//! Phase 18: multi-wiki — interwiki resolution + picker commands.
//!
//! The cross-wiki resolver methods on `Backend` are exercised indirectly
//! through `tower_lsp::LspService`'s test harness via a synthetic
//! `Backend` (the same pattern Phase 13 used). To keep this test suite
//! lightweight we drive the *pure* resolution primitives — the parser
//! producing `LinkKind::Interwiki` targets, then the `WorkspaceIndex`
//! lookup-by-name — and verify the multi-wiki config shape end-to-end.

use std::path::PathBuf;

use nuwiki_core::ast::{InlineNode, LinkKind};
use nuwiki_core::syntax::vimwiki::VimwikiSyntax;
use nuwiki_core::syntax::SyntaxPlugin;
use nuwiki_lsp::config::config_from_json;
use nuwiki_lsp::index::WorkspaceIndex;
use nuwiki_lsp::wiki::{build_wikis, resolve_uri_to_wiki, WikiId};
use tower_lsp::lsp_types::Url;

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

fn first_link(src: &str) -> nuwiki_core::ast::WikiLinkNode {
    let doc = parse(src);
    for block in &doc.children {
        if let nuwiki_core::ast::BlockNode::Paragraph(p) = block {
            for inline in &p.children {
                if let InlineNode::WikiLink(w) = inline {
                    return w.clone();
                }
            }
        }
    }
    panic!("no wikilink in: {src}");
}

// ===== Parser-level: `wiki<N>:` / `wn.<Name>:` produce Interwiki =====

#[test]
fn numbered_interwiki_link_parses_to_wiki_index() {
    let w = first_link("[[wiki1:OtherPage]]\n");
    assert_eq!(w.target.kind, LinkKind::Interwiki);
    assert_eq!(w.target.wiki_index, Some(1));
    assert_eq!(w.target.path.as_deref(), Some("OtherPage"));
    assert!(w.target.wiki_name.is_none());
}

#[test]
fn named_interwiki_link_parses_to_wiki_name() {
    let w = first_link("[[wn.work:Project]]\n");
    assert_eq!(w.target.kind, LinkKind::Interwiki);
    assert_eq!(w.target.wiki_name.as_deref(), Some("work"));
    assert_eq!(w.target.path.as_deref(), Some("Project"));
    assert!(w.target.wiki_index.is_none());
}

#[test]
fn plain_wikilink_is_not_interwiki() {
    let w = first_link("[[Home]]\n");
    assert_eq!(w.target.kind, LinkKind::Wiki);
    assert!(w.target.wiki_index.is_none());
    assert!(w.target.wiki_name.is_none());
}

// ===== Config: `wikis = [...]` shape =====

#[test]
fn multi_wiki_config_loads_two_entries() {
    let cfg = config_from_json(serde_json::json!({
        "wikis": [
            { "root": "/tmp/personal", "name": "personal" },
            { "root": "/tmp/work", "name": "work" },
        ],
    }));
    assert_eq!(cfg.wikis.len(), 2);
    assert_eq!(cfg.wikis[0].name, "personal");
    assert_eq!(cfg.wikis[1].name, "work");
}

#[test]
fn v1_0_single_root_still_works_alongside_multi_wiki_shape() {
    // Single-wiki shorthand is the v1.0 form; ensure it still desugars.
    let cfg = config_from_json(serde_json::json!({
        "wiki_root": "/tmp/legacy",
    }));
    assert_eq!(cfg.wikis.len(), 1);
    assert_eq!(cfg.wikis[0].root, PathBuf::from("/tmp/legacy"));
}

// ===== Wiki aggregate + URI routing =====

#[test]
fn build_wikis_assigns_sequential_ids_starting_at_zero() {
    let cfg = config_from_json(serde_json::json!({
        "wikis": [
            { "root": "/tmp/p" },
            { "root": "/tmp/q" },
            { "root": "/tmp/r" },
        ],
    }));
    let wikis = build_wikis(&cfg.wikis);
    assert_eq!(wikis.len(), 3);
    for (i, w) in wikis.iter().enumerate() {
        assert_eq!(w.id, WikiId(i as u32));
    }
}

