//! Phase 14 edit-command tests. Drive `commands::ops::*` directly with
//! parsed ASTs so we don't need a live Backend / Client.

use nuwiki_core::syntax::vimwiki::VimwikiSyntax;
use nuwiki_core::syntax::SyntaxPlugin;
use nuwiki_lsp::commands::ops;
use tower_lsp::lsp_types::{DocumentChanges, Url};

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

fn dummy_uri() -> Url {
    Url::parse("file:///tmp/note.wiki").unwrap()
}

fn one_text_edit(edit: tower_lsp::lsp_types::WorkspaceEdit) -> tower_lsp::lsp_types::TextEdit {
    let changes = edit.changes.expect("expected changes map");
    let (_, edits) = changes.into_iter().next().expect("at least one uri");
    assert_eq!(edits.len(), 1, "expected exactly one text edit");
    edits.into_iter().next().unwrap()
}

fn doc_changes_for(edit: tower_lsp::lsp_types::WorkspaceEdit) -> Option<DocumentChanges> {
    edit.document_changes
}

// ===== state transitions =====

#[test]
fn toggle_state_round_trip() {
    assert_eq!(ops::toggle_state("[ ]"), Some("[X]"));
    assert_eq!(ops::toggle_state("[X]"), Some("[ ]"));
    assert_eq!(ops::toggle_state("[.]"), Some("[X]"));
    assert_eq!(ops::toggle_state("[-]"), Some("[ ]"));
    assert_eq!(ops::toggle_state("[?]"), None);
}

#[test]
fn cycle_state_walks_progression() {
    assert_eq!(ops::cycle_state("[ ]"), Some("[.]"));
    assert_eq!(ops::cycle_state("[.]"), Some("[o]"));
    assert_eq!(ops::cycle_state("[o]"), Some("[O]"));
    assert_eq!(ops::cycle_state("[O]"), Some("[X]"));
    assert_eq!(ops::cycle_state("[X]"), Some("[ ]"));
    assert_eq!(ops::cycle_state("[-]"), Some("[ ]"));
}

#[test]
fn reject_state_toggles_dash_marker() {
    assert_eq!(ops::reject_state("[ ]"), Some("[-]"));
    assert_eq!(ops::reject_state("[X]"), Some("[-]"));
    assert_eq!(ops::reject_state("[-]"), Some("[ ]"));
}

// ===== checkbox_edit =====

#[test]
fn toggle_empty_checkbox_to_done() {
    let src = "- [ ] task\n";
    let doc = parse(src);
    let edit = ops::checkbox_edit(src, &doc, &dummy_uri(), 0, 4, true, ops::toggle_state)
        .expect("toggle edit");
    let te = one_text_edit(edit);
    assert_eq!(te.new_text, "[X]");
    assert_eq!(te.range.start.character, 2); // bytes 2..5 = "[ ]"
    assert_eq!(te.range.end.character, 5);
}

#[test]
fn cycle_advances_partial_states() {
    let src = "- [.] half\n";
    let doc = parse(src);
    let edit = ops::checkbox_edit(src, &doc, &dummy_uri(), 0, 0, true, ops::cycle_state)
        .expect("cycle edit");
    let te = one_text_edit(edit);
    assert_eq!(te.new_text, "[o]");
}

#[test]
fn reject_replaces_empty_with_dash() {
    let src = "* [ ] thing\n";
    let doc = parse(src);
    let edit = ops::checkbox_edit(src, &doc, &dummy_uri(), 0, 0, true, ops::reject_state)
        .expect("reject edit");
    let te = one_text_edit(edit);
    assert_eq!(te.new_text, "[-]");
}

#[test]
fn checkbox_edit_returns_none_on_plain_list_item() {
    // No `[…]` at all → no edit.
    let src = "- plain item\n";
    let doc = parse(src);
    let edit = ops::checkbox_edit(src, &doc, &dummy_uri(), 0, 0, true, ops::toggle_state);
    assert!(edit.is_none());
}

#[test]
fn checkbox_edit_returns_none_off_list() {
    let src = "just a paragraph\n";
    let doc = parse(src);
    let edit = ops::checkbox_edit(src, &doc, &dummy_uri(), 0, 0, true, ops::toggle_state);
    assert!(edit.is_none());
}

#[test]
fn checkbox_edit_finds_item_in_sublist() {
    let src = "- top\n  - [ ] nested\n";
    let doc = parse(src);
    // Cursor on line 1, the nested item.
    let edit = ops::checkbox_edit(src, &doc, &dummy_uri(), 1, 5, true, ops::toggle_state)
        .expect("edit on nested item");
    let te = one_text_edit(edit);
    assert_eq!(te.new_text, "[X]");
    assert_eq!(te.range.start.line, 1);
}

