//! Checkbox state transitions and the `checkbox_edit` rewriter that
//! emits `WorkspaceEdit`s for `nuwiki.list.toggleCheckbox`,
//! `nuwiki.list.cycleCheckbox`, and `nuwiki.list.rejectCheckbox`.

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);
}

// ===== 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());
}