import SessionCore
import SwiftUI

/// T-iOS-14 · Three-way sheet for a PLAN gate (B4): Approve+Auto /
/// Approve+Review / Keep Planning — mapping mirrors public/tabs.ts:345-347
/// exactly via `GateState.Affordance.clientMessage` (acceptEdits / default /
/// reject; never raw `auto`, and NO allowAutoMode gating — plan §7 T-iOS-14).
///
/// Render-only: state lives in `GateViewModel`; every tap reports the
/// affordance PLUS the epoch of the gate THIS sheet rendered (stale-tap
/// first-line guard). Presentation (`.sheet`) wiring is T-iOS-15.
struct PlanGateSheet: View {
    /// Mirror of public/tabs.ts:326 plan-gate headline.
    static let title = "Claude finished planning — how should it proceed?"

    let gate: GateState
    let onDecide: (GateState.Affordance, Int) -> Void

    private enum Metrics {
        static let spacing: CGFloat = 12
        static let padding: CGFloat = 20
        static let captionSpacing: CGFloat = 2
    }

    var body: some View {
        VStack(alignment: .leading, spacing: Metrics.spacing) {
            Text(Self.title)
                .font(.headline)
            ForEach(GateChoiceSpec.specs(for: gate), id: \.affordance) { spec in
                choiceButton(spec)
            }
        }
        .padding(Metrics.padding)
        .presentationDetents([.medium])
        .accessibilityElement(children: .contain)
    }

    private func choiceButton(_ spec: GateChoiceSpec) -> some View {
        Button {
            onDecide(spec.affordance, gate.epoch) // epoch of the RENDERED gate
        } label: {
            VStack(alignment: .leading, spacing: Metrics.captionSpacing) {
                Text(spec.label)
                    .font(.body.weight(.medium))
                Text(Self.caption(for: spec.affordance))
                    .font(.caption)
                    .foregroundStyle(.secondary)
            }
            .frame(maxWidth: .infinity, alignment: .leading)
        }
        .buttonStyle(.bordered)
        .tint(tint(for: spec.affordance))
    }

    /// Secondary line under each choice: what the wire mode actually does.
    static func caption(for affordance: GateState.Affordance) -> String {
        switch affordance {
        case .approveAuto: return "执行计划，编辑自动接受（acceptEdits）"
        case .approveReview: return "执行计划，每次编辑需确认（default）"
        case .keepPlanning: return "继续规划，不执行"
        case .approve: return "允许本次工具调用"
        case .reject: return "拒绝本次工具调用"
        }
    }

    private func tint(for affordance: GateState.Affordance) -> Color {
        switch affordance {
        case .approve, .approveAuto, .approveReview: return .green
        case .reject: return .red
        case .keepPlanning: return .indigo
        }
    }
}