//! Helpers shared by command tables.

use notescraft_vim::{Doc, Key, KeyCode, Mode, Vim};

/// Checks final text, cursor and mode for every command table row.
///
/// # Panics
/// Panics if a fixture lacks a cursor marker or command behavior differs.
pub fn check(cases: &[(&str, &str, &str)], mode: Mode) {
    let mut failures = Vec::new();
    for &(initial, input, expected) in cases {
        let (before, after) = initial.split_once('|').expect("cursor marker");
        let mut doc = Doc::new(format!("{before}{after}")).expect("valid document");
        doc.cursor = before.len();
        let mut vim = Vim::new();
        let mut remaining = input;
        while let Some(ch) = remaining.chars().next() {
            let special = [
                ("<Esc>", KeyCode::Esc, false),
                ("<CR>", KeyCode::Enter, false),
                ("<BS>", KeyCode::Backspace, false),
                ("<Tab>", KeyCode::Tab, false),
                ("<Left>", KeyCode::Left, false),
                ("<Right>", KeyCode::Right, false),
                ("<Up>", KeyCode::Up, false),
                ("<Down>", KeyCode::Down, false),
                ("<Home>", KeyCode::Home, false),
                ("<End>", KeyCode::End, false),
                ("<C-r>", KeyCode::Char('r'), true),
                ("<C-d>", KeyCode::Char('d'), true),
                ("<C-u>", KeyCode::Char('u'), true),
            ]
            .into_iter()
            .find(|(token, _, _)| remaining.starts_with(token));
            let (key, consumed) =
                special.map_or_else(|| (Key::char(ch), ch.len_utf8()), |(token, code, ctrl)| (Key { code, ctrl, shift: false, alt: false }, token.len()));
            let outcome = vim.handle(key, &mut doc);
            assert!(doc.cursor <= doc.text.len(), "{initial:?} {input:?}: {outcome:?}");
            assert!(doc.text.is_char_boundary(doc.cursor), "{initial:?} {input:?}");
            if let Some(anchor) = doc.anchor {
                assert!(doc.text.is_char_boundary(anchor), "invalid anchor: {initial:?} {input:?}");
            }
            remaining = remaining.get(consumed..).expect("key boundary");
        }
        let mut actual = doc.text;
        actual.insert(doc.cursor, '|');
        if actual != expected || vim.mode() != mode {
            failures.push(format!("{initial:?} + {input:?}: got {actual:?} {:?}, expected {expected:?} {mode:?}", vim.mode()));
        }
    }
    assert!(failures.is_empty(), "{}", failures.join("\n"));
}