//
// MachineSettingsEditor.swift
// Workouts
//
// Copyright 2025 Rouslan Zenetl. All Rights Reserved.
//

import SwiftUI

/// Reusable editor for an ordered list of machine comfort settings (seat height,
/// back-rest incline, pin position…). Drop it into a `Form`/`List` `Section`: it
/// renders one `name`/`value` row per setting with swipe-to-delete and
/// drag-to-reorder, plus an "Add Setting" row. Shared by the exercise add/edit
/// screen (Surface 1) and the in-workout settings sheet (Surface 2).
///
/// `MachineSetting` is a plain Codable wire type with no identity, so the editor
/// keeps a per-row `UUID` internally (stable across edits/reorders, unlike an
/// index) and mirrors changes back into the `settings` binding. The editor is the
/// sole mutator of `settings` while it's on screen, so a one-way seed at init is
/// enough — there's no external write to reconcile.
struct MachineSettingsEditor: View {
    @Binding var settings: [MachineSetting]
    @State private var rows: [Row]

    init(settings: Binding<[MachineSetting]>) {
        _settings = settings
        _rows = State(initialValue: settings.wrappedValue.map(Row.init))
    }

    var body: some View {
        ForEach($rows) { $row in
            HStack {
                TextField("Setting", text: $row.name)
                    .textInputAutocapitalization(.words)
                TextField("Value", text: $row.value)
                    .multilineTextAlignment(.trailing)
                    .foregroundStyle(.secondary)
                    .frame(maxWidth: 120)
            }
        }
        .onDelete { rows.remove(atOffsets: $0) }
        .onMove { rows.move(fromOffsets: $0, toOffset: $1) }

        Button {
            withAnimation { rows.append(Row(MachineSetting(name: "", value: ""))) }
        } label: {
            Label("Add Setting", systemImage: "plus.circle.fill")
        }
        // Mirror the identified rows back into the plain wire-type binding on every
        // edit/add/delete/reorder.
        .onChange(of: rows) { _, newRows in
            settings = newRows.map(\.setting)
        }
    }

    /// Session-only identified wrapper so `ForEach` and reordering have a stable
    /// identity that survives text edits.
    fileprivate struct Row: Identifiable, Equatable {
        let id = UUID()
        var name: String
        var value: String

        init(_ setting: MachineSetting) {
            name = setting.name
            value = setting.value
        }

        var setting: MachineSetting { MachineSetting(name: name, value: value) }
    }
}