//! Tests for the navigation pieces: WorkspaceIndex queries,
//! page-name derivation, anchor slugify, position lookup, and link
//! resolution. The async LSP handlers are exercised through these
//! helpers; end-to-end JSON-RPC drive lives elsewhere.

use std::path::PathBuf;

use nuwiki_core::ast::{InlineNode, LinkKind};
use nuwiki_core::syntax::vimwiki::VimwikiSyntax;
use nuwiki_core::syntax::SyntaxPlugin;
use nuwiki_lsp::index::{page_name_from_uri, slugify, WorkspaceIndex};
use nuwiki_lsp::nav::{find_inline_at, lsp_to_byte_pos};
use tower_lsp::lsp_types::{Position as LspPosition, Url};

fn parse(src: &str) -> nuwiki_core::ast::DocumentNode {
    VimwikiSyntax::new().parse(src)
}

// ===== Slugify =====

#[test]
fn slugify_basic_title() {
    assert_eq!(slugify("Hello World"), "hello-world");
}

#[test]
fn slugify_strips_punctuation_and_collapses_dashes() {
    assert_eq!(slugify("Hello, World!  Again"), "hello-world-again");
}

#[test]
fn slugify_unicode_lowercase() {
    assert_eq!(slugify("Crème Brûlée"), "crème-brûlée");
}

#[test]
fn slugify_no_trailing_dash() {
    assert_eq!(slugify("Title — "), "title");
}

// ===== Page name from URI =====

#[test]
fn page_name_relative_to_root() {
    let root = PathBuf::from("/wiki");
    let uri = Url::from_file_path("/wiki/dir/Page.wiki").unwrap();
    assert_eq!(page_name_from_uri(&uri, Some(&root)), "dir/Page");
}

#[test]
fn page_name_at_root() {
    let root = PathBuf::from("/wiki");
    let uri = Url::from_file_path("/wiki/Index.wiki").unwrap();
    assert_eq!(page_name_from_uri(&uri, Some(&root)), "Index");
}

#[test]
fn page_name_without_root_falls_back_to_stem() {
    let uri = Url::from_file_path("/tmp/foo.wiki").unwrap();
    assert_eq!(page_name_from_uri(&uri, None), "foo");
}

// ===== Workspace index =====

#[test]
fn upsert_indexes_headings_and_outgoing_links() {
    let mut idx = WorkspaceIndex::new(Some(PathBuf::from("/wiki")));
    let uri = Url::from_file_path("/wiki/Home.wiki").unwrap();
    let ast = parse("= Home =\n[[Other]] and [[#Section]]\n");
    idx.upsert(uri.clone(), &ast);

    let page = idx.page(&uri).expect("page indexed");
    assert_eq!(page.name, "Home");
    assert_eq!(page.headings.len(), 1);
    assert_eq!(page.headings[0].title, "Home");
    assert_eq!(page.headings[0].anchor, "home");
    assert_eq!(page.outgoing.len(), 2);
    assert_eq!(page.outgoing[0].target_page.as_deref(), Some("Other"));
    assert_eq!(page.outgoing[0].kind, LinkKind::Wiki);
    assert_eq!(page.outgoing[1].kind, LinkKind::AnchorOnly);
}

#[test]
fn upsert_registers_page_by_name_and_records_backlinks() {
    let mut idx = WorkspaceIndex::new(Some(PathBuf::from("/wiki")));
    let home = Url::from_file_path("/wiki/Home.wiki").unwrap();
    let about = Url::from_file_path("/wiki/About.wiki").unwrap();

    idx.upsert(home.clone(), &parse("[[About]]\n"));
    idx.upsert(about.clone(), &parse("= About =\n"));

    assert_eq!(idx.page_by_name("About").unwrap().uri, about);

    let backlinks = idx.backlinks_for("About");
    assert_eq!(backlinks.len(), 1);
    assert_eq!(backlinks[0].source_uri, home);
}

#[test]
fn upsert_replaces_prior_indexing_for_same_uri() {
    let mut idx = WorkspaceIndex::new(Some(PathBuf::from("/wiki")));
    let uri = Url::from_file_path("/wiki/Home.wiki").unwrap();
    idx.upsert(uri.clone(), &parse("[[A]]\n"));
    assert_eq!(idx.backlinks_for("A").len(), 1);

    // Re-upsert with different content: old backlinks must drop.
    idx.upsert(uri.clone(), &parse("[[B]]\n"));
    assert_eq!(idx.backlinks_for("A").len(), 0);
    assert_eq!(idx.backlinks_for("B").len(), 1);
}

