//
//  ControlDial.swift
//  Focale
//
//  Author: Simon-Pierre Boucher
//  Contact: contact@spboucher.ai
//
//  Horizontal scrub dial for one manual control, with configurable
//  haptic detents (e.g. a tick every third of a stop — CLAUDE.md §6).
//

import SwiftUI

struct ControlDial: View {
    let control: CaptureControl
    let haptics: HapticProfile
    @Bindable var controls: ManualControls
    var onChanged: () -> Void

    @State private var dragStartValue: Double?
    @State private var lastDetent: Int = -1

    var body: some View {
        VStack(spacing: 4) {
            Text(controls.displayValue(for: control))
                .font(DesignTokens.controlValueFont)
                .foregroundStyle(.white)
                .contentTransition(.numericText())

            Text(control.displayName)
                .font(DesignTokens.controlLabelFont)
                .foregroundStyle(DesignTokens.textSecondary)
        }
        .frame(minWidth: 74)
        .padding(.vertical, 8)
        .padding(.horizontal, 10)
        .background(DesignTokens.surfaceRaised, in: RoundedRectangle(
            cornerRadius: DesignTokens.cornerRadius
        ))
        .sensoryFeedback(.selection, trigger: lastDetent)
        .gesture(dial)
        .accessibilityLabel(control.displayName)
        .accessibilityValue(controls.displayValue(for: control))
    }

    private var dial: some Gesture {
        DragGesture(minimumDistance: 2)
            .onChanged { gesture in
                let start = dragStartValue ?? controls.normalizedValue(for: control)
                if dragStartValue == nil { dragStartValue = start }

                let sensitivity = 1.0 / 220.0   // full range over ~220 pt
                let value = (start + gesture.translation.width * sensitivity)
                    .clamped(to: 0...1)
                controls.setNormalizedValue(value, for: control)

                if haptics.enabled, haptics.detentCount > 0 {
                    let detent = Int(value * Double(haptics.detentCount))
                    if detent != lastDetent { lastDetent = detent }
                }
                onChanged()
            }
            .onEnded { _ in dragStartValue = nil }
    }
}