#[test]
fn resolve_uri_to_wiki_routes_to_the_owning_root() {
    let cfg = config_from_json(serde_json::json!({
        "wikis": [
            { "root": "/tmp/personal" },
            { "root": "/tmp/work" },
        ],
    }));
    let wikis = build_wikis(&cfg.wikis);
    let uri = Url::from_file_path("/tmp/work/Project.wiki").unwrap();
    assert_eq!(resolve_uri_to_wiki(&wikis, &uri), Some(WikiId(1)));
}

#[test]
fn nested_root_picks_longest_prefix_match() {
    let cfg = config_from_json(serde_json::json!({
        "wikis": [
            { "root": "/notes" },
            { "root": "/notes/sub" },
        ],
    }));
    let wikis = build_wikis(&cfg.wikis);
    let uri = Url::from_file_path("/notes/sub/page.wiki").unwrap();
    // The nested wiki wins because its root is a longer prefix.
    assert_eq!(resolve_uri_to_wiki(&wikis, &uri), Some(WikiId(1)));
}

// ===== Cross-wiki resolution (uses WorkspaceIndex per wiki) =====

/// Verify that the cross-wiki resolution semantics match the SPEC:
/// `[[wiki1:Page]]` looks up `Page` in the *second* wiki's index, not
/// the source wiki's. The pure-data check here mirrors what
/// `Backend::resolve_target_uri` does.
#[test]
fn interwiki_resolution_uses_target_wiki_index() {
    // Build two wikis with overlapping page names so we can tell whose
    // index was consulted.
    let mut work = WorkspaceIndex::new(Some(PathBuf::from("/tmp/work")));
    work.upsert(
        Url::from_file_path("/tmp/work/Project.wiki").unwrap(),
        &parse("= Work Project =\n"),
    );

    let mut personal = WorkspaceIndex::new(Some(PathBuf::from("/tmp/personal")));
    personal.upsert(
        Url::from_file_path("/tmp/personal/Project.wiki").unwrap(),
        &parse("= Personal Project =\n"),
    );

    // Simulate the resolver: source is personal, target is `wiki1:Project`
    // which should hit the work index (assumed to be index 1).
    let w = first_link("[[wiki1:Project]]\n");
    assert_eq!(w.target.wiki_index, Some(1));
    let resolved = work.pages_by_name.get("Project").cloned();
    assert!(resolved.is_some(), "work wiki should resolve Project");
    assert!(
        resolved
            .unwrap()
            .as_str()
            .contains("/tmp/work/Project.wiki"),
        "must come from the work wiki, not personal"
    );
}

#[test]
fn interwiki_resolution_falls_back_when_wiki_missing() {
    // Only one wiki registered; `[[wiki2:X]]` references the third
    // wiki by index — no match expected.
    let cfg = config_from_json(serde_json::json!({
        "wikis": [ { "root": "/tmp/only" } ],
    }));
    let wikis = build_wikis(&cfg.wikis);
    // Index 2 is out of range.
    assert!(wikis.get(2).is_none());
}

// ===== Wiki commands: COMMANDS list completeness =====

#[test]
fn commands_list_includes_phase18_entries() {
    let names: Vec<&str> = nuwiki_lsp::commands::COMMANDS.to_vec();
    for name in [
        "nuwiki.wiki.listAll",
        "nuwiki.wiki.select",
        "nuwiki.wiki.openIndex",
        "nuwiki.wiki.tabOpenIndex",
        "nuwiki.wiki.gotoPage",
    ] {
        assert!(names.contains(&name), "missing: {name}");
    }
}

// ===== Multi-wiki link kind matrix =====

#[test]
fn link_kind_matrix_for_typical_targets() {
    let cases = &[
        ("[[Home]]", LinkKind::Wiki),
        ("[[/Page]]", LinkKind::Wiki),       // root-relative still Wiki
        ("[[//abs/path]]", LinkKind::Local), // filesystem-absolute
        ("[[wiki1:X]]", LinkKind::Interwiki),
        ("[[wn.work:Y]]", LinkKind::Interwiki),
        ("[[file:foo.pdf]]", LinkKind::File),
        ("[[local:foo.pdf]]", LinkKind::Local),
        ("[[diary:2026-05-11]]", LinkKind::Diary),
        ("[[#anchor]]", LinkKind::AnchorOnly),
    ];
    for (src, expected) in cases {
        let w = first_link(&format!("{src}\n"));
        assert_eq!(w.target.kind, *expected, "case: {src}");
    }
}