#[test]
fn remove_drops_page_and_backlinks() {
    let mut idx = WorkspaceIndex::new(Some(PathBuf::from("/wiki")));
    let home = Url::from_file_path("/wiki/Home.wiki").unwrap();
    let about = Url::from_file_path("/wiki/About.wiki").unwrap();
    idx.upsert(home.clone(), &parse("[[About]]\n"));
    idx.upsert(about.clone(), &parse("= About =\n"));

    idx.remove(&home);
    assert!(idx.page(&home).is_none());
    assert!(idx.backlinks_for("About").is_empty());
    // The target page is untouched.
    assert!(idx.page(&about).is_some());
}

#[test]
fn resolve_wiki_link_to_uri() {
    let mut idx = WorkspaceIndex::new(Some(PathBuf::from("/wiki")));
    let about = Url::from_file_path("/wiki/About.wiki").unwrap();
    idx.upsert(about.clone(), &parse("= About =\n"));

    let target = nuwiki_core::ast::LinkTarget {
        kind: LinkKind::Wiki,
        path: Some("About".into()),
        ..Default::default()
    };
    assert_eq!(idx.resolve(&target, "Home"), Some(&about));
}

#[test]
fn resolve_anchor_only_link_returns_source_page() {
    let mut idx = WorkspaceIndex::new(Some(PathBuf::from("/wiki")));
    let home = Url::from_file_path("/wiki/Home.wiki").unwrap();
    idx.upsert(home.clone(), &parse("= H =\n[[#Section]]\n"));

    let target = nuwiki_core::ast::LinkTarget {
        kind: LinkKind::AnchorOnly,
        anchor: Some("section".into()),
        ..Default::default()
    };
    assert_eq!(idx.resolve(&target, "Home"), Some(&home));
}

#[test]
fn page_names_lists_indexed_pages_sorted() {
    let mut idx = WorkspaceIndex::new(Some(PathBuf::from("/wiki")));
    for name in ["Charlie", "Alpha", "Bravo"] {
        let uri = Url::from_file_path(format!("/wiki/{name}.wiki")).unwrap();
        idx.upsert(uri, &parse(&format!("= {name} =\n")));
    }
    let names = idx.page_names();
    assert_eq!(names, vec!["Alpha", "Bravo", "Charlie"]);
}

// ===== Position conversion =====

#[test]
fn lsp_to_byte_pos_passthrough_in_utf8() {
    let p = LspPosition {
        line: 2,
        character: 5,
    };
    let (line, col) = lsp_to_byte_pos(p, "ignored", true);
    assert_eq!((line, col), (2, 5));
}

#[test]
fn lsp_to_byte_pos_converts_from_utf16() {
    // 'é' is one UTF-16 code unit, two UTF-8 bytes. Char "2" after 'é':
    // UTF-16 col 2 → byte col 3.
    let text = "héllo\n";
    let p = LspPosition {
        line: 0,
        character: 2,
    };
    let (line, col) = lsp_to_byte_pos(p, text, false);
    assert_eq!(line, 0);
    assert_eq!(col, 3);
}

// ===== Position lookup =====

#[test]
fn find_inline_at_returns_wikilink_under_cursor() {
    let src = "see [[Other]] now\n";
    let doc = parse(src);
    // Cursor inside "Other" — byte col 6 falls inside "[[Other]]" (which
    // starts at byte 4 and ends at byte 13).
    let node = find_inline_at(&doc, 0, 6).expect("wikilink at cursor");
    assert!(matches!(node, InlineNode::WikiLink(_)));
}

#[test]
fn find_inline_at_returns_wikilink_when_cursor_on_description() {
    // Regression: pressing <CR> on the *title* part of a piped link used to
    // descend into the description's Text node, so goto-definition saw a Text
    // (not a WikiLink) and reported "No locations found".
    let src = "see [[Other|My Title]] now\n";
    let doc = parse(src);
    // Byte col 16 is inside "Title" (the description), past the '|' at 11.
    let node = find_inline_at(&doc, 0, 16).expect("wikilink at cursor");
    assert!(matches!(node, InlineNode::WikiLink(_)));
}

#[test]
fn find_inline_at_returns_none_for_plain_text() {
    let src = "just text\n";
    let doc = parse(src);
    let node = find_inline_at(&doc, 0, 3);
    // "just text" → Text node, which is what we get back from the inner
    // walk (not None). Verify it's a Text.
    assert!(matches!(node, Some(InlineNode::Text(_))));
}

#[test]
fn find_inline_at_descends_into_inline_containers() {
    let src = "*bold text*\n";
    let doc = parse(src);
    // Inside "bold" — should return the inner Text, not the wrapping Bold.
    let node = find_inline_at(&doc, 0, 3).expect("hit");
    assert!(matches!(node, InlineNode::Text(_)));
}

#[test]
fn find_inline_at_returns_none_past_eol() {
    let src = "short\n";
    let doc = parse(src);
    assert!(find_inline_at(&doc, 0, 999).is_none());
}