// ===== heading_change_level =====

#[test]
fn add_heading_level_promotes_h2_to_h3() {
    let src = "== Sub ==\n";
    let doc = parse(src);
    let edit =
        ops::heading_change_level(src, &doc, &dummy_uri(), 0, 0, true, 1).expect("add_level edit");
    let te = one_text_edit(edit);
    assert_eq!(te.new_text, "=== Sub ===");
}

#[test]
fn add_heading_level_caps_at_6() {
    let src = "====== Deep ======\n";
    let doc = parse(src);
    let edit = ops::heading_change_level(src, &doc, &dummy_uri(), 0, 0, true, 1);
    // No-op because level 6 is the cap; clamp matched current level.
    assert!(edit.is_none());
}

#[test]
fn remove_heading_level_demotes() {
    let src = "=== Mid ===\n";
    let doc = parse(src);
    let edit = ops::heading_change_level(src, &doc, &dummy_uri(), 0, 0, true, -1)
        .expect("remove_level edit");
    let te = one_text_edit(edit);
    assert_eq!(te.new_text, "== Mid ==");
}

#[test]
fn remove_heading_level_at_h1_is_noop() {
    let src = "= Top =\n";
    let doc = parse(src);
    let edit = ops::heading_change_level(src, &doc, &dummy_uri(), 0, 0, true, -1);
    assert!(edit.is_none());
}

#[test]
fn heading_change_returns_none_when_cursor_not_on_heading() {
    let src = "paragraph\n";
    let doc = parse(src);
    let edit = ops::heading_change_level(src, &doc, &dummy_uri(), 0, 0, true, 1);
    assert!(edit.is_none());
}

#[test]
fn rewrite_heading_with_level_keeps_leading_whitespace_outside_span() {
    // The lexer's heading span starts at the first `=`, not the line's
    // start, so the leading whitespace that marks a "centered" heading
    // lives outside the edit range — preserved automatically. The
    // rewriter's output is just the `=...=` portion.
    let src = "  = Title =\n";
    let doc = parse(src);
    let h = match &doc.children[0] {
        nuwiki_core::ast::BlockNode::Heading(h) => h,
        _ => panic!("expected heading"),
    };
    let new = ops::rewrite_heading_with_level(src, h.span, 2).unwrap();
    assert_eq!(new, "== Title ==");
}

// ===== next_task =====

#[test]
fn next_task_returns_first_unfinished() {
    let src = "- [X] done\n- [ ] todo\n- [ ] later\n";
    let doc = parse(src);
    let loc = ops::next_task(&doc, &dummy_uri(), src, 0, 0, true).expect("found a task");
    // Should be line 1 (the first [ ]).
    assert_eq!(loc.range.start.line, 1);
}

#[test]
fn next_task_wraps_around_when_no_task_after_cursor() {
    // Only task is on line 0; cursor on line 2 → wraps back.
    let src = "- [ ] todo\n- [X] done\n- [X] also done\n";
    let doc = parse(src);
    let loc = ops::next_task(&doc, &dummy_uri(), src, 2, 0, true).expect("found");
    assert_eq!(loc.range.start.line, 0);
}

#[test]
fn next_task_returns_none_when_no_open_tasks() {
    let src = "- [X] a\n- [X] b\n";
    let doc = parse(src);
    let loc = ops::next_task(&doc, &dummy_uri(), src, 0, 0, true);
    assert!(loc.is_none());
}

#[test]
fn next_task_only_counts_items_with_checkboxes() {
    // Plain items without a `[…]` are ignored — they're not tasks.
    let src = "- plain\n- [ ] real task\n";
    let doc = parse(src);
    let loc = ops::next_task(&doc, &dummy_uri(), src, 0, 0, true).expect("found");
    assert_eq!(loc.range.start.line, 1);
}

// ===== smoke: COMMANDS list matches registered handlers =====

#[test]
fn commands_list_is_complete() {
    let names: Vec<&str> = nuwiki_lsp::commands::COMMANDS.to_vec();
    for name in [
        "nuwiki.file.delete",
        "nuwiki.list.toggleCheckbox",
        "nuwiki.list.cycleCheckbox",
        "nuwiki.list.rejectCheckbox",
        "nuwiki.list.nextTask",
        "nuwiki.heading.addLevel",
        "nuwiki.heading.removeLevel",
    ] {
        assert!(names.contains(&name), "missing: {name}");
    }
}

// ===== sanity: workspace edit shape =====

#[test]
fn checkbox_edit_uses_changes_map_not_document_changes() {
    let src = "- [ ] task\n";
    let doc = parse(src);
    let edit = ops::checkbox_edit(src, &doc, &dummy_uri(), 0, 4, true, ops::toggle_state).unwrap();
    assert!(doc_changes_for(edit.clone()).is_none());
    assert!(edit.changes.is_some());
}