//! Link-related LSP commands.
//!
//! Covers:
//! - `nuwiki.link.pasteWikilink` / `nuwiki.link.pasteUrl` — page-name
//!   synthesis from a URI and the textual shape the handler inserts
//!   at the cursor.
//! - Wikilink resolution, including the regression where `<CR>` on a
//!   wikilink to a not-yet-created page must still resolve to a URI
//!   so the editor can open (and on save create) the future page.
//!   The resolver itself is private; we exercise the synthesised-path
//!   semantics via the public config helpers + index lookup.

use std::path::PathBuf;

use nuwiki_core::ast::LinkKind;
use nuwiki_core::syntax::vimwiki::VimwikiSyntax;
use nuwiki_core::syntax::SyntaxPlugin;
use nuwiki_lsp::config::WikiConfig;
use nuwiki_lsp::index::{page_name_from_uri, WorkspaceIndex};
use tower_lsp::lsp_types::Url;

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

// ===== paste helpers =====

#[test]
fn commands_list_advertises_link_helpers() {
    let names: Vec<&str> = nuwiki_lsp::commands::COMMANDS.to_vec();
    for name in [
        "nuwiki.link.pasteWikilink",
        "nuwiki.link.pasteUrl",
        "nuwiki.link.catUrl",
        // Both GenerateLinks forms must be advertised so coc/vim-lsp accept
        // them (the scoped form was previously sent but unregistered).
        "nuwiki.links.generate",
        "nuwiki.links.generateForPath",
    ] {
        assert!(names.contains(&name), "missing: {name}");
    }
}

#[test]
fn page_name_for_root_level_page() {
    let cfg = WikiConfig::from_root(PathBuf::from("/tmp/wiki"));
    let uri = Url::from_file_path("/tmp/wiki/Home.wiki").unwrap();
    assert_eq!(page_name_from_uri(&uri, Some(&cfg.root)), "Home");
}

#[test]
fn page_name_for_subdir_page() {
    let cfg = WikiConfig::from_root(PathBuf::from("/tmp/wiki"));
    let uri = Url::from_file_path("/tmp/wiki/diary/2026-05-11.wiki").unwrap();
    assert_eq!(
        page_name_from_uri(&uri, Some(&cfg.root)),
        "diary/2026-05-11"
    );
}

#[test]
fn paste_url_format_matches_export_output_path_for() {
    // The URL the `pasteUrl` handler emits is `<name>.html`, where
    // `<name>` walks path segments. Mirror that derivation and assert
    // the shape we'd insert at cursor.
    let name = "diary/2026-05-11";
    let mut url = String::new();
    for (i, seg) in name.split('/').enumerate() {
        if i > 0 {
            url.push('/');
        }
        url.push_str(seg);
    }
    url.push_str(".html");
    assert_eq!(url, "diary/2026-05-11.html");
}

#[test]
fn paste_wikilink_shape_for_root_page() {
    // `[[<name>]]` is what the handler inserts at the cursor.
    let name = "Notes";
    assert_eq!(format!("[[{name}]]"), "[[Notes]]");
}

// ===== resolve follow-link to non-existent page =====

#[test]
fn link_to_indexed_page_resolves_via_index() {
    let root = "/tmp/follow-link-1";
    let mut idx = WorkspaceIndex::new(Some(PathBuf::from(root)));
    let target = Url::from_file_path(format!("{root}/Notes.wiki")).unwrap();
    idx.upsert(target.clone(), &parse("= notes =\n"));

    let resolved = idx.pages_by_name.get("Notes").cloned();
    assert_eq!(resolved, Some(target));
}

#[test]
fn missing_page_is_not_in_index() {
    let root = "/tmp/follow-link-2";
    let idx = WorkspaceIndex::new(Some(PathBuf::from(root)));
    // Empty index — "Missing" isn't there, so the fallback synthesise
    // path is the only way to follow `[[Missing]]`.
    assert!(!idx.pages_by_name.contains_key("Missing"));
}

#[test]
fn config_root_plus_path_plus_ext_is_a_valid_uri() {
    // Sanity: the synthesise logic constructs <root>/<path>.<ext>.
    let cfg = WikiConfig::from_root(PathBuf::from("/tmp/follow-link-3"));
    assert_eq!(cfg.file_extension, ".wiki");
    let target_path = cfg.root.join("Missing.wiki");
    assert!(Url::from_file_path(&target_path).is_ok());
}

#[test]
fn wikilink_to_subdir_page_parses_with_slash_in_path() {
    // Synthesis must walk path segments, not just concatenate.
    let doc = parse("[[notes/Daily]]\n");
    let inline = match &doc.children[0] {
        nuwiki_core::ast::BlockNode::Paragraph(p) => &p.children[0],
        _ => panic!("expected paragraph"),
    };
    let target = match inline {
        nuwiki_core::ast::InlineNode::WikiLink(w) => &w.target,
        _ => panic!("expected wikilink"),
    };
    assert_eq!(target.kind, LinkKind::Wiki);
    assert_eq!(target.path.as_deref(), Some("notes/Daily"));
}