//! 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 cycle_state_back_is_exact_inverse() {
    // `glp` walks the progression in reverse — every step must undo the
    // matching `cycle_state` step.
    assert_eq!(ops::cycle_state_back("[ ]"), Some("[X]"));
    assert_eq!(ops::cycle_state_back("[X]"), Some("[O]"));
    assert_eq!(ops::cycle_state_back("[O]"), Some("[o]"));
    assert_eq!(ops::cycle_state_back("[o]"), Some("[.]"));
    assert_eq!(ops::cycle_state_back("[.]"), Some("[ ]"));
    assert_eq!(ops::cycle_state_back("[-]"), Some("[ ]"));
    // Composing forward then backward returns to the start for every
    // in-cycle marker.
    for s in ["[ ]", "[.]", "[o]", "[O]", "[X]"] {
        let fwd = ops::cycle_state(s).unwrap();
        assert_eq!(ops::cycle_state_back(fwd), Some(s));
    }
}

#[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, true)
        .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, true)
        .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, true)
        .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, true);
    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, true);
    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, true)
        .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, true).unwrap();
    assert!(doc_changes_for(edit.clone()).is_none());
    assert!(edit.changes.is_some());
}

// ===== parent propagation (vimwiki listsyms_propagate) =====

/// Collect the (line, new_text) pairs for every TextEdit in the result,
/// sorted by line. Lets propagation tests assert the parent edit
/// without caring about edit ordering.
fn edits_by_line(edit: tower_lsp::lsp_types::WorkspaceEdit) -> Vec<(u32, String)> {
    let changes = edit.changes.expect("expected changes map");
    let (_, edits) = changes.into_iter().next().expect("at least one uri");
    let mut pairs: Vec<(u32, String)> = edits
        .into_iter()
        .map(|e| (e.range.start.line, e.new_text))
        .collect();
    pairs.sort_by_key(|(line, _)| *line);
    pairs
}

#[test]
fn propagate_one_of_four_done_marks_parent_quarter() {
    // Toggle the first child of a 4-child parent. Parent should land at
    // [.] (Quarter, 25%).
    let src = "\
- [ ] root
  - [ ] sub1
  - [ ] sub2
  - [ ] sub3
  - [ ] sub4
";
    let doc = parse(src);
    let edit = ops::checkbox_edit(src, &doc, &dummy_uri(), 1, 6, true, ops::toggle_state, true)
        .expect("toggle edit");
    let pairs = edits_by_line(edit);
    assert_eq!(pairs, vec![(0, "[.]".into()), (1, "[X]".into())]);
}

#[test]
fn propagate_two_of_four_done_marks_parent_half() {
    // sub1 is already done; toggling sub2 → done leaves rate=50% → [o].
    let src = "\
- [ ] root
  - [X] sub1
  - [ ] sub2
  - [ ] sub3
  - [ ] sub4
";
    let doc = parse(src);
    let edit = ops::checkbox_edit(src, &doc, &dummy_uri(), 2, 6, true, ops::toggle_state, true)
        .expect("toggle edit");
    let pairs = edits_by_line(edit);
    assert_eq!(pairs, vec![(0, "[o]".into()), (2, "[X]".into())]);
}

#[test]
fn propagate_three_of_four_done_marks_parent_three_quarters() {
    let src = "\
- [ ] root
  - [X] sub1
  - [X] sub2
  - [ ] sub3
  - [ ] sub4
";
    let doc = parse(src);
    let edit = ops::checkbox_edit(src, &doc, &dummy_uri(), 3, 6, true, ops::toggle_state, true)
        .expect("toggle edit");
    let pairs = edits_by_line(edit);
    assert_eq!(pairs, vec![(0, "[O]".into()), (3, "[X]".into())]);
}

