import MarkdownUI
import SwiftUI
import Testing
import UIKit
@testable import Sybil

@Suite @MainActor
struct MessagePresentationTests {
    @Test func agentMarkdownKeepsAltAndFormattingWithoutImageOrHTMLNodes() {
        let source = """
        **Caption** ![Inline *landscape*](https://images.invalid/inline.png)

        ![Reference landscape][photo]

        [![Linked landscape](//images.invalid/linked.png)](https://example.invalid)

        > ![Nested ![inner](file:///private/image.png)](data:image/png;base64,AAAA)

        <picture><source srcset="https://images.invalid/source.png"><img src="https://images.invalid/html.png" alt="HTML landscape" title="a > b"></picture>

        [Useful link](https://example.invalid)

        [photo]: https://images.invalid/reference.png
        """
        let content = AgentMessageMarkdown.content(source)
        let html = content.renderHTML(), plain = content.renderPlainText()
        for label in ["Inline landscape", "Reference landscape", "Linked landscape", "Nested inner", "HTML landscape"] {
            #expect(plain.contains(label))
        }
        #expect(!html.contains("<img")); #expect(!html.contains("<picture")); #expect(!html.contains("<source"))
        #expect(!html.contains("images.invalid")); #expect(!html.contains("/private/"))
        #expect(html.contains("<strong>Caption</strong>"))
        #expect(html.contains(#"href="https://example.invalid""#))
        // Normal chat still uses unmodified MarkdownUI content.
        #expect(MarkdownContent(source).renderHTML().contains("<img"))
        #expect(AgentMessageMarkdown.content("<img src='https://images.invalid/a.png' alt='HTML landscape'>\n").renderHTML() == "<p>HTML landscape</p>\n")
    }

    @Test func agentMarkdownRetainsCodeTablesAndEscapesImageLikeAltText() {
        let source = """
        `![literal](https://images.invalid/code.png)`

        ```html
        <img src="literal-code">
        ```

        | Image | Value |
        | --- | --- |
        | ![Table alt](https://images.invalid/table.png) | **Kept** |

        <IMG ALT='![literal alt](https://images.invalid/alt.png)' SRC='ignored'>
        """
        let html = AgentMessageMarkdown.content(source).renderHTML()
        #expect(html.contains("<table>")); #expect(html.contains("Table alt"))
        #expect(html.contains("<strong>Kept</strong>"))
        #expect(html.contains("&lt;img src=")); #expect(html.contains("![literal]"))
        #expect(html.contains("![literal alt]")); #expect(!html.contains("<img"))
    }

    @Test func userMarkupRemainsLiteral() {
        let source = "**bold** [link](https://example.invalid) `code`\n- item\n<script>literal</script>"
        let content = SybilMessageText.literalContent(source)
        #expect(content.renderPlainText() == source)
        #expect(!content.renderHTML().contains("<strong>"))
        #expect(!content.renderHTML().contains("<a "))
        #expect(!content.renderHTML().contains("<code>"))
        #expect(!content.renderHTML().contains("<ul>"))
        #expect(content.renderHTML().contains("&lt;script&gt;"))
    }

    @Test func literalLineBreaksAndParagraphsStayDistinct() {
        let content = SybilMessageText.literalContent("First\nSecond\n\nThird")
        #expect(content.renderPlainText() == "First\nSecond\n\nThird")
        #expect(content.renderHTML() == "<p>First\nSecond</p>\n<p>Third</p>\n")
        // Empty paragraphs retain layout space instead of disappearing.
        #expect(SybilMessageText.literalContent("\n\nFirst\n\n\n\nLast\n\n").renderHTML().components(separatedBy: "<p>").count == 6)
    }

    @Test func pastedParagraphBoundariesMatchMarkdown() {
        for source in ["First\r\n\r\nSecond", "First\n \nSecond", "First\n\t\nSecond"] {
            #expect(SybilMessageText.literalContent(source).renderHTML() == "<p>First</p>\n<p>Second</p>\n")
        }
        #expect(SybilMessageText.literalContent("First\r\nSecond").renderPlainText() == "First\nSecond")
        #expect(SybilMessageText.literalContent("  **literal**  \n\nLast").renderPlainText() == "  **literal**  \n\nLast")
        #expect(SybilMessageText.literalContent("First\r\n \r\n\t\r\n\r\nLast") == SybilMessageText.literalContent("First\n\n\n\nLast"))
    }

    @Test func bothFormatsShareLineParagraphMetricsAndDynamicType() {
        func height(_ content: String, _ format: SybilMessageText.Format, _ size: DynamicTypeSize) -> CGFloat {
            let host = UIHostingController(rootView: SybilMessageText(content: content, format: format)
                .environment(\.dynamicTypeSize, size))
            return host.sizeThatFits(in: CGSize(width: 320, height: 10_000)).height
        }
        let literal = "First line\nSecond line\n\nAnother paragraph"
        let markdown = "First line  \nSecond line\n\nAnother paragraph"
        for size in [DynamicTypeSize.large, .accessibility3] {
            #expect(abs(height(literal, .literal, size) - height(markdown, .markdown, size)) < 1)
        }
        for source in ["First\r\n\r\nSecond", "First\n \nSecond", "First\n\t\nSecond"] {
            #expect(abs(height(source, .literal, .large) - height(source, .markdown, .large)) < 1)
        }
        #expect(height(literal, .literal, .accessibility3) > height(literal, .literal, .large) * 1.5)
        #expect(height(markdown, .markdown, .accessibility3) > height(markdown, .markdown, .large) * 1.5)
    }
}