//! Integration tests for the syntax plugin interface.

use nuwiki_core::ast::{
    inline::InlineNode, BlockNode, DocumentNode, ParagraphNode, Span, TextNode,
};
use nuwiki_core::syntax::{Lexer, Parser, SyntaxPlugin, SyntaxRegistry, TokenStream};

// --- A minimal mock plugin: tokenises the input on whitespace, then wraps
// the joined text in a single Paragraph. Just enough surface to exercise
// every trait + the registry.

#[derive(Debug, Clone, PartialEq, Eq)]
struct MockToken(String);

struct MockLexer;
impl Lexer for MockLexer {
    type Token = MockToken;

    fn lex(&self, text: &str) -> TokenStream<MockToken> {
        TokenStream::from_vec(
            text.split_whitespace()
                .map(|w| MockToken(w.to_owned()))
                .collect(),
        )
    }
}

struct MockParser;
impl Parser for MockParser {
    type Token = MockToken;

    fn parse(&self, tokens: TokenStream<MockToken>) -> DocumentNode {
        let joined = tokens
            .iter()
            .map(|t| t.0.as_str())
            .collect::<Vec<_>>()
            .join(" ");
        let paragraph = BlockNode::Paragraph(ParagraphNode {
            span: Span::default(),
            children: vec![InlineNode::Text(TextNode {
                span: Span::default(),
                content: joined,
            })],
        });
        DocumentNode {
            span: Span::default(),
            children: vec![paragraph],
            metadata: Default::default(),
        }
    }
}

struct MockPlugin;
impl SyntaxPlugin for MockPlugin {
    fn id(&self) -> &str {
        "mock"
    }
    fn display_name(&self) -> &str {
        "Mock Syntax"
    }
    fn file_extensions(&self) -> &[&str] {
        &[".mock", ".mk"]
    }
    fn parse(&self, text: &str) -> DocumentNode {
        MockParser.parse(MockLexer.lex(text))
    }
}

#[test]
fn token_stream_roundtrip() {
    let mut s = TokenStream::<u32>::new();
    assert!(s.is_empty());
    s.push(1);
    s.push(2);
    s.push(3);
    assert_eq!(s.len(), 3);
    assert_eq!(s.as_slice(), &[1, 2, 3]);
    assert_eq!(s.iter().sum::<u32>(), 6);
    assert_eq!((&s).into_iter().sum::<u32>(), 6);
    assert_eq!(s.into_vec(), vec![1, 2, 3]);

    let from_vec: TokenStream<&str> = vec!["a", "b"].into();
    assert_eq!(from_vec.len(), 2);
    let collected: Vec<&str> = from_vec.into_iter().collect();
    assert_eq!(collected, vec!["a", "b"]);
}

#[test]
fn lexer_and_parser_chain_through_plugin() {
    let plugin = MockPlugin;
    let doc = plugin.parse("  hello   world  ");

    let BlockNode::Paragraph(p) = &doc.children[0] else {
        panic!("expected a paragraph, got {:?}", doc.children[0]);
    };
    let InlineNode::Text(t) = &p.children[0] else {
        panic!("expected a text node");
    };
    assert_eq!(t.content, "hello world");
}

#[test]
fn registry_lookup_by_id_and_extension() {
    let mut registry = SyntaxRegistry::new();
    assert!(registry.is_empty());

    registry.register(MockPlugin);
    assert_eq!(registry.len(), 1);

    let by_id = registry
        .get("mock")
        .expect("plugin should be findable by id");
    assert_eq!(by_id.display_name(), "Mock Syntax");

    let by_ext = registry
        .detect_from_extension(".mk")
        .expect("plugin should be findable by secondary extension");
    assert_eq!(by_ext.id(), "mock");

    assert!(registry.get("nonexistent").is_none());
    assert!(registry.detect_from_extension(".unknown").is_none());

    // Iteration order matches registration order.
    let ids: Vec<&str> = registry.iter().map(|p| p.id()).collect();
    assert_eq!(ids, vec!["mock"]);
}

#[test]
fn registry_can_parse_through_trait_object() {
    let mut registry = SyntaxRegistry::new();
    registry.register(MockPlugin);

    let plugin = registry.detect_from_extension(".mock").unwrap();
    let doc = plugin.parse("a b c");
    assert_eq!(doc.children.len(), 1);
}

/// Compile-time check: SyntaxRegistry must be Send + Sync so the LSP server
/// can share it across handler tasks.
#[test]
fn registry_is_send_and_sync() {
    fn assert_send_sync<T: Send + Sync>() {}
    assert_send_sync::<SyntaxRegistry>();
}