry>
    <title>Improving app startup performance</title>
    <id>tag:engineering.example.com,2026:post-1</id>
    <updated>2026-03-29T16:00:00Z</updated>
    <published>2026-03-29T15:00:00Z</published>
    <summary>How we reduced cold-start by 25%.</summary>
    <content>Detailed analysis of startup bottlenecks and fixes.</content>
    <author><name>Engineering Team</name></author>
    <link rel="alternate" href="https://engineering.example.com/posts/startup-performance" />
  </entry>
</feed>
"""