//! Metric thread choices use the document's sizing table and the existing designation
//! parameter. Browsing choices does not edit the model or freeze an automatic feature.

use solidcraft_engine::doc::{metric_thread_sizes, parse_metric_thread};

use crate::dialogs::{check, combo, row_label};
use crate::i18n::tr;

/// Common pitch presets, not an exhaustive catalogue of standard diameter/pitch pairs.
/// The coarse and current pitches are included separately; custom pairs remain editable.
const PITCHES: &[f64] = &[0.2, 0.25, 0.35, 0.5, 0.75, 1.0, 1.25, 1.5, 2.0, 3.0, 4.0];

/// Returns (Enter pressed, automatic sizing requested).
pub(crate) fn rows(ui: &mut egui::Ui, designation: &mut String, suggested: &mut Option<String>) -> (bool, bool) {
    row_label(ui, "Profile");
    ui.label(tr("ISO metric"));
    ui.end_row();

    row_label(ui, "Automatic size");
    let before = designation.trim().is_empty() || suggested.as_deref() == Some(designation.as_str());
    let mut automatic = before;
    ui.add_enabled_ui(!designation.trim().is_empty(), |ui| check(ui, &mut automatic));
    let reset = automatic && !before;
    if automatic != before {
        *suggested = None;
        if automatic {
            designation.clear();
        }
    }
    ui.end_row();

    let current = parse_metric_thread(designation);
    let mut diameters: Vec<f64> = metric_thread_sizes().iter().map(|(d, _)| *d).collect();
    if let Some((d, _)) = current
        && !diameters.contains(&d)
    {
        diameters.push(d);
        diameters.sort_by(f64::total_cmp);
    }
    row_label(ui, "Size");
    let labels: Vec<String> = diameters.iter().map(|d| format!("{d} mm")).collect();
    let mut selected = current.and_then(|(d, _)| diameters.iter().position(|n| *n == d)).unwrap_or(diameters.len());
    let before = selected;
    let mut labels: Vec<&str> = labels.iter().map(String::as_str).collect();
    if current.is_none() {
        labels.push("Select size");
    }
    combo(ui, "thread_diameter", &labels, &mut selected);
    // A new diameter starts with its coarse pitch. The current custom diameter, if any,
    // is already selected and retains its explicit pitch.
    if selected != before
        && let Some(d) = diameters.get(selected)
        && let Some((_, coarse)) = metric_thread_sizes().iter().find(|(n, _)| n == d)
    {
        *designation = format!("M{d}x{coarse}");
        *suggested = None;
    }
    ui.end_row();

    let current = parse_metric_thread(designation);
    row_label(ui, "Pitch");
    ui.add_enabled_ui(current.is_some(), |ui| {
        let mut pitches = Vec::new();
        if let Some((d, p)) = current {
            let coarse = metric_thread_sizes().iter().find(|(n, _)| *n == d).map(|(_, p)| *p);
            pitches.extend(PITCHES.iter().copied().filter(|p| *p < d && *p <= coarse.unwrap_or(d)));
            pitches.extend(coarse);
            pitches.push(p);
        }
        pitches.sort_by(|a, b| b.total_cmp(a));
        pitches.dedup();
        let labels: Vec<String> = pitches.iter().map(|p| format!("{p} mm")).collect();
        let labels: Vec<&str> = labels.iter().map(String::as_str).collect();
        let mut selected = current.and_then(|(_, p)| pitches.iter().position(|n| *n == p)).unwrap_or(0);
        let before = selected;
        combo(ui, "thread_pitch", &labels, &mut selected);
        if selected != before
            && let (Some((d, _)), Some(p)) = (current, pitches.get(selected))
        {
            *designation = format!("M{d}x{p}");
            *suggested = None;
        }
    });
    ui.end_row();

    row_label(ui, "Designation");
    let response = ui.add(egui::TextEdit::singleline(designation).hint_text(tr("fits the face, e.g. M8")));
    crate::scenario::publish_handle("dialog:thread_size", response.rect.center());
    if response.changed() {
        *suggested = None;
    }
    let enter = response.lost_focus() && ui.input(|i| i.key_pressed(egui::Key::Enter));
    ui.end_row();
    (enter, reset)
}