#[test]
fn propagate_all_done_marks_parent_done() {
    let src = "\
- [ ] root
  - [X] sub1
  - [X] sub2
  - [X] sub3
  - [ ] sub4
";
    let doc = parse(src);
    let edit = ops::checkbox_edit(src, &doc, &dummy_uri(), 4, 6, true, ops::toggle_state, true)
        .expect("toggle edit");
    let pairs = edits_by_line(edit);
    assert_eq!(pairs, vec![(0, "[X]".into()), (4, "[X]".into())]);
}

#[test]
fn propagate_untoggle_drops_parent_back() {
    // Untoggling the only completed child should put parent back to [ ].
    let src = "\
- [.] root
  - [X] sub1
  - [ ] sub2
  - [ ] sub3
  - [ ] sub4
";
    let doc = parse(src);
    let edit = ops::checkbox_edit(src, &doc, &dummy_uri(), 1, 6, true, ops::toggle_state, true)
        .expect("toggle edit");
    let pairs = edits_by_line(edit);
    assert_eq!(pairs, vec![(0, "[ ]".into()), (1, "[ ]".into())]);
}

#[test]
fn propagate_disabled_only_emits_leaf_edit() {
    let src = "\
- [ ] root
  - [ ] sub1
  - [ ] sub2
  - [ ] sub3
  - [ ] sub4
";
    let doc = parse(src);
    let edit = ops::checkbox_edit(
        src,
        &doc,
        &dummy_uri(),
        1,
        6,
        true,
        ops::toggle_state,
        false,
    )
    .expect("toggle edit");
    let pairs = edits_by_line(edit);
    assert_eq!(pairs, vec![(1, "[X]".into())]);
}

#[test]
fn propagate_skips_parent_without_checkbox() {
    // Parent has no `[…]`, so propagation has nothing to update.
    let src = "\
- root
  - [ ] sub1
  - [ ] sub2
";
    let doc = parse(src);
    let edit = ops::checkbox_edit(src, &doc, &dummy_uri(), 1, 6, true, ops::toggle_state, true)
        .expect("toggle edit");
    let pairs = edits_by_line(edit);
    assert_eq!(pairs, vec![(1, "[X]".into())]);
}

#[test]
fn propagate_walks_multiple_levels() {
    // Toggle the deepest leaf: grandparent has 1 child (parent), parent
    // has 2 children. Sub1 done → parent half → grandparent half.
    let src = "\
- [ ] grand
  - [ ] parent
    - [ ] sub1
    - [ ] sub2
";
    let doc = parse(src);
    let edit = ops::checkbox_edit(src, &doc, &dummy_uri(), 2, 8, true, ops::toggle_state, true)
        .expect("toggle edit");
    let pairs = edits_by_line(edit);
    assert_eq!(
        pairs,
        vec![(0, "[o]".into()), (1, "[o]".into()), (2, "[X]".into())]
    );
}

#[test]
fn propagate_all_rejected_marks_parent_rejected() {
    // Every counted child is rejected → parent becomes [-].
    let src = "\
- [ ] root
  - [-] sub1
  - [ ] sub2
";
    let doc = parse(src);
    // Reject sub2 so both children are rejected.
    let edit = ops::checkbox_edit(src, &doc, &dummy_uri(), 2, 6, true, ops::reject_state, true)
        .expect("reject edit");
    let pairs = edits_by_line(edit);
    assert_eq!(pairs, vec![(0, "[-]".into()), (2, "[-]".into())]);
}

#[test]
fn propagate_rejected_sibling_counts_as_done_for_average() {
    // sub1 rejected, sub2 toggled to done → both "complete" → parent [X].
    let src = "\
- [ ] root
  - [-] sub1
  - [ ] sub2
";
    let doc = parse(src);
    let edit = ops::checkbox_edit(src, &doc, &dummy_uri(), 2, 6, true, ops::toggle_state, true)
        .expect("toggle edit");
    let pairs = edits_by_line(edit);
    assert_eq!(pairs, vec![(0, "[X]".into()), (2, "[X]".into())]);
}